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Brosche J, Wackerle H, Augat P, Lödding H. Individualized workplace ergonomics using motion capture. APPLIED ERGONOMICS 2024; 114:104140. [PMID: 37776714 DOI: 10.1016/j.apergo.2023.104140] [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: 11/30/2022] [Revised: 09/08/2023] [Accepted: 09/12/2023] [Indexed: 10/02/2023]
Abstract
Production workers suffer from musculoskeletal disorders (MSDs) due to excessive workloads that exceed the individual physical capabilities. In order to assess and subsequently reduce the risk to suffer from a MSD at a specific workplace, companies use ergonomic screening methods. However, the current approaches have two major downsides: Firstly, they do not take the individual worker and his/her capabilities into account. Applied thresholds for joint angles or physical loads are standard values that do not address physical limitations, such as age-related loss of flexibility or muscle strength. Secondly, the methods only provide a risk assessment that indicates which workplaces and/or working postures are ergonomically hazardous. Necessary workplace improvements are decoupled from the results and require extensive ergonomic knowledge. This paper presents a method that uses an individualized ergonomics analysis to improve workplaces according to individual needs and helps the industrial engineer to find necessary workplace improvements.
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Affiliation(s)
- Justus Brosche
- Institute of Production Management and Technology, Hamburg University of Technology, 21071 Hamburg, Germany.
| | - Hannes Wackerle
- Institute for Biomechanics, BG Unfallklinik Murnau, 82418 Murnau, Germany; Institute for Biomechanics, Paracelsus Medical University, 5020 Salzburg, Austria.
| | - Peter Augat
- Institute for Biomechanics, BG Unfallklinik Murnau, 82418 Murnau, Germany; Institute for Biomechanics, Paracelsus Medical University, 5020 Salzburg, Austria.
| | - Hermann Lödding
- Institute of Production Management and Technology, Hamburg University of Technology, 21071 Hamburg, Germany.
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Lang AE. Does calibration pose improve scapular kinematic repeatability in functional tasks? J Electromyogr Kinesiol 2023; 73:102829. [PMID: 37801820 DOI: 10.1016/j.jelekin.2023.102829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/22/2023] [Accepted: 09/29/2023] [Indexed: 10/08/2023] Open
Abstract
Tracking scapular motion can be challenging. More research is needed to determine the best practices for scapular measurement in multi-planar tasks. The purpose of this study was to compare the repeatability of scapular kinematics during a functional task protocol calculated from different calibration procedures. It was hypothesized that select poses would improve repeatability in specific tasks. The torso, humerus, and scapula were tracked with optical motion capture in two sessions for ten pain-free participants. Scapular calibrations were completed in five poses: neutral, maximum elevation, 90° abduction, hand to contralateral shoulder, and hand to back. Each participant completed eight functional tasks (Comb Hair, Wash Axilla, Tie Apron, Overhead Reach, Side Reach, Forward Transfer, Floor Lift, Overhead Lift). Scapular angles were calculated with five different calibration procedures and extracted at 30° increments of humeral elevation in each task. Mean difference, limits of agreement, intraclass correlations, and minimal detectable change (MDC) were calculated for each task and elevation level. The inclusion of different calibration poses did not markedly improve outcomes over the maximum elevation double calibration for most tasks. Using this calibration procedure, median MDCs were 10.0° for upward rotation, 13.7° for internal rotation, and 9.8° for tilt.
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Affiliation(s)
- Angelica E Lang
- Canadian Centre for Rural and Agricultural Health, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
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Lang AE, Friesen KB. Defining humeral axial rotation with optical motion capture and inertial measurement units during functional task assessment. Med Biol Eng Comput 2023; 61:2963-2970. [PMID: 37535299 DOI: 10.1007/s11517-023-02894-z] [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: 03/18/2023] [Accepted: 07/19/2023] [Indexed: 08/04/2023]
Abstract
Humeral motion can be challenging to measure and analyze. Typically, Euler/Cardan sequences are used for humeral angle decomposition, but choice of rotation sequence has substantial effects on outcomes. A new method called True axial rotation calculation may be more precise. The objective of this study is to compare humeral axial rotation measured from two systems (optical motion capture and inertial measurement units (IMUs)) and calculated with two methods (Euler angles and True axial). Motion of torso and dominant humerus of thirty participants free from any upper limb impairments was tracked using both systems. Each participant performed a functional tasks protocol. Humeral axial rotation was calculated with Euler decomposition and the True axial method. Waveforms were compared with two-way ANOVA statistical parametric mapping. A consistent pattern emerged: axial rotation was not different between motion capture systems when using the True axial method (p > .05), but motion capture systems showed relatively large magnitude differences (~ 20-30°) when using Euler angle calculation. Between-calculation method differences were large for both motion capture systems. Findings suggest that the True axial rotation method may result in more consistent findings that will allow for precise measurements and comparison between motion capture systems. Two methods for calculating humeral axial rotation measured from optical motion capture and inertial measurement units were compared.
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Affiliation(s)
- Angelica E Lang
- Canadian Centre for Health and Safety in Agriculture, College of Medicine, University of Saskatchewan, 104 Clinic Place, Saskatoon, SK, S7N 2Z4, Canada.
| | - Kenzie B Friesen
- Canadian Centre for Health and Safety in Agriculture, College of Medicine, University of Saskatchewan, 104 Clinic Place, Saskatoon, SK, S7N 2Z4, Canada
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Friesen KB, Wu LZ, Waslen A, Lang AE. Defining repeatability for scapulothoracic and thoracohumeral motion during the novel work-related activities and functional task (WRAFT) protocol. J Biomech 2023; 153:111596. [PMID: 37126882 DOI: 10.1016/j.jbiomech.2023.111596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 03/31/2023] [Accepted: 04/19/2023] [Indexed: 05/03/2023]
Abstract
Upper limb motion can be challenging to measure and analyze during work or daily life tasks. Further, humeral angle calculation method substantially influences angle outcomes. Therefore, the purpose of this study was to assess the repeatability of scapular and humeral kinematics and compare thoracohumeral angle calculation during a work-related and functional task (WRAFT) protocol. Thirty healthy young adults completed the WRAFT protocol (Comb Hair, Wash Axilla, Tie Apron, Overhead Reach, Side Reach, Forward Transfer, Floor Lift, and Overhead Lift) on two separate occasions. Peak humeral angles and select scapular angles were extracted for each task. Intra-class correlation coefficients (ICCs), standard error of measurement, and minimal detectable change (MDC) were examined. Humeral angles were compared using the XZY and ZXY rotation sequences and "true" axial rotation for incidence of gimbal lock and amplitude coherence. Results showed that for scapular kinematics, elevation-based WRAFTs produced overall better ICC scores (0.23-0.90) compared to those tasks primarily driven by lateral humeral motion (0.02-0.84). MDCs ranged from 7°-78°, suggesting some tasks demonstrated good repeatability (Comb Hair, Overhead Reach, Floor Lift), while others had very high variability (Side Reach, Tie Apron). Amplitude coherence for thoracohumeral angles was best for ZXY for all tasks except the Comb Hair and Tie Apron, for which XZY is recommended. "True" axial rotation demonstrated good coherence for all but Tie Apron. The WRAFT protocol may be used for functionally relevant scapular and humeral kinematic assessment for select task and posture combinations.
