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Arshad R, Moglo K, El-Rich M, Schmidt H. Spinal loads during dynamic full flexion and return to standing posture in different age and sex groups: A musculoskeletal model study. J Biomech 2024; 172:112223. [PMID: 38986275 DOI: 10.1016/j.jbiomech.2024.112223] [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: 09/01/2023] [Revised: 06/28/2024] [Accepted: 07/01/2024] [Indexed: 07/12/2024]
Abstract
During forward flexion, spine motion varies due to age and sex differences. Previous studies showed that lumbar/pelvis range of flexion (RoF) and lumbo-pelvic ratio (L/P) are age/sex dependent. How variation of these parameters affects lumbar loading in a normal population requires further assessment. We aimed to estimate lumbar loads during dynamic flexion-return cycle and the differences in peak loads (compression) and corresponding trunk inclinations due to variation in lumbar/pelvis RoF and L/P. Based on in vivo L/P (0.11-3.44), temporal phases of flexion (early, middle, and later), the lumbar (45-55°) and hip (60-79°) RoF; full flexion-return cycles of six seconds were reconstructed for three age groups (20-35, 36-50 and 50+ yrs.) in both sexes. Six inverse dynamic analyses were performed with a 50th percentile model, and differences in peak loads and corresponding trunk inclinations were calculated. Peak loads at L4-L5 were 179 N higher in younger males versus females, but 228 N and 210 N lower in middle-aged and older males, respectively, compared to females. Females exhibited higher trunk inclinations (6°-20°) than males across all age groups. Age related differences in L4-L5 peak loads and corresponding trunk inclinations were found up to 415 N and 19° in males and 152 N and 13° in females. With aging, peak loads were reduced in males but were found non-monotonic in females, whereas trunk inclinations at peak loads were reduced in both sexes from young to middle/old age groups. In conclusion, lumbar loading and corresponding trunk inclinations varied notably due to age/sex differences. Such data may help distinguishing normal or pathological condition of the lumbar spine.
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Affiliation(s)
- Rizwan Arshad
- Biomechanics Laboratory, Department of Mechanical and Aerospace Engineering, Royal Military College of Canada, Kingston, Ontario K7K7B4, Canada; Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Augustenburger Platz 1 13353, Berlin, Germany
| | - Kodjo Moglo
- Biomechanics Laboratory, Department of Mechanical and Aerospace Engineering, Royal Military College of Canada, Kingston, Ontario K7K7B4, Canada
| | - Marwan El-Rich
- Healthcare Engineering Innovation Center (HEIC), Department of Mechanical Engineering, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Hendrik Schmidt
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Augustenburger Platz 1 13353, Berlin, Germany.
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Kazemi Z, Arjmand N, Mazloumi A, Karimi Z, Keihani A, Ghasemi MS. Effect of muscular fatigue on the cumulative lumbar damage during repetitive lifting task: a comparative study of damage calculation methods. ERGONOMICS 2024; 67:566-581. [PMID: 37418312 DOI: 10.1080/00140139.2023.2234678] [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: 04/14/2023] [Accepted: 07/02/2023] [Indexed: 07/09/2023]
Abstract
Several methods have been put forward to quantify cumulative loads; however, limited evidence exists as to the subsequent damages and the role of muscular fatigue. The present study assessed whether muscular fatigue could affect cumulative damage imposed on the L5-S1 joint. Trunk muscle electromyographic (EMG) activities and kinematics/kinetics of 18 healthy male individuals were evaluated during a simulated repetitive lifting task. A traditional EMG-assisted model of the lumbar spine was modified to account for the effect of erector spinae fatigue. L5-S1 compressive loads for each lifting cycle were estimated based on varying (i.e. actual), fatigue-modified, and constant Gain factors. The corresponding damages were integrated to calculate the cumulative damage. Moreover, the damage calculated for one lifting cycle was multiplied by the lifting frequency, as the traditional approach. Compressive loads and the damages obtained through the fatigue-modified model were predicted in close agreement with the actual values. Similarly, the difference between actual damages and those driven by the traditional approach was not statistically significant (p = 0.219). However, damages based on a constant Gain factor were significantly greater than those based on the actual (p = 0.012), fatigue-modified (p = 0.017), and traditional (p = 0.007) approaches.Practitioner summary: In this study, we managed to include the effect of muscular fatigue on cumulative lumbar damage calculations. Including the effect of muscular fatigue leads to an accurate estimation of cumulative damages while eliminating computational complexity. However, using the traditional approach also appears to provide acceptable estimates for ergonomic assessments.
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Affiliation(s)
- Zeinab Kazemi
- Department of Industrial Engineering, Clemson University, Clemson, SC, USA
| | - Navid Arjmand
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Adel Mazloumi
- Department of Occupational Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Sports Medicine Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Zanyar Karimi
- Department of Ergonomics, School of Public Health, Urmia University of Medical Sciences, Tehran, Iran
| | - Ahmadreza Keihani
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Armstrong DP, Davidson JB, Fischer SL. Determining whether biomechanical variables that describe common 'safe lifting' cues are associated with low back loads. J Electromyogr Kinesiol 2024; 75:102867. [PMID: 38325138 DOI: 10.1016/j.jelekin.2024.102867] [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: 07/13/2023] [Revised: 01/17/2024] [Accepted: 01/25/2024] [Indexed: 02/09/2024] Open
Abstract
Lift technique training programs have been implemented to help reduce injury risk, but the underlying content validity of cues used within these programs is not clear. The objective of this study was to determine whether biomechanical variables, that commonly used lifting cues aim to elicit, are associated with resultant low back extensor moment exposures. A sample of 72 participants were recruited to perform 10 repetitions of a floor-to-waist height barbell lift while whole-body kinematics and ground reaction forces were collected. Kinematic, kinetic, and energetic variables representative of characteristics commonly targeted by lifting cues were calculated as predictor variables, while peak and cumulative low back moments were calculated as dependent measures. Multiple regression revealed that 56.6-59.2% of variance in low back moments was explained by predictor variables. From these regression models, generating motion with the legs (both greater hip and knee work), minimizing the horizontal distance of the body to the load, maintaining a stable body position, and minimizing lift time were associated with lower magnitudes of low back moments. These data support that using cues targeting these identified variables may be more effective at reducing peak low back moment exposures via lift training.
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Affiliation(s)
- Daniel P Armstrong
- Department of Kinesiology, Faculty of Health Sciences, University of Waterloo, Waterloo, Canada
| | - Justin B Davidson
- Department of Kinesiology, Faculty of Health Sciences, University of Waterloo, Waterloo, Canada
| | - Steven L Fischer
- Department of Kinesiology, Faculty of Health Sciences, University of Waterloo, Waterloo, Canada.
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Street S, Matur AV, Tao X, Shukla G, Garcia-Vargas J, Mehta J, Childress K, Gibson J, Cass D, Wu A, Duah HO, Motley B, Webb D, Cheng J, Adogwa O. Correlation Between Rod Fracture and Shear Stress: A Novel Parameter. World Neurosurg 2024; 183:e268-e275. [PMID: 38128759 DOI: 10.1016/j.wneu.2023.12.077] [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: 09/14/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 12/23/2023]
Abstract
BACKGROUND We sought to assess the accuracy of a novel parameter proportional to the rod shear stress (RSS) in identifying patients at risk of rod fracture (RF) after surgery for correction of adult spinal deformity. METHODS We performed a retrospective medical record review of patients aged ≥18 years treated for adult spinal deformity between 2004 and 2014 with ≥24 months of follow-up. The primary outcome was RFs identified radiographically. Patient weight (w), number of instrumented levels (N), and minimum rod diameter (d) were recorded and used to calculate the RSS parameter (RSS=Nwd2). Receiver operating characteristic curves were produced and the area under the curve (AUC ± 95% confidence interval [CI]) was calculated to compare this parameter's discriminative accuracy to that of its constituent variables. The sensitivity, specificity, and likelihood ratios (LRs) were calculated. RESULTS A total of 28 RF-positive and 154 RF-negative patients were included. The average age was 59.2 ± 9.6 years, and 93.4% were women. The RSS parameter produced the greatest AUC (0.73 ± 0.11). At an RSS cutoff of 30.1, it achieved a sensitivity of 71.4% and specificity of 71.4% (LR, 2.5; 95% CI, 1.8-3.5). The number of instrumented levels produced the next-greatest AUC (0.65 ± 0.12), with a sensitivity of 78.6% and specificity of 50.0% at a cutoff of 15 (LR, 1.6; 95% CI, 1.2-2.0). CONCLUSIONS The RSS is calculated using easily obtainable information and shows potential as a tool for predicting patient-specific risk of RF after spinal fusion. The number of instrumented levels also correlates strongly with the occurrence of RFs and is not significantly less accurate than the RSS. A larger sample size and prospective validation would be useful in determining with greater confidence which parameter is superior for predicting RFs after spinal fusion.
