Modifications occurring in motor programs during learning of a complex task in man

This study was designed to investigate the modifications due to learning occurring in the motor program controlling a maximum speed arm adduction/forearm flexion movement. Twenty male subjects participated in 8 training sessions involving a total of 800 repetitions of the bi-articular movement. Significant improvements in arm adduction and forearm flexion speed as well as in posterior deltoid and triceps brachii latencies attributable to learning were found. Pectoralis major and biceps brachii motor times and posterior deltoid and triceps brachii activity times were not affected by training. The results support the hypothesis that a pre-established motor program exists in the cerebellum for bi-articular movements and that subroutines within this program control the agonist-antagonist coupling within each joint.