Acute corticospinal and spinal modulation after whole body vibration

Area of Science:

• Neuroscience
• Exercise Physiology
• Rehabilitation

Background:

• Whole body vibration (WBV) is increasingly used in various settings, from sports training to rehabilitation.
• Understanding the neural mechanisms underlying WBV's effects is crucial for optimizing its application.
• Previous research has explored acute effects, but detailed analysis of corticospinal and spinal excitability is ongoing.

Purpose of the Study:

• To investigate the acute neural effects of whole body vibration (WBV) on lower limb muscles.
• To examine changes in corticospinal excitability using motor evoked potentials (MEPs).
• To assess spinal excitability through H-reflex measurements in the soleus (SOL) and gastrocnemius medialis (GM) muscles.

Main Methods:

• Forty-four healthy subjects (16 female, 28 male) participated in the study.
• MEPs and H-reflexes were recorded from SOL and GM muscles before and at multiple time points after WBV exposure.
• Measurements were taken immediately after WBV, and at 2, 4, and 10 minutes post-vibration.

Main Results:

• MEP amplitudes were significantly increased in the soleus (SOL) muscle post-WBV, indicating enhanced corticospinal excitability.
• No significant changes in MEP amplitudes were observed in the gastrocnemius medialis (GM) muscle.
• H-reflex amplitudes were significantly reduced in both SOL and GM muscles, suggesting spinal inhibition.

Conclusions:

• Acute WBV induces a temporary enhancement of corticospinal excitability.
• Concurrently, WBV leads to spinal inhibition in lower limb muscles.
• These findings suggest that WBV modulates the central nervous system, potentially emphasizing descending pathways over spinal contributions.