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Age-related neuromuscular function during drop jumps
M Hoffrén1, M Ishikawa, P V Komi
1Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, 40014 Jyväskylä, Finland. merja.hoffren@sport.jyu.fi
Journal of Applied Physiology (Bethesda, Md. : 1985)
|August 11, 2007
Summary
Elderly individuals exhibit distinct muscle activation patterns and mechanical behaviors during drop jumps, utilizing less tendinous tissue elasticity compared to younger adults. This impacts neuromuscular control and ankle joint stiffness.
Area of Science:
- Biomechanics
- Human Movement Science
- Gerontology
Background:
- Fascicle-tendon interaction is crucial for neuromuscular performance.
- Age-related changes in this interaction are not well understood, impacting neuromuscular control in the elderly.
Purpose of the Study:
- To investigate age-specific fascicle-tendon interactions of the gastrocnemius medialis (GM) muscle during drop jump (DJ) exercises.
- To understand how these interactions contribute to age-related differences in neuromuscular control.
Main Methods:
- Compared twelve young and thirteen elderly subjects performing squat jumps and DJs.
- Measured joint angles, force, electromyography (EMG), and GM fascicle length via ultrasonography.
- Analyzed ankle joint stiffness (AJS) and muscle activation patterns.
Main Results:
- Elderly subjects had significantly lower AJS and rebound speed compared to young subjects.
- AJS correlated positively with soleus EMG and GM activation in the elderly.
- Elderly subjects showed reduced GM activation in the braking phase and increased activation in the push-off phase, indicating less tendinous tissue elasticity utilization.
Conclusions:
- Age-specific muscle activation patterns and mechanical behaviors exist during drop jumps.
- Elderly individuals utilize tendinous tissue elasticity less effectively, affecting neuromuscular performance.
- Findings contribute to understanding age-related decline in neuromuscular control.
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