Occupational Ergonomics - Volume 12, issue 4

Authors: Braithwaite, Irene | Mackintosh, Stephen | Mallon, Anthony | Weatherall, Mark | Beasley, Richard

Article Type: Research Article

Abstract: BACKGROUND: Prolonged sitting causes lower limb venous stasis. OBJECTIVE: To assess the effect on lower limb venous blood flow of the floor-based dome device (Legflow® ) in healthy seated adults. METHODS: In a randomised controlled trial, 10 participants sat on an office chair. After 10 minutes, baseline popliteal vein flow was measured by ultrasound. One limb was randomised to be mobilised over the Legflow® device at 15 and 20 minutes while the other limb remained immobile. The primary outcome variable was the difference in peak systolic velocity (PSV) (cm/s), in the popliteal …vein between the Legflow® -mobilised and non-mobilised limb at 20 minutes, assessed by mixed linear model adjusted for baseline flow. RESULTS: Mean (SD) PSV (cm/s) in the Legflow® -mobilised limb was 5.82 (1.59), and 63.3 (21.6) at baseline, and 20 minutes respectively. Mean (SD) PSV (cm/s) in the immobile limb was 5.21 (1.45), and 4.58 (1.09) at baseline, and 20 minutes respectively. After 20 minutes, the difference in mean (SD) PSV was 58.8 (21.5) cm/s greater in the Legflow® -mobilised compared with immobile limb. The estimate (95% CI) of the true difference in PSV between the Legflow® -mobilised and immobile limb adjusted for baseline was 60.0 (44.6 to 75.3) cm/s, P< 0.001. CONCLUSIONS: Legflow® -mobilisation of the lower limb while seated increases popliteal venous flow. Show more

Keywords: Venous stasis, prolonged sitting, deep vein thrombosis, prevention, venous haemodynamics

DOI: 10.3233/OER-150231

Citation: Occupational Ergonomics, vol. 12, no. 4, pp. 131-140, 2015

Authors: Costa, Nicole | de Vries, Linda | Dahlman, Joakim | MacKinnon, Scott

Article Type: Research Article

Abstract: BACKGROUND: The more complex and perilous a sociotechnical system is, the more crucial it is to have users and other relevant stakeholder groups in focus throughout its design lifecycle. In the design and development of ships and ship systems, there has been resistance towards the integration of ergonomic principles through a human-centred approach as well as to involving the user. This inattention can result in an inadequate design, which may have negative repercussions on usability, ultimately threatening the safety of onboard operations, overall system performance and the well-being of the crew. OBJECTIVE: This study explores the …perceived success factors of participatory ergonomics based on the standpoint of young seafarers. METHODS: Such is achieved by examining a focus group with cadets inspired by Grounded Theory approach. RESULTS: The findings reveal user participation as a designer's essential contact with reality, provided that a set of pre-conditions that supports the success of participatory ergonomics can be fulfilled: involving the right users and filling in the gap between end-user needs and ship-owner requirements. The consequent success factors are described at a usability level, an intrinsic level for the end-users, and ultimately at the level of increased safety and efficiency. CONCLUSIONS: User input may not only affect design as an outcome, it may also influence the way participatory ergonomics is performed in the maritime sector. Show more

Keywords: User involvement, the human element, human factors, maritime

DOI: 10.3233/OER-150230

Citation: Occupational Ergonomics, vol. 12, no. 4, pp. 141-150, 2015

Authors: Drew, Kelsey E. | Kozey, John W. | Moreside, Janice M.

