Abstract

Balance impairment secondary to stroke is an important issue to consider since it significantly increases the risk of falling and can lead to pathological events. The purpose of this study was to determine the effects of physical exertion induced by walking on postural stability in hemiparetic stroke participants. Twelve hemiparetic participants and 12 control participants walked over-ground for a duration of 6 minutes and 18 minutes at their comfortable speed. The control participants walked at a speed that allowed them to maintain the heart rate of their hemiparetic counterpart. Postural stability was measured during double-legged stance, sit-to-stand, and step reaction time tasks before the walk, immediately after the walk, 15 minutes post-walk, and 30 minutes post-walk. Measures of physical exertion during walking were also obtained from cardiorespiratory parameters, time-distance parameters, and subjective scales. The results indicated that physical exertion measures significantly increased when the duration of walk was increased from 6 minutes to 18 minutes in both control and hemiparetic participants. For postural stability measures, increasing the duration of walking led to a significant increase (p<0.05) of postural sway in double-legged stance and sit-to-stand for the hemiparetic participants only. This effect on balance of hemiparetic participants was observed immediately after the end of the walk. In conclusion, this study demonstrated that physical exertion can increase postural sway in hemiparetic participants which could possibly lead to an increased risk of falling in these individuals.