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Luger, Tessy
Publications (5 of 5) Show all publications
Luger, T., Mathiassen, S. E., Bosch, T., Hoozemans, M., Douwes, M., Veeger, D. & de Looze, M. (2017). Changing variation by work station design. Industrial and Systems Engineering at Work, 49(8), 53-54
Open this publication in new window or tab >>Changing variation by work station design
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2017 (English)In: Industrial and Systems Engineering at Work, ISSN 2168-9210, Vol. 49, no 8, p. 53-54Article in journal (Other academic) Published
National Category
Occupational Health and Environmental Health
Identifiers
urn:nbn:se:hig:diva-25249 (URN)
Available from: 2017-09-15 Created: 2017-09-15 Last updated: 2018-03-13Bibliographically approved
Luger, T., Mathiassen, S. E., Bosch, T., Hoozemans, M., Douwes, M., Veeger, D. & de Looze, M. (2017). Influence of posture variation on shoulder muscle activity, heart rate, and perceived exertion in a repetitive manual task. IISE Transactions on Occupational Ergonomics and Human Factors, 5, 47-64
Open this publication in new window or tab >>Influence of posture variation on shoulder muscle activity, heart rate, and perceived exertion in a repetitive manual task
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2017 (English)In: IISE Transactions on Occupational Ergonomics and Human Factors, ISSN 2472-5838, Vol. 5, p. 47-64Article in journal (Refereed) Published
Abstract [en]

Background: Repetitive light assembly work is associated with an increased risk for developing work-related musculoskeletal disorders. More exposure variation, for instance by redesigning the workstation, is generally proposed as an effective intervention. Purpose: We investigated the effect of upper arm posture variation in a one-hour repetitive pick-and-place task on shoulder muscle activity, heart rate and perceived exertion, measured on the Borg CR-10 scale and in terms of maximal acceptable work pace (MAWP). Methods: Thirteen healthy participants performed the task in three workstation designs where the hand was moved either horizontal (H30/30), diagonal (D20/40), or vertical (V10/50) with a mean upper arm elevation of ~30°. In a fourth design, the hand was moved horizontally at ~50° mean arm elevation (H50/50). Results: As intended, upper arm posture variation, measured by the upper arm elevation SD and range of motion, differed between H30/30, D20/40, and V10/50. However, MAWP (10.7 cycles·min-1 on average across conditions; determined using a psychophysical approach), average upper trapezius activity (54% reference voluntary exertion [RVE]), and heart rate (69 bpm) did not differ between these workstation designs. In H50/50, MAWP was lower (9.3 cycles·min-1), while trapezius activity (78% RVE) and perceived exertion (Borg CR-10) tended to be higher. Conclusions: Our results indicate that posture variation to the extent achieved in the current experiment leads to less effects on muscle activity and perceived exertion than a moderate change in working height.

Keywords
maximal acceptable work pace; exposure variation; arm elevation; repetitive work; muscle activity
National Category
Occupational Health and Environmental Health
Identifiers
urn:nbn:se:hig:diva-21295 (URN)10.1080/24725838.2017.1303655 (DOI)000442411100001 ()
Funder
Forte, Swedish Research Council for Health, Working Life and Welfare, 2009-1761
Available from: 2016-03-04 Created: 2016-03-04 Last updated: 2018-12-06Bibliographically approved
Luger, T., Mathiassen, S. E., Srinivasan, D. & Bosch, T. (2017). Influence of work pace on upper extremity kinematics and muscle activity in a short-cycle repetitive pick-and-place task. Annals of Occupational Hygiene, 61(3), 356-368
Open this publication in new window or tab >>Influence of work pace on upper extremity kinematics and muscle activity in a short-cycle repetitive pick-and-place task
2017 (English)In: Annals of Occupational Hygiene, ISSN 0003-4878, E-ISSN 1475-3162, Vol. 61, no 3, p. 356-368Article in journal (Refereed) Published
Abstract [en]

