Plantar loads characteristics of male non-rearfoot strikers running on different overground surfaces at preferred speed

Abstract

Background: This study aimed to investigate the plantar loads of male non-rearfoot strike runners running on different overground surfaces at their preferred speeds. Methods: A total of 32 male runners with non-rearfoot strike were required to run for 15 m on concrete, synthetic rubber and grass surfaces at their preferred speeds. An insole sensor system was used to determine the runners’ foot strike pattern and measure peak pressure, pressure-time integral, maximum force, force-time integral and contact area of the total foot and nine selected foot regions. Results: No significant differences on their preferred speeds were observed running on concrete, synthetic rubber and grass surfaces. No significant differences on plantar loads parameters of the total foot were found when running on the three overground surfaces. Running on concrete showed higher peak pressure in the lateral forefoot compared with grass and synthetic rubber (283.49 kPa vs. 264.31 kPa, P < 0.023; 283.49 kPa vs. 263.18 kPa, P < 0.019, respectively). Maximum force in the medial forefoot was lower when running on concrete compared with grass and synthetic rubber (40.16 %BW vs. 42.52 %BW, P < 0.042; 40.16 %BW vs. 43.21 %BW, P < 0.022, respectively). Conclusions: Repetitive and excessive plantar loads during long-distance running may result in loads-related injury in lower extremity skeletal tissues for non-rearfoot runners at preferred speeds. Therefore, male non-rearfoot strikers should choose the appropriate overground surface to reduce the risk of lower extremity musculoskeletal injuries.