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Armstrong DP, Beach TAC, Fischer SL. The Influence of Contextual and Theoretical Expertise on Generic and Occupation-Specific Lifting Strategy. HUMAN FACTORS 2024; 66:2590-2605. [PMID: 38299447 PMCID: PMC11475631 DOI: 10.1177/00187208231223429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 12/10/2023] [Indexed: 02/02/2024]
Abstract
OBJECTIVE To determine whether (i) low back loads and/or (ii) kinematic coordination patterns differed across theoretical expert, contextual expert and novice groups when completing both generic and occupation-specific lifts. BACKGROUND Experience has been proposed as a factor that could reduce biomechanical exposures in lifting, but the literature reports mixed effects. The inconsistent relationship between experience and exposures may be partially attributable to the broad classification of experience and experimental lifting protocols not replicating the environment where experience was gained. METHODS Purposive sampling was used to recruit 72 participants including theoretical experts (formal training on lifting mechanics), contextual experts (paramedics), and novices. Participants performed 10 barbell and crate (generic) lifts, as well as backboard and stretcher (occupation-specific) lifts while whole-body kinematics and ground reaction forces were collected. Peak low back compression and anteroposterior shear loads normalized to body mass, as well as kinematic coordination patterns, were calculated as dependent variables. RESULTS No significant differences in low back loads were observed across expertise groups. However, significant differences were seen in kinematic coordination patterns across expertise groups in occupation-specific lifts, but not in generic lifts. CONCLUSION Increasing expertise is unlikely to minimize low back loads in lifting. However, contextual expertise did influence lifting kinematics, but only when performing occupationally specific lifts. APPLICATION Contextual expertise may help lifters adopt lifting kinematics that enhance the tolerance of their musculoskeletal system to withstand applied loads, but does not seem to reduce the applied low back loads relative to noncontextual expert groups.
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Nail-Ulloa I, Zabala M, Sesek R, Chen H, Schall MC, Gallagher S. Estimating Compressive and Shear Forces at L5-S1: Exploring the Effects of Load Weight, Asymmetry, and Height Using Optical and Inertial Motion Capture Systems. SENSORS (BASEL, SWITZERLAND) 2024; 24:1941. [PMID: 38544203 PMCID: PMC10976016 DOI: 10.3390/s24061941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/08/2024] [Accepted: 03/15/2024] [Indexed: 04/01/2024]
Abstract
This study assesses the agreement of compressive and shear force estimates at the L5-S1 joint using inertial motion capture (IMC) within a musculoskeletal simulation model during manual lifting tasks, compared against a top-down optical motion capture (OMC)-based model. Thirty-six participants completed lifting and lowering tasks while wearing a modified Plug-in Gait marker set for the OMC and a full-body IMC set-up consisting of 17 sensors. The study focused on tasks with variable load weights, lifting heights, and trunk rotation angles. It was found that the IMC system consistently underestimated the compressive forces by an average of 34% (975.16 N) and the shear forces by 30% (291.77 N) compared with the OMC system. A critical observation was the discrepancy in joint angle measurements, particularly in trunk flexion, where the IMC-based model underestimated the angles by 10.92-11.19 degrees on average, with the extremes reaching up to 28 degrees. This underestimation was more pronounced in tasks involving greater flexion, notably impacting the force estimates. Additionally, this study highlights significant differences in the distance from the spine to the box during these tasks. On average, the IMC system showed an 8 cm shorter distance on the X axis and a 12-13 cm shorter distance on the Z axis during lifting and lowering, respectively, indicating a consistent underestimation of the segment length compared with the OMC system. These discrepancies in the joint angles and distances suggest potential limitations of the IMC system's sensor placement and model scaling. The load weight emerged as the most significant factor affecting force estimates, particularly at lower lifting heights, which involved more pronounced flexion movements. This study concludes that while the IMC system offers utility in ergonomic assessments, sensor placement and anthropometric modeling accuracy enhancements are imperative for more reliable force and kinematic estimations in occupational settings.
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Affiliation(s)
- Iván Nail-Ulloa
- Department of Industrial and Systems Engineering, Auburn University, Auburn, AL 36849, USA; (I.N.-U.); (R.S.); (S.G.)
- Institute of Industry and Management, Universidad Austral de Chile, Puerto Montt 5480000, Chile
| | - Michael Zabala
- Department of Mechanical Engineering, Auburn University, Auburn, AL 36849, USA;
| | - Richard Sesek
- Department of Industrial and Systems Engineering, Auburn University, Auburn, AL 36849, USA; (I.N.-U.); (R.S.); (S.G.)
| | - Howard Chen
- Department of Industrial and Systems Engineering and Engineering Management, The University of Alabama at Huntsville, Huntsville, AL 35899, USA
| | - Mark C. Schall
- Department of Industrial and Systems Engineering, Auburn University, Auburn, AL 36849, USA; (I.N.-U.); (R.S.); (S.G.)
| | - Sean Gallagher
- Department of Industrial and Systems Engineering, Auburn University, Auburn, AL 36849, USA; (I.N.-U.); (R.S.); (S.G.)
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Proud JK, Garofolini A, Mudie KL, Lai DTH, Begg RK. The highs and lows of lifting loads: SPM analysis of multi-segmental spine angles in healthy adults during manual handling with increased load. Front Bioeng Biotechnol 2024; 12:1282867. [PMID: 38333083 PMCID: PMC10850312 DOI: 10.3389/fbioe.2024.1282867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 01/08/2024] [Indexed: 02/10/2024] Open
Abstract
Introduction: Manual handling personnel and those performing manual handling tasks in non-traditional manual handling industries continue to suffer debilitating and costly workplace injuries. Smart assistive devices are one solution to reducing musculoskeletal back injuries. Devices that provide targeted assistance need to be able to predict when and where to provide augmentation via predictive algorithms trained on functional datasets. The aim of this study was to describe how an increase in load impacts spine kinematics during a ground-to-platform manual handling task. Methods: Twenty-nine participants performed ground-to-platform lifts for six standardised loading conditions (50%, 60%, 70%, 80%, 90%, and 100% of maximum lift capacity). Six thoracic and lumbar spine segments were measured using inertial measurement units that were processed using an attitude-heading-reference filter and normalised to the duration of the lift. The lift was divided into four phases weight-acceptance, standing, lift-to-height and place-on-platform. Statistical significance of sagittal angles from the six spine segments were identified through statistical parametric mapping one-way analysis of variance with repeated measures and post hoc paired t-tests. Results: Two regions of interest were identified during a period of peak flexion and a period of peak extension. There was a significant increase in spine range of motion and peak extension angle for all spine segments when the load conditions were increased (p < 0.001). There was a decrease in spine angles (more flexion) during the weight acceptance to standing phase at the upper thoracic to upper lumbar spine segments for some condition comparisons. A significant increase in spine angles (more extension) during the place-on-platform phase was seen in all spine segments when comparing heavy loads (>80% maximum lift capacity, inclusive) to light loads (<80% maximum lift capacity) (p < 0.001). Discussion: The 50%-70% maximum lift capacity conditions being significantly different from heavier load conditions is representative that the kinematics of a lift do change consistently when a participant's load is increased. The understanding of how changes in loading are reflected in spine angles could inform the design of targeted assistance devices that can predict where and when in a task assistance may be needed, possibly reducing instances of back injuries in manual handling personnel.
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Affiliation(s)
- Jasmine K. Proud
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia
| | - Alessandro Garofolini
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia
| | - Kurt L. Mudie
- Land Division, Defence Science and Technology (DST), Melbourne, VIC, Australia
| | - Daniel T. H. Lai
- College of Sport, Health and Engineering, Victoria University, Melbourne, VIC, Australia
| | - Rezaul K. Begg
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia
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Vallée Marcotte J, Robert-Lachaine X, Muller A, Denis D, Mecheri H, Plamondon A, Corbeil P. The influence of transfer distance and pace of work on foot positioning strategies and low back loading in a manual material handling task. APPLIED ERGONOMICS 2024; 114:104129. [PMID: 37666008 DOI: 10.1016/j.apergo.2023.104129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 08/16/2023] [Accepted: 08/25/2023] [Indexed: 09/06/2023]
Abstract
Foot positioning strategies are a key parameter in manual materials handling. The objective of this study was to assess the effects of transfer distance, pace and foot positioning on low back loading. Sixteen handlers performed a free handling task with conditions of pace (self-selected and 25% faster), distance (1.5 m, 1.0 m and 0.5 m), height (near-ground and above-waist levels), and mass (10 kg and 20 kg). A linear mixed model was used to evaluate the effects of mass, distance, pace and height on foot positioning occurrences. A non-parametric test (nparLD) was used to evaluate the effects of Pace × Foot positioning and Distance × Foot positioning on L5/S1 sagittal and asymmetrical moments. Positioning the feet aside from the lifting pallet was more prevalent when transferring at shorter transfer distances, high lifting height, and faster pace. When the feet were oriented aside the lifting area, asymmetrical peak moments were slightly higher when transferring at short distance. Facing the lifting pallet may ensure load symmetry, but orienting the feet aside may help to adapt to fast pace or short transfer distance.
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Affiliation(s)
| | - Xavier Robert-Lachaine
- Department of Kinesiology, Laval University, Québec, Québec, Canada; Institut de recherche Robert Sauvé en santé et en sécurité du travail (IRSST), 505 Boul. De Maisonneuve Ouest, Montréal, Québec, H3A 3C2, Canada
| | - Antoine Muller
- Univ Lyon, Univ Gustave Eiffel, Univ Claude Bernard Lyon 1, LBMC UMR_T 9406, F-69622, France
| | - Denys Denis
- Université du Québec à Montréal (UQAM), Montréal, Québec, Canada
| | - Hakim Mecheri
- Institut de recherche Robert Sauvé en santé et en sécurité du travail (IRSST), 505 Boul. De Maisonneuve Ouest, Montréal, Québec, H3A 3C2, Canada
| | - André Plamondon
- Institut de recherche Robert Sauvé en santé et en sécurité du travail (IRSST), 505 Boul. De Maisonneuve Ouest, Montréal, Québec, H3A 3C2, Canada
| | - Philippe Corbeil
- Department of Kinesiology, Laval University, Québec, Québec, Canada
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Yan C, Lynch AC, Alemi MM, Banks JJ, Bouxsein ML, Anderson DE. Validity of evaluating spinal kinetics without participant-specific kinematics. J Biomech 2023; 161:111821. [PMID: 37805384 DOI: 10.1016/j.jbiomech.2023.111821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 09/12/2023] [Accepted: 09/26/2023] [Indexed: 10/09/2023]
Abstract
Musculoskeletal models are commonly used to estimate in vivo spinal loads under various loading conditions. Typically, participant-specific measured kinematics (PSMK) are coupled with participant-specific models, but obtaining PSMK data can be costly and infeasible in large studies or clinical practice. Thus, we evaluated two alternative methods to estimate spinal loads without PSMK: 1) ensemble average kinematics (EAK) based on kinematics from all participants; and 2) using separately measured individual kinematics (SMIK) from multiple other participants as inputs, then averaging the resulting loads. This study compares the dynamic spine loading patterns and peak loads in older adults performing five lifting tasks using PSMK, EAK and SMIK. Median root mean square errors of EAK and SMIK methods versus PSMK ranged from 18 to 72% body weight for compressive loads and from 2 to 25% body weight for shear loads, with median cross-correlations ranging from 0.931 to 0.991. The root mean square errors and cross-correlations between repeated PSMK trials fell within similar ranges. Compressive peak loads evaluated by EAK and SMIK were not different than PSMK in 12 of 15 cases, while by comparison repeated PSMK trials were not different in 13 of 15 cases. Overall, the resulting spine loading magnitudes and profiles using EAK or SMIK were not notably different than using a PSMK approach, and differences were not greater than between two PSMK trials. Thus, these findings indicate that these approaches may be used to make reasonable estimates of dynamic spinal loading without direct measurement of participant kinematics.
