Shoulder Joint Anatomy

Shoulder Joint Anatomy Shoulder joint is a complex multi-dimension joint in the human body, also known as the “ball-and-socket”. The fact behind the label of this joint that it’s very mobile and it can be easily injured. For example, people can suffer instability of the glenohumeral joint by posture, sports, or normal due to aging. Shoulder joint has multiple bones, ligaments, tendons and muscles to maintain equilibrium. The bones are scapula, humerus, clavicle and sternum. Moreover, these bones have muscles to balance strength for the shoulder joint, which are: pectoris minor, biceps, S.I.T.S. (supraspinatus, infraspinatus, teres major and minor, and subscapularis). In addition, there is a bursa that is located between the humerus head and
Also known as the kinematic chain, an important role of balance of shoulder complex. Important terms to know in order to understand the biomechanics of muscles are primer, secondary, and stabilizers. Primary movers is a muscle that produces the main motion also known as an agonist. A secondary mover is defined as it sounds, which is a helper to produce a movement along with the agonist, called as an assistant. Stabilizers helps prevent injuries and forces to make a static or dynamic motion. For example, if you are going downward on a regular push up position, then the stabilizers are the back and abdominal muscles. Furthermore, your agonist muscles of this motion would be your biceps and scapular muscles. At the same time, your assistant muscles would be pectoralis minor and
However, “it may be difficult to find the location of instability, if there is no dislocation involved” ( Gerber & Ganz, 1984). Therefore, the place of dislocation can help find the primary source of location on the bone surfaces and weak muscles. There are signs and symptoms can de identify if a patient is suffering instability, which are “exclusively of pain in the affected shoulder or dead arm; indicates anterior instability” (Gerber & Ganz, 1984). A posterior instability can happen voluntary motion or a trauma event. In addition, it is possible that an inferior and anterior is part of the reason being a posterior instability. “The patient can either voluntary moves or complain on weakness and instability of a shoulder moving forward flexion and medial rotation” (Gerber & Ganz, 1984). Lastly, inferior instability helps determine that multiple-axial instability. Anterior and posterior instability are tested by having the patient on supine position and moves the arm horizontal adduction or abduction. In contrast, inferior instability test has a patient standing and examine the difference of shoulder height. Depending, shoulder instability is located will help determine which muscles need to improve in