The Shoulder = glenohumeral jt. The glenohumeral joint is a ball-and-socket joint that allows for the arm to move in a circular rotation as well as movement of the arm towards and away from the body. The motion that the glenohumeral joint provides is flexion, extension, abduction and adduction. .
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
In Anatomical Position, the head of the humerus is medial, slightly posterior and superior in the glenoid fossa.
While the glenoid cavity faces laterally forward and superior.
The AV joint is formed between the clavicle and the scapula. The acromion, a section of the scapula, is the binding site for the clavicle. These two bones fit together, but are not stable on their own. Ligaments & muscles are used to stabilize the AV joint.
Two sets of muscles are important for the stabilization of this joint in the proper joint formation. [ help stabilize the clavicle and the scapula]
1) the trapezius: The upper trapezius muscle fibers connects the lower base of the skull to the clavicle. The middle and lower trapezius muscle fibers connect vertebrae in the spine to the scapula.
2) the deltoid: The anterior deltoid connects the clavicle to the humerus, while the posterior and lateral deltoid fibers connect the scapula to the humerus.
they superiorly (upwardly) rotate the scapula.
an anatomical term given to the group of muscles & their tendons that act to stabilize the shoulder.
hold the head of the humerus in the small and shallow glenoid fossa of the scapula. During elevation of the arm, the rotator cuff compresses the glenohumeral joint in order to allow the large deltoid muscle to further elevate the arm. In other words, without the rotator cuff, the humeral head would ride up partially out of the glenoid fossa and the efficiency of the deltoid muscle would be much less.