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Affiliation(s)
- Seth Street
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
| | - Abhijith V Matur
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Xu Tao
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Geet Shukla
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Julia Garcia-Vargas
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Jay Mehta
- Department of Environmental and Public Health Sciences, University of Cincinnati, Cincinnati, Ohio, USA
| | - Kelly Childress
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Justin Gibson
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Daryn Cass
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Andrew Wu
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Henry O Duah
- Institute for Nursing Research and Scholarship, University of Cincinnati College of Nursing, Cincinnati, Ohio, USA
| | - Benjamin Motley
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Daniel Webb
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Joseph Cheng
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Owoicho Adogwa
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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Firouzabadi A, Arjmand N, Zhang T, Pumberger M, Schmidt H. Effect of low back pain on the kinetics and kinematics of the lumbar spine - a combined in vivo and in silico investigation. J Biomech 2024; 164:111954. [PMID: 38310006 DOI: 10.1016/j.jbiomech.2024.111954] [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: 09/15/2023] [Revised: 01/03/2024] [Accepted: 01/12/2024] [Indexed: 02/05/2024]
Abstract
Lifting is a significant risk factor for low back pain (LBP). Different biomechanical factors including spinal loads, kinematics, and muscle electromyography (EMG) activities have previously been investigated during lifting activities in LBP patients and asymptomatic individuals to identify their association with LBP. However, the findings were contradictory and inconclusive. Accurate and subject-specific prediction of spinal loads is crucial for understanding, diagnosing, planning tailored treatments, and preventing recurrent pain in LBP patients. Therefore, the present study aimed to estimate the L5-S1 compressive and resultant shear loads in 19 healthy and 17 non-specific chronic LBP individuals during various static load-holding tasks (holding a 10 kg box at hip, chest, and head height) using full-body and personalized musculoskeletal models driven by subject-specific in vivo kinematic/kinetic, EMG, and physiological cross-sectional areas (PCSAs) data. These biomechanical characteristics were concurrently analyzed to identify potential differences between the two groups. Statistical analyses showed that LBP had almost no significant effect on the range of motion (trunk, lumbar, pelvis), PCSA, and EMG. There were no significant differences (p > 0.05) in the predicted L5-S1 loads. However, as the task became more demanding, by elevating the hand-load from hip to head, LBP patients experienced significant increases in both compressive (33 %, p = 0.00) and shear (25 %, p = 0.02) loads, while asymptomatic individuals showed significant increases only in compressive loads (30 %, p = 0.01). This suggests that engaging in more challenging activities could potentially magnify the effect of LBP on the biomechanical factors and increase their discrimination capacity between LBP and asymptomatic individuals.
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Affiliation(s)
- Ali Firouzabadi
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Navid Arjmand
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Tianwei Zhang
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Matthias Pumberger
- Center for Musculoskeletal Surgery, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Hendrik Schmidt
- Julius Wolff Institute, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Berlin, Germany.
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6
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Hosseini N, Arjmand N. An artificial neural network for full-body posture prediction in dynamic lifting activities and effects of its prediction errors on model-estimated spinal loads. J Biomech 2024; 162:111896. [PMID: 38072705 DOI: 10.1016/j.jbiomech.2023.111896] [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: 06/18/2023] [Revised: 11/07/2023] [Accepted: 11/30/2023] [Indexed: 01/16/2024]
Abstract
Musculoskeletal models have indispensable applications in occupational risk assessment/management and clinical treatment/rehabilitation programs. To estimate muscle forces and joint loads, these models require body posture during the activity under consideration. Posture is usually measured via video-camera motion tracking approaches that are time-consuming, costly, and/or limited to laboratories. Alternatively, posture-prediction tools based on artificial intelligence can be trained using measured postures of several subjects performing many activities. We aimed to use our previous posture-prediction artificial neural network (ANN), developed based on many measured static postures, to predict posture during dynamic lifting activities. Moreover, effects of the ANN posture-prediction errors on dynamic spinal loads were investigated using subject-specific musculoskeletal models. Seven individuals each performed twenty-five lifting tasks while their full-body three-dimensional posture was measured by a 10-camera Vicon system and also predicted by the ANN as functions of the hand-load positions during the lifting activities. The measured and predicted postures (i.e., coordinates of 39 skin markers) and their model-estimated L5-S1 loads were compared. The overall root-mean-squared-error (RMSE) and normalized (by the range of measured values) RMSE (nRMSE) between the predicted and measured postures for all markers/tasks/subjects was equal to 7.4 cm and 4.1 %, respectively (R2 = 0.98 and p < 0.05). The model-estimated L5-S1 loads based on the predicted and measured postures were generally in close agreements as also confirmed by the Bland-Altman analyses; the nRMSE for all subjects/tasks was < 10 % (R2 > 0.7 and p > 0.05). In conclusion, the easy-to-use ANN can accurately predict posture in dynamic lifting activities and its predicted posture can drive musculoskeletal models.
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Affiliation(s)
- Nesa Hosseini
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Navid Arjmand
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran.
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7
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Mohseni M, Zargarzadeh S, Arjmand N. Multi-task artificial neural networks and their extrapolation capabilities to predict full-body 3D human posture during one- and two-handed load-handling activities. J Biomech 2024; 162:111884. [PMID: 38043495 DOI: 10.1016/j.jbiomech.2023.111884] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 11/20/2023] [Accepted: 11/23/2023] [Indexed: 12/05/2023]
Abstract
Machine-learning based human posture-prediction tools can potentially be robust alternatives to motion capture measurements. Existing posture-prediction approaches are confined to two-handed load-handling activities performed at heights below 120 cm from the floor and to predicting a limited number of body-joint coordinates/angles. Moreover, the extrapolating power of these tools beyond the range of the input dataset they were trained for (e.g., for underweight, overweight, or left-handed individuals) has not been investigated. In this study, we trained/validated/tested two posture-prediction (for full-body joint coordinates and angles) artificial neural networks (ANNs) using both 70%/15%/15% random-hold-out and leave-one-subject-out methods, based on a comprehensive kinematic dataset of forty-one full-body skin markers collected from twenty right-handed normal-weight (BMI = 18-26 kg/m2) subjects. Subjects performed 204 one- and two-handed unloaded activities at different vertical (0 to 180 cm from the floor) and horizontal (up to 60 cm lateral and/or anterior) destinations. Subsequently, the extrapolation capability of the trained/validated/tested ANNs was evaluated using data collected from fifteen additional subjects (unseen by the ANNs); three individuals in five groups: underweight, overweight, obese, left-handed individuals, and subjects with a hand-load. Results indicated that the ANNs predicted body joint coordinates and angles during various activities with errors of ∼ 25 mm and ∼ 10°, respectively; considerable improvements when compared to previous posture-prediction ANNs. Extrapolation errors of our ANNs generally remained within the error range of existing ANNs with obesity and being left-handed having, respectively, the most and least compromising effects on their accuracy. These easy-to-use ANNs appear, therefore, to be robust alternatives to common posture-measurement approaches.
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Affiliation(s)
- Mahdi Mohseni
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Sadra Zargarzadeh
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Navid Arjmand
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran.
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Tabasi A, Brouwer NP, Kingma I, van Dijk W, de Looze MP, Moya-Esteban A, Kooij HVD, van Dieën JH. The effect of back muscle fatigue on EMG and kinematics based estimation of low-back loads and active moments during manual lifting tasks. J Electromyogr Kinesiol 2023; 73:102815. [PMID: 37688848 DOI: 10.1016/j.jelekin.2023.102815] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 07/10/2023] [Accepted: 08/30/2023] [Indexed: 09/11/2023] Open
Abstract
This study investigated the effects of back muscle fatigue on the estimation of low-back loads and active low-back moments during lifting, using an EMG and kinematics based model calibrated with data from an unfatigued state. Fourteen participants performed lifting tasks in unfatigued and fatigued states. Fatigue was induced through semi-static forward bending. EMG, kinematics, and ground reaction forces were measured, and low-back loads were estimated using inverse dynamics and EMG-driven muscle model. A regression model was developed using data from a set of calibration lifts, and its accuracy was evaluated for unfatigued and fatigued lifts. During the fatigue-inducing task, the EMG amplitude increased by 2.8 %MVC, representing a 38% increase relative to the initial value. However, during the fatigued lifts, the peak EMG amplitude was found to be 1.6 %MVC higher than that observed during the unfatigued lifts, representing a mere 4% increase relative to the baseline unfatigued peak EMG amplitude. Kinematics and low-back load estimates remained unaffected. Regression model estimation errors remained unaffected for 5 kg lifts, but increased by no more than 5% of the peak active low-back moment for 15 kg lifts. We conclude that the regression-based estimation quality of active low-back moments can be maintained during periods of muscle fatigue, although errors may slightly increase for heavier loads.
