The power struggle: definition and evaluation of power of muscular performance

The authors define five different measurements of power of muscular performance. Using an isokinetic dynamometer, the velocity of motion is constant and thus can be controlled. Power, therefore, can be readily assessed. The speed of muscular contraction is of physiological and functional interest. The time it takes for muscles to develop force, the rate at which muscles can contract and sustain a force throughout the range of motion, and the relationship of speed to force are all facets of power. At least five terms which connote power of muscular performances are used today. These terms are power, peak power, average power, instantaneous power, and contractile power. The current misunderstanding of the terms and their misuses are discussed. Suggestions are offered for circumventing confusion in using power to describe motor performance.