Long distance running and acute effects on plantar foot sensitivity and plantar foot loading.

The plantar surface of the foot senses local pressures during stance and locomotion. These foot loading characteristics may be affected by long distance running. Little is known about the physiological effects of sports-related loading on plantar sensitivity and their relationship with plantar foot loading. The purpose of this study was to investigate the acute effects of long distance running on plantar sensitivity to touch and their relationship with foot loading characteristics. It was hypothesized that plantar sensation would decrease after long distance running and may be related to foot loading characteristics. In 15 middle-aged runners, sensory detection thresholds to light touch and plantar pressures were measured before and after a 10 km run. After the run, no significant changes in sensory perception thresholds were observed so that correlations between foot sensitivity and foot loading could not be calculated. A significant decrease of force-time integrals and maximum forces was demonstrated in the whole foot (-6.2%, p=0.003; -3.9%, p=0.001) and the heel (-10.5%, p=0.003; -8.5%, p=0.002). Furthermore, maximum force was significantly reduced in the lateral midfoot (-6.4%, p=0.002). In conclusion, a sub-maximal 10 km running exercise appears to have no significant acute effects on plantar sensitivity, plantar pressure distribution and peak forces.