Certain Terrains Lead to Larger, Faster Ground Reaction Forces During Loaded Running

Running with body borne load reportedly leads to larger, faster vertical ground reaction forces (GRF), and elevates risk of musculoskeletal injury. It is currently unclear, however, whether terrains, such as rocky, squishy, and firm, impact speed and magnitude of vertical GRFs. This study sought to determine how loaded running over different terrain impacts speed and magnitude of vertical GRFs. We hypothesize that the speed and magnitude of vertical GRFs will be larger on the rocky and firm, but smaller on the squishy surface compared to flat terrain. Each participant will run (4.0 m/s) with a body borne load over a rocky, squishy, firm, and flat terrain. During each run, impact peak, loading rate and peak magnitude of vertical GRF will be quantified and submitted to statistical analysis. We expect participants to exhibit a significant increase in impact peak, loading rate, and peak vertical GRF of loaded running when the terrain changes from squishy to flat, flat to firm, and firm to rocky, respectively