Upper extremity muscles include muscles that connect the scapula to the thorax and support its motion, muscles that connect the humerus to the scapula and allow motion of the arm, and muscles situated in the arm or forearm that allow supports the motion of the forearm, wrist, and hand. Figure 1 shows the location of the different muscles found in the upper extremity. Rebounding in sports is defined as attempting to reach a ball after a missed shot. This is differentiated from simple raising of arms since it extends the shoulder reach of the player’s arm.
On the other hand, an overhead military press is an exercise intended for bodybuilding or powerlifting. In this exercise, the lifter in standing position tries to raise a barbell above his head and extending it upwards. Rebounding during a basketball game and doing an overhead military press are two compound movements that make use of the muscles in the upper extremity. These motions include medial rotation, abduction/adduction, and extension/flexion actions of the joints. In general, the two motions use the same basic actions of the upper extremity muscles.
The motions mentioned above are basic joint movements that are responsible for the rebounding and lifting motions. Medial rotation is the rotation of the joint towards the middle. This medial rotation action in the shoulder joints results to the lifting of the arm which is true for the two sample motions. This action is controlled by latissimus dorsi, subscapularis, teres and pectoralis major, and with the aid of the anterior fibers of deltoid muscle. Another joint movement is abduction. In this action, the arm is moved away from the body that is, raising the arms sideways.
This motion is initiated by suprastinatus muscle and maintained by the deltoid muscle located in the shoulder joints. The opposite of this action is called adduction which returns the arms back to the body’s sagittal plane. Pectoralis major and latissimus dorsi are the two muscles responsible for the adduction action and completed with the aid of teres major and subscapularis muscles. Another important action is the extension and flexion actions of the joints which completes the two motions mentioned above.
The arm is said to be extended when it straightens by extending the flexed elbow that is situated between the two points in the arm. This action is controlled by teres major, latissimus dorsi, and posterior deltoid fibers. Flexion, which is the opposite of extension, also called bending of the joint, is controlled by anterior fibers of deltoid coracobrachialis, pertoralis major, and biceps brachii (long head). These actions are present in both rebounding and overhead military press. The difference of the actions of the upper extremity muscles in each motion can be explained using basic experiences.
It is obvious to note that in a basketball rebound, the goal of the player is to reach the falling ball after a missed shot. In this case, the muscles are not subjected to a high amount of stress and it can freely move in any direction. In the lifting motion of the overhead military press, the goal of the lifter is to raise the barbell up and down to cause developments in the muscles (i. e. increase upper body strength) not just found in the upper extremity but as well as the whole body. Large amount of physical stress is experienced by the muscles in the upper extremity when dealing with lifting motion.
References
Muscles of the Upper Extremity. Retrieved April 7, 2007, from National Cancer Institute website http://training. seer. cancer. gov/module_anatomy/unit4_4_muscle_grp3_upper_extremity. html Quinn, E. (July 19, 2005). Barbell Military Press for Upper Body Strength. Retrieved April 8, 2007, from http://sportsmedicine. about. com/od/strengthtraining/a/militarypress. htm Upper Extremity Muscle Actions. Retrieved April 8, 2007, from http://www. meddean. luc. edu/Lumen/MedEd/GrossAnatomy/UE/UEActions. html