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Affiliation(s)
- Chenxi Yan
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Orthopedic Surgery, Harvard Medical School, Boston, MA, United States
| | - Andrew C Lynch
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Mohammad Mehdi Alemi
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Orthopedic Surgery, Harvard Medical School, Boston, MA, United States
| | - Jacob J Banks
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Orthopedic Surgery, Harvard Medical School, Boston, MA, United States
| | - Mary L Bouxsein
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Orthopedic Surgery, Harvard Medical School, Boston, MA, United States
| | - Dennis E Anderson
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Orthopedic Surgery, Harvard Medical School, Boston, MA, United States.
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Niederauer S, Hunt G, Foreman KB, Merryweather A, Hitchcock R. Intrinsic factors contributing to elevated intra-abdominal pressure. Comput Methods Biomech Biomed Engin 2023; 26:941-951. [PMID: 35837994 PMCID: PMC9840719 DOI: 10.1080/10255842.2022.2100220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 05/02/2022] [Accepted: 06/22/2022] [Indexed: 01/18/2023]
Abstract
Pelvic floor disorders affect 24% of US women, and elevated intra-abdominal pressure may cause pelvic injury through musculoskeletal strain. Activity restrictions meant to reduce pelvic strain after traumatic events, such as childbirth, have shown little benefit to patients. Reported high variability in abdominal pressure suggests that technique plays a substantial role in pressure generation. Understanding these techniques could inform evidence-based recommendations for protective pelvic care. We hypothesized use of a motion-capture methodology could identify four major contributors to elevated pressure: gravity, acceleration, abdominal muscle contraction, and respiration. Twelve women completed nineteen activities while instrumented for whole body motion capture, abdominal pressure, hip acceleration, and respiration volume. Correlation and partial least squares regression were utilized to determine primary technique factors that increase abdominal pressure. The partial least squares model identified two principal components that explained 59.63% of relative intra-abdominal pressure variability. The first component was primarily loaded by hip acceleration and relative respiration volume, and the second component was primarily loaded by flexion moments of the abdomen and thorax. While reducing abdominal muscle use has been a primary strategy in protective pelvic floor care, the influence of hip acceleration and breathing patterns should be considered with similar importance in future work.
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Affiliation(s)
- Stefan Niederauer
- Department of Biomedical Engineering, University of Utah, Salt Lake City, United States
| | - Grace Hunt
- Department of Mechanical Engineering, University of Utah, Salt Lake City, United States
| | - K Bo Foreman
- Department of Mechanical Engineering, University of Utah, Salt Lake City, United States
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, United States
| | - Andrew Merryweather
- Department of Mechanical Engineering, University of Utah, Salt Lake City, United States
| | - Robert Hitchcock
- Department of Biomedical Engineering, University of Utah, Salt Lake City, United States
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Oomen NMCW, Graham RB, Fischer SL. Exploring the role of task on kinematic variability and assessing consistency in individual responses across repetitive manual tasks. ERGONOMICS 2023; 66:749-761. [PMID: 36102976 DOI: 10.1080/00140139.2022.2125178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 09/05/2022] [Indexed: 05/24/2023]
Abstract
To gain a greater understanding of motor variability (MV) as an individual trait, the effect of task type on MV and individual consistency in MV across three tasks was investigated. Twenty participants performed repetitive carrying, lifting, and simulated sawing tasks. MV was assessed using the linear measure of mean point-by-point standard deviation in three-dimensional upper body joint angles. Task type affected MV, where carrying showed higher MV compared to sawing (23-29%) and lifting (12-19%). Furthermore, MV was higher in lifting compared to sawing (12-25%). Poor to moderate individual consistency (ICC = 0.42-0.63) was found across tasks. Task type determined MV and only some support for MV as an individual trait across tasks was found. Based on this work, differences in degrees of freedom afforded by the task influence the opportunity to exploit MV, and possibly individual consistency in MV magnitude is specific to the degrees of freedom afforded by the task. Practitioner summary: In repetitive tasks, movement variability has been proposed as an individual characteristic independent of task characteristics, where repeaters show consistently low variability, while replacers show consistently high variability. In the current study, only moderate support was demonstrated for variability as a consistent individual characteristic across different manual tasks.AbbreviationMV: Motor variability; WRMSDs: Work-related musculoskeletal disorders; DOF: Degrees of freedom; meanSD: Mean standard deviation; SD: Standard deviation; H: Handle (of simulated sawing setup); T: Track (of simulated sawing setup); F: Frame (of simulated sawing setup); ICC: Intraclass correlation; UE: Upper extremity; MMH: Manual material handling; EMG: Electromyography.
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Affiliation(s)
- Nathalie M C W Oomen
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Canada
| | - Ryan B Graham
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Canada
- Faculty of Health Sciences, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Steven L Fischer
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Canada
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Oomen NMCW, Graham RB, Fischer SL. Exploring the relationship between kinematic variability and fatigue development during repetitive lifting. APPLIED ERGONOMICS 2023; 107:103922. [PMID: 36335654 DOI: 10.1016/j.apergo.2022.103922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 10/17/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
To investigate the variability-fatigue and repeaters-replacers hypotheses, motor variability (MV) and indicators of fatigue were assessed during repetitive lifting. Eighteen participants performed sequential repetitive bouts of lifting divided into a short bout, and three phases of a prolonged bout until volitional fatigue (or until a 1-h time limit). Whole-body kinematics were collected to calculate variability in three-dimensional joint angles and in continuous relative phase (CRP) of sagittal joint angle couplings, which were summed for the upper and lower body, and whole-body. Excellent individual consistency (ICC = 0.95-0.97) was demonstrated across lifting bouts as fatigue developed. Therefore, strong evidence was obtained for MV as an individual trait in support of the repeaters-replacers hypothesis. Associations were found for endurance and baseline effort with lower body variability, while no associations were found for rate of fatigue. Thus, some support was found for the variability-fatigue hypothesis which suggests that repeaters are less fatigue-resistant than replacers.
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Affiliation(s)
- Nathalie M C W Oomen
- Department of Kinesiology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Ryan B Graham
- Department of Kinesiology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada; School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, 75 Laurier Avenue East, Ottawa, ON K1N 6N5, Canada
| | - Steven L Fischer
- Department of Kinesiology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.
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Marcotte JV, Robert-Lachaine X, Denis D, Muller A, Plamondon A, Corbeil P. Biomechanical differences in experts' and novices' footstep patterns during a palletizing task. APPLIED ERGONOMICS 2023; 106:103880. [PMID: 36063564 DOI: 10.1016/j.apergo.2022.103880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
Very few studies have examined differences between experts' and novices' foot positioning and movements during manual materials handling tasks. The impact of footstep patterns on low back loading needs to be better understood. The goals of this study were to characterize foot placement and movements in novices and experts and to assess their impact on back loading considering the height of grasp. The task consisted in transferring 24 15 kg boxes from a pallet to another. Foot placement and movements were classified with a recently developed taxonomy. Results show that experts' feet remained static more often than novices' feet during the lifting phase. Positioning the feet towards the deposit site during lifting increased asymmetrical moments, especially for novices. Positioning one foot forward increased asymmetrical moments for novices. Overall, footstep strategies are an effective indicator of low back exposure and should be considered in ergonomic studies.
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Affiliation(s)
- Jasmin Vallée Marcotte
- Department of Kinesiology, Université Laval, Québec, Québec, Canada; Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale (CIRRIS), Centre Intégré Universitaire de Santé et de Services Sociaux de La Capitale-Nationale (CIUSSS-CN), Québec, Canada.
| | - Xavier Robert-Lachaine
- Department of Kinesiology, Université Laval, Québec, Québec, Canada; Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale (CIRRIS), Centre Intégré Universitaire de Santé et de Services Sociaux de La Capitale-Nationale (CIUSSS-CN), Québec, Canada; Institut de Recherche Robert Sauvé en Santé et en Sécurité Du Travail (IRSST), 505 Boul. De Maisonneuve Ouest, Montréal, Québec, H3A 3C2, Canada
| | - Denys Denis
- Université Du Québec à Montréal (UQAM), Montréal, Québec, Canada
| | - Antoine Muller
- Univ Lyon, Université Claude Bernard Lyon 1, Univ Gustave Eiffel, LBMC UMR_T 9406, F-69622, Lyon, France
| | - André Plamondon
- Institut de Recherche Robert Sauvé en Santé et en Sécurité Du Travail (IRSST), 505 Boul. De Maisonneuve Ouest, Montréal, Québec, H3A 3C2, Canada
| | - Philippe Corbeil
- Department of Kinesiology, Université Laval, Québec, Québec, Canada; Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale (CIRRIS), Centre Intégré Universitaire de Santé et de Services Sociaux de La Capitale-Nationale (CIUSSS-CN), Québec, Canada.
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Ashok P, Madhan Mohan G, Manojkumar S. An ergonomic evaluation of workers in the winding section of the pump manufacturing industry. Work 2022; 72:1455-1467. [DOI: 10.3233/wor-210725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND: Work-related musculoskeletal disorders (WMSDs) are prevalent and have an impact across occupations. However, there are very few studies that document the prevalence of WMSDs in the pump industry. In manufacturing industries, the common issue for WMSDs and physiological stress among the workers is caused by poor working posture. OBJECTIVE: To investigate the occupational risks at the winding station in the pump manufacturing industry. In addition, this study examined the influence of work-study on mitigating occupational risks. METHODS: Workers who were involved in circular coil winding and insulation testing were considered for the study. Awkward postures adopted while performing these tasks cause fatigue, injuries and WMSDs. Tasks were evaluated as per the National Institute for Occupational Safety and Health (NIOSH) standards. A work-study was conducted to better understand the workflow. Virtual ergonomic postural evaluation (Rapid Upper Limb Assessment, RULA) was used to identify the occupational risks. RESULTS: Time taken for making circular windings and insulation testing (7.5 Hp submersible motor) was found to be 4.04 minutes and 0.95 minutes, respectively. A CAD model was used for ergonomic evaluation in the virtual environment. The RULA final score of 2 and 3 is attributed to coil winding and insulation testing. CONCLUSION: For further studies, the whole pump manufacturing process should be taken into account. The ergonomic tools used in this study will considerably reduce the occupation risks at the winding station in the pump manufacturing industry.
