PROTECTIVE SENSATION OF THE PLANTAR ASPECT OF THE FOOT

The scientific literature suggests that barefoot activity may be benef icial. There is a current trend in recreational barefoot activity in c hildren and adults, and barefoot running among athletes. Although the type of skin over most of the body (hairy skin) seems to be easily inj ured by painful abrading loads, little is known about protection provi ded by plantar sensory feedback against damage from excessive wear dur ing barefoot locomotion. To evaluate this, we administered a volley of 35 painful abrading loads to glabrous and hairy skin sites over a 5-m in period, and examined its effects for signs of cutaneous injury in a sample of 12 normally shod healthy male subjects. Compared with hairy skin of the thigh, plantar skin required approximately 600% greater a brading loads to reach pain threshold. Furthermore, painful stimulatio n produced visible redness and hypersensitivity in all subjects at the hairy skin site 24 hr after stimulation, whereas only 8.3% reported h ypersensitivity and none showed erythema at the plantar area 1 day lat er. We found that plantar skin possesses a higher pain threshold to ab rading stimuli than hairy skin. In fact, loading of the plantar area w as limited to innocuous levels due to intolerable pain. We conclude th at plantar skin is well protected through sensory feedback from abrasi ve injuries when barefoot. This information combined with previous rep orts suggests that risk of injury when normally shod individuals perfo rm barefoot locomotion should be low.