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Affiliation(s)
- A Tabasi
- Dept. of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; TNO, Leiden, the Netherlands.
| | - N P Brouwer
- Dept. of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - I Kingma
- Dept. of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | | | | | - A Moya-Esteban
- Department of Biomechanical Engineering, University of Twente, Enschede, the Netherlands
| | - H V D Kooij
- Department of Biomechanical Engineering, University of Twente, Enschede, the Netherlands
| | - J H van Dieën
- Dept. of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
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Xiang X, Tanaka M, Umeno S, Kikuchi Y, Kobayashi Y. Dynamic assessment for low back-support exoskeletons during manual handling tasks. Front Bioeng Biotechnol 2023; 11:1289686. [PMID: 38026894 PMCID: PMC10667710 DOI: 10.3389/fbioe.2023.1289686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/01/2023] [Indexed: 12/01/2023] Open
Abstract
Exoskeletons can protect users' lumbar spine and reduce the risk of low back injury during manual lifting tasks. Although many exoskeletons have been developed, their adoptability is limited by their task- and movement-specific effects on reducing burden. Many studies have evaluated the safety and effectiveness of an exoskeleton using the peak/mean values of biomechanical variables, whereas the performance of the exoskeleton at other time points of the movement has not been investigated in detail. A functional analysis, which presents discrete time-series data as continuous functions, makes it possible to highlight the features of the movement waveform and determine the difference in each variable at each time point. This study investigated an assessment method for exoskeletons based on functional ANOVA, which made it possible to quantify the differences in the biomechanical variables throughout the movement when using an exoskeleton. Additionally, we developed a method based on the interpolation technique to estimate the assistive torque of an exoskeleton. Ten men lifted a 10-kg box under symmetric and asymmetric conditions five times each. Lumbar load was significantly reduced during all phases (flexion, lifting, and laying) under both conditions. Additionally, reductions in kinematic variables were observed, indicating the exoskeleton's impact on motion restrictions. Moreover, the overlap F-ratio curves of the lumbar load and kinematic variables imply that exoskeletons reduce the lumbar load by restricting the kinematic variables. The results suggested that at smaller trunk angles (<25°), an exoskeleton neither significantly reduces the lumbar load nor restricts trunk movement. Our findings will help increasing exoskeleton safety and designing effective products for reducing lumbar injury risks.
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Affiliation(s)
- Xiaohan Xiang
- Institute of Agricultural Machinery, National Agriculture and Food Research Organization (NARO), Saitama, Japan
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10
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Wang W, Wang D, Li G. Towards improving the accuracy of musculoskeletal simulation of dynamic three-dimensional spine rotations with optimizing model and algorithm. Med Eng Phys 2022; 110:103916. [PMID: 36564141 DOI: 10.1016/j.medengphy.2022.103916] [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: 02/26/2022] [Revised: 07/02/2022] [Accepted: 10/28/2022] [Indexed: 11/05/2022]
Abstract
BACKGROUND The accuracy of musculoskeletal simulations greatly relies on model structures and optimization algorithms. This study investigated the unclarified influence of accounting for several commonly-simplified different model components and optimization criteria on spinal musculoskeletal simulations. METHODS The study constructed a full-body musculoskeletal model with passive components of functional spinal units and spinal muscles subject-specifically refined. A muscle redundancy solver was built with 15 optimization criteria. Three-dimensional spine rotations and spinal muscle activities were measured using optical motion capture and electromyogram techniques when eight healthy volunteers performed standing, flexion/extension, lateral bending, and axial rotation. The effect of the model with four different conditions of the passive components and the sensitivity of the 15 optimization criteria on simulations were investigated. RESULTS Accounting for the refined passive components significantly improved the simulation accuracy. Different optimization criteria behaved distinctly for different motions. Generally minimizing the sum of squared muscle activations outperformed the others, with the highest averaged correlation coefficient (0.82) between the estimated erector spinae muscle activations and measured electromyography and with the estimated joint compression forces comparable to in vivo reference data. CONCLUSION This study highlights the importance of passive model components and proposes a suitable optimization framework for realistic spinal musculoskeletal simulations.
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Affiliation(s)
- Wei Wang
- The CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology (SIAT), and Guangdong-Hong Kong-Macau Joint Laboratory of Human-Machine Intelligence-Synergy Systems, SIAT, Chinese Academy of Sciences, Shenzhen 518055, China; The SIAT Branch, Shenzhen Institute of Artificial Intelligence and Robotics for Society, Shenzhen 518055, China
| | - Dongmei Wang
- School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Guanglin Li
- The CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology (SIAT), and Guangdong-Hong Kong-Macau Joint Laboratory of Human-Machine Intelligence-Synergy Systems, SIAT, Chinese Academy of Sciences, Shenzhen 518055, China; The SIAT Branch, Shenzhen Institute of Artificial Intelligence and Robotics for Society, Shenzhen 518055, China.
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11
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Ghaneh-Ezabadi S, Abdoli-Eramaki M, Arjmand N, Abouhossein A, Zakerian SA. The Validity and Inter-Rater Reliability of a Video-Based Posture-Matching Tool to Estimate Cumulative Loads on the Lower Back. J Biomed Phys Eng 2022; 12:417-430. [PMID: 36059286 PMCID: PMC9395627 DOI: 10.31661/jbpe.v0i0.2203-1474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 06/19/2022] [Indexed: 06/15/2023]
Abstract
Background Low back pain (LBP) is known as one of the most common work-related musculoskeletal disorders. Spinal cumulative loads (CLs) during manual material handling (MMH) tasks are the main risk factors for LBP. However, there is no valid and reliable quantitative lifting analysis tool available for quantifying CLs among Iranian workers performing MMH tasks. Objective This study aimed to investigate the validity and inter-rater reliability of a posture-matching load assessment tool (PLAT) for estimating the L5-S1 static cumulative compression (CC) and shear (CS) loads based on predictive regression equations. Material and Methods This experimental study was conducted among six participants performing four lifting tasks, each comprised of five trials during which their posture was recorded via a motion capture (Vicon) and simultaneously a three-camera system located at three different angles (0°, 45°, and 90°) to the sagittal plane. Results There were no significant differences between the two CLs estimated by PLAT from the three-camera system and the gold-standard Vicon. In addition, ten raters estimated CLs of the tasks using PLAT in three sessions. The calculated intra-class correlation coefficients for the estimated CLs within each task revealed excellent inter-rater reliability (> 0.75), except for CS in the first and third tasks, which were good (0.6 to 0.75). Conclusion The proposed posture-matching approach provides a valid and reliable ergonomic assessment tool suitable for assessing spinal CLs during various lifting activities.
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Affiliation(s)
- Saeed Ghaneh-Ezabadi
- PhD Candidate, Department of Occupational Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Abdoli-Eramaki
- PhD, Professor, School of Occupational and Public Health, Ryerson University, Toronto, Canada
| | - Navid Arjmand
- PhD, Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Alireza Abouhossein
- PhD, Department of Ergonomics, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- PhD, Workplace Health Promotion Research Center (WHPRC), School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyed Abolfazl Zakerian
- PhD, Department of Occupational Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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Firouzabadi A, Arjmand N, Pan F, Zander T, Schmidt H. Sex-Dependent Estimation of Spinal Loads During Static Manual Material Handling Activities-Combined in vivo and in silico Analyses. Front Bioeng Biotechnol 2021; 9:750862. [PMID: 34796167 PMCID: PMC8592996 DOI: 10.3389/fbioe.2021.750862] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 10/13/2021] [Indexed: 11/13/2022] Open
Abstract
Manual material handling (MMH) is considered as one of the main contributors to low back pain. While males traditionally perform MMH tasks, recently the number of females who undertake these physically-demanding activities is also increasing. To evaluate the risk of mechanical injuries, the majority of previous studies have estimated spinal forces using different modeling approaches that mostly focus on male individuals. Notable sex-dependent differences have, however, been reported in torso muscle strength and anatomy, segmental mass distribution, as well as lifting strategy during MMH. Therefore, this study aimed to use sex-specific models to estimate lumbar spinal and muscle forces during static MHH tasks in 10 healthy males and 10 females. Motion-capture, surface electromyographic from select trunk muscles, and ground reaction force data were simultaneously collected while subjects performed twelve symmetric and asymmetric static lifting (10 kg) tasks. AnyBody Modeling System was used to develop base-models (subject-specific segmental length, muscle architecture, and kinematics data) for both sexes. For females, female-specific models were also developed by taking into account for the female’s muscle physiological cross-sectional areas, segmental mass distributions, and body fat percentage. Males showed higher absolute L5-S1 compressive and shear loads as compared to both female base-models (25.3% compressive and 14% shear) and female-specific models (41% compressive and 23.6% shear). When the predicted spine loads were normalized to subjects’ body weight, however, female base-models showed larger loads (9% compressive and 16.2% shear on average), and female-specific models showed 2.4% smaller and 9.4% larger loads than males. Females showed larger forces in oblique abdominal muscles during both symmetric and asymmetric lifting tasks, while males had larger back extensor muscle forces during symmetric lifting tasks. A stronger correlation between measured and predicted muscle activities was found in females than males. Results indicate that female-specific characteristics affect the predicted spinal loads and must be considered in musculoskeletal models. Neglecting sex-specific parameters in these models could lead to the overestimation of spinal loads in females.
