The Acute Effects of Whole Body Vibration on Isometric Mid-Thigh Pull Performance

W Guy Hornsby,Michael H Stone,Mark A South,G Gregory Haff,Hugh S Lamont,Jason D Stone

doi:10.3390/vibration3020008

Abstract

The purpose of the present investigation was to examine the acute effects of whole body vibration (WBV) on isometric mid-thigh pull force–time curve (FTC) characteristics. Eleven recreationally trained subjects were randomly assigned to three treatment conditions: sham no vibration protocol (T1), vibration protocol 30 Hz 2–4 mm amplitude (T2), and vibration protocol 30 Hz 2–4 mm (T3). After completing a standardized warm-up, the subject stood on a vibration platform with the knee at a 120° angle and performed one of the three interventions. Each treatment condition required the subject to stand on the platform for thirty-second treatments, each separated by thirty seconds of recovery. Five minutes after the completion of the treatment conditions, the subjects performed the isometric mid-thigh pull. All FTCs were analyzed with standardized procedures for peak force (PF) and peak rate of force development (PRFD). A 1 × 3 repeated measures analysis of variance (ANOVA) was used to compare the three treatments. Additionally, coefficients of variance (CV), as well as intraclass and interclass correlations, were performed. There were no significant differences (p > 0.05) for any of the FTC analyses performed in this investigation. The CV and the 95% confidence interval (CI) indicate that the WBV protocol resulted in trivial changes in PF and beneficial changes in PRFD. A 30 Hz 2–4 mm amplitude WBV does not result in a significant increase in isometric mid-thigh pull performance.

Highlights

The use of whole body vibration (WBV) as a method to enhance neuromuscular and strength-power performance has only recently begun to be explored by sport scientists [1,2,3,4,5,6,7]
Most studies have ascribed the observed improvements to the likelihood of WBV producing a “tonic vibration reflex” (TVR) in which a moderate level of force is produced, and maintained following an initial high phasic discharge from primary Ia muscle spindle afferents
Note: ICCα = intraclass correlation; 95% CI = 95% confidence interval; R = Pearson’s correlation; PRFD = peak rate of force development

Summary

Introduction

The use of whole body vibration (WBV) as a method to enhance neuromuscular and strength-power performance has only recently begun to be explored by sport scientists [1,2,3,4,5,6,7]. Acute exposure to WBV has been suggested to produce transient increases in force production [12,13,14], vertical jump displacement [1,7,13], and power output [7,12,15,16] recorded while performing various ballistic and non-ballistic tasks. Vibration 2020, 3 activation potentiation (PAP) [1,4,18] Such alterations have been suggested to reside in motor unit, recruitment, and synchronization, as well as increased sensory input resulting in improvements in force generation and enhanced proprioception [19]. The resultant motor response evoked is thought to result in the excitation of the alpha-motor neurons innervating extrafusal fibers [1]. This response may lead to a greater synchronization of motor units as a result of homonymous motor unit contraction [19,20]

Methods

Results

Conclusion