Effectiveness of cycloid vibration therapy for promoting exercise recovery

INTERVENTION: Muscle damage will be induced by performing 100 maximal voluntary eccentric isokinetic contractions of the knee extensors of the right leg at 45°/sec through an 80° range of motion. The cycloidal vibration therapy treatment will involve the participant placing a therapy cushion under their right thigh while in a seated position with their legs hanging at approximately 90° which will vibrate their upper leg. Participants will undergo 15 min of treatment immediately after the post‐exercise assessments are completed, and then twice daily for 20 min for seven days. CONDITION: delayed onset muscle soreness PRIMARY OUTCOME: Recovery of muscle force generating capacity. Maximal isometric knee extensor strength will then be assessed as the best of 3 maximal contractions with the knee flexed to an angle of 90 degrees on an isokinetic dynamometer (Biodex System 4, Chattanooga Group, USA). SECONDARY OUTCOME: Alleviation of muscle pain. Muscle soreness will be evaluated using a visual analogue scale (VAS). The VAS will consist of a 100 mm horizontal line with anchor points consisting of 'no soreness' on the left to the 'worst soreness possible' on the right hand end. Participants will be seated and requested to extend the knee of the right leg (so the leg is horizontal) while a 5 kg mass is suspended from the ankle. The participants will place a mark at the point on the VAS corresponding to their perception of the soreness in the quadricep muscles of the leg. The extent of the muscle soreness will be quantified using the measured distance (in mm) from the left hand end of the continuum to the mark made by the participant. Change in markers of muscle damage and inflammation. Serum creatine kinase and myoglobin will be measured as markers of muscle damage using standard commercial assays. Serum C‐reactive protein concentrations will be measured as a marker of inflammation using a commercial autoanalyser (Konelab 20 XTi, Thermo Electron Corporation). Change in muscle edema (measured by thigh circumference). Thigh circumference will be measured at the level of the mid‐trochanterion‐tibiale laterale site. The mean of three measures will be determined at each point. INCLUSION CRITERIA: sedentary (i.e. participate in regular physical activity no more than once per week for the purpose of improving or maintaining their physical fitness)