The effects of vibration on explosive and reactive strength when applying individualized vibration frequencies

Abstract

The aim of this study was to assess the effects of 8 weeks of whole-body vibrations on explosive and reactive leg strength. Thirty-three physically active students took part in the study and were randomly assigned to an individualized-vibration group, a fixed-vibration group or a control group. The frequency of vibration was set to 30 Hz for the fixed-vibration group, whereas the frequency for the individualized-vibration group was determined by monitoring the participants' EMG_rms activity. The participants in the two vibration groups were exposed three times a week for 8 weeks to a series of 10 × 1-min whole-body vibrations with a 1-min pause between series of vibrations and a 4-min pause after the first five series of vibrations. Jump height in the squat jump increased significantly in all three groups (by 11% for the individualized-vibration group, p = 0.001; by 3% for the fixed-vibration group, p = 0.011; and by 2% for the control group, p = 0.006), but countermovement jump height was not affected. In continuous rebound jumps by the individualized-vibration group, jumping height increased by 22% (p = 0.006) and power increased by 18% (p = 0.002). The results of this study suggest that the use of an individualized vibration frequency produces a greater response from the neuromuscular system and is more beneficial than vibrations at a fixed pre-selected frequency.     

Peer Helpers in Hungary: A Qualitative Analysis

Hungary is a country in transition that has no real tradition of peer helping. A qualitative study was carried out involving 13 peer helpers of two kinds (a) age-based peers, and (b) way-of-life-based peers (fellow helpers). The motivations for and the processes of becoming a peer helper were analyzed. Results showed the largest difference being that the motivation for becoming an aged-based peer helper tended to involve aspirations for a professional helping career, whereas way-of-life-based peer helpers typically involved recovery narratives. The experiences suggest that a helping system involving civil society (peers) might develop from a state-controlled help system.