1. Wrist Extensors
1.1. Extensor carpi Ulnaris: Actions: extension of wrist, adduction of wrist, and weak flexion of elbow, Origin : common extensor tendon and ulna. Insertion: 5th metacarpal. Innervation: radial nerve
1.1.1. extensor carpi radialis brevis Actions: extension of wrist and abduction of the wrist. Origin anterior of lateral epicondlye of Humerus. Insertion: posterior base of the third metacarpal. Innervation: radial nerve.
1.1.1.1. extensor carpi radialis longus. Actions: wrist extension and abduction, and weak pronation from neutral. Origin: lateral supracondylar ridge. Insertion: 2nd metacarpal. Innervation: radial nerve
2. Finger Flexors
2.1. Flexor digitorum superficialis: Actions: Flexion at the MCP and PIP joints of fingers, flexion of wrist, weak flexion of elbow. Origin: Medial epicondyle of humerus. Insertion: Anterior margins of the middle phalanges. Innervation: median nerve
2.1.1. Flexor digitorum profundus: Actions: Flexion of the four finger at the MCP, PIP, and DIP Joints and flexion of the wrist. Origin: upper 3/4 of the anterior and medial surfaces of the body of the ulna. Insertion: Base of the distal phalanges. Innervation: median and ulnar
2.1.1.1. Flexor pollicis longus: Actions: Flexion of the thumb at the CMC, MCP, and IP joints, flexion of wrist, Abduction of wrist. Origin: the middle anterior surface of the radius and the adjacent interosseus membrane, ulna Insertion: The base of the distal phalanx of the thumb. Innervation: median nerve.
3. Finger extensors
3.1. Extensor Digitorum Actions: extension of fingers at thte MCP joints, extension of the wrist, and weak extension of the elbow. Origin: common extensor tendon, lateral epicondlye. Insertion: extensor expansion of middle and distal phalanges. Innervation: Radial nerve
3.1.1. Extensor indicis: Actions: Extension of index finger at MCP joint, weak wrist extension and weak supination from prone position. Origin: posterior distal third of the ulna and interosseous membrane. Insertion: middle and distal phalanxes of 2nd phalange. Innervation: posterior interosseous nerve
3.1.1.1. EXtensor digiti minimi: Actions: extension of pinky at MCP joint, weak wrist and elbow extension. Origin: lateral portion of the lateral epicondyle of the humerus. Insertion: middle and distal phalanx. Innervation: Posterior interosseous nerve.
3.1.1.1.1. Extensor pollicis longus: Actions: extension of the thumb at the CMC, MCP , and IP joints, extension of wrist, abduction of the wrist, and weak supination of the forearm. Origin: middle third of the posterior surface of the ulna. Insertion: base of thumb and middle phalanx. Innervation: radial nerve.
4. Hand Bones
4.1. Lunate
4.1.1. Hamate
4.1.1.1. trapezoid
4.1.1.1.1. Scaphoid
5. Wrist Flexors
5.1. Flexor Carpi Radialis Actions: Flexion of wrist , abduction of wrist , weak flexion of elbow , Weak pronation of forearm. origin: Medial epicondlye of humerus , Insertion: Bases of second and third metacarpal , Innervation: median nerve
5.1.1. Palmaris Longus, Actions: Flexion of wrist and weak flexion of weak flexion of elbow, Origin: Medial epicondlye of Humerus, Insertion: palmar aponeurosis and flexor retinaculum of hand. Innervation: median nerve
5.1.1.1. Flexor Carpi Ulnaris, Actions: Flexion of wrist , Adduction of wrist , and weak flexion of the elbow. Origin: Medial epicondlye and medial margin of olecranon, Insertion: pisiform, hook of Hamate. Innervation: ulnar nerve