B-13 Grip Designing based on Hill Running Motion Analyses

Abstract

In trail running, runners often meet slippery condition, such as uneven, wet, muddy surfaces with slope. On these surfaces, slip/fall risk gets drastically higher and running performance gets decreased due to traction loss between shoe and floor. Therefore, grip property is crucially important function in the designing process of trail running shoe. The purpose of this study is to clarify grip generation mechanism for trail running shoe designing based on uphill and downhill running (hill running) motion analyses. Ground reaction force (GRF) distributions in hill running were corrected by using a specific sensor shoe system. In comparison of GRF distribution between hill and flat surface running, higher horizontal force was produced in forefoot medial side area at kicking phase during uphill running. On the other hand in downhill, higher horizontal force got higher in lateral side of fore-midfoot area at the beginning of contact phase than that in flat surface running. Interestingly, it is confirmed that force direction of these areas was quite different between hill and flat surface running. In order to check the validity of obtained results, grip properties were evaluated with two pair of developed test shoes having different tread patterns. As a result, it was concluded that the oblique shaped tread patterns corresponding to horizontal force direction on hill running motion efficiently increase grip.