51088 skanuj0031 (110)

Interossei

(C8-T1)

i

Abductor pollicis brevis (C8—Tl)

Biceps brachii (C5-C6)

Pectoralis major (C 7—Tl)

Diaphragm

(C3-C5)

Adductor magnus(L2—L4)

Quadriceps femoris(L2—L4)

Extensor hallucis longus (L5—SI)

Tibialis anterior (L4-L5)

Conus or cauda equina lesion

±'= level of spinał cord lesions tfte spinał cord segments that innervate them. Most ■hafcisegmental, i.e., they receive innervation from sev-segments. Thus, forexample, a lesion at the C7 level

ranse rnmnlete naralysis of the latissimus dorsi. b

with the “indicator muscles,” which are supplied almost exclusively by a single segment (see B, p. 347). A lesion at the L 3 level, for exam-ple, will cause almost complete paralysis of the quadriceps femoris because that muscle is innervated almost entirely by L3.

The dearee of disability yaries, depending on the level of the com-