Effect of Surface Type on Impact Force, Loading Rate, and Free Moment during Stance Phase of Running

More than 60 % of runners suffer from overuse injuries each year. Exercise and Running surfaces can prevent injuries and/or improve performance. The present study aims to investigate the effect of three types of running surfaces (Polyvinyl Chloride (PVC), artificial turf, and sand) on the Ground Reaction Force (GRF) components in the stance phase of running.

Impact force, loading rate, and free moment of 15 men were recorded while running barefoot on three PVC, artificial turf, and sand surfaces at a speed of 3±0.2 m/s (Average of 5 correct attempts). Comparison between different conditions was performed using repeated measures ANOVA and Bonferroni’s Post-Hoc Test.

The sand surface significantly reduced the impact force compared to the PVC and artificial turf. Both sand and artificial turf caused a significant reduction in the force loading rate compared to the PVC surface. The second peak of vertical GRF (propulsive force) increased at sand (P=0.001) and artificial turf (P=0.005) surfaces compared to the PVC surface. Moreover, the sand surface reduced adductor torque compared to the PVC (p < 0.001) and artificial turf (P=0.003) surfaces, while the artificial turf reduced abductor torque compared to the PVC surface (P=0.011).

Sand is a safer surface for preventing running injuries due to eliminating impact force, reducing loading rate, and having high shock absorption. Training on a sand surface may improve performance on harder surfaces.