Electromyographic analysis of the intermittent modifications occurring during the acquisition of a novel throwing skill

Recently, several authors have published evidence that muscle action potentials are modified during the acquisition of a novel motor skill. Most agree that practice results in an improvement in the coordination or the timing of muscle response (Finley, Wirta, and Cody, 1968; Hobart, 1972; Kamon and Gormley, 1968; Payton and Kelley, 1972; Person, 1958). The changes in the integrated electrical activity attributable to practice have been investigated by several authors, with each producing different results. Brush (1966) found no changes attributable to practice; Finley et al. (1968) found an increase; and Payton and Kelley (1972) found a decline in the integrated electrical activity of one muscle and no change in another. Finley and Wirta (1967), supported by Hobart (1972), suggested that a shift in the electrical activity of the muscles may occur because of practice. Some muscles increase their activity, others decrease, each contributing to a smoother performance of the task.