Article

Standing work is associated with discomfort and symptoms in the trunk and lower
limb. However, mechanisms underlying these observations are poorly understood.
Moreover, most research on standing-related symptoms has focused on only one
region (lower limb or trunk), and has not considered the impact and interactions
between vascular, muscular and balance outcomes. We measured foot and soleus
blood flow, ankle mean arterial pressure, muscle activity of the plantar and
dorsi flexors, gluteus medius and trunk flexors and extensors, center of pressure
changes and leg and back discomfort in 18 healthy volunteers performing a
repetitive box-folding task for 34 min. Results show significant decreases with
time in lower limb muscle activity (p<0.00053), and increases in foot blood flow
and center-of-pressure mediolateral sway amplitude (p=0.00066). There were
significant time effects on back (p=0.017) and lower limb (p<0.000001)
discomfort, the latter significantly correlated (r=0.35) to time-related
increases in foot blood volume. No changes were correlated to the increase in
back discomfort. Results suggest that the origin of standing-related lower limb
discomfort is likely vascular in origin, whereas back discomfort is likely
multifactorial, involving muscular, vascular and postural control variables.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS