Understanding the linkage system of the upper extremity

The purpose of this article is to identify interrelationships within the body during pitching, tennis, and swimming. In the pitch the body's forces are relatively low during wind-up and early cocking. If the lower extremities and trunk exhibit appropriate mechanics here, the risk of injury to the upper extremity later is minimized. One reason for tennis elbow may be that the feet have not caught up with the body during the backhand. The body's mechanics are off and the power must be generated by the small wrist extensors. In the freestyle stroke the relationship within the scapular muscles is identified. The muscles must antagonistically work together to minimize the risk of injury. If one muscle doesn't function (such as the serratus anterior), other muscles attempt to substitute (such as the rhomboids) and pathology may ensue. These examples demonstrate the clinical need to understand the mechanics of sport as well as to evaluate the patient beyond the painful anatomic area.