Physical Therapy in Sport, 2003; 5/1: 37-43

Gravitational forces and whole body vibration: implications for prescription of vibratory stimulation

Year: 2003

Crewther B, Cronin J, Keogh J
Division of Sport and Recreation, Sport Performance Research Centre, Auckland University of Technology, Private Bag 92006, Auckland 1020, New Zealand

Abstract

The purpose of this study was to determine the gravitational forces (g-forces) associated with different postures (standing single leg, standing double leg, semi-squat), amplitudes (1.25, 3.0, 5.25 mm), frequencies (10, 20, 30 Hz) and at different anatomical sites (tibial tuberosity, greater trochanter, jaw). Twenty-three subjects underwent whole body vibratory stimulation on a teetering platform that oscillated about a sagittal shaft (Galileo™ 2000). The analysis involved collapsing all the data into four categories (frequency, amplitude, posture, damping) and investigating the g-forces within each category. The 20 Hz frequencies resulted in significantly greater g-forces (2.05g) than 10 and 30 Hz (1.83 and 1.76g, respectively). As amplitude increased so to did the g-forces (1.25 mm, 1.6g; 3.0 mm, 1.85g; 5.25 mm, 2.2g; P<0.05). G-forces associated with the semi-squat (2.34g) were significantly greater (P<0.001) than the standing postures. Significant damping was observed as the vibratory stimulation was transmitted to the proximal segments (tibial tuberosity, 3.91g; greater trochanter, 1.26g and jaw, 0.34g). Findings were discussed in terms of safe, progressive and effective prescription of vibratory stimulation.

Keywords: Galileo Acceleration
GID: 337; Last update: 03.12.2007