Abstract
The evaluation of the ability to exert force instantly (the rate of force development) has been little examined. This study aimed to examine the reliability and output properties of single (Experiment 1) and repeated (Experiment 2) muscle power values exerted from ballistic elbow flexion using simple multi-muscle power measurement device with a rotary encoder.
In single muscle power measurement in Experiment 1, thirty young adult males pulled a submaximal load mass (25% MVC) by only concentric contraction as quickly as possible. The muscle power was drawn from the product of pulling velocity and load mass. The reproducibility of a time series output pattern in single muscle power exertion was high, and the intraclass correlation between measurement values was very high (ICC = 0.89). Although time to peak velocity showed an individual variation (a range of 0.25-0.35 sec) after concentric contraction, time to peak acceleration was about 0.1 sec (0.12 ± 0.02 sec) for most subjects.
In repeated muscle power measurement in Experiment 2, another 10 males and 10 females repeatedly pulled, at a stretch relative loads (30%, 40% and 50% MVC) 30 times every two seconds for one minute by ballistic elbow flexion. The reproducibility of exertion patterns was very high (r = 0.86-0.98) at 40% MVC and 50% MVC in both genders. Also, peak velocity of any time point in the both of the above % MVC was higher in males than females. A gender difference in a decline tendency of muscle power values was found, and the decrease rate of 50% MVC in males was especially large.
In summary, reliability of measurements in single and repeated muscle power values is high, and it was judged that different muscle power from an isokinetic dynamometer is measured by the muscle measurement device using weight loading method.