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Affiliation(s)
- Ali Firouzabadi
- Julius Wolff Institute, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Navid Arjmand
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Fumin Pan
- Julius Wolff Institute, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Thomas Zander
- Julius Wolff Institute, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Hendrik Schmidt
- Julius Wolff Institute, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Berlin, Germany
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13
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Marker-less versus marker-based driven musculoskeletal models of the spine during static load-handling activities. J Biomech 2020; 112:110043. [DOI: 10.1016/j.jbiomech.2020.110043] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 08/13/2020] [Accepted: 09/01/2020] [Indexed: 12/15/2022]
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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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Barrett JM, Karakolis T, Callaghan JP. A Mobile Application to Measure Trunk Flexion Angles in Lifting Tasks. IISE Trans Occup Ergon Hum Factors 2020; 8:63-71. [PMID: 32673166 DOI: 10.1080/24725838.2020.1767228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Occupational Abstract The aim of this project was to develop and test an application capable of quickly and repeatedly measuring trunk flexion angles during sagittal plane lifting tasks. The developed application uses the built-in accelerometer in mobile devices to approximate trunk flexion angle, as the user follows an operator as they perform a lift. A black line is superimposed over the camera feed, allowing the user to approximate the angle of inclination of a line connecting the operator's seventh cervical and first sacral vertebrae-thereby estimating the trunk flexion angle. The magnitude of this angle and its velocity have been linked to the development of occupational low back pain; thus the application provides ergonomists a more refined means of screening tasks beyond currently available survey tools.
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Affiliation(s)
- Jeff M Barrett
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Thomas Karakolis
- Defence Research and Development Canada, Toronto, Ontario, Canada
| | - Jack P Callaghan
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
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16
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Ghezelbash F, Shirazi-Adl A, El Ouaaid Z, Plamondon A, Arjmand N. Subject-specific regression equations to estimate lower spinal loads during symmetric and asymmetric static lifting. J Biomech 2020; 102:109550. [DOI: 10.1016/j.jbiomech.2019.109550] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 11/26/2019] [Accepted: 11/29/2019] [Indexed: 01/11/2023]
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17
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Byrne RM, Aiyangar AK, Zhang X. A Dynamic Radiographic Imaging Study of Lumbar Intervertebral Disc Morphometry and Deformation In Vivo. Sci Rep 2019; 9:15490. [PMID: 31664074 PMCID: PMC6820767 DOI: 10.1038/s41598-019-51871-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 10/04/2019] [Indexed: 12/11/2022] Open
Abstract
Intervertebral discs are important structural components of the spine but also are significant sources of morbidity, especially for the “low back” lumbar region. Mechanical damage to, or degeneration of, the lumbar discs can diminish their structural integrity and elicit debilitating low back pain. Advancement of reparative or regenerative means to treat damaged or degenerated discs is hindered by a lack of basic understanding of the disc load-deformation characteristics in vivo. The current study presents an in vivo analysis of the morphometry and deformation of lumbar (L2-S1) intervertebral discs in 10 healthy participants while performing a common lifting act, using novel dynamic radiographic imaging of the lumbar vertebral body motion. Data analyses show uniquely different (p < 0.05) characteristics in morphometry, normal and shear strain patterns of the L5S1 discs, while the rest of lumbar discs exhibit great similarity. In particular shear strains in L2-L5 discs exhibited stronger linear correlations (R2 ≥ 0.80) between strain changes and amount of lumbar flexion-extension motion compared to L5S1 (R2 ≤ 0.5). The study therefore advances the state of knowledge on in vivo mechanical responses of the lumbar intervertebral discs during functional tasks.
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Affiliation(s)
- Ryan M Byrne
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA, 15203, USA
| | - Ameet K Aiyangar
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, 15203, USA.,Mechanical Systems Engineering, EMPA (Swiss Federal Laboratories for Materials Science and Technology), 8600, Duebendorf, Switzerland
| | - Xudong Zhang
- Department of Industrial & Systems Engineering, Texas A&M University, College Station, TX, 77843, USA. .,Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA. .,Department of Mechanical Engineering, Texas A&M University, College Station, TX, 77843, USA.
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The effect of sagittal hip angle on lumbar and hip coordination and pelvic posterior shift during forward bending. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2019; 29:438-445. [PMID: 31473814 DOI: 10.1007/s00586-019-06129-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 07/20/2019] [Accepted: 08/21/2019] [Indexed: 10/26/2022]
Abstract
PURPOSE The purpose of this study was to investigate the effects of dynamic sagittal hip angle on lumbar and hip coordination and pelvic posterior shift during forward bending. METHODS A total of 44 asymptomatic younger female volunteers were recruited to this study. Following measurement of trunk forward bending, participants were divided into three groups based on hip flexion angle: group 1, < 30°; group 2, ≥ 30° and < 50°; and group 3, ≥ 50°. Lumbar spine and hip coordination and pelvic backward shift were recorded during trunk forward bending using a three-dimensional ultrasonic motion analysis system. RESULTS Pelvic and total angles increased with hip angle (group 3 > group 2 > group 1; p = 0.003 and p < 0.001, respectively), whereas lumbar/hip and pelvic/hip angle ratios decreased significantly (p < 0.001). The degree of pelvic posterior shift increased to a limited extent, whereas the pelvic posterior shift/hip angle ratio decreased significantly (p < 0.05). CONCLUSIONS Asymptomatic subjects with limited hip flexion showed reduced total pelvic anterior rotation and greater relative proportion of pelvic motion than insufficient hip motion. These subjects tended to increase the pelvic posterior shift/hip angle ratio during trunk forward bending, possibly increasing passive tension by elongating the hamstring muscles to increase hip motion. The results of this study provide information that will improve the assessment of lumbar spine and hip coordination patterns and facilitate movement strategies by determining the specific requirements of individuals. These slides can be retrieved under Electronic Supplementary Material.
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Behjati M, Arjmand N. Biomechanical Assessment of the NIOSH Lifting Equation in Asymmetric Load-Handling Activities Using a Detailed Musculoskeletal Model. HUMAN FACTORS 2019; 61:191-202. [PMID: 30222936 DOI: 10.1177/0018720818795038] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
OBJECTIVE To assess adequacy of the National Institute for Occupational Safety and Health (NIOSH) Lifting Equation (NLE) in controlling lumbar spine loads below their recommended action limits during asymmetric load-handling activities using a detailed musculoskeletal model, that is, the AnyBody Modeling System. BACKGROUND The NIOSH committee employed simplistic biomechanical models for the calculation of the spine compressive loads with no estimates of the shear loads. It is therefore unknown whether the NLE would adequately control lumbar compression and shear loads below their recommended action limits during asymmetric load-handling activities. METHOD Twenty-four static stoop lifting tasks at different load asymmetry angles, heights, and horizontal distances were performed by one normal-weight (70 kg) and one obese (93 kg) individual. For each task, the recommended weight limit computed by the NLE and body segment angles measured by a video-camera system (VICON) were prescribed in the participant-specific models developed in the AnyBody Modeling System that estimated spinal loads. RESULTS For both individuals, the NLE adequately controlled L5-S1 loads below their recommended action limits for all activities performed in upright postures. Both individuals, however, experienced compressive and/or shear L5-S1 loads beyond the recommended action limits when lifting was performed near the floor with large load asymmetry. CONCLUSION The NLE failed to control spinal loads below the recommended limits during asymmetric lifting tasks performed near the floor. APPLICATION The NLE should be used with caution for extreme tasks involving load handling near the floor with large load asymmetry.
