OIA upper limb

Teres Minor

Origin: Lateral border of scapula | Insertion: Greater tubercle of humerus | Action: Lateral rotation and adduction at shoulder

Supraspinatus

Origin: Supraspinous fossa of scapula | Insertion: Greater tubercle of humerus | Action: Abduction at shoulder

Infraspinatus

Origin: Infraspinous fossa of scapula | Insertion: Greater tubercle of humerus | Action: Lateral rotation at shoulder

Subscapularis

Origin: Subscapular fossa of scapula | Insertion: Lesser tubercle of humerus | Action: Medial rotation at shoulder

Biceps Brachii

Origin: Short head – coracoid process; Long head – supraglenoid tubercle | Insertion: Radial tuberosity | Action: Flexion at elbow and shoulder

Triceps Brachii

Origin: Lateral head – humerus; Long head – infraglenoid tubercle of scapula; Medial head – posterior surface of humerus | Insertion: Olecranon of ulna | Action: Extension at elbow

Brachioradialis

Origin: Lateral 2/3 of superior humerus | Insertion: Distal radius | Action: Flexes forearm at elbow

Flexor Carpi Radialis

Origin: Medial epicondyle of humerus | Insertion: Second and third metacarpal bones | Action: Flexion and abduction at wrist

Flexor Digitorum Superficialis

Origin: Medial epicondyle of humerus & coronoid process | Insertion: Middle phalanges 2–5 | Action: Flexion at wrist, metacarpophalangeal, and proximal interphalangeal joints

Extensor Digitorum

Origin: Lateral epicondyle of humerus | Insertion: Posterior surface of phalanges 2–5 | Action: Extension at finger joints and wrist

Extensor Carpi Ulnaris

Origin: Lateral epicondyle of humerus | Insertion: Fifth metacarpal | Action: Extension and adduction at wrist

Abductor Pollicis Brevis

Origin: Scaphoid and trapezium | Insertion: Lateral aspect of proximal phalanx | Action: Abducts thumb