Flexor Carpi Radialis

Origin: Medial epicondyle of Humerus

Insertion: 2nd & 3rd Metacarpals

Action: Flexes and abducts hand (radial deviation) @ wrist joint

Innervation: Median Nerve

Flexor Carpi Ulnaris

Origin: Medial Epicondyle of Humerus and Superior Posterior border of Ulna

Insertion: Pisiform, Hamate, and base of 5th metacarpal

Action: Flexes and adducts hand (ulnar diviation) @ wrist joint

Innervation: Ulnar Nerve

Flexor Digitorum Superficialis

Origin: Medial epicondyle of Humerus, Coronoid process of ulna, Ridge along Lateral margin of anterior surface (anterior oblique line) of radius

Insertion: Middle Phalanx of each finger

Action: Flexes middle Phalanx of each finger at PIP joint, Proximal Phalanx of each finger @ Metacarpophalangeal joint, and hand @ wrist joint.

Innervation: Median Nerve

1. Flexor Pollicis Longus
2. Flexor Digitorum Profundus

Flexor Pollicis Longus

Origin: Anterior Surface of Radius and Interosseous membrand of Ulna and Radius

Insertion: Base of Distal phalanx of thumb

Action: Flexes Distal Phalanx of thumb @ interphalangeal joint

Innervation: Median Nerve

Flexor Digitorum Profundus

Origin: Anterior medial surface of body of Ulna

Insertion: BASE of Distal phalanx of each Finger

Action: Flexes distal & middle phalanges of each finger @ interphalangeal joints, Proximal phalanx of each finger @ Metacarpophalangeal joint, and hand @ wrist joint

Innervation: Median and Ulnar Nerves

1. Extensor Carpi Radialis Longus
2. Extensor Carpi Radialis Brevis
3. Extensor Digitorum
4. Extensor Digiti Minimi
5. Extensor Carpi Ulnaris

Extensor Carpi Radialis Longus

Origin: Lateral Supracondylar Ridge of Humerus

Insertion: Second Metacarpal

Action: Extends and Abducts hand @ wrist joint

Innervation: Radial Nerve

Extensor Carpi Radialis Brevis

Origin: Lateral epicondyle of Humerus

Insertion: 3rd Metacarpal

Action: Extends and Abducts hand @ wrist joint

Innervation: Radial Nerve

Extensor Digitorum

Origin: Lateral Epicondyle of humerus

Insertion: Distal and middle phalanges of each finger

Action: Extends distal and middle phalanges of each finger @ interphalangeal joints, proximal phalanx of each finger @ metacarpophalangeal joint, and hand at wrist joint.

Innervation: Deep Radial Nerve

Extensor Digiti Minimi

Origin: Lateral epicondyle of humerus

Insertion: Tendon of extensor digitorum on 5th Phalanx

Action: Extends Proximal phalanx of little finger @ metacarpophalangeal joint and hand @ wrist joint.

Innervation: Deep Radial Nerve

Extensor Carpi Ulnaris

Origin: Lateral epicondyle of humerus and Posterior border of Ulna

Insertion: 5th Metacarpal

Action: Extends and adducts hand @ wrist joint

Innervation: Deep Radial Nerve

Deep Posterior (Extensor) Compartment of the Forearm

1. Abductor Pollicis Longus
2. Extensor Pollicis Brevis
3. Extensor Pollicis Longus
4. Extensor Indicis

Abductor Pollicis Longus

Origin: Posterior Surface of middle of radius and Ulna and interosseous membrane.

Insertion: 1st Metacarpal

Action: Abducts and extends thumb @ carpometacarpal joint and abducts hand @ wrist joint.

Innervation: Deep Radial Nerve

Extensor Pollicis Brevis

Origin: Posterior surface of middle of radius and interosseous Membrane

Insertion: Base of Proximal Phalanx of thumb.

Action: Extends proximal phalanx of thumb @ metacarpophalangeal joint, 1st metacarpal of thumb @ carpometacarpal joint, and hand @ wrist joint.

Innervation: Deep Radial Nerve

Extensor Pollicis Longus

Origin: Posterior Surface of middle of ulna and interosseous membrane.

Insertion: Base of distal phalanx of thumb

Action: Extends distal phalanx of thumb @ interphalangeal joints, first metacarpal of thumb @ carpometacarpal joint, and abducts hand @ wrist joint.

Innervation: Deep Radial Nerve

Extensor Indicis

Origin: Posterior Surface of Ulna

Insertion: Tendon of extensor digitorum of index finger