Aim: This study investigated the extent to which controlled changes in work pace in a cyclic pick-and-place task influence upper extremity kinematics and muscle activity, and whether an effect depends on working height. Methods: Thirteen participants performed the task four minutes at each of five work paces ranging from 8 to 12 cycles·min-1 in each of two experimental conditions where the hand was moved horizontally with an average upper arm elevation of 30° and 50°, respectively. For each work cycle, we calculated the average and standard deviation of the upper arm elevation angle and the activity of the trapezius and deltoid muscles, as well as the angular peak velocity. We summarized these seven variables by calculating averages across cycles and cycle-to-cycle variabilities. Results: At 30° arm elevation, pace significantly influenced within-cycle angle variation, cycle-to-cycle variability of the average angle, angular peak velocity, and cycle-to-cycle variability of peak velocity. However, only angular peak velocity increased monotonically across all paces from 8 to 12 cycles·min-1). Average activity in the trapezius and the deltoid were the only muscle activity variables to increase consistently with pace. These effects of work pace did not change with working height. Conclusion: The present study did not find any consistent work pace effect on upper extremity kinematics and muscle activity, in spite of a comprehensive empirical basis compared to previous literature. While our results suggest that work pace may not be of critical concern in an occupational health context, we encourage further studies verifying or disproving this notion.

Keywords
work pace, muscle activity, motor variability, upper arm elevation
National Category
Occupational Health and Environmental Health
Identifiers
urn:nbn:se:hig:diva-21507 (URN)10.1093/annweh/wxx001 (DOI)000405570200009 ()28355412 (PubMedID)2-s2.0-85028733295 (Scopus ID)
Funder
Forte, Swedish Research Council for Health, Working Life and Welfare, 2009-1761
Available from: 2016-05-19 Created: 2016-05-19 Last updated: 2018-09-05Bibliographically approved
Luger, T., Bosch, T., Douwes, M., Veeger, D., Hoozemans, M., de Looze, M. & Mathiassen, S. E. (2016). Influence of posture variation in a repetitive manual task on maximal acceptable work pace and perceived exertion. In: : . Paper presented at Ninth International Conference on the Prevention of Work-Related Musculoskeletal Disorders (PREMUS), June 20-23, 2016, Toronto, Canada.
Open this publication in new window or tab >>Influence of posture variation in a repetitive manual task on maximal acceptable work pace and perceived exertion
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2016 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Background. It is generally agreed that constrained postures during assembly work can lead to musculoskeletal disorders in the neck and shoulders. In a controlled experiment, we investigated the extent to which more variation of upper arm postures in a one-hour repetitive task influences maximal acceptable work pace (MAWP), perceived exertion (RPE), kinematics and muscle activity.

Methods. 13 participants (6 females, 7 males; age 26 (SD 3) years) performed a pick-and-place task for one hour, using their dominant hand to movie pins between two targets. We compared three conditions in which the hand was moved: (1) horizontally, at an intended upper arm elevation of 30°; (2) obliquely, at an upper arm elevation between 20° and 40°; and (3) vertically, at an upper arm elevation between 10° and 50°. Using a psychophysical approach — with imposed work paces changing every two minutes (7-13 cycles/min) — we arrived at the MAWP of each participant. Postures of the arm, trunk and shoulder were recorded throughout, as was the activity of selected muscles (not reported here). Participants reported their RPE (Borg CR-10) at baseline and at MAWP.

Results. The kinematics data confirmed that the conditions had similar average upper arm elevations (32.3° (SD 1.0°) but differed in variation (arm elevation SD: 5.2°, 8.1°, 10.9°). Increased posture variation did not lead to changes in MAWP (10.7, 10.6, 10.8 cycles/min), though it did lead to slightly lower RPE values (average increase from baseline: 5.4, 4.8, 4.7).

Discussion.Increased biomechanical variation has been suggested to reduce the risk of developing musculoskeletal disorders. Even though our data suggest that there may be a trend towards a positive effect of variation on work perception, the increase in posture variation imposed here was not sufficient to influence performance. Further analyses of arm, shoulder and trunk kinematics and muscle activity patterns may reveal biomechani-cal differences of interest between the protocols.

