Plantar Loads of Habitual Forefoot Strikers during Running on Different Overground Surfaces

The objective of this study is to investigate plantar loads characteristics of habitual forefoot strike runners while running on different surfaces. Twenty-six runners (age: 28.2 +/- 6.8 y, height: 172.9 +/- 4.1 cm, weight: 67.7 +/- 9.6 kg, BMI (body mass index): 22.6 +/- 2.8 kg/m(2), running age: 5.0 +/- 4.2 y, running distance per week: 14.6 +/- 11.7 km) with habitual forefoot strike participated in the study. Runners were instructed to run at 3.3 +/- 0.2 m/s on three surfaces: grass, synthetic rubber and concrete. An in-shoe pressure measurement system was used to collect and analyze plantar loads data. Running on the synthetic rubber surface produced a lower plantar pressure in the lateral forefoot (256.73 kPa vs. 281.35 kPa, p = 0.006) than running on concrete. Compared with the concrete surface, lower pressure-time integrals were shown at the central forefoot (46.71 kPa.s vs. 50.73 kPa.s, p = 0.001) and lateral forefoot (36.13 kPa.s vs. 39.36 kPa.s, p = 0.004) when running on the synthetic rubber surface. The different surfaces influence plantar loads of habitual forefoot strikers and runners should choose appropriate overground surface to reduce the risk of lower extremity musculoskeletal injuries.