First dorsal interosseous muscle Extensor indicis Extensor pollicis longus Extensor pollicis brevis B Abductor pollicis longus
Figure 10.23 cont’d (B) The extensor tendons as they pass through the six canals and the extensor retinaculum. (From Starkey C, Brown D. Examination of Orthopedic & Athletic Injuries, 4th ed. Philadelphia, PA: F. A. Davis Company, 2015, p. 732, with permission.)
Extensor carpi ulnaris
1 2 3 4 5 6
Extensor digiti minimi
Extensor digitorum
Extensor digitorum
Palmar interosseus Metacarpal Dorsal hood
Distal phalanx
Lateral bands
Central band
Lumbrical A Dorsal interosseus
Figure 10.24 Extensor mechanism of the hand. (A) Dorsal view. (B) Lateral view.