MUSCLES OF SHOULDER 



19 



The capsule is very loose, so that were it not for atmospheric 

 pressure the humerus could be pulled at least an inch away 

 from the scapula ; this adds to the mobility of the joint. 



Glenoid ligament,, a band of circular fibres round the edge of 

 the glenoid fossa to deepen the socket.* 



Transverse humeral ligament bridges over the bicipital groove 

 and allows the tendon of the biceps to pass under it. 



C Draco-humeral ligament between the root of the coracoid 

 process and the upper surface of the head of the humerus. 



Gleno-humeral ligaments, three in number, from the anterior 

 edge of the glenoid fossa to the anterior surface of the head of 

 the humerus. 



All these ligaments are in reality part of the capsule. 



Accessory Ligaments : Coraco-acromial ligament, a strong band 

 of fibres passing between the coracoid and acromion processes. 

 This arches over the top of the joint and prevents dislocation 

 upwards. 



The tendons of subscapularis, supra- and infra-spmatus are 

 closely applied to the capsule of the joint as they near their 

 insertions, so strengthening it; but it will be noticed that the 

 joint is weak inf eriorly, having no strengthening ligaments in 

 that aspect. 



The tendon of the biceps from the edge of the glenoid fossa ! 

 passes through the joint over the head of the humerus, emerging 

 from under the transverse ligament. 



The synovia! membrane is Very extensive, lining all the joint, j 

 and is prolonged down on the tendon of the biceps. 



MUSCLES ACTJING ON THE JOINT. 