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Affiliation(s)
- P. Ashok
- Department of Production Engineering, PSG College of Technology, Peelamedu, Coimbatore, Tamil Nadu, India
| | - G. Madhan Mohan
- Department of Production Engineering, PSG College of Technology, Peelamedu, Coimbatore, Tamil Nadu, India
| | - S. Manojkumar
- Department of Production Engineering, PSG College of Technology, Peelamedu, Coimbatore, Tamil Nadu, India
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Lamooki SR, Cavuoto LA, Kang J. Adjustments in Shoulder and Back Kinematics during Repetitive Palletizing Tasks. SENSORS (BASEL, SWITZERLAND) 2022; 22:5655. [PMID: 35957219 PMCID: PMC9370918 DOI: 10.3390/s22155655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Repetitive task performance is a leading cause of musculoskeletal injuries among order-picking workers in warehouses. The repetition of lifting tasks increases the risk of back and shoulder injuries among these workers. While lifting in this industry is composed of loaded and unloaded picking and placing, the existing literature does not address the separate analysis of the biomechanics of the back and shoulder for these events. To that end, we investigated the kinematics of the back and shoulder movements of nine healthy male participants who performed three sessions of a simulated de/palletization task. Their back and shoulder kinematics were sensed using an optical motion capture system to determine the back inclination and shoulder flexion. Comparison of the kinematics between the first and last sessions indicated statistically significant changes in the timings, angles, coordination between the back and shoulder, and moments around the shoulder (p<0.05). The majority of the significant changes were observed during the loaded events, which confirms the importance of the separation of these events for biomechanical analysis. This finding suggests that focusing worker evaluation on the loaded periods can provide important information to detect kinematic changes that may affect musculoskeletal injury risk.
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Affiliation(s)
- Saeb R. Lamooki
- Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14260, USA;
| | - Lora A. Cavuoto
- Industrial and Systems Engineering, University at Buffalo, Buffalo, NY 14260, USA
| | - Jiyeon Kang
- Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14260, USA;
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Oomen NMCW, Graham RB, Fischer SL. Exploring the role of task constraints on motor variability and assessing consistency in individual responses during repetitive lifting using linear variability of kinematics. APPLIED ERGONOMICS 2022; 100:103668. [PMID: 34929475 DOI: 10.1016/j.apergo.2021.103668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 11/10/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
To better understand the assessment of motor variability (MV) in an occupational context, this study determined the role of task constraints on MV and consistency in individual MV responses. Twenty participants performed repetitive lifting under four constraints differing in restriction of foot movement and load weight. MV was assessed for three body regions and for the whole-body using linear variability of three-dimensional joint angles. Foot movement caused significant increases of lower body (11-17%), low back (318-439%) and a reduction in upper body variability (4%), whereas no effects of weight nor interaction of foot restriction and weight were found. Good individual consistency (ICC = 0.71-0.84) was demonstrated across constraints. Even though MV is affected by constraints, this study supports that MV is largely an individual trait independent of constraints. Future work should evaluate if MV remains an individual trait across different tasks, and if MV is confounded by other task constraints.
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Affiliation(s)
- Nathalie M C W Oomen
- Department of Kinesiology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Ryan B Graham
- Department of Kinesiology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada; School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, 75 Laurier Avenue East, Ottawa, ON K1N 6N5, Canada
| | - Steven L Fischer
- Department of Kinesiology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.
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13
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Skals S, Bláfoss R, de Zee M, Andersen LL, Andersen MS. Effects of load mass and position on the dynamic loading of the knees, shoulders and lumbar spine during lifting: a musculoskeletal modelling approach. APPLIED ERGONOMICS 2021; 96:103491. [PMID: 34126573 DOI: 10.1016/j.apergo.2021.103491] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
Musculoskeletal models may enhance our understanding of the dynamic loading of the joints during manual material handling. This study used state-of-the-art musculoskeletal models to determine the effects of load mass, asymmetry angle, horizontal location and deposit height on the dynamic loading of the knees, shoulders and lumbar spine during lifting. Recommended weight limits and lifting indices were also calculated using the NIOSH lifting equation. Based on 1832 lifts from 22 subjects, we found that load mass had the most substantial effect on L5-S1 compression. Increments in asymmetry led to large increases in mediolateral shear, while load mass and asymmetry had significant effects on anteroposterior shear. Increased deposit height led to higher shoulder forces, while the horizontal location mostly affected the forces in the knees and shoulders. These results generally support the findings of previous research, but notable differences in the trends and magnitudes of the estimated forces were observed.
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Affiliation(s)
- Sebastian Skals
- Musculoskeletal Disorders and Physical Workload, National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen East, Denmark; Sport Sciences - Performance and Technology, Department of Health Science and Technology, Aalborg University, Niels Jernes Vej 12, 9220 Aalborg East, Denmark.
| | - Rúni Bláfoss
- Musculoskeletal Disorders and Physical Workload, National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen East, Denmark; Research Unit for Muscle Physiology and Biomechanics, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
| | - Mark de Zee
- Sport Sciences - Performance and Technology, Department of Health Science and Technology, Aalborg University, Niels Jernes Vej 12, 9220 Aalborg East, Denmark.
| | - Lars Louis Andersen
- Musculoskeletal Disorders and Physical Workload, National Research Centre for the Working Environment, Lersø Parkallé 105, 2100 Copenhagen East, Denmark; Sport Sciences - Performance and Technology, Department of Health Science and Technology, Aalborg University, Niels Jernes Vej 12, 9220 Aalborg East, Denmark.
| | - Michael Skipper Andersen
- Department of Materials and Production, Aalborg University, Fibigerstræde 16, 9220 Aalborg, Denmark.
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14
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Struška M, Hora M, Rocek TR, Sládek V. Influence of upper limb training and analyzed muscles on estimate of physical activity during cereal grinding using saddle quern and rotary quern. PLoS One 2021; 16:e0243669. [PMID: 34464409 PMCID: PMC8407586 DOI: 10.1371/journal.pone.0243669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 08/18/2021] [Indexed: 11/18/2022] Open
Abstract
Experimental grinding has been used to study the relationship between human humeral robusticity and cereal grinding in the early Holocene. However, such replication studies raise two questions regarding the robusticity of the results: whether female nonathletes used in previous research are sufficiently comparable to early agricultural females, and whether previous analysis of muscle activation of only four upper limb muscles is sufficient to capture the stress of cereal grinding on upper limb bones. We test the influence of both of these factors. Electromyographic activity of eight upper limb muscles was recorded during cereal grinding in an athletic sample of 10 female rowers and in 25 female nonathletes and analyzed using both an eight- and four-muscle model. Athletes had lower activation than nonathletes in the majority of measured muscles, but except for posterior deltoid these differences were non-significant. Furthermore, both athletes and nonathletes had lower muscle activation during saddle quern grinding than rotary quern grinding suggesting that the nonathletes can be used to model early agricultural females during saddle and rotary quern grinding. Similarly, in both eight- and four-muscle models, upper limb loading was lower during saddle quern grinding than during rotary quern grinding, suggesting that the upper limb muscles may be reduced to the previously used four-muscle model for evaluation of the upper limb loading during cereal grinding. Another implication of our measurements is to question the assumption that skeletal indicators of high involvement of the biceps brachii muscle can be interpreted as specifically indicative of saddle quern grinding.
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Affiliation(s)
- Michal Struška
- Faculty of Science, Department of Anthropology and Human Genetics, Charles University, Prague, Czech Republic
- * E-mail:
| | - Martin Hora
- Faculty of Science, Department of Anthropology and Human Genetics, Charles University, Prague, Czech Republic
| | - Thomas R. Rocek
- Department of Anthropology, University of Delaware, Newark, Delaware, United States of America
| | - Vladimír Sládek
- Faculty of Science, Department of Anthropology and Human Genetics, Charles University, Prague, Czech Republic
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15
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Reist RM, Bath BL, Jelinski MD, Erickson NEN, Clark CR, Trask CM. Ergonomic assessment of veterinarians during performance of bovine reproductive examinations. J Am Vet Med Assoc 2021; 258:1243-1253. [PMID: 33978445 DOI: 10.2460/javma.258.11.1243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To identify and quantify potential ergonomic hazards associated with routine reproductive examinations of cattle. SAMPLE 7 bovine veterinarians. PROCEDURES Each veterinarian was observed and videotaped during 2 bovine reproductive examination appointments. During each appointment, a force-matching protocol was used to estimate the entry force used by the veterinarian to insert an arm into a cow's rectum. Veterinarian posture and repetitive movements and the work environment were assessed and quantified during review of the video recordings. Descriptive data were generated. RESULTS Of the 14 appointments observed, 9 and 5 involved examination of beef and dairy cows, respectively. For all veterinarians, an arm inclination ≥ 60° was observed during most reproductive examinations. The number of examinations performed per hour ranged from 19.1 to 116.8. The estimated entry force ranged from 121 to 349 N. During all 9 appointments involving beef cows, the veterinarian participated in other tasks (eg, operating overhead levers, opening gates, or assisting with cattle handling) that represented ergonomic hazards. CONCLUSIONS AND CLINICAL RELEVANCE Results confirmed that reproductive examination of cattle exposes veterinarians to various ergonomic hazards involving awkward positions and repetitive and forceful exertions that can contribute to musculoskeletal discomfort and injury, particularly of the upper extremities (neck, shoulders, upper back, arms, elbows, wrists, and hands). Veterinarians frequently participated in other tasks during reproductive examination appointments that exposed them to additional ergonomic hazards. Risk mitigation strategies should prioritize minimizing exposure of veterinarians to tasks not directly associated with the reproductive examination procedure to decrease their overall ergonomic hazard burden.
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16
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Schall MC, Zhang X, Chen H, Gallagher S, Fethke NB. Comparing upper arm and trunk kinematics between manufacturing workers performing predominantly cyclic and non-cyclic work tasks. APPLIED ERGONOMICS 2021; 93:103356. [PMID: 33454432 PMCID: PMC9298156 DOI: 10.1016/j.apergo.2021.103356] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/30/2020] [Accepted: 01/04/2021] [Indexed: 05/27/2023]
Abstract
Musculoskeletal disorders (MSDs) are common among manufacturing workers. Exposure to non-neutral postures and high movement speeds associated with MSDs among manufacturing workers may depend on the extent of the variability in the work tasks performed (i.e., predominantly "cyclic" versus "non-cyclic" work). The objectives of this study were to (i) compare mean levels of full-shift exposure summary metrics based on both posture and movement speed between manufacturing workers performing predominantly cyclic (n = 18) and non-cyclic (n = 17) tasks, and (ii) explore patterns of between- and within-worker exposure variance and between-minute (within-shift) exposure level and variation within each group. Inertial sensors were used to measure exposures for up to 15 full shifts per participant. Results indicated (i) substantially higher upper arm and trunk movement speeds among workers performing predominantly cyclic tasks relative to workers performing non-cyclic tasks despite similar postures, and (ii) greater exposure variability both between and within workers in the non-cyclic group.
