Post vibratory effects on fractionated reaction time and maximum isometric strength

Area of Science:

• Biomechanics
• Sports Science
• Neuromuscular Physiology

Background:

• Vibration therapy is increasingly explored for athletic performance enhancement and rehabilitation.
• Its effects on muscle strength and reaction time, particularly the components of premotor and motor time, require further investigation.

Purpose of the Study:

• To investigate the effects of 100 seconds of vibration on knee and ankle extension isometric strength and reaction time.
• To differentiate between premotor and motor time responses to vibration.
• To determine if initial strength levels influence the response to vibration.

Main Methods:

• Isometric strength and reaction time (fractionated into premotor and motor time) were measured in 10 low-strength distance runners and 9 high-strength power athletes.
• Measurements were taken before and after a 100-second vibration stimulus.
• Both unresisted and resisted conditions were assessed.

Main Results:

• No significant changes were observed in ankle or knee extension strength after vibration.
• Ankle extension reaction time components (premotor and motor) remained unaffected by vibration.
• A significant increase in unresisted knee extension motor time was noted post-vibration.
• The observed effects were consistent across both low-strength and high-strength athlete groups.

Conclusions:

• The post-vibratory period does not appear to offer significant therapeutic benefits for enhancing knee or ankle extension strength or reaction time.
• While vibration may alter specific neuromuscular parameters like knee extension motor time, its overall efficacy for immediate performance enhancement or therapeutic application is not supported by these findings.