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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 .
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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. Extension Flexion
Adduction / abduction at the wrist joint. Adduction Abduction
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)
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
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
Muscles of the Forearm (Post. View) Anconeus
Posterior Forearm (Superficial dissection) Nerve Supply Radial Nerve Anatomical snuff box
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 polliucislongus extensor pollicis brevis extensor pollicis longus extensor indicis
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:
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 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 medial lateral 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 • Flexor Digitorum Superficialis • Ulnar Artery • Ulnar Nerve • 9. Flexor Carpi Ulnaris • Brachioradialis • Superficial Radial n. • Radial Artery • Flexor Carpi Radialis • 5. Median Nerve Thumb