“…The impact forces and shock waves are influenced by the subject's weight, speed, kinematic arrival of the foot to the ground, the footwear and surface properties, among others (10,11). Some studies analyzed various methods and materials for determining the shock absorption during gait (10,11,12) however, studies have been found (10,11,13,14,15,16,17,18,19) which used the rate of loading, first peak force and temporal variables of the vertical ground reaction force to compare/analyze shoes or parameters during gait. Currently, there are several studies focused on minimalist shoes, leaving aside the unstable shoes.…”