Distribution of the sensory endings of the C7 nerve root and its clinic significance.

50 patients with root avulsion of the brachial plexus have been treated with contralateral C7 root neurotization. Abnormal cutaneous sensation was found on the index finger in 37 cases (74%), on the middle finger in 29 cases (58%), on the thumb in 19 cases (38%), on the ring finger in ten cases (20%), and on the little finger in one case (2%). Seven patients had no abnormal cutaneous sensation. It is suggested that the area of skin innervated by C7 is centred on the index finger, together with the thumb and middle fingers.