Keywords
posture, musculuskeletal disorders, neck, shoulder, work pace, maximal acceptable work pace, perceived exertion, kinematics, muscle activity
National Category
Occupational Health and Environmental Health
Identifiers
urn:nbn:se:hig:diva-21904 (URN)
Conference
Ninth International Conference on the Prevention of Work-Related Musculoskeletal Disorders (PREMUS), June 20-23, 2016, Toronto, Canada
Available from: 2016-06-23 Created: 2016-06-23 Last updated: 2018-12-03Bibliographically approved
Luger, T., Mathiassen, S. E., Bosch, T., Hoozemans, M., Douwes, M., Veeger, D. & de Looze, M. (2016). Posture variation and maximal acceptable work pace during repetitive work. In: : . Paper presented at 21st Congress of the International Society of Electrophysiology and Kinesiology, Bridges to innovation,5-8 July 2016, Chicago, Illinois,USA (pp. 183). , Article ID O.8.6.
Open this publication in new window or tab >>Posture variation and maximal acceptable work pace during repetitive work
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2016 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Aim. It is generally agreed that work postures can lead to musculoskeletal disorders in the neck and shoulders. We investigated the extent to which more variation of upper arm postures in a repetitive task influences maximal acceptable work pace (MAWP), muscle activity, and perceived exertion.

Methods. Thirteen healthy subjects (6F/7M; age 26 (SD 3) years) performed a repetitive pick-and-place task using their dominant hand in four one-hour conditions. In three conditions the average upper arm elevation was 30°, and the hand was moved (1) horizontally (H30), (2) diagonally with upper arm elevation between 20° and 40° (D20/40), (3) vertically, with upper arm elevation between 10° and 50° (V10/50). In the fourth condition, the hand was moved horizontally at 50° average upper arm elevation angle (H50). The travelled distance of the hand was the same for all conditions. Using a psychophysical approach with imposed work paces changing every two minutes (7-13 cycles/min), we arrived at the MAWP of each participant after 50 minutes. Postures of the arm were recorded throughout, as well as dominant upper trapezius muscle activity. Participants reported their perceived exertion (Borg CR-10) just after each protocol.

Results. Kinematic analyses showed that we successfully designed protocols (Figure) differing in posture variation but not in average upper arm elevation angle (H30, D20/40, V10/50), and differing in average upper arm elevation angle but not in posture variation (H30, H50). MAWP was comparable in the conditions with differing posture variation (10.7 cycles/min), but lower in H50, although not significant (9.3 cycles/min). Subjects worked at MAWP with an upper trapezius activity level that did not significantly differ between experimental conditions (median 54% RVE). Dominant trapezius muscle activity at MAWP in H50 (78% RVE) was higher than in H30 (47% RVE), but not significant. Perceived exertion of the upper arm was higher in H50 (2.5) than H30 (1.5), but also not significant.

Conclusion. Variation in upper arm elevation within the investigated limits did not affect MAWP although upper trapezius activity showed a tendency to increase with more variation. Increased working height tended to increase especially upper trapezius muscle activity and decrease MAWP. Thus, our results indicate that posture variation as applied in the current setting did not lead to significant differences in MAWP or muscle activity variables. More thorough workplace redesigns are apparently needed than those investigated by us to accomplish any major changes in psychophysical outcomes as measured by MAWP. Our results do show that engineers should pay attention to working height when advising companies on work pace.

National Category
Occupational Health and Environmental Health
Identifiers
urn:nbn:se:hig:diva-22359 (URN)
Conference
21st Congress of the International Society of Electrophysiology and Kinesiology, Bridges to innovation,5-8 July 2016, Chicago, Illinois,USA
Available from: 2016-09-06 Created: 2016-09-06 Last updated: 2018-03-13Bibliographically approved
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