Does whole-body vibration acutely improve power performance via increased short latency stretch reflex response?

Abstract Objectives It remains unclear whether an increased intrafusal mechanical sensitivity is related to the vibration-induced performance improvement. This investigation aimed to determine the residual acute effect of whole-body vibration and its duration on pre-activation levels, short-latency stretch reflex and performance during drop jumps. Design Repeated measures. Methods Eleven amateur athletes performed a set of three 45 cm-drop jumps before and during a 20 min-interval following three randomized conditions: No, Low (30 Hz, 5 mm) and High vibration (45 Hz, 5 mm). Ground reaction force peak, Soleus and Vastus Lateralis short latency stretch reflex onset and amplitude were assessed during drop jumps. Results A significant effect for time revealed an immediate drop jump height increase after High vibration. A longer contact time also followed High vibration while no changes were detected after Low vibration. Vibration did not affect ground reaction force peak and short latency stretch reflex component. Conclusions High vibration constituted an intervention for improving performance although there was no evidence of increased stretch reflex responses.