Shoulder Joint, Rotator Cuff Muscles and Shoulder Joint Muscles Flashcards
The glenohumeral joint is what type of joint
Synovial ball and socket where the ball is the head of the humerus and the socket is the glenoid cavity of the scapula.
The rim of cartilage surrounding the socket is
The glenoid Labrum
What is the function of the glenoid labrum
To reduce the disproportion of the surfaces of the joint
What type of cartilage covers both of the articulating surfaces
Hyaline Cartilage
The head of the humerus is much larger than the glenoid fossa, what is the reason for this
Giving the joint inherant stability
The joint capsule
A fibrous sheath which encloses the structures of the joint. It extends from the anatomical neck of the humerus to the border of the glenoid fossa. The joint capsule is lax, creating greater mobility.
Subacromial Bursa
Located inferiorly to the deltoid and the acromion, and superiorly to the supraspinatus tendon and the joint capsule. It supports the deltoid and supraspinatus muscles. Inflammation of this muscle can result in several shoulder problems.
Subscapular bursa
Located between the subscapularis tendon and the scapula. It reduces wear and tear on the tendon during movement at the shoulder joint.
The majority of the shoulder joint ligaments are
Thickenings of the joint capsule
Glenohumeral Ligaments (superior, middle and inferior)
Consits of three bands, which run with the joint capsule from the glenoid fossa to the anatomical neck of the humerus. They act to stabilise the anterior aspect of the joint.
Coracohumeral ligament
Attaches the base of the coracoid process to the greater tubercle of the humerus. It supports the superior part of the joint capsule.
Transverse Humeral Ligament
This spans the distance between the two tubercles of the humerus. It holds the tendon of the long head of the biceps in the intertubercular groove.
Coracoacromial Ligament
Runs between the acromion and the coracoid process of the scapula forming the coraco-acrimial arch. The structure overlies the shoulder joint preventing superior displacement of the humeral head.
Common injury to damage the subacromial bursa
Subacromial bursitis
Arterial supply to the glenohumeral joint
Anterior and posterior circumflex humeral arteries and the subscapular artery.
Nerve supply to the glenohumeral joint
Axillary, suprascapular and lateral pectoral nerves.
Extension of the shoulder
Upper limb backwards in a sagittal plane. This is produced by the posterior deltoid, latissimus dorsi, long head of triceps brachii and teres major
Flexion of the shoulder
Upper limb forwards. Biceps brachii, pectoralis major, anterior deltoid and coracobrachilais
Abduction of the shoulder
Away from the midline. The first 0-15 degrees of abduction is produced by the supraspinatus. The middle fibres of the deltoid are responsible for the next 15-90 degrees. Past 90 degrees, the scapula needs to be rotated to achieve abduction – that is carried out by the trapezius and serratus anterior.