JOINTS

p {margin: 0; padding: 0;} .ft00{font-size:16px;font-family:Arial;color:#cc0000;} .ft01{font-size:16px;font-family:ArialMT;color:#000000;} .ft02{font-size:16px;font-family:MS-PGothic;color:#37751c;} .ft03{font-size:16px;font-family:Arial;color:#37751c;} .ft04{font-size:16px;font-family:MS-PGothic;color:#000000;} .ft05{font-size:16px;font-family:Arial;color:#000000;} .ft06{font-size:16px;line-height:21px;font-family:ArialMT;color:#000000;} JOINTS The joints of the shoulder girdle are three in number (two joints interosseous and the slidingplane of the scapula against the thorax, usually considered as a fourth joint). ➢ Scapulohumeral The scapulohumeral joint is the most mobile of the three joints of the shoulder girdle, itincludes three degrees of freedom. The humeral head is approximately one third of asphere. It responds to a practically flat surface, the humeral glenoid. The stability of thissystem is ensured by the presence of a glenoid labrum, ligaments and the capsule, as wellas by the numerous muscles participating in the constitution of the cuff. ❉ Glenoid labrum It is a fibro-cartilaginous ring that surrounds the outer edge of the glenoid cavity. Itsphysiological role is to increase the joint surface and increase its depth. ❉ Ligaments They have two possible origins, the coracoid or the glenoid. We distinguish: - The coraco-humeral ligament is a fibrous lamina which connects the coracoid process tothe humeral processes (trochin and greater tuberosity). This ligament comes from fibrousregression of the external part of the pectoralis minor muscle. This very particulararrangement recalls the time when, still subject to quadrupedalism, our coracoid processwas only a vestige of our old coracoid bone, while our small pectoral muscle inserted directlyonto the humerus to participate in propulsion. of the animal. -The development of brachiation has recently transformed this arrangement by giving thecoracoid process a considerable development, very interesting on a mechanical level(distance from the point of support of the axis of force) and the pectoralis minor muscle arole of anterior stabilizer of the scapula. The coracohumeral ligament plays a suspensoryrole in the humeral head. - The coraco glenoid ligament joins the external edge of the coracoid process to the glenoidlabrum. Its origin would be identical to that of the glenohumeral ligament. - Theglenohumeral ligaments (upper, middle and lower). . The superior glenohumeral ligamentconnects the upper part of the glenoid labrum at the trochin on which it unites by a commonstructure with the coraco-humeral ligament. . The middle glenohumeral ligament attaches tothe labrum glenoid, to the part near the neck of the scapula, then moves outwards to inserton the lower part of the trochin. -The inferior glenohumeral ligament connects the lower part of the glenoid labrum (to thelower pole of the glenoid) to a region located at the lower end of the trochin. The essentialfunction of these three ligaments is to serve as a brake during external rotation andabduction movements