RESPONSE OF PERIPHERAL-NERVE TO CYCLIC COMPRESSION IN A LABORATORY RAT MODEL

Repetitive cyclic loading of a nerve has been proposed as a pathogenic factor in the development of occupational compression neuropathies. L ittle is known about the basic response of peripheral nerve to cyclic compression. We investigated the hypothesis that cyclic compression is more detrimental to nerve function than constant compression. We meas ured the amplitudes and velocities of distally evoked action potential s in the presence of constant or cyclic compression of the tibial nerv e in rats. Seven groups were subjected to constant or cyclic compressi on for 6 h by a computer controlled, hydraulically activated compressi on chamber. Nerves were compressed with 0 (control group), 30, 60, or 90 mm Hg of constant pressure or 0-30, 20-50, or 30-60 mm Hg of cyclic compression for approximately 20,000 compression cycles. Action poten tials were recorded every 15 min. The effects of cyclic compression on nerve conduction were equivalent to the effects of constant compressi on at the average applied pressure. Cyclic loading itself does not app ear to be an important pathogenic factor in the development of nerve c onduction block.