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Affiliation(s)
- Mark C Schall
- Auburn University, Department of Industrial and Systems Engineering, 3323F Shelby Center for Engineering Technology, Auburn, AL, 36849-5346, USA.
| | - Xuanxuan Zhang
- Marshall University, Department of Applied Sciences and Technology, One John Marshall Drive, Huntington, 25755, WV, USA.
| | - Howard Chen
- Auburn University, Department of Mechanical Engineering, 1418 Wiggins Hall, Auburn, AL, 36849-5346, USA.
| | - Sean Gallagher
- Auburn University, Department of Industrial and Systems Engineering, 3304 Shelby Center for Engineering Technology, Auburn, AL, 36849-5346, USA.
| | - Nathan B Fethke
- University of Iowa, Department of Occupational and Environmental Health, S347 College of Public Health Building, Iowa City, IA, 52242, USA.
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17
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Robert-Lachaine X, Corbeil P, Muller A, Vallée-Marcotte J, Mecheri H, Denis D, Plamondon A. Combined influence of transfer distance, pace, handled mass and box height on spine loading and posture. APPLIED ERGONOMICS 2021; 93:103377. [PMID: 33556886 DOI: 10.1016/j.apergo.2021.103377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/18/2020] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
Work-related low back disorders are commonly associated with handling tasks. The objective of this study was to determine the combined influence of distance, pace, handled mass and height, on back loading and posture during free box transfer. Kinematics and kinetics of 17 handlers were recorded during a box transfer task between two pallets. Four-way repeated measures ANOVA were conducted on four lift-deposit height conditions (from lift and deposit of 0.16 or 1.16 m), three distances between pallets (1.5, 1.0 and 0.5 m), two handled masses (10 and 20 kg) and two paces (free and faster). The interaction between distance and height on back loading and posture (P < 0.001) showed that increasing distance to more than 1 m is not recommended to avoid unnecessary cumulative loading. The shorter distance of 0.5 m, which generally reduced the most spine loading, may increase it for transfers varying in height. The effect of pace to reduce spine cumulative loading and increase the peak asymmetric loading (P < 0.05) was accentuated by mass, height and distance. The combined factors revealed the importance of tradeoff between peak, cumulative and asymmetric loading.
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Affiliation(s)
- Xavier Robert-Lachaine
- Institut de Recherche Robert-Sauvé en Santé et en Sécurité du Travail, Montréal, QC, Canada; Département de Kinésiologie, Faculté de Médecine, Université Laval, Quebec City, QC, Canada; Centre for interdisciplinary research in rehabilitation and social integration (CIRRIS), Centre intégré universitaire de santé et de services sociaux de la Capitale-Nationale (CIUSSS-CN), Quebec City, QC, Canada.
| | - Philippe Corbeil
- Département de Kinésiologie, Faculté de Médecine, Université Laval, Quebec City, QC, Canada; Centre for interdisciplinary research in rehabilitation and social integration (CIRRIS), Centre intégré universitaire de santé et de services sociaux de la Capitale-Nationale (CIUSSS-CN), Quebec City, QC, Canada
| | - Antoine Muller
- Institut de Recherche Robert-Sauvé en Santé et en Sécurité du Travail, Montréal, QC, Canada
| | - Jasmin Vallée-Marcotte
- Département de Kinésiologie, Faculté de Médecine, Université Laval, Quebec City, QC, Canada; Centre for interdisciplinary research in rehabilitation and social integration (CIRRIS), Centre intégré universitaire de santé et de services sociaux de la Capitale-Nationale (CIUSSS-CN), Quebec City, QC, Canada
| | - Hakim Mecheri
- Institut de Recherche Robert-Sauvé en Santé et en Sécurité du Travail, Montréal, QC, Canada
| | - Denys Denis
- Département des Sciences de l'activité physique, Faculté des sciences, Université du Québec à Montréal, Montréal, QC, Canada
| | - André Plamondon
- Institut de Recherche Robert-Sauvé en Santé et en Sécurité du Travail, Montréal, QC, Canada
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18
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Goubault E, Verdugo F, Pelletier J, Traube C, Begon M, Dal Maso F. Exhausting repetitive piano tasks lead to local forearm manifestation of muscle fatigue and negatively affect musical parameters. Sci Rep 2021; 11:8117. [PMID: 33854088 PMCID: PMC8047012 DOI: 10.1038/s41598-021-87403-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 03/23/2021] [Indexed: 02/02/2023] Open
Abstract
Muscle fatigue is considered as a risk factor for developing playing-related muscular disorders among professional pianists and could affect musical performance. This study investigated in 50 pianists the effect of fatiguing repetitive piano sequences on the development of forearm muscle fatigue and on piano performance parameters. Results showed signs of myoelectric manifestation of fatigue in the 42-electromyographic bipolar electrodes positioned on the forearm to record finger and wrist flexor and extensor muscles, through a significant non-constant decrease of instantaneous median frequency during two repetitive Digital (right-hand 16-tones sequence) and Chord (right-hand chords sequence) excerpts, with extensor muscles showing greater signs of fatigue than flexor muscles. In addition, muscle fatigue negatively affected key velocity, a central feature of piano sound intensity, in both Digital and Chord excerpts, and note-events, a fundamental aspect of musicians' performance parameter, in the Chord excerpt only. This result highlights that muscle fatigue may alter differently pianists' musical performance according to the characteristics of the piece played.
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Affiliation(s)
- Etienne Goubault
- grid.14848.310000 0001 2292 3357Laboratoire de Simulation et Modélisation du Mouvement, École de Kinésiologie et des Sciences de l’activité Physique, Université de Montréal, 1700 Rue Jacques-Tétreault, Laval, QC Canada
| | - Felipe Verdugo
- grid.14709.3b0000 0004 1936 8649Input Devices and Music Interaction Laboratory, Centre for Interdisciplinary Research in Music Media and Technology, Schulich School of Music, McGill University, Montreal, QC Canada ,grid.267180.a0000 0001 2168 0285EXPRESSION Team, Université Bretagne-Sud, Vannes, France
| | - Justine Pelletier
- grid.38678.320000 0001 2181 0211Laboratoire Arts vivants et interdisciplinarité, Département de danse, Université du Québec à Montréal, Montreal, QC Canada
| | - Caroline Traube
- grid.14848.310000 0001 2292 3357Laboratoire de recherche sur le geste musicien, Faculté de musique, Université de Montréal, Montreal, QC Canada
| | - Mickaël Begon
- grid.14848.310000 0001 2292 3357Laboratoire de Simulation et Modélisation du Mouvement, École de Kinésiologie et des Sciences de l’activité Physique, Université de Montréal, 1700 Rue Jacques-Tétreault, Laval, QC Canada ,grid.411418.90000 0001 2173 6322Sainte-Justine Hospital Research Center, Montreal, QC Canada
| | - Fabien Dal Maso
- grid.14848.310000 0001 2292 3357Laboratoire de Simulation et Modélisation du Mouvement, École de Kinésiologie et des Sciences de l’activité Physique, Université de Montréal, 1700 Rue Jacques-Tétreault, Laval, QC Canada ,Centre interdisciplinaire de recherche sur le cerveau et l’apprentissage, Montréal, QC Canada
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19
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The Impact of Participants' Anthropometry on Muscle Activation Levels While Interacting with the Level of Expertise, Task Type, and Single Muscles. J Funct Morphol Kinesiol 2020; 5:jfmk5040088. [PMID: 33467303 PMCID: PMC7739408 DOI: 10.3390/jfmk5040088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/24/2020] [Accepted: 12/01/2020] [Indexed: 11/23/2022] Open
Abstract
In this research paper, we implemented a mixed factor design in order to investigate the effect of four anthropometries: height, weight, lower-arm dimensions, and upper-arm dimensions on the muscle activation level of participants when interacting with three types of moderators: experiment expertise, task type, and muscle type. The research paper focused on two levels of expertise (novice and expert), two tasks (deck-building and picket installation), and four arm muscles (Brachioradialis (BR), Extensor Carpi Ulnaris (ECU), Flexor Carpi Radialis (FCR), and Flexor Carpi Ulnaris (FCU)), which resulted in 16 (2 × 2 × 4) groups. For each of the 16 groups, the data were analyzed in order to investigate the relationship between the four anthropometries and the four muscle activation levels of the participants. Amos software (IBM, Armonk, NY, USA), along with multiple group structural equation modeling, was used to test a total of 16 direct relationships, as well as the moderation effects in the designed experiment. The results show that the participants' expertise can moderate the relationship between their height and muscle activation levels, the relationship between their weight and muscle activation levels, and the relationship between their lower arm dimensions and muscle activation levels. Moreover, the findings of this research paper demonstrate that the relationship between the lower arm dimensions and muscle activation levels, and the relationship between weight and muscle activation levels are moderated by the type of muscle used by the participants (i.e., BR, ECU, FCR, and FCU).
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20
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Liew BXW, De Nunzio AM, Srivastava S, Falla D. Influence of low back pain and its remission on motor abundance in a low-load lifting task. Sci Rep 2020; 10:17831. [PMID: 33082380 PMCID: PMC7576852 DOI: 10.1038/s41598-020-74707-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 10/06/2020] [Indexed: 11/09/2022] Open
Abstract
Having an abundance of motor solutions during movement may be advantageous for the health of musculoskeletal tissues, given greater load distribution between tissues. The aim of the present study was to understand whether motor abundance differs between people with and without low back pain (LBP) during a low-load lifting task. Motion capture with electromyography (EMG) assessment of 15 muscles was performed on 48 participants [healthy control (con) = 16, remission LBP (rLBP) = 16, current LBP (cLBP) = 16], during lifting. Non-negative matrix factorization and uncontrolled manifold analysis were performed to decompose inter-repetition variability in the temporal activity of muscle modes into goal equivalent (GEV) and non-goal equivalent (NGEV) variabilities in the control of the pelvis and trunk linear displacements. Motor abundance occurs when the ratio of GEV to NGEV exceeds zero. There were significant group differences in the temporal activity of muscle modes, such that both cLBP and rLBP individuals demonstrated greater activity of muscle modes that reflected lumbopelvic coactivation during the lifting phase compared to controls. For motor abundance, there were no significant differences between groups. Individuals with LBP, including those in remission, had similar overall motor abundance, but use different activation profiles of muscle modes than asymptomatic people during lifting.