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Liu T, Khalaf K, Adeeb S, El-Rich M. Effects of lumbo-pelvic rhythm on trunk muscle forces and disc loads during forward flexion: A combined musculoskeletal and finite element simulation study. J Biomech 2019; 82:116-123. [DOI: 10.1016/j.jbiomech.2018.10.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 10/10/2018] [Accepted: 10/17/2018] [Indexed: 10/28/2022]
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21
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Senteler M, Aiyangar A, Weisse B, Farshad M, Snedeker JG. Sensitivity of intervertebral joint forces to center of rotation location and trends along its migration path. J Biomech 2018; 70:140-148. [DOI: 10.1016/j.jbiomech.2017.10.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 10/04/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022]
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22
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Narimani M, Arjmand N. Three-dimensional primary and coupled range of motions and movement coordination of the pelvis, lumbar and thoracic spine in standing posture using inertial tracking device. J Biomech 2018; 69:169-174. [DOI: 10.1016/j.jbiomech.2018.01.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 01/03/2018] [Accepted: 01/08/2018] [Indexed: 11/30/2022]
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23
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Azari F, Arjmand N, Shirazi-Adl A, Rahimi-Moghaddam T. A combined passive and active musculoskeletal model study to estimate L4-L5 load sharing. J Biomech 2018; 70:157-165. [DOI: 10.1016/j.jbiomech.2017.04.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 04/13/2017] [Accepted: 04/24/2017] [Indexed: 10/19/2022]
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24
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Changes of lumbar posture and tissue loading during static trunk bending. Hum Mov Sci 2017; 57:59-68. [PMID: 29161614 DOI: 10.1016/j.humov.2017.11.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 11/11/2017] [Accepted: 11/12/2017] [Indexed: 01/07/2023]
Abstract
Static trunk bending is an occupational risk factor for lower back pain (LBP). When assessing relative short duration trunk bending tasks, existing studies mostly assumed unchanged spine biomechanical responses during task performance. The purpose of the current study was to assess the biomechanical changes of lumbar spine during the performance of relatively short duration, sustained trunk bending tasks. Fifteen participants performed 40-s static trunk bending tasks in two different trunk angles (30° or 60°) with two different hand load levels (0 or 6.8 kg). Results of the current study revealed significantly increased lumbar flexion and lumbar passive moment during the 40 s of trunk bending. Significantly reduced lumbar and abdominal muscle activities were also observed in most conditions. These findings suggest that, during the performance of short duration, static trunk bending tasks, a shift of loading from lumbar active tissues to passive tissues occurs naturally. This mechanism is beneficial in reducing the accumulation of lumbar muscle fatigue; however, lumbar passive tissue creep could be introduced due to prolonged or repetitive exposure.
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25
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Gómez L, Díaz CA, Orozco GA, García JJ. Dynamic analysis of forces in the lumbar spine during bag carrying. INTERNATIONAL JOURNAL OF OCCUPATIONAL SAFETY AND ERGONOMICS 2017; 24:605-613. [PMID: 28753120 DOI: 10.1080/10803548.2017.1352224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVE The intervertebral disc supports axial and shear forces generated during tasks such as lifting and carrying weights. The objective of this study was to determine the forces in the lumbar spine of workers carrying a bag on the head, on the shoulder and on the anterior part of the trunk. METHODS Kinematic measurements were recorded for 10 subjects carrying bags of 10, 20 and 25 kg on each of the three aforementioned positions. A simple dynamic model implemented in a custom program was then developed to determine the lumbar forces using the accelerations and positions obtained from the kinematic analysis. RESULTS The analyses yielded a maximum compressive force of 2338.4 ± 422 N when a 25-kg bag was carried on the anterior part of the trunk. CONCLUSION Carrying bags on the anterior part of the trunk generated higher lumbar forces compared to those developed by carrying the bag on the head or on the shoulder. Force levels suggest that this activity represents a moderate risk for the subjects. However, future biomechanical models should be developed to analyze the cumulative effect in the discs when longer periods of time are spent in this activity.
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Affiliation(s)
- Lessby Gómez
- a Escuela de Rehabilitación Humana , Universidad del Valle , Colombia.,b Facultad de Ciencias de la Salud , Universidad Libre-Cali , Colombia
| | - Carlos A Díaz
- c Escuela de Ingeniería Mecánica , Universidad del Valle , Colombia
| | - Gustavo A Orozco
- b Facultad de Ciencias de la Salud , Universidad Libre-Cali , Colombia
| | - José J García
- d Escuela de Ingeniería Civil y Geomática , Universidad del Valle , Colombia
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26
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Loslever P, Schiro J, Gabrielli F, Pudlo P. Comparing multiple correspondence and principal component analyses with biomechanical signals. Example with turning the steering wheel. Comput Methods Biomech Biomed Engin 2017; 20:1038-1047. [PMID: 28562073 DOI: 10.1080/10255842.2017.1331341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The purpose of this article is to compare Principal Component Analysis (PCA) and a much less used method, i.e. MCA (Multiple Correspondence Analysis) with data being first changed into membership values to fuzzy space windows. For such a comparison, data from an experimental study about turning the steering wheel is used. In a didactic perspective, this article only considers one multidimensional signal with 5 components: 3 linked to the steering wheel angle and hand positions and 2 to hand effort variables. A discussion weighs out the pros and the cons of both methods with criteria such as the possibility to show complex relational phenomena, the analysis/computing time or the information loss inherent to the averaging stage (in the perspective to analyze several hundreds of large multidimensional signals).
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Affiliation(s)
- P Loslever
- a Laboratory of Industrial and Human Automation Control, Mechanical Engineering and Computer Sciences , University of Valenciennes , Valenciennes , France
| | - J Schiro
- a Laboratory of Industrial and Human Automation Control, Mechanical Engineering and Computer Sciences , University of Valenciennes , Valenciennes , France
| | - F Gabrielli
- a Laboratory of Industrial and Human Automation Control, Mechanical Engineering and Computer Sciences , University of Valenciennes , Valenciennes , France
| | - P Pudlo
- a Laboratory of Industrial and Human Automation Control, Mechanical Engineering and Computer Sciences , University of Valenciennes , Valenciennes , France
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27
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Wettenschwiler PD, Lorenzetti S, Ferguson SJ, Stämpfli R, Aiyangar AK, Rossi RM, Annaheim S. Loading of the lumbar spine during backpack carriage. Comput Methods Biomech Biomed Engin 2016; 20:558-565. [PMID: 27873535 DOI: 10.1080/10255842.2016.1261849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Backpack carriage is significantly associated with a higher prevalence of low back pain. Elevated compression and shear forces in the lumbar intervertebral discs are known risk factors. A novel method of calculating the loads in the lumbar spine during backpack carriage is presented by combining physical and numerical modelling. The results revealed that to predict realistic lumbar compression forces, subject-specific lumbar curvature data were not necessary for loads up to 40 kg. In contrast, regarding shear forces, using subject-specific lumbar curvature data from upright MRI measurements as input for the rigid body model significantly altered lumbar joint force estimates.
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Affiliation(s)
- Patrick D Wettenschwiler
- a Empa, Swiss Federal Laboratories for Materials Science and Technology , St. Gallen , Switzerland.,b Institute for Biomechanics , ETH Zurich , Zürich , Switzerland
| | | | | | - Rolf Stämpfli
- a Empa, Swiss Federal Laboratories for Materials Science and Technology , St. Gallen , Switzerland
| | - Ameet K Aiyangar
- c Empa, Swiss Federal Laboratories for Materials Science and Technology , Dübendorf , Switzerland
| | - René M Rossi
- a Empa, Swiss Federal Laboratories for Materials Science and Technology , St. Gallen , Switzerland
| | - Simon Annaheim
- a Empa, Swiss Federal Laboratories for Materials Science and Technology , St. Gallen , Switzerland
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28
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Gholipour A, Arjmand N. Artificial neural networks to predict 3D spinal posture in reaching and lifting activities; Applications in biomechanical models. J Biomech 2016; 49:2946-2952. [DOI: 10.1016/j.jbiomech.2016.07.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/20/2016] [Accepted: 07/08/2016] [Indexed: 10/21/2022]
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29
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Investigating the effects of movement speed on the lumbopelvic coordination during trunk flexion. Hum Mov Sci 2016; 48:153-60. [DOI: 10.1016/j.humov.2016.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 05/06/2016] [Accepted: 05/16/2016] [Indexed: 11/22/2022]
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30
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Hwang J, Knapik GG, Dufour JS, Aurand A, Best TM, Khan SN, Mendel E, Marras WS. A biologically-assisted curved muscle model of the lumbar spine: Model structure. Clin Biomech (Bristol, Avon) 2016; 37:53-59. [PMID: 27323286 DOI: 10.1016/j.clinbiomech.2016.06.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/27/2016] [Accepted: 06/13/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Biomechanical models have been developed to assess the spine tissue loads of individuals. However, most models have assumed trunk muscle lines of action as straight-lines, which might be less reliable during occupational tasks that require complex lumbar motions. The objective of this study was to describe the model structure and underlying logic of a biologically-assisted curved muscle model of the lumbar spine. METHODS The developed model structure including curved muscle geometry, separation of active and passive muscle forces, and personalization of muscle properties was described. An example of the model procedure including data collection, personalization, and data evaluation was also illustrated. FINDINGS Three-dimensional curved muscle geometry was developed based on a predictive model using magnetic resonance imaging and anthropometric measures to personalize the model for each individual. Calibration algorithms were able to reverse-engineer personalized muscle properties to calculate active and passive muscle forces of each individual. INTERPRETATION This biologically-assisted curved muscle model will significantly increase the accuracy of spinal tissue load predictions for the entire lumbar spine during complex dynamic occupational tasks. Personalized active and passive muscle force algorithms will help to more robustly investigate person-specific muscle forces and spinal tissue loads.
