Fig. 2From: Spinal accessory neuropathy in patients with chronic trapezius myofascial pain syndromeThe spinal accessory nerve (SAN) compound muscle action potentials (CMAP) obtained from an apparently healthy volunteer. The sweep speed was 5 ms/division and sensitivity was 5 mV/division. SAN CMAP latency was 2.4 ms and amplitude was 11.7 mVBack to article page