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Affiliation(s)
- Bernard X W Liew
- School of Sport, Rehabilitation and Exercise Sciences, University of Essex, Colchester, CO4 3SQ, Essex, UK.
| | - Alessandro Marco De Nunzio
- LUNEX International University of Health, Exercise and Sports, 50, avenue du Parc des Sports, 4671, Differdange, Luxembourg
| | - Shraddha Srivastava
- Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, 77 President Street, Charleston, SC, 29425, USA
| | - Deborah Falla
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, B152TT, UK
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21
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Burkhart K, Grindle D, Bouxsein ML, Anderson DE. Between-session reliability of subject-specific musculoskeletal models of the spine derived from optoelectronic motion capture data. J Biomech 2020; 112:110044. [PMID: 32977297 DOI: 10.1016/j.jbiomech.2020.110044] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/30/2020] [Accepted: 09/01/2020] [Indexed: 01/18/2023]
Abstract
This study evaluated the between-session reliability of creating subject-specific musculoskeletal models with optoelectronic motion capture data, and using them to estimate spine loading. Nineteen healthy participants aged 24-74 years underwent the same set of measurements on two separate occasions. Retroreflective markers were placed on anatomical regions, including C7, T1, T4, T5, T8, T9, T12 and L1 spinous processes, pelvis, upper and lower limbs, and head. We created full-body musculoskeletal models with detailed thoracolumbar spines, and scaled these to create subject-specific models for each individual and each session. Models were scaled from distances between markers, and spine curvature was adjusted according to marker-estimated measurements. Using these models, we estimated vertebral compressive loading for five different standardized postures: neutral standing, 45˚ trunk flexion, 15˚ trunk extension, 20˚ lateral bend to the right, and 45˚ axial rotation to the right. Intraclass correlation coefficients (ICCs) and standard error of measurement were calculated as measures of between-session reliability and measurement error, respectively. Spine curvature measures showed excellent reliability (ICC = 0.79-0.91) and body scaling segments showed fair to excellent reliability (ICC = 0.46-0.95). We found that musculoskeletal models showed mostly excellent between-session reliability to estimate spine loading, with 91% of ICC values > 0.75 for all activities. This information is a necessary precursor for using motion capture data to estimate spine loading from subject-specific musculoskeletal models, and suggests that marker data will deliver reproducible subject-specific models and estimates of spine loading.
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Affiliation(s)
- Katelyn Burkhart
- Harvard-MIT Health Sciences and Technology Program, Massachusetts Institute of Technology, Cambridge 02139, MA, United States; Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston 02215, MA, United States; Department of Orthopaedic Surgery, Harvard Medical School, Boston 02115, MA, United States
| | - Daniel Grindle
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston 02215, MA, United States; Division of Engineering Mechanics, Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Mary L Bouxsein
- Harvard-MIT Health Sciences and Technology Program, Massachusetts Institute of Technology, Cambridge 02139, MA, United States; Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston 02215, MA, United States; Department of Orthopaedic Surgery, Harvard Medical School, Boston 02115, MA, United States
| | - Dennis E Anderson
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston 02215, MA, United States; Department of Orthopaedic Surgery, Harvard Medical School, Boston 02115, MA, United States.
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22
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Jackson JA, Srinivasan D, Mathiassen SE. Consistent individual motor variability traits demonstrated by females performing a long-cycle assembly task under conditions differing in temporal organisation. APPLIED ERGONOMICS 2020; 85:103046. [PMID: 32174342 DOI: 10.1016/j.apergo.2020.103046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/01/2020] [Accepted: 01/08/2020] [Indexed: 06/10/2023]
Abstract
Research suggests an association between motor variability (MV) during repetitive work and work-related musculoskeletal disorders (MSDs). However, whether MV is a consistent individual trait, even across working conditions or tasks, remains unknown. This study assessed whether individual MV traits were consistent during complex work performed under different temporal conditions. Fifteen women performed cyclic assembly under four conditions differing in pace and organisation (line-type, batch-type). MV of trapezius muscle activity and upper arm elevation was quantified and partitioned into variance components. For all MV metrics, a non-zero between-subjects variance was found, indicating consistent individual MV traits across conditions. Variance between subjects was higher for electromyography (EMG) MV metrics compared with kinematic metrics. Our results showed individuals exhibited consistent MV traits across working conditions differing in pace and production process. Further research is needed to understand whether MV is an individual predictive factor for MSD onset or progression.
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Affiliation(s)
- Jennie A Jackson
- Centre for Musculoskeletal Research, Department of Occupational Health Sciences and Psychology, Faculty of Health and Occupational Studies, University of Gävle, Gävle, Sweden.
| | - Divya Srinivasan
- Department of Industrial and Systems Engineering, Virginia Tech, Blacksburg, VA, USA.
| | - Svend Erik Mathiassen
- Centre for Musculoskeletal Research, Department of Occupational Health Sciences and Psychology, Faculty of Health and Occupational Studies, University of Gävle, Gävle, Sweden.
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23
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Beach TAC, Frost DM, Zehr JD, Howarth SJ, McGill SM, Callaghan JP. Spine loading during laboratory-simulated fireground operations - inter-individual variation and method of load quantification. ERGONOMICS 2019; 62:1426-1438. [PMID: 31424329 DOI: 10.1080/00140139.2019.1657183] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 08/07/2019] [Indexed: 06/10/2023]
Abstract
Spine loading data are needed to design low-back health-preserving ergonomic interventions for firefighters. Study objectives were to quantify spine loads during simulated fireground operations using simple (polynomial) and advanced (EMG-assisted musculoskeletal model) methods and to describe the variation in spine loads between performers (N = 20). Spine compression forces differed by as much as 5.5 times bodyweight between individuals performing identical tasks. Anteroposterior and mediolateral shear forces varied by as much 3.2 and 2.1 times bodyweight between individuals performing the same tasks, respectively. Large variations in spine load magnitudes were documented regardless of whether simple or advanced quantification methods were used. Results suggest that low-back loading demands on the fireground would vary widely depending on the physical characteristics of individual firefighters, movement strategies employed, and tasks performed. Thus, personalised ergonomic interventions are warranted to regulate spine loading and load tolerance in firefighters. Practitioner summary: Even when performing the same work, the associated spine loading demands will vary widely across people due to differences in their body sizes, shapes, and movement strategies. Therefore, personalised interventions are needed to regulate spine loading and load tolerance in workers (e.g. obesity prevention, physical capacity-building exercise, and movement [re]training).
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Affiliation(s)
- Tyson A C Beach
- Faculty of Kinesiology and Physical Education, University of Toronto , Toronto , ON , Canada
| | - David M Frost
- Faculty of Kinesiology and Physical Education, University of Toronto , Toronto , ON , Canada
| | - Jackie D Zehr
- Department of Kinesiology, University of Waterloo , Waterloo , ON , Canada
| | - Samuel J Howarth
- Faculty of Kinesiology and Physical Education, University of Toronto , Toronto , ON , Canada
- Department of Research, Canadian Memorial Chiropractic College , North York , ON , Canada
| | - Stuart M McGill
- Department of Kinesiology, University of Waterloo , Waterloo , ON , Canada
| | - Jack P Callaghan
- Department of Kinesiology, University of Waterloo , Waterloo , ON , Canada
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24
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Zehr JD, Tennant LM, Callaghan JP. Examining endplate fatigue failure during cyclic compression loading with variable and consistent peak magnitudes using a force weighting adjustment approach: an in vitro study. ERGONOMICS 2019; 62:1339-1348. [PMID: 31343393 DOI: 10.1080/00140139.2019.1648879] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 07/17/2019] [Indexed: 06/10/2023]
Abstract
Repetitive movement is common in many occupational contexts. Therefore, cumulative load is a widely recognised risk factor for lowback injury. This study quantified the effect of force weighting factors on cumulative load estimates and injury prediction during cyclic loading. Forty-eight porcine cervical spine motion segments were assigned to experimental groups that differed by average peak compression magnitude (30%, 50% and 70% of predicted tolerance) and amplitude variation (consistent, variable). Cyclic loading was performed at a frequency of 0.5 Hz until fatigue failure occurred. Weighting factors were determined and applied instantaneously. Inclusion of weighting factors resulted in statistically similar cumulative load estimates at injury between variable and consistent loading (p > .071). Further, survivorship was generally greater when the peak compression magnitude was consistent compared to variable. These results emphasise the importance of weighting factors as an equalisation tool for the evaluation of cumulative low back loading exposures in occupational contexts. Practitioner summary: Weighting factors can equalise the risk of injury based on compression magnitude. When weighted, the cumulative compression was similar between consistent and variable cyclic loading protocols, despite being significantly different when unweighted and having similar injury rates. Therefore, assessing representative occupational exposures without evaluating task performance variability may underestimate injury risk. Abbreviations: FSU: functional spinal unit; UCT: ultimate compression tolerance.
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Affiliation(s)
- Jackie D Zehr
- Department of Kinesiology, University of Waterloo , Waterloo , ON , Canada
| | - Liana M Tennant
- Department of Kinesiology, University of Waterloo , Waterloo , ON , Canada
| | - Jack P Callaghan
- Department of Kinesiology, University of Waterloo , Waterloo , ON , Canada
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Armstrong DP, Ross GB, Graham RB, Fischer SL. Considering movement competency within physical employment standards. Work 2019; 63:603-613. [DOI: 10.3233/wor-192955] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
| | - Gwyneth B. Ross
- School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Ryan B. Graham
- School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
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Bauer CM, Kankaanpää MJ, Meichtry A, Rissanen SM, Suni JH. Efficacy of six months neuromuscular exercise on lumbar movement variability - A randomized controlled trial. J Electromyogr Kinesiol 2019; 48:84-93. [PMID: 31252284 DOI: 10.1016/j.jelekin.2019.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 06/11/2019] [Accepted: 06/20/2019] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION Lumbar movement variability during heavy, repetitive work may be a protective mechanism to diminish the progression of lumbar disorders and maintain neuromuscular functional integrity. The effect of neuromuscular exercise (NME) on the variability of lumbar movement is still to be determined. METHODS A randomised controlled trial was conducted on a population of nursing personnel with subacute LBP. Following randomization, the NME group participants completed an NME program of six months duration. The participants in the control group only attended the assessment sessions. The outcomes were assessed at: baseline; after six months intervention; 12 months. The primary outcome was lumbar movement variability based on angular displacement and velocity. RESULTS A positive treatment effect on lumbar movement variability was seen after six months of NME intervention. Angular displacement improved, and angular velocity remained constant. At the 12-month follow up, however, the effect faded in the NME group. Lumbar movement variability worsened in the control group over all time periods. CONCLUSION NME may improve lumbar movement variability in the short term and may indicate improved neuromuscular functional integrity. The design of an optimal NME program to achieve long-term improvement in lumbar movement variability is a subject worthy of further research.