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Affiliation(s)
- Jaejin Hwang
- Biodynamics Laboratory, Spine Research Institute, The Ohio State University, Department of Integrated Systems Engineering, 1971 Neil Avenue, 210 Baker Systems Engineering, Columbus, OH 43210, USA.
| | - Gregory G Knapik
- Biodynamics Laboratory, Spine Research Institute, The Ohio State University, Department of Integrated Systems Engineering, 1971 Neil Avenue, 210 Baker Systems Engineering, Columbus, OH 43210, USA.
| | - Jonathan S Dufour
- Biodynamics Laboratory, Spine Research Institute, The Ohio State University, Department of Integrated Systems Engineering, 1971 Neil Avenue, 210 Baker Systems Engineering, Columbus, OH 43210, USA.
| | - Alexander Aurand
- Biodynamics Laboratory, Spine Research Institute, The Ohio State University, Department of Integrated Systems Engineering, 1971 Neil Avenue, 210 Baker Systems Engineering, Columbus, OH 43210, USA.
| | - Thomas M Best
- Department of Family Medicine, The Ohio State University, Martha Moorehouse Medical Plaza, 2050 Kenny Dr., Columbus, OH 43210, USA.
| | - Safdar N Khan
- Department of Orthopeadics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA.
| | - Ehud Mendel
- Department of Neurological Surgery, The Ohio State University, Columbus, OH 43210, USA.
| | - William S Marras
- Biodynamics Laboratory, Spine Research Institute, The Ohio State University, Department of Integrated Systems Engineering, 1971 Neil Avenue, 210 Baker Systems Engineering, Columbus, OH 43210, USA.
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31
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Lee YP, Ihn HE, McGarry MH, Farhan SD, Bhatia N, Lee TQ. Biomechanical Analysis of an S1 Pedicle Screw Salvage Technique via a Superior Articulating Process Entry Point. Spine (Phila Pa 1976) 2016; 41:E778-E784. [PMID: 26679872 PMCID: PMC5962033 DOI: 10.1097/brs.0000000000001382] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Biomechanical, cadaveric study. OBJECTIVE To compare the fixation strength of a novel S1 pedicle screw insertion technique in a revision setting to a standard S1 pedicle screw and an L5 pedicle screw. SUMMARY OF BACKGROUND DATA Fusions to the sacrum remain a difficult clinical challenge. Very few salvage techniques exist when a nonunion occurs. METHODS The biomechanical integrity of three screw fixations, L5 pedicle screws, a standard S1 pedicle screw, and an S1 pedicle screw placed via a superior articulating process entry point (SAP S1), was characterized by performing pullout tests using cadaveric specimens including L5 and sacrum. RESULTS SAP S1 constructs (735.5 ± 110.1 N/mm) were significantly stiffer than standard S1 (P = 0.005) and L5 (P = 0.02) constructs. There was no statistically significant difference between the L5 constructs and the standard S1 constructs for linear stiffness. There was no statistical difference between the three fixations for yield load, displacement at yield load, and energy absorbed to yield load.The ultimate pullout force for the SAP S1 was statistically higher than the standard S1 (1213.7 ± 579.6 vs. 478.6 ± 452.9 N; P = 0.004). Displacement at ultimate load was significantly greater for L5 screw fixation (3.3 ± 1.1 mm) compared to the other two constructs. Both the L5 (2277.4 ± 1873.3 N-mm) and SAP S1 (2628.2 ± 2054.4 N-mm) constructs had significantly greater energy absorbed to ultimate load than the standard S1 construct (811.7 ± 937.6 N-mm), but there was no statistical difference between the L5 and SAP S1 constructs. CONCLUSION S1 pedicle screw fixation via an SAP entry point provides biomechanical advantages compared to screws placed via the standard S1 or L5 entry point and may be a viable option for revision of a failed L5-S1 fusion with a compromised standard S1 entry point. LEVEL OF EVIDENCE N/A.
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Affiliation(s)
- Yu-Po Lee
- Department of Orthopaedic Surgery, University of California, Irvine, School of Medicine, Irvine, CA
| | - Hansel E Ihn
- Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System and University of California, Irvine, CA
| | - Michelle H McGarry
- Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System and University of California, Irvine, CA
| | - Saifal-Deen Farhan
- Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System and University of California, Irvine, CA
| | - Nitin Bhatia
- Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System and University of California, Irvine, CA
| | - Thay Q Lee
- Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System and University of California, Irvine, CA
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The influences of foot placement on lumbopelvic rhythm during trunk flexion motion. J Biomech 2016; 49:1692-1697. [DOI: 10.1016/j.jbiomech.2016.03.048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 01/05/2016] [Accepted: 03/28/2016] [Indexed: 11/19/2022]
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Subject-specific biomechanics of trunk: musculoskeletal scaling, internal loads and intradiscal pressure estimation. Biomech Model Mechanobiol 2016; 15:1699-1712. [DOI: 10.1007/s10237-016-0792-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 04/25/2016] [Indexed: 10/21/2022]
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Hajibozorgi M, Arjmand N. Sagittal range of motion of the thoracic spine using inertial tracking device and effect of measurement errors on model predictions. J Biomech 2016; 49:913-918. [DOI: 10.1016/j.jbiomech.2015.09.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 08/16/2015] [Accepted: 09/05/2015] [Indexed: 10/23/2022]
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Dreischarf M, Shirazi-Adl A, Arjmand N, Rohlmann A, Schmidt H. Estimation of loads on human lumbar spine: A review of in vivo and computational model studies. J Biomech 2016; 49:833-845. [DOI: 10.1016/j.jbiomech.2015.12.038] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 12/18/2015] [Indexed: 01/09/2023]
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Differences in lumbopelvic rhythm between trunk flexion and extension. Clin Biomech (Bristol, Avon) 2016; 32:274-9. [PMID: 26577865 DOI: 10.1016/j.clinbiomech.2015.10.012] [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: 08/10/2015] [Revised: 10/28/2015] [Accepted: 10/29/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND Trunk flexion and extension have already been found to have different characteristics, such as those in lumbopelvic rhythm. Although a more advanced method of quantifying such rhythm, lumbopelvic continuous relative phase and phase variability have not been used to explore the differences between trunk flexion and extension motions. This information is important since abnormal lumbopelvic coordination patterns increase the risk of low back pain. The current study investigated the differences in lumbopelvic rhythm between trunk flexion and extension, and how the rhythm changed within each of the two motions. METHODS Thirteen subjects performed pace-controlled trunk flexion/extension motions in the sagittal plane while lumbar and pelvis kinematics data were recorded, such that the lumbopelvic continuous relative phase and phase variability could be calculated to quantify lumbopelvic rhythm. FINDINGS Trunk extension motion had significantly smaller lumbopelvic continuous relative phase and phase variability than flexion motion, which indicated a more in-phase and stable rhythm. Additionally, the lumbopelvic rhythm within trunk extension motion changed from a more in-phase and stable pattern to a more out-of-phase and unstable pattern; by contrast, the opposite change (from out-of-phase and unstable to in-phase and stable) was observed in trunk flexion. INTERPRETATION Findings of the current study provided important information about the differences in lumbopelvic rhythm between trunk flexion and extension motions. Quantifying these patterns provides the means for identifying abnormal patterns in a clinical setting, and could serve as normative benchmarks during low back pain rehabilitation plans.
