Their muscle fibers end at the upper third and the mid forearm respectively, continuing as flat tendons along the lateral border of the radius, beneath the APL and EPB. 42 terms. Reproductive System (Female) 39 terms. Johnston JA, Bobich LR, Santello M. Coordination of intrinsic and extrinsic hand muscle activity as a function of wrist joint angle during two-digit grasping. flexor digitorum superficialis [2] The EPL arises from the dorsal surface of the ulna and the EI from the distal third of the dorsal part of the body of ulna. They are termed extrinsic muscles because the muscle belly is positioned on the forearm. The extrinsic muscles of the hand are muscles that originate outside the hand but insert into structures within the hand 1,2. Gravity. Chapter 7. By David Terfera, Shereen Jegtvig . The EDM has a similar role for the little finger. They include the extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor digitorum (ED), extensor digiti minimi (EDM), extensor carpi ulnaris (ECU), abductor pollicis longus (APL), extensor pollicis brevis (EPB), extensor pollicis longus (EPL), and extensor indicis (EI). [5] Spell. The Extrinsic Muscles of the Wrist and Hand; The Extrinsic Muscles of the Wrist and Hand. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. The EPB inserts into the base of the first phalanx of the thumb[2] to extend and abduct the thumb at the carpometacarpal and MCP joints. The tendon to the index finger is accompanied by the EI, which lies on its ulnar side. 32 terms. OTHER SETS BY THIS CREATOR. Opposite the metacarpophalangeal joint each tendon is bound by fasciculi to the collateral ligaments and serves as the dorsal ligament of this joint; after having crossed the joint, it spreads out into a broad aponeurosis, which covers the dorsal surface of the first phalanx and is reinforced, in this situation, by the tendons of the Interossei and Lumbricalis. The muscles of the hand are redivided into two groups: the extrinsic muscles and the intrinsic muscle groups. As the tendons cross the interphalangeal joints, they furnish them with dorsal ligaments. Most of the extrinsic muscles have their origins within the forearm, with several solely/also originating from the humerus: flexor carpi radialis. Andreisek G, Kislinger B, Dessouky R, Chhabra A. MRI of the Intrinsic Muscles of the Hand. Flashcards. Start studying Extrinsic Hand Muscles. The extrinsic muscles are located in the anterior and posterior compartments of the forearm. https://www.ypo.education/orthopaedics/hand-wrist/hand-anatomy-t191/video They control crude movements and produce a forceful grip. For a quick reference on these muscles, see the, "Boxer Knuckle (Injury of the Extensor Hood with Extensor Tendon Subluxation): Diagnosis with Dynamic US—Report of Three Cases", "Clinical Example: Sagittal band rupture reconstruction", https://en.wikipedia.org/w/index.php?title=Extrinsic_extensor_muscles_of_the_hand&oldid=975684287, Wikipedia articles incorporating text from the 20th edition of Gray's Anatomy (1918), Creative Commons Attribution-ShareAlike License, This page was last edited on 29 August 2020, at 21:09. The ECRL inserts into the dorsal surface of the base of the second metacarpal bone on its radial side[1] to extend and abduct the wrist. The APL, EPB, EPL, EI, ED, and EDM are supplied by the Posterior interosseous artery, a branch of the ulnar artery. 2. If this were the case, the requirement of exerting the same fingertip force regardless of wrist angle would elicit modulation of both extrinsic and intrinsic hand muscles. The ECRB has additional origins from the radial collateral ligament, the ECU from the dorsal border of the ulna (shared with the flexor carpi ulnaris and flexor digitorum profundus), and all four also originate from various fascia. [1] Distal to this, the extensor carpi radialis brevis (ECRB), extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris (ECU) originate from the lateral epicondyle via the common extensor tendon. They are termed extrinsic muscles because the muscle belly is positioned on the forearm. The extensor muscles are all extrinsic, except for the interosseous-lumbrical complex, which is involved in interphalangeal joint extension. Several individual muscles redirect here. Intrinsic Muscles. Kinesiology - Extrinsic Hand Muscles. Extensor denotes their action which is to extend, or open flat, joints in the hand. The ECRL and ECRB, (with the brachioradialis) form the lateral compartment. (2017) Seminars in musculoskeletal radiology. Intrinsic muscles on the palmar side of the hand can be divided into three groups: (1) thenar eminence, (2) hypothenar eminence, and (3) central compartment. Occasionally the first tendon is connected to the second by a thin transverse band. This may be corrected surgically by using a slip of the extensor tendon to replace the damaged ligamentous band [4]. [1] The ED divides into four tendons which, with the EI tendons, go through the fourth tendon compartment of the dorsal carpal ligament. Most of the extrinsic muscles have their origins within the forearm, with several solely/also originating from the humerus: ADVERTISEMENT: Supporters see fewers/no ads, Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys.