Surface effects on in-shoe plantar pressure and tibial impact during running

Abstract

Purpose: This study aims to explore the effects of running on different surfaces on the characteristics of in-shoe plantar pressure and tibial acceleration. Methods: Thirteen male recreational runners were required to run at 12 km/h velocity on concrete, synthetic track, natural grass, a normal treadmill, and a treadmill equipped with an ethylene vinyl acetate (EVA) cushioning underlay (treadmill_EVA), respectively. An in-shoe plantar pressure system and an accelerometer attached to the tibial tuberosity were used to record and analyze the characteristics of plantar pressure and tibial impact during running. Results: The results showed that there were no significant differences in the 1st and 2nd peak plantar pressures (time of occurrence), pressure-time integral, and peak pressure distribution for the concrete, synthetic, grass, and normal treadmill surfaces. No significant differences in peak positive acceleration were observed among the five tested surface conditions. Compared to the concrete surface, however, running on treadmill_EVA showed a significant decrease in the 1st peak plantar pressure and the pressure-time integral for the impact phase (p < 0.05). These can be further ascribed to a reduced peak pressure observed at heel region (p < 0.05). Conclusion: There may not be an inevitable relationship between the surface and the lower-limb impact in runners. It is, however, still noteworthy that the effects of different treadmill surfaces should be considered in the interpretation of plantar pressure performance and translation of such results to overground running.