Outdoor surfaces are generally uneven as the surface topography diverges in terms of its inclination. Due to variation of inclination, there are risks of injury caused by muscle response and force reaction during gait. The objective of this review is to characterize the effects of incline surface on muscle and forces during walking that contribute to injury. The search strategy was carried out from Worldcat.org database. Majority of the previous studies agree on the fact that muscle response and force significantly change according to the changes of surface inclination. Future studies involving ligament force should be performed in order to obtain a valid result on muscle response and force reaction during inclined gait.