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Affiliation(s)
- C M Bauer
- University of Tampere, School of Medicine, Kalevantie 4, 33014 University of Tampere, Finland; Zurich University of Applied Sciences, Department of Health, Institute of Physiotherapy, Technikumstrasse 71, 8400 Winterthur, Switzerland.
| | - M J Kankaanpää
- University of Tampere, School of Medicine, Kalevantie 4, 33014 University of Tampere, Finland; Pirkanmaa Hospital District, Physical and Rehabilitation Medicine Outpatient Clinic, Box 2000, 33521 Tampere, Finland.
| | - A Meichtry
- Zurich University of Applied Sciences, Department of Health, Institute of Physiotherapy, Technikumstrasse 71, 8400 Winterthur, Switzerland.
| | - S M Rissanen
- University of Eastern Finland, Department of Applied Physics, P.O. Box 1627, 70211 Kuopio, Finland.
| | - J H Suni
- UKK Institute for Health Promotion Research, Kaupinpuistonkatu 1, 33500 Tampere, Finland.
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Zehr JD, Tennant LM, Callaghan JP. Incorporating loading variability into in vitro injury analyses and its effect on cumulative compression tolerance in porcine cervical spine units. J Biomech 2019; 88:48-54. [PMID: 30904332 DOI: 10.1016/j.jbiomech.2019.03.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 03/07/2019] [Accepted: 03/10/2019] [Indexed: 10/27/2022]
Abstract
During repetitive movement, low-back loading exposures are inherently variable in magnitude. The current study aimed to investigate how variation in successive compression exposures influences cumulative load tolerance in the spine. Forty-eight porcine cervical spine units were randomly assigned to one of six combinations of mean peak compression force (30%, 50%, 70% of the predicted tolerance) and loading variation (consistent peak amplitude, variable peak amplitude). Following preload and passive range-of-motion tests, specimens were positioned in a neutral posture and then cyclically loaded in compression until failure occurred or the maximum 12 h duration was reached. Specimens were dissected to classify macroscopic injury and measurements of cumulative load, cycles, and height loss sustained at failure were calculated. Statistical comparisons were made between loading protocols within each normalized compression group. A significant loading variation × compression interaction was demonstrated for cumulative load (p = 0.026) and cycles to failure (p = 0.021). Cumulative compression was reduced under all normalized compression loads (30% p = 0.016; 50% p = 0.030; 70% p = 0.020) when variable loading was incorporated. The largest reduction was by 33% and occurred in the 30% compression group. The number of sustained cycles was reduced by 31% (p = 0.017), 72% (p = 0.030), and 76% (p = 0.009) under normalized compression loads of 30%, 50%, and 70%, respectively. These findings suggest that variation in compression exposures interact to reduce cumulative compression tolerance of the spine and could elevate low-back injury risk during time-varying repetitive tasks.
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Affiliation(s)
- Jackie D Zehr
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Liana M Tennant
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Jack P Callaghan
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
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Ahmad I, Kim JY. Assessment of Whole Body and Local Muscle Fatigue Using Electromyography and a Perceived Exertion Scale for Squat Lifting. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15040784. [PMID: 29670002 PMCID: PMC5923826 DOI: 10.3390/ijerph15040784] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 11/30/2022]
Abstract
This research study aims at addressing the paradigm of whole body fatigue and local muscle fatigue detection for squat lifting. For this purpose, a comparison was made between perceived exertion with the heart rate and normalized mean power frequency (NMPF) of eight major muscles. The sample consisted of 25 healthy males (age: 30 ± 2.2 years). Borg’s CR-10 scale was used for perceived exertion for two segments of the body (lower and upper) and the whole body. The lower extremity of the body was observed to be dominant compared to the upper and whole body in perceived response. First mode of principal component analysis (PCA) was obtained through the covariance matrix for the eight muscles for 25 subjects for NMPF of eight muscles. The diagonal entries in the covariance matrix were observed for each muscle. The muscle with the highest absolute magnitude was observed across all the 25 subjects. The medial deltoid and the rectus femoris muscles were observed to have the highest frequency for each PCA across 25 subjects. The rectus femoris, having the highest counts in all subjects, validated that the lower extremity dominates the sense of whole body fatigue during squat lifting. The findings revealed that it is significant to take into account the relation between perceived and measured effort that can help prevent musculoskeletal disorders in repetitive occupational tasks.
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Affiliation(s)
- Imran Ahmad
- Department of Industrial Management Engineering, Hanyang University, Ansan 15588, Korea.
| | - Jung-Yong Kim
- Department of Industrial Management Engineering, Hanyang University, Ansan 15588, Korea.
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29
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Weston EB, Alizadeh M, Knapik GG, Wang X, Marras WS. Biomechanical evaluation of exoskeleton use on loading of the lumbar spine. APPLIED ERGONOMICS 2018; 68:101-108. [PMID: 29409622 DOI: 10.1016/j.apergo.2017.11.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 11/07/2017] [Accepted: 11/08/2017] [Indexed: 06/07/2023]
Abstract
The objective of this study was to investigate biomechanical loading to the low back as a result of wearing an exoskeletal intervention designed to assist in occupational work. Twelve subjects simulated the use of two powered hand tools with and without the use of a Steadicam vest with an articulation tool support arm in a laboratory environment. Dependent measures of peak and mean muscle forces in ten trunk muscles and peak and mean spinal loads were examined utilizing a dynamic electromyography-assisted spine model. The exoskeletal device increased both peak and mean muscle forces in the torso extensor muscles (p < 0.001). Peak and mean compressive spinal loads were also increased up to 52.5% and 56.8%, respectively, for the exoskeleton condition relative to the control condition (p < 0.001). The results of this study highlight the need to design exoskeletal interventions while anticipating how mechanical loads might be shifted or transferred with their use.
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Affiliation(s)
- Eric B Weston
- Spine Research Institute, The Ohio State University, Columbus, OH, United States; Department of Integrated Systems Engineering, The Ohio State University, Columbus, OH, United States.
| | - Mina Alizadeh
- Spine Research Institute, The Ohio State University, Columbus, OH, United States; Department of Integrated Systems Engineering, The Ohio State University, Columbus, OH, United States
| | - Gregory G Knapik
- Spine Research Institute, The Ohio State University, Columbus, OH, United States; Department of Integrated Systems Engineering, The Ohio State University, Columbus, OH, United States
| | - Xueke Wang
- Department of Integrated Systems Engineering, The Ohio State University, Columbus, OH, United States
| | - William S Marras
- Spine Research Institute, The Ohio State University, Columbus, OH, United States; Department of Integrated Systems Engineering, The Ohio State University, Columbus, OH, United States
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30
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Pranata A, Perraton L, El-Ansary D, Clark R, Mentiplay B, Fortin K, Long B, Brandham R, Bryant A. Trunk and lower limb coordination during lifting in people with and without chronic low back pain. J Biomech 2018; 71:257-263. [DOI: 10.1016/j.jbiomech.2018.02.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 01/20/2018] [Accepted: 02/11/2018] [Indexed: 10/18/2022]
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31
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Effects of Daily Physical Activity Level on Manual Wheelchair Propulsion Technique in Full-Time Manual Wheelchair Users During Steady-State Treadmill Propulsion. Arch Phys Med Rehabil 2017; 98:1374-1381. [DOI: 10.1016/j.apmr.2017.01.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 01/05/2017] [Accepted: 01/08/2017] [Indexed: 11/20/2022]
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Kim HK, Zhang Y. Estimation of lumbar spinal loading and trunk muscle forces during asymmetric lifting tasks: application of whole-body musculoskeletal modelling in OpenSim. ERGONOMICS 2017; 60:563-576. [PMID: 27194401 DOI: 10.1080/00140139.2016.1191679] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Large spinal compressive force combined with axial torsional shear force during asymmetric lifting tasks is highly associated with lower back injury (LBI). The aim of this study was to estimate lumbar spinal loading and muscle forces during symmetric lifting (SL) and asymmetric lifting (AL) tasks using a whole-body musculoskeletal modelling approach. Thirteen healthy males lifted loads of 7 and 12 kg under two lifting conditions (SL and AL). Kinematic data and ground reaction force data were collected and then processed by a whole-body musculoskeletal model. The results show AL produced a significantly higher peak lateral shear force as well as greater peak force of psoas major, quadratus lumborum, multifidus, iliocostalis lumborum pars lumborum, longissimus thoracis pars lumborum and external oblique than SL. The greater lateral shear forces combined with higher muscle force and asymmetrical muscle contractions may have the biomechanical mechanism responsible for the increased risk of LBI during AL. Practitioner Summary: Estimating lumbar spinal loading and muscle forces during free-dynamic asymmetric lifting tasks with a whole-body musculoskeletal modelling in OpenSim is the core value of this research. The results show that certain muscle groups are fundamentally responsible for asymmetric movement, thereby producing high lumbar spinal loading and muscle forces, which may increase risks of LBI during asymmetric lifting tasks.
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Affiliation(s)
- Hyun-Kyung Kim
- a Biomechanics Laboratory, Department of Exercise Sciences , University of Auckland , Auckland , New Zealand
| | - Yanxin Zhang
- a Biomechanics Laboratory, Department of Exercise Sciences , University of Auckland , Auckland , New Zealand
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Chehrehrazi M, Sanjari MA, Mokhtarinia HR, Jamshidi AA, Maroufi N, Parnianpour M. Goal equivalent manifold analysis of task performance in non-specific LBP and healthy subjects during repetitive trunk movement: Effect of load, velocity, symmetry. Hum Mov Sci 2016; 51:72-81. [PMID: 27915152 DOI: 10.1016/j.humov.2016.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 11/17/2016] [Accepted: 11/18/2016] [Indexed: 11/16/2022]
Abstract
Motor abundance allows reliability of motor performance despite its variability. The nature of this variability provides important information on the flexibility of control strategies. This feature of control may be affected by low back pain (LPB) and trunk flexion/extension conditions. Goal equivalent manifold (GEM) analysis was used to quantify the ability to exploit motor abundance during repeated trunk flexion/extension in healthy individuals and people with chronic non-specific LBP (CNSLBP). Kinematic data were collected from 22 healthy volunteers and 22 CNSLBP patients during metronomically timed, repeated trunk flexion/extension in three conditions of symmetry, velocity, and loading; each at two levels. A goal function for the task was defined as maintaining a constant movement time at each cycle. Given the GEM, flexibility index and performance index were calculated respectively as amounts of goal-equivalent variability and the ratio of goal-equivalent to non-goal-equivalent variability. CNSLBP group was as similar as healthy individuals in both flexibility index (p=0.41) and performance index (p=0.24). Performance index was higher in asymmetric (p<0.001), high velocity (p<0.001), and loaded (p=0.006) conditions. Performance and flexibility in using motor abundance were influenced by repeated trunk flexion/extension conditions. However, these measures were not significantly affected by CNSLBP.