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Chen YL, Chiou WK. Comparison of static lifting capacity between experienced and novice Taiwanese female workers. Work 2015; 52:549-58. [PMID: 26528842 DOI: 10.3233/wor-152184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Previous studies have analyzed the lifting capacity of either experienced workers or novices, but a systematic comparison of the lifting capacity of experienced female workers and novices has not been conducted. OBJECTIVE This study was conducted to identify differences in lifting strengths and postures between experienced and novice Taiwanese female workers. METHODS Twenty-three experienced female workers and 23 novices volunteered for this study. Their static lifting strengths (n = 46) and lifting postures (n = 22) were analyzed using statistical analysis software. RESULTS Experienced workers' vertical lifting strengths were approximately 5-7 kg lower than those of novices at lower heights (≤50 cm). However, at heights equal to or higher than 90 cm, the experienced workers generated approximately 2-3 kg higher toward-body lifting strengths than did novices. The experienced workers' strengths at all 15 lifting heights were relatively unchanged, compared with changes in the novices' strengths. Experienced workers tended to adopt a consistently deep squat at lower heights and a more flexed arm posture at higher heights. CONCLUSIONS Through daily work experience, experienced workers may have subconsciously learned to shift their postures to avoid overexertion. These techniques for safe lifting should be taught to new Taiwanese female workers.
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Affiliation(s)
- Yi-Lang Chen
- Department of Industrial Engineering and Management, Ming Chi University of Technology, New Taipei, Taiwan
| | - Wen-Ko Chiou
- Department of Industrial Design, Chang Gung University, Taoyuan, Taiwan
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Mohammadi Y, Arjmand N, Shirazi-Adl A. Comparison of trunk muscle forces, spinal loads and stability estimated by one stability- and three EMG-assisted optimization approaches. Med Eng Phys 2015; 37:792-800. [DOI: 10.1016/j.medengphy.2015.05.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 05/12/2015] [Accepted: 05/31/2015] [Indexed: 10/23/2022]
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Mawston GA, G. Boocock M. Lumbar posture biomechanics and its influence on the functional anatomy of the erector spinae and multifidus. PHYSICAL THERAPY REVIEWS 2015. [DOI: 10.1179/1743288x15y.0000000014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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40
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Rajaee MA, Arjmand N, Shirazi-Adl A, Plamondon A, Schmidt H. Comparative evaluation of six quantitative lifting tools to estimate spine loads during static activities. APPLIED ERGONOMICS 2015; 48:22-32. [PMID: 25683528 DOI: 10.1016/j.apergo.2014.11.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 10/25/2014] [Accepted: 11/07/2014] [Indexed: 06/04/2023]
Abstract
Different lifting analysis tools are commonly used to assess spinal loads and risk of injury. Distinct musculoskeletal models with various degrees of accuracy are employed in these tools affecting thus their relative accuracy in practical applications. The present study aims to compare predictions of six tools (HCBCF, LSBM, 3DSSPP, AnyBody, simple polynomial, and regression models) for the L4-L5 and L5-S1 compression and shear loads in twenty-six static activities with and without hand load. Significantly different spinal loads but relatively similar patterns for the compression (R(2) > 0.87) were computed. Regression models and AnyBody predicted intradiscal pressures in closer agreement with available in vivo measurements (RMSE ≈ 0.12 MPa). Due to the differences in predicted spinal loads, the estimated risk of injury alters depending on the tool used. Each tool is evaluated to identify its shortcomings and preferred application domains.
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Affiliation(s)
- Mohammad Ali Rajaee
- Department of Mechanical Engineering, Sharif University of Technology, Tehran 11155-9567, Iran
| | - Navid Arjmand
- Department of Mechanical Engineering, Sharif University of Technology, Tehran 11155-9567, Iran.
| | - Aboulfazl Shirazi-Adl
- Division of Applied Mechanics, Department of Mechanical Engineering, École Polytechnique, Montréal, Québec, Canada
| | - André Plamondon
- Institut de recherche Robert Sauvé en santé et en sécurité du travail, Montréal, Québec, Canada
| | - Hendrik Schmidt
- Julius Wolff Institut Charité - Universitätsmedizin Berlin, Germany
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Nasseroleslami B, Vossoughi G, Boroushaki M, Parnianpour M. Simulation of movement in three-dimensional musculoskeletal human lumbar spine using directional encoding-based neurocontrollers. J Biomech Eng 2015; 136:091010. [PMID: 24828450 DOI: 10.1115/1.4027664] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Accepted: 05/14/2014] [Indexed: 11/08/2022]
Abstract
Despite development of accurate musculoskeletal models for human lumbar spine, the methods for prediction of muscle activity patterns in movements lack proper association with corresponding sensorimotor integrations. This paper uses the directional information of the Jacobian of the musculoskeletal system to orchestrate adaptive critic-based fuzzy neural controller modules for controlling a complex nonlinear redundant musculoskeletal system. The proposed controller is used to control a 3D 3-degree of freedom (DOF) musculoskeletal model of trunk, actuated by 18 muscles. The controller is capable of learning to control from sensory information, without relying on pre-assumed model parameters. Simulation results show satisfactory tracking of movements and the simulated muscle activation patterns conform to previous EMG experiments and optimization studies. The proposed controller can be used as a computationally inexpensive muscle activity generator to distinguish between neural and mechanical contributions to movement and for study of sensory versus motor origins of motor function and dysfunction in human spine.
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42
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Trunk active response and spinal forces in sudden forward loading – analysis of the role of perturbation load and pre-perturbation conditions by a kinematics-driven model. J Biomech 2015; 48:44-52. [DOI: 10.1016/j.jbiomech.2014.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 10/11/2014] [Accepted: 11/05/2014] [Indexed: 11/21/2022]
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Abstract
Low-back pain is one of the most common painful conditions experienced by humans throughout their life. Some occupational risk factors (namely, heavy manual material handling) may also contribute to the development of low-back pain: due to the high prevalence of both low-back pain and manual material handling in the adult working population, it has been estimated that low-back pain is probably the most common occupational disorder worldwide. Lifetime prevalence of low-back pain has been reported to be as high as 84%, depending on the case definition used, and no age group is spared, even children. Although low-back pain is not a lethal condition, it was estimated at the third rank among all diseases by disability-adjusted life-years in 2010 in the USA, after ischemic heart disease and chronic obstructive pulmonary disease, and at the first rank by years lived with disability. It also ranked high (13th) globally for the same year, in disability-adjusted life-years. Low-back pain is currently classified as nonspecific/specific as to putative cause and as acute (lasting less than 6 weeks), subacute (6-12 weeks), or chronic (more than 12 weeks) according to duration of symptoms. The distinction between nonspecific/specific and acute/subacute/chronic low-back pain is useful not only for epidemiologic studies, but also (mainly) for choosing the appropriate strategy for the diagnosis and treatment of the disorder. Workplace risk factors for low-back pain include manual lifting and whole-body vibration exposure. This chapter will provide an overview of modern concepts of low-back pain (in general) and will then outline some distinctive features of work-related low-back pain.
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A novel stability and kinematics-driven trunk biomechanical model to estimate muscle and spinal forces. Med Eng Phys 2014; 36:1296-304. [DOI: 10.1016/j.medengphy.2014.07.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 05/14/2014] [Accepted: 07/08/2014] [Indexed: 11/20/2022]
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Ghezelbash F, Arjmand N, Shirazi-Adl A. Effect of intervertebral translational flexibilities on estimations of trunk muscle forces, kinematics, loads, and stability. Comput Methods Biomech Biomed Engin 2014; 18:1760-7. [DOI: 10.1080/10255842.2014.961440] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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46
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Effect of changes in orientation and position of external loads on trunk muscle activity and kinematics in upright standing. J Electromyogr Kinesiol 2014; 24:387-93. [DOI: 10.1016/j.jelekin.2014.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 11/20/2022] Open
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BRANDOLINI NICOLA, CRISTOFOLINI LUCA, VICECONTI MARCO. EXPERIMENTAL METHODS FOR THE BIOMECHANICAL INVESTIGATION OF THE HUMAN SPINE: A REVIEW. J MECH MED BIOL 2014. [DOI: 10.1142/s0219519414300026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In vitro mechanical testing of spinal specimens is extremely important to better understand the biomechanics of the healthy and diseased spine, fracture, and to test/optimize surgical treatment. While spinal testing has extensively been carried out in the past four decades, testing methods are quite diverse. This paper aims to provide a critical overview of the in vitro methods for mechanical testing the human spine at different scales. Specimens of different type are used, according to the aim of the study: spine segments (two or more adjacent vertebrae) are used both to investigate the spine kinematics, and the mechanical properties of the spine components (vertebrae, ligaments, discs); single vertebrae (whole vertebra, isolated vertebral body, or vertebral body without endplates) are used to investigate the structural properties of the vertebra itself; core specimens are extracted to test the mechanical properties of the trabecular bone at the tissue-level; mechanical properties of spine soft tissue (discs, ligaments, spinal cord) are measured on isolated elements, or on tissue specimens. Identification of consistent reference frames is still a debated issue. Testing conditions feature different pre-conditioning and loading rates, depending on the simulated action. Tissue specimen preservation is a very critical issue, affecting test results. Animal models are often used as a surrogate. However, because of different structure and anatomy, extreme caution is required when extrapolating to the human spine. In vitro loading conditions should be based on reliable in vivo data. Because of the high complexity of the spine, such information (either through instrumented implants or through numerical modeling) is currently unsatisfactory. Because of the increasing ability of computational models in predicting biomechanical properties of musculoskeletal structures, a synergy is possible (and desirable) between in vitro experiments and numerical modeling. Future perspectives in spine testing include integration of mechanical and structural properties at different dimensional scales (from the whole-body-level down to the tissue-level) so that organ-level models (which are used to predict the most relevant phenomena such as fracture) include information from all dimensional scales.
