Muscles of the Forearm Dr. Sama ul Haque

Objectives Identify the muscles in the anterior and posterior compartments of the forearm in terms of their origin, insertion, nerve supply and actions. Know the neurovascular structures in the anterior and posterior compartments of the forearm. Discuss the functions of the muscles in the anterior and posterior compartment of the forearm.

Functional organization of Anterior and posterior Compartments of forearm.

Names of the Muscles of forearm Long names: good guide to location and function Location: ie. superficial / deep radial / ulnar Function: ie. flexor / extensor adductor / abductor Does it act on the thumb (pollux) or the fingers (digits)?

Functional Organization Anterior compartment – flexor / pronator Posterior Compartment – extensor / supinator Flex the wrist ………[flexor] Extend the wrist ……..[extensor] Pronate the forearm ……..[pronator] Acting on wrist (carpus) only ……[carpi] Acting on fingers ……..[digiti / digitorum] Acting on thumb (pollux) ……[pollicus]

Flexion / Extension at the wrist joint.

Adduction / abduction at the wrist joint.

X X Movements of fingers. Metacarpophalangeal (condyloid joints): flexion / extension and abduction / adduction Interphalangeal (hinge joints): flexion / extension X X

Movements of the thumb – a specialized digit, occur at right angles to the fingers. Mainly at the Carpometacarpal (saddle) joint. MCP – condyloid; IP – hinge (like fingers).

Radius and Ulna

Radius and Ulna (Pronated)

Muscles of the anterior compartment of forearm

Muscles of the anterior compartment of forearm

Anterior Compartment of forearm Pronator teres Superficial: Common flexor origin Pronator Teres Flexor Carpi Radialis Palmaris Longus Flexor Digitorum Superficialis, Flexor Carpi Ulnaris Brachioradialis flexor carpi radialis Palmaris longus flexor digitorum superficialis flexor carpi ulnaris

Functional organization: Only flex at the wrist. Flexor carpi radialis Anterior Compartment of forearm Functional organization: Only flex at the wrist. Flexor carpi radialis Palmaris longus Flexor carpi ulnaris Flexor Carpi Radialis Palmaris Longus Flexor Carpi ulnaris

Anterior Compartment of forearm

Deep Dissection Forearm (Anterior)

Neurovasculature of Anterior Compartment of forearm

Muscles of the posterior compartment of forearm

Muscles of the posterior compartment of forearm

Muscles of the posterior compartment of forearm

Muscles of Forearm

Muscles of the Forearm (Post. View) Anconeus

Posterior Forearm (Superficial dissection) Nerve Supply Radial Nerve Anatomical snuff box

Functional Organization: Deep Posterior Compartment Abductor Pollicis Longus Extensor Pollicis Brevis Extensor Pollicis Longus Extensor Indicis Supinator Functional Organization: Extend Hand At Wrist Extend / Abduct Thumb Extend Index Finger Supinate abductor polliucis longus extensor pollicis brevis extensor pollicis longus extensor indicis

Deep Dissection Forearm (Posterior)

Superior and Inferior radioulnar Joints Superior radioulnar Joint: Head of radius articulates with radial notch of ulna Type: Pivot joint). It is held in place by the annular ligament. Radio-ulnar articulation is stabilized by interosseous membrane. Inferior radioulnar Joint:

Supination and Pronation

Course of radial and ulnar arteries in forearm

Neurovasculature (deep). Lateral: radial artery radial nerve Midline: median nerve anterior interosseus a. anterior interosseus n. (deep branch of median) Medial: ulnar artery (gives off common interosseus artery divides into anterior and posterior branches) ulner nerve radial n ulnar a radial a. ulnar n median n anterior interosseus a + n

Radial nerve and its branches supply Neurovasculature. Radial nerve and its branches supply all muscles in posterior compartment, including Brachioradialis (!). - superficial radial nerve - deep radial nerve - posterior interosseous nerve. Posterior interosseous artery runs between superficial and deep muscles Brachioradialis Deep branch posterior interosseus branch Superficial branch

Radial & Ulnar Arteries lateral medial Radial artery Ulnar artery Common interosseous Anterior Posterior Dorsal and palmer carpal branches Dorsal and palmer carpal branches Deep (superficial) palmar arches superficial (deep)palmar arches

RELATION OF ARTERIES, NERVES AND TENDONS AT THE WRIST NANAN Superficial Radial Nerve Radial Artery Median Nerve Ulnar Artery Ulnar Nerve MOVING LATERAL TO MEDIAL 1-9 Brachioradialis Superficial Radial n. Radial Artery Flexor Carpi Radialis 5. Median Nerve Flexor Digitorum Superficialis Ulnar Artery Ulnar Nerve 9. Flexor Carpi Ulnaris Pulanous Longous Thumb

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