Extrait

Whole Body Vibration (WBV) applies thrust force in opposite direction to gravity to body.This mechanical stimulation induces reflex muscular activity. Tonic vibration reflex (TVR) is most commonly cited mechanism to explain WBV-induced reflex muscular activity (WBV-IRMA), although there is no conclusive evidence that TVR occurs. The bone myoregulation reflex is another neurologic mechanism used to explain the effects of vibration on muscular performance. Investigators hypothesized that latency of WBV-IRMA is different from latency of TVR. Primary aim of this study is to determine latency of WBV-IRMA. Secondary aim is to investigate whether WBV-IRMA is explained with TVR. Twenty healthy young adult men are planned to include in this study. Participants will stand upright with their knees locked during WBV. PowerPlate Pro5 will be used for WBV. WBV with high amplitude at 25,30,35,40,45 and 50 Hz will be applied. Surface electrodes will be placed on both the soleus muscles. To measure TVR latency, piezo-electric accelerometer will be placed on the achilles tendon and this achilles tendon will be stimulated with spring based mechanical reflex hammer. Our pilot study was showed that motor unit potentials (MUAP) occurred in a 1:1 response with vibration. After confirmation of this finding, WBV-IRMA latency will be measured in the present study. To measure WBV-IRMA latency, piezo-electric force sensor will be placed between heel and WBV platform. Exact moment of initial strike of heel when thrust force expressed by WBV begin to be transferred to body will be determined. The time between moment of the initial strike and corresponding MUAP is defined as "WBV-IRMA latency". Piezo-electric stretch sensor will be placed between knee and malleol to simulate muscle spindle. The reflex muscle activity of soleus muscles will be measured by PowerLab (data acquisition system, ADInstruments, Australia) device. This project is planed to be completed in 1 months.

Critère d'inclusion

• Effects of vibration

Liens

• ictrp
• nct