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Affiliation(s)
- NICOLA BRANDOLINI
- Laboratory for Medical Technology, Rizzoli Orthopaedic Institute, Via di Barbiano 1/10, 40136 Bologna, Italy
- School of Mechanical Engineering, University of Leeds, Woodhouse Lane, LS2 9JT Leeds, UK
| | - LUCA CRISTOFOLINI
- Department of Industrial Engineering, School of Engineering and Architecture, University of Bologna, Viale Risorgimento 2, 40136 Bologna, Italy
| | - MARCO VICECONTI
- Laboratory for Medical Technology, Rizzoli Orthopaedic Institute, Via di Barbiano 1/10, 40136 Bologna, Italy
- Department of Mechanical Engineering, University of Sheffield, Sheffield, UK
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Wang S, Park WM, Kim YH, Cha T, Wood K, Li G. In vivo loads in the lumbar L3-4 disc during a weight lifting extension. Clin Biomech (Bristol, Avon) 2014; 29:155-60. [PMID: 24345591 PMCID: PMC3943591 DOI: 10.1016/j.clinbiomech.2013.11.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 09/16/2013] [Accepted: 11/27/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND Knowledge of in vivo human lumbar loading is critical for understanding the lumbar function and for improving surgical treatments of lumbar pathology. Although numerous experimental measurements and computational simulations have been reported, non-invasive determination of in vivo spinal disc loads is still a challenge in biomedical engineering. The object of the study is to investigate the in vivo human lumbar disc loads using a subject-specific and kinematic driven finite element approach. METHODS Three dimensional lumbar spine models of three living subjects were created using MR images. Finite element model of the L3-4 disc was built for each subject. The endplate kinematics of the L3-4 segment of each subject during a dynamic weight lifting extension was determined using a dual fluoroscopic imaging technique. The endplate kinematics was used as displacement boundary conditions to calculate the in-vivo disc forces and moments during the weight lifting activity. FINDINGS During the weight lifting extension, the L3-4 disc experienced maximum shear load of about 230 N or 0.34 bodyweight at the flexion position and maximum compressive load of 1500 N or 2.28 bodyweight at the upright position. The disc experienced a primary flexion-extension moment during the motion which reached a maximum of 4.2 Nm at upright position with stretched arms holding the weight. INTERPRETATION This study provided quantitative data on in vivo disc loading that could help understand intrinsic biomechanics of the spine and improve surgical treatment of pathological discs using fusion or arthroplasty techniques.
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Affiliation(s)
- Shaobai Wang
- Bioengineering Lab, Department of Orthopaedic Surgery Massachusetts General Hospital/Harvard Medical School Boston, MA, USA,Department of Mechanical Engineering Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Won Man Park
- Department of Mechanical Engineering Kyung Hee University, Suwon, Korea
| | - Yoon Hyuk Kim
- Department of Mechanical Engineering Kyung Hee University, Suwon, Korea
| | - Thomas Cha
- Bioengineering Lab, Department of Orthopaedic Surgery Massachusetts General Hospital/Harvard Medical School Boston, MA, USA
| | - Kirkham Wood
- Bioengineering Lab, Department of Orthopaedic Surgery Massachusetts General Hospital/Harvard Medical School Boston, MA, USA
| | - Guoan Li
- Bioengineering Lab, Department of Orthopaedic Surgery Massachusetts General Hospital/Harvard Medical School Boston, MA, USA
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Pavlova AV, Meakin JR, Cooper K, Barr RJ, Aspden RM. The lumbar spine has an intrinsic shape specific to each individual that remains a characteristic throughout flexion and extension. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2014; 23 Suppl 1:S26-32. [PMID: 24413745 DOI: 10.1007/s00586-013-3162-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 12/30/2013] [Accepted: 12/31/2013] [Indexed: 11/29/2022]
Abstract
PURPOSE We have previously shown that the lumbar spine has an intrinsic shape specific to the individual and characteristic of sitting, standing and supine postures. The purpose of this study was to test the hypothesis that this intrinsic shape is detectable throughout a range of postures from extension to full flexion in healthy adults. METHODS Sagittal images of the lumbar spine were taken using a positional MRI with participants (n = 30) adopting six postures: seated extension, neutral standing, standing with 30, 45 and 60° and full flexion. Active shape modelling (ASM) was used to identify and quantify 'modes' of variation in the shape of the lumbar spine. RESULTS ASM showed that 89.5% of the variation in the shape of the spine could be explained by the first two modes; describing the overall curvature and the distribution of curvature of the spine. Mode scores were significantly correlated between all six postures (modes 1-9, r = 0.4-0.97, P < 0.05), showing that an element of intrinsic shape was maintained when changing postures. The spine was most even in seated extension (P < 0.001) and most uneven between 35 and 45° flexion (P < 0.05). CONCLUSIONS This study shows that an individual's intrinsic lumbar spine shape is quantifiable and detectable throughout lumbar flexion and extension. These findings will enable the role of lumbar curvature in injury and low back pain to be assessed in the clinic and in the working and recreational environments.
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Affiliation(s)
- Anastasia V Pavlova
- Musculoskeletal Research Programme, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, AB25 2ZD, Aberdeen, UK,
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Park JY, Park GD, Lee SG, Lee JC. The effect of scoliosis angle on center of gravity sway. J Phys Ther Sci 2014; 25:1629-31. [PMID: 24409036 PMCID: PMC3885855 DOI: 10.1589/jpts.25.1629] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 07/05/2013] [Indexed: 11/24/2022] Open
Abstract
[Purpose] The purpose of this study was to verify the effects of idiopathic scoliosis on the human body by comparing the postural balance of adolescents with and without idiopathic scoliosis, to provide basic data for the optimal desirable growth and development of adolescents. [Subjects] The subjects were 128 adolescents diagnosed with scoliosis on X-ray by orthopedists. The subjects were divided into a 10 to 19 degree group, 20 to 29 degree group, and 30 degree and over group according to the degree of scoliosis. For comparison, 15 normal adolescents without orthopedic injury within the last 6 months were selected as a control group. [Methods] As measurement tools, DK2 525R (Dongkang Medical: Korea) was used to measure the Cobb angle and a multifunktional traininggeraete device (MFT, Germany) was used to measure balance. One-way variance of analysis was conducted in order to examine differences among the four groups in left and right balance, forward and backward balance, and overall postural balance, and when there were differences, they were compared in detail using Duncan's post-hoc test. [Results] The results of scoliosis angle and body mass index (BMI) showed significant differences between the normal group (NG) and the scoliosis groups (GI, G II, G III), but there were no significant differences among the scoliosis groups. The scoliosis groups showed a significantly lower BMI than that of the normal group. In addition, the results of the left/right and the front/rear balance abilities showed significant differences between the normal group and the scoliosis groups. Furthermore, the results of whole body balance ability were showed significant differences between the normal group and the scoliosis groups.
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Affiliation(s)
- Jae-Yong Park
- Department of Division of Sport Science, Sunmoon University, Republic of Korea
| | - Gi Duck Park
- Department of Leisure Sport, Kyungpook National University, Republic of Korea
| | | | - Joong-Chul Lee
- Department of Exercise Prescription, Dongshin University, Republic of Korea
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