Affiliations: [a] Department of Kinesiology and Physical Education, McGill University, Montréal, QC, Canada | [b] Occupational Biomechanics and Ergonomics Laboratory, Michael Feil and Ted Oberfeld/CRIR Research Centre, Jewish Rehabilitation Hospital, Laval, QC, Canada | [c] Département de Kinanthropologie, Université du Québec à Montréal, Montréal, QC, Canada | [d] Centre de Recherche Interdisciplinaire sur la Biologie, la Santé, la Société et L'environnement, Université du Québec à Montréal, Montréal, QC, Canada
Correspondence:
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Corresponding author: David M. Antle, Department of Kinesiology and Physical Education, McGill University, Montréal, QC, Canada. E-mail: [email protected]
Abstract: Background:Some proposed mechanisms for the development of back discomfort and musculoskeletal disorders relate to fatigue of trunk musculature, but these phenomena require further investigation. Hydrostatic pressure changes in vascular tissue are thought to drive development of lower limb discomfort and vascular disorders; however, specific vascular outcomes during standing work have not been investigated experimentally. Objectives:The goals of this experiment were to evaluate the effects of standing work on indicators of discomfort and on biological variables related to risk for trunk musculoskeletal andlower limb vascular disorders. Methods:Ten university-aged female volunteers, who did not work in jobs requiring prolonged standing, moved small objects between two containers for 32 minutes while standing. Electromyography from the erector spinae and rectus abdominis, lower limb blood flow data, brachial and ankle blood pressure, heart rate, and discomfort ratings were collected every 4 minutes. Results:There were no significant changes in electromyography outcomes for either muscle group. Foot and soleus blood flow (p < 0.05) and ankle blood pressure (p < 0.05) increased over time. There were strong correlations (> 0.8) between lower limb discomfort (feet and knees) and blood flow in the foot and soleus. Conclusions:Blood pooling may explain the discomfort associated with the simulated standing work evaluated here, and this vascular indicator should be tracked when attempting to alleviate lower limb symptoms in various working postures. Additional work is needed to determine which musculoskeletal indicators might explain back discomfort during standing.
