Age-Related Differences in the Acute Effects of Muscle Fatigue on Stability
Faculty Mentor
Kristyne Wiegand
Presentation Type
Oral Presentation
Start Date
5-7-2025 1:20 PM
End Date
5-7-2025 1:40 PM
Location
PUB 319
Primary Discipline of Presentation
Exercise Science
Abstract
Postural stability is necessary for maintaining body position, achieving coordination, and reducing fall risk. With advancing age, fall risk increases, due in part to a decreasing ability to maintain postural stability. Muscular fatigue, which results from activities of daily life or exercise, may further intensify instability and increase the risk of falls. Some research indicates older individuals develop muscular fatigue sooner than younger adults, but less is known about the differences in the time to recover stability. PURPOSE: To compare the acute effects of muscular fatigue on stability and time to recover stability between older and younger adults. METHODS: Participants from two age groups (n = 30; younger, 18-28 y; and older, 55-65 y) will be recruited. Twenty participants, 10 per group, have completed the study. Limits of Stability (LOS) testing and a fatiguing protocol, comprised of sit-to-stand to volitional fatigue, were performed. LOS tests were conducted at baseline and 0, 5, 10, 15, and 20 minutes after the fatiguing protocol. The variables of interest from LOS include reaction time (RT) and maximum excursion (MXE). The effects of age and recovery time on RT and MXE were analyzed with a 2 (group) by 6 (time) ANCOVA, with time to fatigue as a covariate (α = .05). RESULTS: Preliminary analysis indicates that after adjusting for time to fatigue for MXE, there was no significant group by time interaction (p = .11), and no main effect of time (p = .07) or group (p = .07). For RT there was no significant interaction (p= .71) or main effect of time (p = .34), but there was a significant group effect (p = .002), with younger participants exhibiting faster reaction times (0.45 ± 0.14 s) compared to older participants (0.53 ± 0.11 s) on average. CONCLUSION: Based on these early results, balance measures were not significantly affected by fatigue. However, given the low sample size currently, these results may differ as additional data are collected. Between groups, there was no difference in maximum excursion based on age, which indicates that both groups were effective in reaching their limits of stability. There was a significant difference in reaction times between groups, with younger participants having faster reaction times at all testing points. This is to be expected with changes in the neuromuscular system that occur with age.
Recommended Citation
Hatch, Katherine, "Age-Related Differences in the Acute Effects of Muscle Fatigue on Stability" (2025). 2025 Symposium. 13.
https://dc.ewu.edu/srcw_2025/op_2025/o2_2025/13
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Age-Related Differences in the Acute Effects of Muscle Fatigue on Stability
PUB 319
Postural stability is necessary for maintaining body position, achieving coordination, and reducing fall risk. With advancing age, fall risk increases, due in part to a decreasing ability to maintain postural stability. Muscular fatigue, which results from activities of daily life or exercise, may further intensify instability and increase the risk of falls. Some research indicates older individuals develop muscular fatigue sooner than younger adults, but less is known about the differences in the time to recover stability. PURPOSE: To compare the acute effects of muscular fatigue on stability and time to recover stability between older and younger adults. METHODS: Participants from two age groups (n = 30; younger, 18-28 y; and older, 55-65 y) will be recruited. Twenty participants, 10 per group, have completed the study. Limits of Stability (LOS) testing and a fatiguing protocol, comprised of sit-to-stand to volitional fatigue, were performed. LOS tests were conducted at baseline and 0, 5, 10, 15, and 20 minutes after the fatiguing protocol. The variables of interest from LOS include reaction time (RT) and maximum excursion (MXE). The effects of age and recovery time on RT and MXE were analyzed with a 2 (group) by 6 (time) ANCOVA, with time to fatigue as a covariate (α = .05). RESULTS: Preliminary analysis indicates that after adjusting for time to fatigue for MXE, there was no significant group by time interaction (p = .11), and no main effect of time (p = .07) or group (p = .07). For RT there was no significant interaction (p= .71) or main effect of time (p = .34), but there was a significant group effect (p = .002), with younger participants exhibiting faster reaction times (0.45 ± 0.14 s) compared to older participants (0.53 ± 0.11 s) on average. CONCLUSION: Based on these early results, balance measures were not significantly affected by fatigue. However, given the low sample size currently, these results may differ as additional data are collected. Between groups, there was no difference in maximum excursion based on age, which indicates that both groups were effective in reaching their limits of stability. There was a significant difference in reaction times between groups, with younger participants having faster reaction times at all testing points. This is to be expected with changes in the neuromuscular system that occur with age.
