International Journal of Physiotherapy and Rehabilitation, October 2010, Vol. 1, Issue 1, 30-40

Acute Effects of Whole Body Vibration on Rate of Force Development and Electromechanical Delay.

Junggi Hong Assistant Professor, Department of Exercise Science, Willamette University.  K. Kipp, Dept of PM&R University of Michigan. S.T. Johnson & M.A. Hoffman University of Oregon State

ABSTRACT

Background: The ability to generate rapid and powerful muscle contractions within a short period of time is an important factor for both enhancing sports performance and preventing injuries. Recently, whole-body vibration (WBV) has been introduced as a novel training method designed to produce neuromuscular improvement similar to that of power and strength training. However, to date there are only limited data on the acute effects of WBV on the neuromuscular system. Furthermore, there is little understanding about the responsiveness of the neuromuscular system to acute exposure WBV.

Research question: The present study examined the effect of acute WBV training on the rate of force development (RFD) and electromechanical delay (EMD) in the soleus muscle.

Type of study: Randomized controlled study.

Methods: Forty young individuals with no leg injuries were randomly assigned to an experimental or control group. The experimental group received acute WBV (3 bouts of 2 minutes). The control group adopted the same position (squat position) on the vibration platform for an equal time but received no vibration.

Results: The experimental (WBV) group demonstrated a significant group °— time interaction for the rate of force development (RFD) and electromechanical delay (EMD) representing 15.6% (from 274Nm/sec to 323 Nm/sec) and 16% (from 23.42 ms to 19.3 ms) improvement.

Conclusions: It appears that acute WBV enhances RFD and EMD of the soleus musclin young healthy subjects.

KEY WORDS: Whole body vibration, Neurological adaptation, Rate of force development, Electromechanical delay, EMG