Compressive Neuropathy of the Deep Motor Branch of the Ulnar Nerve in Amateur Cyclist

A 36-year-old female amateur cyclist developed mononeuropathy of the deep branch of the ulnar nerve due to nerve compression adjacent to the ulnar tunnel (type II Guyon’s canal syndrome) caused by prolonged bicycle riding. The patient’s signs and symptoms persisted even after refraining from cycling for 4 weeks; thus, she underwent decompression of the deep branch of the ulnar nerve in the palm and wrist. Three months postoperation, she recovered nearly full power and function of her left hand.