Effects of Muscle Fatigue on Postural Control in Neurologically-Impaired Populations

Abstract

Purpose: Research has shown that acute muscle fatigue alters postural control in neurologically healthy young and older individuals, but there is little research on the effects of muscle fatigue on neurologically impaired individuals. The purpose of this literature review was to examine the effects of short-term muscle fatigue on postural control as it relates to neurologically impaired populations. We hypothesized that muscle fatigue would cause declines in postural control in persons with neurological impairment such as stroke, Parkinson’s disease (PD), and Cerebral palsy. Subjects: N/A Methods: A literature review using the key words “muscle fatigue” and “postural control” was performed in PubMed and PTNow. Twenty titles and abstracts were reviewed in order to exclude subjects without neurologic disease. After checking the available abstracts four full text articles were evaluated. Data Analysis: N/A Results: 4 articles were included aimed at the effects of muscle fatigue on postural control in neurologically-impaired persons. Individuals with stroke showed a statistically significant decline in maximum walking speed (pre = 0.97±0.5 m/s; post = 0.71±.4 m/s, P post fatigue measurement, time effect, P Conclusions: The results of this study indicate that persons with neurological impairments are negatively affected by muscle fatigue. Similar effects have been found in neurologically healthy adults. Individuals with stroke showed declines in maximum walking speeds and hip flexion velocity and range of motion compared to their healthy counterparts after fatiguing exercise. There was a correlation between walking speed and paretic leg variability; slower walkers had greater fluctuations in motor output. Children with Cerebral palsy displayed a deterioration in postural control after fatigue, demonstrated by the increase in path length and range of the COP. Muscle fatigue had a minor effect on lower extremity joint kinematics in persons with PD. Clinical Relevance: Acute bouts of muscle fatigue have negative consequences on gait and postural control in individuals with neurologic disease. Physical therapists should be aware of the potential for decreased postural control following acute bouts of intense exercise in clinical care settings.