The effects of active scapular protraction on the muscle activation and function of the upper extremity.

[Purpose] The purpose of this study was to determine the effects of adjusting the scapula into its ideal position through active scapular protraction on the muscle activation and function of the upper extremity. [Subjects] Twenty female college students aged 19-21 without any physical or functional disability were the subjects of this study. They had no history of injury to their upper extremities or hands. [Methods] After the initial measurements the experimental group was asked to perform active scapular protraction; then, their grip strength and muscle activation were measured again. Every action was maintained for 5 seconds and repeated 3 times. The mean values of the measurements were analyzed. A resting of 1 minute was given between each action. [Results] The results revealed a significant change in the experimental group's grip strength after active scapular protraction had been performed. The surrounding muscles of the scapula, such as the serratus anterior, upper trapezius, flexor carpi ulnaris, flexor carpi radialis and palmaris longus, showed significant changes in muscle activation after active scapular protraction. The muscles of the upper extremity also showed significant changes after active scapular protraction. [Conclusion] The adjustment of scapula into its ideal position through active scapular protraction increased the activations of the muscles surrounding the shoulder joint and improved the function of the upper extremity.