The legend of plantar neuropraxia in long-distance athletes

Abstract

Background. Legend has it that endurance athletes who develop plantar foot pain during long-distance running frequently experience an eventual relief of pain due to a transient neuropraxia brought on by continued activity.
Objective. To evaluate the nature of this legend, we assessed long-distance runners for the presence of sensory deficits before and after completion of an ultramarathon, expecting to find an induced neuropraxia  and abnormal sensory results.
Methods. Twenty-five adult participants of an ultramarathon were evaluated prior to their 50/100 km run and again upon completion of the race. Neurosensory testing was performed using a 10 g monofilament at 4 locations on each foot and a 128 Hz tuning fork at one location on each foot. The same techniques were used prior to, and at conclusion of the race.
Results. We detected no neuropraxia or sensory deficits in any participant, despite reports by the same subjects that they had experienced the phenomenon during the race. While runners commonly report losing sensation in their feet during long runs, we were unable to demonstrate any sensory deficit with simple field-based testing.
Conclusion. We believe that there is room for additional research to be performed using more sensitive means of neurosensory evaluation.