• The chronic and acute effects of whole body vibration training

      Ross Cloak (2016-02)
      Whole body vibration training (WBVT) has gained a lot of interest for its proposed benefits across a range of populations both active and injured. The purpose of the present thesis was to test the efficacy of WBVT in terms of injury rehabilitation and performance enhancement amongst professional and amateur athletes. The five papers submitted for the degree of PhD by publication are grouped into two key themes relevant to the development of knowledge and evidence to advance a better understanding of the chronic and acute effects of WBVT. The themes encompass the efficacy of WBVT (Chronic) as a rehabilitation tool and as an addition to a warm-up routine (acute). The explanatory narrative provides a brief background to WBVT, a summary of each paper and what the paper has contributed to the field both in terms of knowledge and methodological development. The papers presented provide evidence that chronic WBVT is an effective method of improving balance and stability in athletes suffering functional ankle instability (FAI) (Paper 1). Even when compared to traditional methods of rehabilitation for FAI, the addition of WBVT enhances the benefits of traditional rehabilitation protocols (Paper 2). The use of acute WBVT enhances reactive strength, again showing a significant benefit as an addition to a more traditional warm-up (FIFA 11+) amongst amateur soccer players (Paper 3). When training status was considered (amateur vs. professional), high frequency acute WBVT stimulus significantly improved landing stability (DPSI) amongst professional players only (Paper 4). These differences between groups were also identified when examining knee extensor potentiation and force output with significant improvements amongst professional but not amateur soccer players. Professional players also reported significantly greater beliefs in the effectiveness of WBVT (Paper 5). In conclusion the body of work presented discusses the practical and methodological implications of the new knowledge presented and identifies a series of future lines of research.
    • The effect of vibration training on balance and muscular performance within functionally unstable ankle populations

      Wyon, Matthew A.; Cloak, Ross James (University of Wolverhampton, 2011)
      Ankle injuries are one of the most common injuries in sport, often leading to functional deficits and instability, a vicious cycle of recurrent sprains and time loss due to injury. Although research has been conducted on the best methods of treating such deficits and instability, new training methodologies are continually being sought to help improve clinical outcomes and with this comes a need for designed research to test such hypotheses. The purpose of the present research was to investigate the effect of vibration training on balance and muscle function in physically active individuals suffering self reported functional ankle instability (FAI). Stage one of the research was to initially investigate the effect of a six week whole body vibration training (WBVT) exercise routine on 38 University dancers reporting FAI. An initial assessment of the severity of the instability was done using the Cumberland Ankle Instability Tool (CAIT), to identify those who classed themselves functionally unstable but still able to participate in their chosen sport. The group was randomly arranged into one of two groups (treatment and control) and a pre/post test study was undertaken, with the control group asked to continue normal activity. The selection of participants was based on instability score from the CAIT. A larger sample of athletes was initially recruited across two accessible sports of football and dance due to access and availability. These groups then completed CAIT and where included if scoring criteria were met. The treatment group undertook six weeks of progressive vibration training on a stabile vibration system. Pre and post testing consisted of measures of static single leg balance, a Star Excursion Balance Test (SEBT) and Electromyography (EMG) of peroneus longus in demi-pointe. Results indicated a significant improvement in static balance (p = .04) and certain SEBT directions within the treatment group compared to the control group (p <.05). Neither group reported any significant difference in mean power frequency for the peroneus longus (p >.05). The results of the study suggested six weeks vibration training improved certain balance parameters within FAI populations. These results although initially encouraging, identified the need for further research with not just a direct comparison between treatment and control, but a closer examination of the effect of vibration training in comparison to more classical methods of rehabilitation before it can be recommended as a serious methods of treatment for FAI. The second stage of the research involved the implementation of a new piece of rehabilitation equipment which combined a vibration unit within a wobble board (Vibrosphere TM, Sweden). The manufactures claim the combination of the two principles accelerates rehabilitation for numerous lower body injuries and disorders. This specially designed unit allowed direct analysis of the effect of the vibration component of the unit on balance and muscle function, by comparing those who used the combined vibration/wobble board and those who simply used the wobble board alone. A control group was also included to analyse any difference over time as the testing was done during a pre-season training cycle. The research consisted of 33 semi-professional footballers reporting FAI as confirmed by CAIT and taler tilt and an anterior drawer test, being randomly assigned to one of three groups; Vibration/wobble board, Wobble board alone and Control. Both Vibration/wobble board and Wobble board alone completed identical exercises on identical equipment so results could not be attributed to different equipment. The results of the study suggest a significant difference in static balance; modified SEBT and Single leg triple hop for distance between groups with the greatest improvement being within the combined vibration/wobble board group (p <.05). The results suggest the combination of vibration and wobble board improve balance and functional strength in those footballers reporting FAI compared to wobble board training alone. The precise mechanisms behind the current results are unclear. It has been suggested that it may be due to vibration having a positive effect on the stimulation of mechanoreceptors and the combination of that and unstable surface control seems to be optimal. It is difficult to compare studies but the research has highlighted certain areas for further research. The difference in static balance and SEBT scores between the dancers and footballers seems to suggest that the CAIT scores although similar may identify the need for more specific tests for each population. Also a longitudinal study is required to access injury rates following intervention and effect duration of the improvements seen.