- Email: [email protected]
Median and Ulnar Nerves in the Hand
ELECTROMYOGRAPHY
1047-9651/98 $8.00
+ .00
MEDIAN AND ULNAR NERVES IN THE HAND Aaron W. Sable, MD
This article addresses a variety of testing techniques that evaluate the median and ulnar nerves in the wrist and hand. ANATOMY Median Motor Innervation
The median nerve innervates most of the forearm flexors and the muscles of the thenar eminences. The nerve passes through the two heads of the pronator teres it innervates. It then supplies the flexor carpi radialis, palmaris longus, and flexor digitorum superficialis before giving off the pure motor anterior interosseous nerve. The main branch enters the hand, passing through the carpal tunnel. At the distal edges of the carpal ligaments, it gives off the recurrent thenar nerve that innervates the abductor pollicis brevis, opponens pollicis, and the lateral half of the flexor pollicis brevis. It then terminates in the first and second lumbricals. Median Sensory Innervation
The median nerve is formed from C6, C7, C8, and Tl anterior roots from the lateral and median cords of the brachial plexus. Its dermatomes cover the lateral aspect of the palm and the dorsal surfaces of the terminal phalanges, along with the volar surfaces of the first three digits and generally the lateral half of the fourth digit. Sensory fibers of the thumb and long fingers enter the C6 and C7 anterior roots through the upper or middle trunk and the lateral cord. The skin of the third digit is subserved by the lateral cord, middle trunk, and C7 anterior root. From Concentra Rehabilitation and Performance Therapy, Livonia, Michigan
PHYSICAL MEDICINE AND REHABILITATION CLINICS OF NORTH AMERICA VOLUME 9 • NUMBER 4 • NOVEMBER 1998
737
1047-9651/98 $8.00
+ .00
MEDIAN AND ULNAR NERVES IN THE HAND Aaron W. Sable, MD
This article addresses a variety of testing techniques that evaluate the median and ulnar nerves in the wrist and hand. ANATOMY Median Motor Innervation
The median nerve innervates most of the forearm flexors and the muscles of the thenar eminences. The nerve passes through the two heads of the pronator teres it innervates. It then supplies the flexor carpi radialis, palmaris longus, and flexor digitorum superficialis before giving off the pure motor anterior interosseous nerve. The main branch enters the hand, passing through the carpal tunnel. At the distal edges of the carpal ligaments, it gives off the recurrent thenar nerve that innervates the abductor pollicis brevis, opponens pollicis, and the lateral half of the flexor pollicis brevis. It then terminates in the first and second lumbricals. Median Sensory Innervation
The median nerve is formed from C6, C7, C8, and Tl anterior roots from the lateral and median cords of the brachial plexus. Its dermatomes cover the lateral aspect of the palm and the dorsal surfaces of the terminal phalanges, along with the volar surfaces of the first three digits and generally the lateral half of the fourth digit. Sensory fibers of the thumb and long fingers enter the C6 and C7 anterior roots through the upper or middle trunk and the lateral cord. The skin of the third digit is subserved by the lateral cord, middle trunk, and C7 anterior root. From Concentra Rehabilitation and Performance Therapy, Livonia, Michigan
PHYSICAL MEDICINE AND REHABILITATION CLINICS OF NORTH AMERICA VOLUME 9 • NUMBER 4 • NOVEMBER 1998
737