Article Type: Research Article

Abstract: BACKGROUND: Slide sheets (SS) are friction-reducing devices used during patient-handling tasks. A modified SS position (modSS), with the slider placed beneath the regular bedsheet, may decrease a caregiver's workload and reduce low back injuries, as the SS could remain in place for longer periods of time, thus reducing patient re-positioning frequency. OBJECTIVE: To investigate the efficacy of modSS use on back muscle activity, pulling force, and perceived effort during lateral patient-handling tasks, and determine whether lumbar electromyography (EMG) correlates with perceived effort (RPE) during such tasks. METHODS: Ten females completed 9 lateral patient-handling …tasks with 3 simulated patients (45 kg, 68 kg and 91 kg) and 3 SS conditions (absent, normal, modSS). Outcomes included peak pulling force, back muscle EMG, RPE and subjective reports of low-back discomfort and preference. RESULTS: ModSS use was as effective as or better than normal SS use at reducing back muscle EMG, pulling force, RPE and perceived discomfort in all 9 conditions, when compared to no SS (p< 0.05). The relationship between RPE and EMG was moderately strong (r= 0.75). CONCLUSION: ModSS use may reduce caregiver injury rates, as it reduces biomechanical and perceived demands associated with lateral patient-handling tasks at least as well as normal SS use, if not better. Show more

Keywords: Lumbar spine, injury, nursing, patient handling, patient care, slide sheet, electromyography

DOI: 10.3233/OER-160233

Citation: Occupational Ergonomics, vol. 12, no. 4, pp. 151-163, 2015

Authors: Sengupta, Arijit K. | Jiang, Xiaopeng

Article Type: Research Article

Abstract: BACKGROUND: The relaxing effect of music has been shown to reduce stress induced subjective anxiety and improve the performance of stressful cognitive tasks. OBJECTIVE: This experimental study evaluated the effect of music and induced mental load in a word processing task in terms of correct strokes and accuracy, typing force, variability of typing force and EMG (electromyography) of extensor digitorum muscle. METHODS: Eight subjects participated in the study. A 2 × 2 repeated measure design was adopted, with or without background music, and with or without induced mental load. A computer algorithm detected …the shift, drift and fidget patterns of finger and hand movements, which caused the variation of the typing force. RESULTS: Although the overall typing productivity was compromised by music by 3.1%, the beneficial effect of music was the reduction of standard deviation of typing force by 23.2%, indicating a smoother or less erratic hand movement during typing. CONCLUSIONS: The behavior change by music resulted in reduction in hand motions during typing may reduce the risk of musculoskeletal disorder related to typing task. Show more

Keywords: Keyboard, force variability, EMG

DOI: 10.3233/OER-150232

Citation: Occupational Ergonomics, vol. 12, no. 4, pp. 165-177, 2015

Authors: Johnston, Heather | Dewis, Colleen | Kozey, John

Article Type: Research Article

Abstract: BACKGROUND: Reach envelope used in the design and layout of workstation is important for decreasing fatigue and injury by improving productivity, health, and safety. OBJECTIVES: The objective of this investigation was to determine differences between maximum reach envelope with and without a load in a seated position. METHODS: Measurements were conducted using a computerized potentiometric system for anthropometric measures (CPSAM). Participants performed six trials of each three load conditions of 0 Kg, 0.5 Kg and 1.0 Kg. RESULTS: Cylindrical coordinates (r, θ , Z) were determined in panels of …Z-level by θ angle in relation to each participant's acromion. Mean and median reach values were computed for each panel to create the envelope. The reach envelope for the load conditions was smaller than the control (0 Kg). There was no significant difference between the two load conditions. CONCLUSIONS: The decrease in reach envelope when a load is added suggests that load is a factor affecting reach and should be considered when designing a workspace. Layouts requiring hand-held items such as tools or protective equipment may require considerations of a decreased reach. At what specific load level reach is affected should be further investigated. Show more

Keywords: Maximum reach envelope, seated reach, shoulder, hand-held load

DOI: 10.3233/OER-160234

Citation: Occupational Ergonomics, vol. 12, no. 4, pp. 179-187, 2015

Article Type: Other

Citation: Occupational Ergonomics, vol. 12, no. 4, pp. 189-191, 2015

Article Type: Other

Citation: Occupational Ergonomics, vol. 12, no. 4, pp. 193-, 2015