WBV Reflex Latency and Mechanical Load

This study investigates how the magnitude of mechanical loading alters reflex latency patterns during whole-body vibration (WBV), focusing specifically on the tonic vibration reflex (TVR) and the bone myoregulation reflex (BMR). Experimental data suggest that WBV may activate different reflex mechanisms depending on the level of postural loading, frequency, and amplitude of the vibration. Previous studies have shown that low-amplitude WBV tends to activate TVR under voluntary contraction, while higher mechanical loads and neutral standing posture are more likely to induce BMR.

Surface electromyography (sEMG) recordings will be obtained from the soleus muscle during vibration stimuli applied at different frequencies (30, 32, 34, and 36 Hz). Recordings will be taken under multiple loading conditions: standing on both feet, standing on one foot. Reflex latency will be calculated using cumulative averaging techniques, and data will be analyzed offline using Spike2 software.

Findings from this study may contribute to a deeper understanding of reflex integration during vibratory stimulation and inform future neurorehabilitation protocols that utilize WBV as a therapeutic modality.

Inclusion criteria

• Aged between 18 and 40 years
• Healthy adult volunteers with no known neurological or musculoskeletal disorders
• Able to provide informed consent
• Willing to comply with the procedures of the study, including EMG and vibration exposure

Exclusion criteria

• History of any neurological condition (e.g., peripheral neuropathy, spinal cord injury, stroke)
• Musculoskeletal injury or surgery involving the lower extremities
• Use of medications affecting neuromuscular function
• Pregnancy
• Presence of implanted electronic devices (e.g., pacemaker)
• Known intolerance to vibration exposure