THE EFFECT OF LONG-DISTANCE BICYCLING ON ULNAR AND MEDIAN NERVES. AN ELECTROPHYSIOLOGIC EVALUATION OF CYCLIST PALSY

Professor Martin P Schwellnus, University of Cape Town, South Africa

Background: Distal ulnar neuropathies (cyclist palsy) are postulated to be an entrapment neuropathy of the ulnar nerve in the Guyon canal of the wrist – previous nerve conduction studies have not been prospective in nature.

Research question/s: Is there evidence of neuropathy (electrophysiologic change) in the ulnar and median nerves after a long-distance multi-day cycling event?

Methodology:Subjects: 14 cyclists (28 adult hands) participating in a 6-day, 420-mile bike tour.

Experimental procedure: All the subjects underwent median and ulnar motor and sensory nerve conduction studies (documenting peak latency, peak to peak latency in sensory nerve conduction, onset latency and amplitude in motor nerve conductions) of both hands before and after the 6-day tour. In addition, a questionnaire was also administered after the ride, evaluating the experience level of the cyclist, equipment use, hand position, and symptoms.

Measures of outcome: Sensory nerve function (peak latency, peak to peak latency), motor nerve function (onset latency and amplitude).

Main finding/s:

• Ulnar nerve: motor studies to the first dorsal interosseus (FDI) changes significantly, while sensory and motor studies of the abductor digiti minimi (ADM) did not change significantly

• Median nerve: median motor and sensory function did not change significantly

• Symptoms: in three hands there was symptomatic worsening of carpal tunnel syndrome, and in one hand carpal tunnel syndrome …