Acute Effects of a Brisk Walk on Muscle Function and Balance in Females
Abstract (300 words maximum)
BACKGROUND: Research examining fatigue typically employs exercise that is strenuous or specific to an isolated joint. Muscle function and balance responses to activity resembling acts of daily living represent a more prevalent issue for non-exercising individuals. Rate of torque development (RTD), how quickly muscle force is generated, is more sensitive than peak torque (maximal strength) to fatigue, so modest fatigue from a brisk walk might cause meaningful decrements. PURPOSE: The purpose of our ongoing study is to identify differences in muscle function and dynamic balance between young and middle-aged females. Here, we report on preliminary findings with no age-related comparisons. METHODS: Thirteen untrained females (28.7±15.1 yrs) completed a testing visit 3-7 days after a familiarization visit. Subjects performed balance and muscle function testing before and up to 10.5 min following a 6-min walking task. Instructions for the 6-min walk were to “cover as much distance as possible”. The Biodex Balance system captured overall postural instability and an index in the sagittal and frontal plane. Muscle function testing consisted of rapid maximal voluntary isometric contractions of the plantar flexors. Peak torque, and RTD at early (0-50 ms) and late (0-200 ms) time intervals were recorded from the torque-time curve. One-way ANOVAs with Bonferroni corrected post hoc comparisons were used to assess changes across time. RESULTS: Overall postural instability increased 2 min after the 6-min walking task indicating poorer balance. PT and RTD remained unchanged after the walking task (p > 0.05), though some large effect sizes were notable for the latter. CONCLUSIONS: Our findings indicate that balance was negatively affected after a 6-min brisk walking in young females. We expect middle-aged females to demonstrate greater fatigability than young females, thus increased fall risk. We plan to incorporate age-related comparisons in our future analysis to test this hypothesis.
Academic department under which the project should be listed
WCHHS - Exercise Science and Sport Management
Primary Investigator (PI) Name
Garrett Hester
Acute Effects of a Brisk Walk on Muscle Function and Balance in Females
BACKGROUND: Research examining fatigue typically employs exercise that is strenuous or specific to an isolated joint. Muscle function and balance responses to activity resembling acts of daily living represent a more prevalent issue for non-exercising individuals. Rate of torque development (RTD), how quickly muscle force is generated, is more sensitive than peak torque (maximal strength) to fatigue, so modest fatigue from a brisk walk might cause meaningful decrements. PURPOSE: The purpose of our ongoing study is to identify differences in muscle function and dynamic balance between young and middle-aged females. Here, we report on preliminary findings with no age-related comparisons. METHODS: Thirteen untrained females (28.7±15.1 yrs) completed a testing visit 3-7 days after a familiarization visit. Subjects performed balance and muscle function testing before and up to 10.5 min following a 6-min walking task. Instructions for the 6-min walk were to “cover as much distance as possible”. The Biodex Balance system captured overall postural instability and an index in the sagittal and frontal plane. Muscle function testing consisted of rapid maximal voluntary isometric contractions of the plantar flexors. Peak torque, and RTD at early (0-50 ms) and late (0-200 ms) time intervals were recorded from the torque-time curve. One-way ANOVAs with Bonferroni corrected post hoc comparisons were used to assess changes across time. RESULTS: Overall postural instability increased 2 min after the 6-min walking task indicating poorer balance. PT and RTD remained unchanged after the walking task (p > 0.05), though some large effect sizes were notable for the latter. CONCLUSIONS: Our findings indicate that balance was negatively affected after a 6-min brisk walking in young females. We expect middle-aged females to demonstrate greater fatigability than young females, thus increased fall risk. We plan to incorporate age-related comparisons in our future analysis to test this hypothesis.