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Affiliation(s)
- Mahshid Chehrehrazi
- Department of Physical Therapy, Faculty of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran.
| | - Mohammad Ali Sanjari
- Biomechanics Lab, Rehabilitation Research Center, and Faculty of Rehabilitation, Department of Rehabilitation Basic Sciences, Iran University of Medical Sciences, Tehran, Iran.
| | - Hamid Reza Mokhtarinia
- Department of Ergonomics, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
| | - Ali Ashraf Jamshidi
- Department of Physical Therapy, Faculty of Rehabilitation, Iran University of Medical Sciences, Tehran, Iran.
| | - Nader Maroufi
- Department of Physical Therapy, Faculty of Rehabilitation, Iran University of Medical Sciences, Tehran, Iran.
| | - Mohamad Parnianpour
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran.
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A biologically-assisted curved muscle model of the lumbar spine: Model validation. Clin Biomech (Bristol, Avon) 2016; 37:153-159. [PMID: 27484459 DOI: 10.1016/j.clinbiomech.2016.07.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 07/19/2016] [Accepted: 07/26/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Biomechanical models have been developed to predict spinal loads in vivo to assess potential risk of injury in workplaces. Most models represent trunk muscles with straight-lines. Even though straight-line muscles behave reasonably well in simple exertions, they could be less reliable during complex dynamic exertions. A curved muscle representation was developed to overcome this issue. However, most curved muscle models have not been validated during dynamic exertions. Thus, the objective of this study was to investigate the fidelity of a curved muscle model during complex dynamic lifting tasks, and to investigate the changes in spine tissue loads. METHODS Twelve subjects (7 males and 5 females) participated in this study. Subjects performed lifting tasks as a function of load weight, load origin, and load height to simulate complex exertions. Moment matching measures were recorded to evaluate how well the model predicted spinal moments compared to measured spinal moments from T12/L1 to L5/S1 levels. FINDINGS The biologically-assisted curved muscle model demonstrated better model performance than the straight-line muscle model between various experimental conditions. In general, the curved muscle model predicted at least 80% of the variability in spinal moments, and less than 15% of average absolute error across levels. The model predicted that the compression and anterior-posterior shear load significantly increased as trunk flexion increased, whereas the lateral shear load significantly increased as trunk twisted more asymmetric during lifting tasks. INTERPRETATION A curved muscle representation in a biologically-assisted model is an empirically reasonable approach to accurately predict spinal moments and spinal tissue loads of the lumbar spine.
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35
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Lee H, Hong JH. Comparison of trunk muscle activities in lifting and lowering tasks at various heights. J Phys Ther Sci 2016; 28:585-8. [PMID: 27065548 PMCID: PMC4793015 DOI: 10.1589/jpts.28.585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 11/17/2015] [Indexed: 11/24/2022] Open
Abstract
[Purpose] Biomechanical data for manual material handling are important for appropriate
engineering design. The goal of this study was to investigate differences in trunk muscle
activity in lifting and lowering tasks at various heights. [Subjects and Methods] Thirty
healthy, young adult subjects performed 6 asymmetrical lifting and lowering tasks at
various heights. Trunk muscle activity of the abdominal external oblique muscle (EO),
rectus abdominis muscle (RA), and lumbar erector spinae muscles (ES) were recorded using
surface electromyography (EMG). [Results] The EMG activities of the bilateral ES differed
significantly among heights. The left EO activity in the ankle to knee lifting task was
significantly increased compared with that of the knee to ankle lowering task. However,
there were no significant differences in the right EO, bilateral ES, or RA between lifting
and lowering tasks. [Conclusion] The results show that the optimal range for manual
material handling was at trunk height, not only for lifting but also for lowering
tasks.
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Affiliation(s)
- Hyun Lee
- Department of Computer Science and Engineering, Sun Moon University, Republic of Korea
| | - Ji Heon Hong
- Department of Physical Therapy, Sun Moon University, Republic of Korea
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36
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Trunk coordination in healthy and chronic nonspecific low back pain subjects during repetitive flexion–extension tasks: Effects of movement asymmetry, velocity and load. Hum Mov Sci 2016; 45:182-92. [DOI: 10.1016/j.humov.2015.11.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 11/15/2015] [Accepted: 11/15/2015] [Indexed: 11/21/2022]
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37
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A proposed method to detect kinematic differences between and within individuals. J Electromyogr Kinesiol 2015; 25:479-87. [DOI: 10.1016/j.jelekin.2015.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Revised: 02/20/2015] [Accepted: 02/27/2015] [Indexed: 11/24/2022] Open
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Srinivasan D, Mathiassen SE, Samani A, Madeleine P. The combined influence of task accuracy and pace on motor variability in a standardised repetitive precision task. ERGONOMICS 2015; 58:1388-1397. [PMID: 25683668 DOI: 10.1080/00140139.2015.1005174] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
UNLABELLED Thirty-five healthy women, experienced in pipetting, each performed four pipetting sessions at different pace and accuracy levels relevant to occupational tasks. The size and structure of motor variability of shoulder and elbow joint angles were quantified using cycle-to-cycle standard deviations of several kinematics properties, and indices based on sample entropy and recurrence quantification analysis. Decreasing accuracy demands increased both the size and structure of motor variability. However, when simultaneously lowering the accuracy demand and increasing pace, motor variability decreased to values comparable to those found when pace alone was increased without changing accuracy. Thus, motor variability showed some speed-accuracy trade-off, but the pace effect dominated the accuracy effect. Hence, this trade-off was different from that described for end-point performance by Fitts' law. The combined effect of accuracy and pace and the resultant decrease in motor variability are important to consider when designing sustainable work systems comprising repetitive precision tasks. PRACTITIONER SUMMARY Variability in movements and/or muscle activities between repeats of the same repetitive task is associated with important occupational outcomes, including fatigue, discomfort and pain. This study showed that simultaneously decreasing accuracy and increasing pace in short-cycle repetitive work led to decreased motor variability in arm movements, indicating less favourable ergonomics conditions.
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Affiliation(s)
- Divya Srinivasan
- a Department of Occupational and Public Health Sciences, Faculty of Health and Occupational Studies , Centre for Musculoskeletal Research, University of Gävle , Gävle , Sweden
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Lee J, Nussbaum MA, Kyung G. Effects of work experience on fatigue-induced biomechanical changes during repetitive asymmetric lifts/lowers. ERGONOMICS 2014; 57:1875-1885. [PMID: 25216272 DOI: 10.1080/00140139.2014.957733] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Repetitive lifting/lowering is associated with an increased risk of work-related low back disorders (WRLBDs), and fatigue may exacerbate such risk. Work methods used by experienced workers are potential models for developing worker training to reduce WRLBDs, though whether experience modifies the effects of fatigue on WRLBD risk is largely unknown. Here, six novices and six experienced workers completed 185 cycles of repetitive, asymmetric lifts/lowers. Physical demands, whole-body balance and torso movement stability were assessed using torso kinematics/kinetics, linear/angular momenta and Lyapunov exponents, respectively. Several fatigue-induced changes in movement strategies were evident. Novices decreased and experienced workers increased peak lumbar moments post-fatigue, suggesting lower WRLBD risks among the former in terms of torso kinetics. Other than lumbar moments, though, fatigue substantially reduced group-level differences in torso twisting velocities and accelerations. Post-fatigue movement strategies of experienced workers thus did not appear to be advantageous in terms of WRLBD risk.
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Affiliation(s)
- Jungyong Lee
- a Ergonomics Team, Hyundai Motor Company , Gyeonggi-Do , Republic of Korea
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40
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Plamondon A, Delisle A, Bellefeuille S, Denis D, Gagnon D, Larivière C. Lifting strategies of expert and novice workers during a repetitive palletizing task. APPLIED ERGONOMICS 2014; 45:471-481. [PMID: 23891462 DOI: 10.1016/j.apergo.2013.06.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 05/27/2013] [Accepted: 06/21/2013] [Indexed: 06/02/2023]
Abstract
Thirty manual material handlers (15 experts and 15 novices) were invited to perform series of box transfers under conditions similar to those of large distribution centers. The objective of the present study was to verify whether multiple box transfers leading to fatigue would also lead to differences between expert and novice workers in joint motions and in back loading variables (L5/S1 moments). The task consisted in transferring 24 15-kg boxes from one pallet to another (4 layers of boxes; 6 boxes/layer: 3 in the front row, 3 in the back) at a self-determined pace and then at an imposed pace of 9 lifts/min for a total of 240 lifts. The underlying idea was to set a challenging task that would force the experts to use their skills. Full-body 3D kinematic data were collected as well as external foot forces. A dynamic 3D linked segment model was used to estimate the net moments at L5/S1. The results clearly show that the experts bent their lumbar spine less (10° less) and were closer (4 cm) to the box than novice workers. Knee flexions were similar in both groups except when the box was lifted from ground level (expert ≈ 71°, novice ≈ 48°). The peak resultant moment was not statistically different (expert = 168 Nm, novice = 184 Nm) although experts had lower values on average than novices when lifting heights (and deposit heights) of the boxes increased. Therefore, experts differed from novice workers mostly in the posture-related variables. These differences are especially important to consider when the box is located on the ground, as the back posture and back loading are then at their greatest magnitude and could have a major impact on the distribution of internal forces on the spine.
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Affiliation(s)
- A Plamondon
- Institut de recherche Robert Sauvé en santé et en sécurité du travail (IRSST), 505 Boul. De Maisonneuve Ouest, Montréal, Québec, Canada H3A 3C2.
| | - A Delisle
- Faculté d'éducation physique et sportive, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - S Bellefeuille
- Institut de recherche Robert Sauvé en santé et en sécurité du travail (IRSST), 505 Boul. De Maisonneuve Ouest, Montréal, Québec, Canada H3A 3C2
| | - D Denis
- Institut de recherche Robert Sauvé en santé et en sécurité du travail (IRSST), 505 Boul. De Maisonneuve Ouest, Montréal, Québec, Canada H3A 3C2
| | - D Gagnon
- Faculté d'éducation physique et sportive, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - C Larivière
- Institut de recherche Robert Sauvé en santé et en sécurité du travail (IRSST), 505 Boul. De Maisonneuve Ouest, Montréal, Québec, Canada H3A 3C2
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Abstract
The advantages and disadvantages of different methods of carrying objects on spine loading are still not fully understood. Previous studies have either examined the effects of carrying using physiological measures or examined isolated spine segments using biomechanical models. Additionally, most studies have been restricted to only a small number of carrying conditions. Very few studies have attempted to examine the various factors influencing spine loading together. To improve understanding of interacting factors on carrying, this study assessed the lumbar spine loads of 16 subjects as they assumed six styles of carrying at two weight levels and two activity levels (walking vs. standing). Concurrent with each trial, a subject-specific biomechanical model was used to assess spine forces over the full lumbar spine. Most carrying methods in the trials resulted in relatively low levels of spine loading. Anterior/posterior (A/P) shear loading was the only spine-loading dimension that reached biomechanically meaningful levels. Two carrying conditions, with bins carried in front of the body, significantly increased A/P shear compared with other carrying styles. This increase appeared to be due to the greater moment arms occurring in these conditions. Many of the other carrying styles produced A/P shears that were similar to those observed when carrying nothing at all. Of all the tasks, the backpack carry characteristically produced especially low spine loads. The findings of the study suggest that to achieve optimal carrying in terms of spine loading, loads should be positioned close to the body, even when carrying relatively light loads.
