Muscles of the Forearm

Superficial Muscle Group: pronator teres (PT) flexor carpi radialis (FCR) palmaris longus (PL) flexor carpi ulnaris (FCU) Intermediate Muscle Group: flexor digitorum superficialis (FDS) Deep Muscle Group (do not cross the elbow joint): flexor digitorum profundus (FDP) flexor pollicis longus (FPL) pronator quadratus (PQ)

All supplied by the median nerve, except for the FCU and the medial half of the FDP which are supplied by the ulnar nerve

PA- Humeral head: Medial epicondyle of humerus (CFO) Ulnar head: Coronoid process DA- Lateral surface of the radius, middle section N/S- Median nerve A- Pronates and flexes forearm

PA- Medial epicondyle of humerus (CFO) DA- Base of 2nd metacarpal (anteriorly) N/S- Median nerve A- Flexes and radially deviates (abducts) hand at wrist joint

PA- Medial epicondyle of humerus (CFO) DA- Flexor retinaculum and palmer aponeurosis N/S- Median nerve A- Flexes hand at wrist joint and tenses palmer aponeurosis

PA- Humeral head: Medial epicondyle of humerus (CFO) Ulnar head: Olecranon process of ulna DA- Pisiform, hook of the hamate & 5th metacarpal (anteriorly) N/S- Ulnar nerve A- Flexes and ulnar deviates (adducts) hand at wrist joint

PA- Medial epicondyle of humerus (CFO) & anterior surface radius DA- Middle phalanges of medial 4 digits (2-5) N/S- Median nerve A- Flexes middle phalanges, producing flexion at the proximal interphalangeal joints (PIPs) and metacarpophalangeal joints (MCPs)

Divides into 4 tendons for insertion Tendons pass under the split tendons of FDS PA- Medial and anterior surfaces of proximal ulna and interosseous membrane DA- Distal phalanges of medial 4 digits (2-5) N/S- Lateral half (digits 2&3): Median nerve. Medial half (digits 4&5): Ulnar nerve A- Flexes distal phalanges at the distal interphalangeal joints (DIPs)

PA- Distal anterior radius, and interosseous membrane DA- Distal phalanx of thumb N/S- Median nerve A- Flexes phalanges of the first digit (thumb)

PA- Distal ¼ of anterior ulna DA- Distal ¼ of anterior radius N/S- Median nerve A- Pronates the forearm

Transverse fibrous tissue band between the outer carpal bones Prevents bow stringing of tendons Forms the carpal tunnel (covered in later workshop) through which the flexor tendons and median nerve pass Clinical relevance: carpal tunnel syndrome

Superficial Muscle Group: Brachioradialis Extensor carpi radialis longus (ECRL) Extensor carpi radialis brevis (ECRB) Extensor digitorum (ED) Extensor digiti minimi (EDM) Extensor carpi ulnaris (ECU) Deep Muscle Group: Supinator Abductor pollicis longus (APL) Extensor pollicis brevis (EPB) Extensor pollicis longus (EPL) Extensor indicis (EI)

All muscles are supplied by the radial nerve

Attaches to the distal ulnar and radius Creates 6 osseofibrous tunnels which the extensor tendons pass through Holds the extensor tendons in position and prevents bow stringing

PA- Lateral supracondylar ridge of humerus DA- Lateral surface of distal radius N/S- Radial nerve A- Flexes forearm when it is in the mid-prone position

PA- Lateral supracondylar ridge of humerus DA- Base of 2nd metacarpal bone (posteriorly) N/S- Radial nerve A- Extends and radially deviates (abducts) hand at wrist joint

PA- Lateral epicondyle of humerus (CEO) DA- Base of 3rd metacarpal bone (posteriorly) N/S- Radial nerve A- Extends and radially deviates (abducts) hand at wrist joint

PA- Lateral epicondyle of humerus (CEO) DA- Extensor expansions of medial 4 digits N/S- Radial nerve A- Extends medial 4 digits (2-5) at metacarpophalangeal (MCP) & interphalangeal joints

PA- Lateral epicondyle of humerus (CEO) I- Extensor expansion 5th digit N/S- Radial nerve A- Extends 5th digit at metacarpophalangeal (MCP) & interphalangeal joints

PA- Lateral epicondyle of humerus (CEO) and posterior border of ulna DA- Base of 5th metacarpal bone (posteriorly) N/S- Radial nerve A- Extends & ulnar deviates (adducts) hand at wrist joint

PA- Lateral epicondyle of humerus (CEO) & supinator crest of ulnar DA- lateral, posterior & anterior surfaces of the proximal radius N/S- Radial nerve A- Supinates forearm

PA- Posterior surface of radius, interosseous membrane and ulna DA- Base of 1st metacarpal N/S- Radial nerve A- Abducts thumb and extends it at the carpometacarpal joint

PA- Posterior of distal radius and interosseous membrane DA- Base of proximal phalanx of thumb N/S- Radial nerve A- Extends proximal phalanx of thumb at metacarpophalangeal joint (MCP) (as well as carpometacarpal joint of thumb)

PA- Posterior surface of ulna (middle 1/3) and interosseous membrane DA- Base of distal phalanx of thumb N/S- Radial nerve A- Extends distal phalanx of thumb at interphalangeal joint (as well as metacarpophalangeal & carpometacarpal joint)