Internal rotation (rotation towards the midline, so that the thumb is pointing medially) – subscapularis, pectoralis major, latissimus dorsi, teres major and anterior deltoid.Adduction (upper limb towards midline in coronal plane) – pectoralis major, latissimus dorsi and teres major.Past 90 degrees, the scapula needs to be rotated to achieve abduction – that is carried out by the trapezius and serratus anterior.The middle fibres of the deltoid are responsible for the next 15-90 degrees.The first 0-15 degrees of abduction is produced by the supraspinatus.Abduction (upper limb away from midline in coronal plane):.Biceps brachii weakly assists in forward flexion. Flexion (upper limb forwards in sagittal plane) – pectoralis major, anterior deltoid and coracobrachialis.Extension (upper limb backwards in sagittal plane) – posterior deltoid, latissimus dorsi and teres major.This structure overlies the shoulder joint, preventing superior displacement of the humeral head.Īs a ball and socket synovial joint, there is a wide range of movement permitted: Running between the acromion and coracoid process of the scapula it forms the coraco-acromial arch. The other major ligament is the coracoacromial ligament. In severe ACJ injury, the coraco-clavicular ligaments may require surgical repair. after a high energy fall) can rupture these ligaments as part of an acromio-clavicular joint (ACJ) injury. They have significant strength but large forces (e.g. They work alongside the acromioclavicular ligament to maintain the alignment of the clavicle in relation to the scapula. Coraco– clavicular ligament – composed of the trapezoid and conoid ligaments and runs from the clavicle to the coracoid process of the scapula.It holds the tendon of the long head of the biceps in the intertubercular groove.] Transverse humeral ligament – spans the distance between the two tubercles of the humerus.It supports the superior part of the joint capsule. Coracohumeral ligament – attaches the base of the coracoid process to the greater tubercle of the humerus.They act to stabilise the anterior aspect of the joint. They are the main source of stability for the shoulder, holding it in place and preventing it from dislocating anteriorly. Glenohumeral ligaments (superior, middle and inferior) – the joint capsule is formed by this group of ligaments connecting the humerus to the glenoid fossa.In the shoulder joint, the ligaments play a key role in stabilising the bony structures. There are other minor bursae present between the tendons of the muscles around the joint, but this is beyond the scope of this article.įig 2 – The major bursae of the shoulder joint. It reduces wear and tear on the tendon during movement at the shoulder joint. Subscapular – located between the subscapularis tendon and the scapula.inflammation of the bursa) can be a cause of shoulder pain.
#SIGN ME CUFF BACKWARDS FREE#
The subacromial bursa reduces friction beneath the deltoid, promoting free motion of the rotator cuff tendons. Subacromial – located deep to the deltoid and acromion, and superficial to the supraspinatus tendon and joint capsule.The bursae that are important clinically are: A bursa is a synovial fluid filled sac, which acts as a cushion between tendons and other joint structures. To reduce friction in the shoulder joint, several synovial bursae are present. The synovial membrane lines the inner surface of the joint capsule, and produces synovial fluid to reduce friction between the articular surfaces. The joint capsule is lax, permitting greater mobility (particularly abduction). It extends from the anatomical neck of the humerus to the border or ‘rim’ of the glenoid fossa. The joint capsule is a fibrous sheath which encloses the structures of the joint. Fig 1 – The articulating surfaces of the shoulder joint.