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Affiliation(s)
- J D Rose
- a Biodynamics Laboratory, The Ohio State University , Columbus , OH 43210 , USA
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42
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Preatoni E, Hamill J, Harrison AJ, Hayes K, Van Emmerik RE, Wilson C, Rodano R. Movement variability and skills monitoring in sports. Sports Biomech 2013; 12:69-92. [DOI: 10.1080/14763141.2012.738700] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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43
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Seay JF, Sauer SG, Frykman PN, Roy TC. A history of low back pain affects pelvis and trunk mechanics during a sustained lift/lower task. ERGONOMICS 2013; 56:944-953. [PMID: 23586619 DOI: 10.1080/00140139.2013.781234] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
UNLABELLED This study compared three-dimensional trunk and pelvis range of motion (ROM) during a sustained asymmetric box lift/lower task between a group with a history of low back pain (HBP, n = 9) and a group with no history of low back pain (NBP, n = 9). Participants lifted an 11-kg box for 10 min at 12 cycles/min from ankle height in front to shelves 45 deg off-centre at waist height. Kinematic data were collected at the beginning (min1), middle (min5) and end of the bout (min9). Two-way analyses of variance were performed for all variables. Pelvis and trunk transverse ROM were similar at min1. By min9, HBP group did not change (31.9 ± 9 deg); however, ROM decreased in NBP group (21.6 ± 6 deg, p < 0.05). Therefore, despite no current pain, the HBP group demonstrated protective lifting mechanics compared to controls. Also discussed are implications for studying lifting paradigms at sub-maximal effort over longer periods of time. PRACTITIONER SUMMARY Differences between groups over time demonstrate residual consequences of low back pain (LBP) in a manual materials handling scenario. Individuals with a history of LBP (pain free for 6 months) demonstrated more conservative lifting mechanics towards the end of the bout compared to controls with no history of LBP.
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Affiliation(s)
- Joseph F Seay
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, USA.
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44
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Lee J, Nussbaum MA. Experienced workers may sacrifice peak torso kinematics/kinetics for enhanced balance/stability during repetitive lifting. J Biomech 2013; 46:1211-5. [DOI: 10.1016/j.jbiomech.2013.01.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 01/16/2013] [Accepted: 01/17/2013] [Indexed: 11/26/2022]
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45
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Eriksson Crommert M, Ekblom MM, Thorstensson A. Motor control of the trunk during a modified clean and jerk lift. Scand J Med Sci Sports 2013; 24:758-63. [DOI: 10.1111/sms.12064] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2013] [Indexed: 11/30/2022]
Affiliation(s)
- M. Eriksson Crommert
- Family Medicine Research Centre; Örebro County Council; Örebro Sweden
- School of Health and Medical Sciences; Örebro University; Örebro Sweden
- The Swedish School of Sport and Health Sciences; Stockholm Sweden
| | - M. M. Ekblom
- The Swedish School of Sport and Health Sciences; Stockholm Sweden
- Department of Neuroscience; Karolinska Institutet; Stockholm Sweden
| | - A. Thorstensson
- The Swedish School of Sport and Health Sciences; Stockholm Sweden
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46
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Van Driel R, Trask C, Johnson PW, Callaghan JP, Koehoorn M, Teschke K. Anthropometry-corrected exposure modeling as a method to improve trunk posture assessment with a single inclinometer. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2013; 10:143-54. [PMID: 23351120 DOI: 10.1080/15459624.2012.757479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Measuring trunk posture in the workplace commonly involves subjective observation or self-report methods or the use of costly and time-consuming motion analysis systems (current gold standard). This work compared trunk inclination measurements using a simple data-logging inclinometer with trunk flexion measurements using a motion analysis system, and evaluated adding measures of subject anthropometry to exposure prediction models to improve the agreement between the two methods. Simulated lifting tasks (n=36) were performed by eight participants, and trunk postures were simultaneously measured with each method. There were significant differences between the two methods, with the inclinometer initially explaining 47% of the variance in the motion analysis measurements. However, adding one key anthropometric parameter (lower arm length) to the inclinometer-based trunk flexion prediction model reduced the differences between the two systems and accounted for 79% of the motion analysis method's variance. Although caution must be applied when generalizing lower-arm length as a correction factor, the overall strategy of anthropometric modeling is a novel contribution. In this lifting-based study, by accounting for subject anthropometry, a single, simple data-logging inclinometer shows promise for trunk posture measurement and may have utility in larger-scale field studies where similar types of tasks are performed.
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Affiliation(s)
- Robin Van Driel
- School of Population and Public Health, University of British Columbia, Vancouver, Canada
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47
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Srinivasan D, Mathiassen SE. Motor variability in occupational health and performance. Clin Biomech (Bristol, Avon) 2012; 27:979-93. [PMID: 22954427 DOI: 10.1016/j.clinbiomech.2012.08.007] [Citation(s) in RCA: 171] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 08/13/2012] [Accepted: 08/16/2012] [Indexed: 02/07/2023]
Abstract
Several recent reviews have reported that 'repetitive movements' constitute a risk factor for occupational musculoskeletal disorders in the neck, shoulder and arm regions. More variation in biomechanical exposure is often suggested as an effective intervention in such settings. Since increasing variation using extrinsic methods like job rotation may not always be possible in an industrial context, the intrinsic variability of the motor system may offer an alternative opportunity to increase variation. Motor variability refers to the natural variation in postures, movements and muscle activity observed to different extents in all tasks. The current review discusses research appearing in motor control, sports sciences and occupational biomechanics literature to answer whether motor variability is important to consider in an occupational context, and if yes, whether it can be manipulated by training the worker or changing the working conditions so as to increase biomechanical variation without jeopardizing production. The review concludes that motor variability is, indeed, a relevant issue in occupational health and performance and suggests a number of key issues for further research.
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Affiliation(s)
- Divya Srinivasan
- Centre for Musculoskeletal Research, Department of Occupational and Public Health Sciences, University of Gavle, 801 76 Gavle, Sweden.
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48
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Yoon J, Shiekhzadeh A, Nordin M. The effect of load weight vs. pace on muscle recruitment during lifting. APPLIED ERGONOMICS 2012; 43:1044-1050. [PMID: 22475433 DOI: 10.1016/j.apergo.2012.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 03/05/2012] [Accepted: 03/06/2012] [Indexed: 05/31/2023]
Abstract
The purpose of this study was to compare the effect on the trunk and upper extremity muscle recruitment when controlling the lifting pace and the lifting weight. Thirty nine healthy subjects performed a total of 12 lifts (3 lifting trials per condition, 2 lifting weights, and 2 lifting paces), from waist height to shoulder height. Kinematics of upper extremity and the box and electromyography of trunk and upper extremity muscles were collected. Temporal muscle recruitment pattern varied between muscles based on their function. Heavier lifting weight evenly increased the muscle recruitment throughout the lifting period without changing their temporal pattern. In contrary, lifting pace affected the temporal recruitment pattern in most of muscles. The faster lifting pace increased the muscle recruitment at the beginning phase but decreased at the terminal phase of lifting. It is important to educate the workers about the effect of lifting pace and weight on the biomechanical load to control the mechanical load on the muscles and spine.
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Affiliation(s)
- Jangwhon Yoon
- Department of Physical Therapy, Dongshin University, Naju, Jeonnam, Republic of Korea.
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Lee J, Nussbaum MA. Experienced workers exhibit distinct torso kinematics/kinetics and patterns of task dependency during repetitive lifts and lowers. ERGONOMICS 2012; 55:1535-1547. [PMID: 23009048 DOI: 10.1080/00140139.2012.723139] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
UNLABELLED Individual differences in work methods may be related to the risk of injury during manual material handling tasks, yet existing evidence comparing experienced workers and novices is mixed. This study assessed torso kinematics and kinetics among six experienced workers and six novices during repetitive lifts/lowers under different task configurations (symmetric vs. asymmetric and lift vs. lower). Several important potential confounding effects were controlled. Peak kinematic and kinetic measures were typically higher among experienced workers and suggestive of exposure to higher levels of low back injury risk, though overall exposure levels were moderate. Work methods used by experienced workers were modified between task conditions, whereas novice behaviours were more consistent. Control of torso kinematics/kinetics may thus not be a primary factor in determining experienced worker's work methods, and future investigation is needed to establish if, or under what conditions, these methods are protective and/or should be the basis for interventions including training. PRACTITIONER SUMMARY Whether lifting experience reduces low back injury risk is unclear from earlier findings. Results from a controlled experiment suggest that lifting experience may not be associated consistently with reduced physical demands or injury risk. Further investigation is needed to assess the utility of training based on the methods of experienced workers.
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Affiliation(s)
- Jungyong Lee
- Department of Industrial and Systems Engineering, Virginia Tech, Blacksburg, USA
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50
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Kim S, Nussbaum MA, Jia B. The benefits of an additional worker are task-dependent: assessing low-back injury risks during prefabricated (panelized) wall construction. APPLIED ERGONOMICS 2012; 43:843-849. [PMID: 22226545 DOI: 10.1016/j.apergo.2011.12.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 12/12/2011] [Accepted: 12/15/2011] [Indexed: 05/31/2023]
Abstract
Team manual material handling is a common practice in residential construction where prefabricated building components (e.g., wall panels) are increasingly used. As part of a larger effort to enable proactive control of ergonomic exposures among workers handling panels, this study explored the effects of additional workers on injury risks during team-based panel erection tasks, specifically by quantifying how injury risks are affected by increasing the number of workers (by one, above the nominal or most common number). Twenty-four participants completed panel erection tasks with and without an additional worker under different panel mass and size conditions. Four risk assessment methods were employed that emphasized the low back. Though including an additional worker generally reduced injury risk across several panel masses and sizes, the magnitude of these benefits varied depending on the specific task and exhibited somewhat high variability within a given task. These results suggest that a simple, generalizable recommendation regarding team-based panel erection tasks is not warranted. Rather, a more systems-level approach accounting for both injury risk and productivity (a strength of panelized wall systems) should be undertaken.
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Affiliation(s)
- Sunwook Kim
- Department of Industrial and Systems Engineering, Virginia Tech, 250 Durham Hall (0118), Blacksburg, VA 24061, USA.
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