musculature of the shoulder joint

articulations of the shoulder name + type

Glenohumeral joint

synovial ball and socket joint

movements: flexion, extension, abduction, adduction, lateral rotation, medial rotation and circumduction

articulations of the shoulder name + type

acromioclavicular joint

synovial plane joint

movements: protraction, retraction, elevation, depression and Axial rotation

articulations of the shoulder name + type

Sternoclavicular joint

synovial saddle joint

movements: elevation, depression, protraction, retraction and axial rotation

articulations of the shoulder name + type

Scapulothoracic joint

Scapulothoracic joint not a true joint and is instead comprised of: acromioclavicular, sternoclavicular, and the scapulothoracic junction.

movements: elevation, depression, protraction, retraction, external and internal rotation.

pectoralis major

origin - clavicular head from medial half of anterior surface of the clavicle sternal head arises from the anterior surface of the manubrium sternum, upper six costal cartilages and anterior aspect of the rectus sheath

insertion - lateral lip of the intertubercular groove

action - flexion, horizontal adduction and internal rotation of the humerus

coracobrachialis

origin - tip of the coracoid process

insertion - medial aspect of the mid shaft of the humerus

action - flexion and horizontal adduction of humerus

Biceps Brachii (Long head) + (short head)

short head - tip of coracoid process

long head - supraglenoid tubercle

insertion: posterior aspect of radial tuberosity

forearm flexion and supination whilst the long head also assists shoulder flexion

Teres Major

origin: inferior angle and the adjacent lateral border of the scapula

Insertion: medial lip of the intertubercular groove

Action: extension, medial rotation and adduction

Latissimus Dorsi

Origin: spinous processes and supraspinous ligaments of T7 to T12, spines of all lumbar and sacral vertebrae via thoracolumbar fascia, posterior part of iliac crest and the lower four ribs.

insertion: floor of intertubercular groove of humerus

Action: extension, adduction and medial rotation of humerus

Triceps

Origin: long head: infraglenoid tubercle of the scapula Medial head: posterior surface of the humerus Lateral head: lateral border of humerus

Insertion: upper surface of olecranon process of ulna

Action: elbow extension and long head assists extension of humerus at the shoulder

Supraspinatus

origin: supraspinous fossa of scapula

insertion: upper facet of greater tubercle of humerus

Action: initiates abduction

Infraspinatus

origin: medial 2/3rds of infraspinous fossa of scapula

insertion: middle facet of greater tubercle of humerus

Action: lateral rotation of humerus

Teres Minor

Origin: upper 2/3rds of lateral border of the scapula

insertion: lower facet of greater tubercle of humerus

Action: lateral rotation and adduction of humerus

subscapularis

origin: medial 2/3rds of subscapular fossa

insertion: lesser tubercle of humerus

Action: medial rotation, and assists adduction of humerus

Name the 4 rotator cuff muscles in this diagram

yellow - supraspinatus

Blue - infraspinatus

Purple - teres minor

Red - sub scapularis

serratus anterior

Origin: external surfaces of the upper eight (nine or ten) ribs and intercostal fascia

Insertion: costal surface of the medial border of the scapula

Action: protracts scapula

Trapezius

Origin: medial third of the superior nuchal line, the ligamentum nuchae and the lips of the spinous processes and intervening supraspinous ligaments form C7 to T12

Insertion: superior fibers attach to posterior border of the lateral third of the clavicle. the middle fibers pass horizontally to attach to the crest

Action: retraction, elevation and depression of scapula, also cervical extension and side flexion

Rhomboids

Origin: spinous processes and intervening supraspinous ligaments of T2 to T5 vertebrae

Insertion: medial border of the scapula between base of spine and inferior angle

Action: medial rotation and retraction of the scapula

Pectoralis minor

Origin: outer surface of the 3rd, 4th and 5th ribs

insertion: tip of coracoid process

Action: protraction and depression of scapula

Deltoid

Origin: anterior border of lateral third of clavicle, the lateral border of acromion and the lower lip of scapular spine

Insertion: Deltoid tuberosity ½ way down the lateral aspect of the shaft of the humerus. (where you can visibly see the deltoid muscle end)

Action: Abduction of humerus, also anterior fibers aid flexion and posterior fibers aid extension.