Abstract Title

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

RAD Assignment Number

2407

Presenter Name

Trey Jeffers

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 < 0.05) after 6-minute bout of walking, while control subjects did not decline (pre = 1.85±0.2 m/s; post 1.80±0.2 m/s). Also, decreases in hip flexion velocity (8°/s) and hip range of motion after the walking exercise (pre-fatigue > post fatigue measurement, time effect, P < 0.05). (Rybar, MM. et al., 2014). In a similar study, individuals with stroke were fatigued using isometric hip flexion contraction. Paretic leg coefficient of variation (CV) was negatively correlated with comfortable walking speed (p < 0.05) indicating that slower walkers had greater fluctuations in motor output. In addition, there was an inverse relationship between the paretic leg mean CV and the Berg Balance Test score (p < 0.05) (Hyngstrom, AS. et al., 2012). In children with Cerebral Palsy, postural control deteriorated after walking on a pathway as shown by the significant increase in the path length of the center of pressure (COP) and the COP range in the anterior-posterior axis (P<0.05). The COP range and velocity in the medial-lateral axis also tended to be larger after fatigue (P< 0.08) (Hart, R, et al., 2014). Persons with PD were fatigued using eccentric muscle contractions of the quadriceps and hip extensors. Increases in ankle angular displacement in the support/landing limb during reproducible falls were found after fatiguing exercise (p=.02).

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.

Research Area

Rehabilitative Sciences

Presentation Type

Poster

This document is currently not available here.

Share

COinS
 

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

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 < 0.05) after 6-minute bout of walking, while control subjects did not decline (pre = 1.85±0.2 m/s; post 1.80±0.2 m/s). Also, decreases in hip flexion velocity (8°/s) and hip range of motion after the walking exercise (pre-fatigue > post fatigue measurement, time effect, P < 0.05). (Rybar, MM. et al., 2014). In a similar study, individuals with stroke were fatigued using isometric hip flexion contraction. Paretic leg coefficient of variation (CV) was negatively correlated with comfortable walking speed (p < 0.05) indicating that slower walkers had greater fluctuations in motor output. In addition, there was an inverse relationship between the paretic leg mean CV and the Berg Balance Test score (p < 0.05) (Hyngstrom, AS. et al., 2012). In children with Cerebral Palsy, postural control deteriorated after walking on a pathway as shown by the significant increase in the path length of the center of pressure (COP) and the COP range in the anterior-posterior axis (P<0.05). The COP range and velocity in the medial-lateral axis also tended to be larger after fatigue (P< 0.08) (Hart, R, et al., 2014). Persons with PD were fatigued using eccentric muscle contractions of the quadriceps and hip extensors. Increases in ankle angular displacement in the support/landing limb during reproducible falls were found after fatiguing exercise (p=.02).

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.