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Affiliation(s)
- Kenzie B Friesen
- College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Laura Z Wu
- College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Alexander Waslen
- College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Angelica E Lang
- College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
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Lang AE, Lin JH, Dickerson CR. Activation patterns of shoulder internal and external rotators during pure axial moment generation across a postural range. J Biomech 2021; 123:110503. [PMID: 34020122 DOI: 10.1016/j.jbiomech.2021.110503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 04/27/2021] [Accepted: 05/02/2021] [Indexed: 11/16/2022]
Abstract
Musculoskeletal risk is mediated by body posture, especially for static tasks. Workstations that require non-neutral postures can lead to increased load, muscular fatigue and injury risk. However, demands during simple axial rotation tasks are not well-defined. The purpose of this study is to quantify the muscular activity of during static axial rotation in a range of postures. Eighteen participants performed 76 axial rotation exertions in varying combinations of humeral elevation angles (30°-60°-90°-120°-150°), plane of elevation (30°-60°-90°-120°) and exertion intensity (20-40%). Six unilateral (right) muscles (pectoralis major (clavicular and sternal), posterior deltoid, teres major, infraspinatus, latissiumus dorsi) were monitored using surface electromyography (EMG). EMG was normalized and integrated over 2 s. The influences of elevation, plane, and intensity on activity levels were then tested with a 3-way ANOVAs (p < .05). During internal rotation, activity was highest at low elevation/high plane combinations for the internal rotators, but at high elevation/low plane combinations for the external rotators. During the 40% intensity exertions, activity levels were highest at lower elevations for internal rotator but at high elevations for the external rotators. During external rotation, as the degree of elevation increased, the activity of the external rotator muscles also increased while internal rotators were unaffected. Humeral muscles responsible for axial rotation are influenced by arm posture during axial rotation exertions. High elevation and plane combinations resulted in high demands for external rotator muscles and this should be considered for job design and injury risk.
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Affiliation(s)
- Angelica E Lang
- School of Rehabilitation Science, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jia-Hua Lin
- Safety and Health Assessment and Research for Prevention Program, Washington State Department of Labor and Industries, Tumwater, WA, USA
| | - Clark R Dickerson
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
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Lang AE, Dickerson CR, Kim SY, Stobart J, Milosavljevic S. Impingement pain affects kinematics of breast cancer survivors in work-related functional tasks. Clin Biomech (Bristol, Avon) 2019; 70:223-230. [PMID: 31669920 DOI: 10.1016/j.clinbiomech.2019.10.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 10/08/2019] [Accepted: 10/10/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Breast cancer survivors may encounter upper limb morbidities post-surgery. It is currently unclear how these impairments affect arm kinematics, particularly during functional task performance. This investigation examined upper body kinematics during functional tasks for breast cancer survivors and an age-matched control group. METHODS Fifty women (aged 35-65) participated: 25 breast cancer survivors who had undergone mastectomy and 25 age-range matched controls. Following basic clinical evaluation, including shoulder impingement tests, motion of the torso and upper limbs were tracked during six upper limb-focused functional tasks from which torso, scapular, and thoracohumeral angles were calculated. Between-group differences were evaluated with independent t-tests (p < .05). The breast cancer group was then divided based upon impingement tests and differences between the three new groups were tested with one-way ANOVAs (p < .05). FINDINGS Breast cancer survivors had higher disability scores, lower range of motion, and lower performance scores. The largest kinematic differences existed between the breast cancer survivors with impingement pain and the two non-pain groups. During overhead tasks, right peak scapular upward rotation was significantly reduced (d = 0.80-1.11) in the breast cancer survivors with impingement pain. This group also demonstrated trends of decreased peak humeral abduction and internal rotation at extreme postures (d = 0.54-0.78). These alterations are consistent with kinematics considered high risk for rotator cuff injury development. INTERPRETATION Impingement pain in breast cancer survivors influences functional task performance and may be more important to consider than self-reported disability when evaluating pain and potential injury development.
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Affiliation(s)
- Angelica E Lang
- Department of Health Sciences, College of Medicine, University of Saskatchewan, Canada
| | - Clark R Dickerson
- Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Canada
| | - Soo Y Kim
- School of Rehabilitation Science, College of Medicine, University of Saskatchewan, Canada
| | - Jamie Stobart
- School of Rehabilitation Science, College of Medicine, University of Saskatchewan, Canada
| | - Stephan Milosavljevic
- School of Rehabilitation Science, College of Medicine, University of Saskatchewan, Canada.
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Lang AE, Milosavljevic S. Visual estimation of shoulder posture: accuracy and reliability across five planes of motion. PHYSICAL THERAPY REVIEWS 2019. [DOI: 10.1080/10833196.2019.1637594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Angelica E. Lang
- Department of Health Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Stephan Milosavljevic
- School of Rehabilitation Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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