A patient with compelling clinical and electrodiagnostic evidence of a
right L5 radiculopathy had focal atrophy of the multifidus at the app
ropriate level, which served to confirm the radicular nature of the pr
ocess. The multifidus muscles are innervated by a single root, in cont
rast to the polysegmental innervation of the rest of the paraspinal mu
scle mass. Imaging studies may complement needle electromyography in t
he evaluation of this important structure. (C) 1998 John Wiley & Sons,
Inc.