The purpose of this article is to review the literature that deals with the biomechanical analysis of the ankle during gait stance phase on slopes, on uneven and rock surfaces, on sand, and on grass surfaces, as well as to present the observed differences.

Methods:
The literature was searched in the databases of PubMed and Google Scholar, for the years of 2005–2015. The keywords were: biomechanics, gait analysis, ankle joint, stance phase, uphill walking, downhill walking, sand surface, uneven surface, grass surface, and ballast.

Results:
The kinetic and kinematic gait behaviour is directly influenced by the surface on which it is being performed. The uphill or downhill surfaces, the surfaces of stone, sand, grass, and uneven surfaces have a direct impact on the biomechanics on joints of the lower limb, changing the energy cost, muscle activation, the resulting mechanical work, ground reaction forces and balance, and the parameters of the gait cycle. All these changes are raising many questions about the safety and comfort of these surfaces. In the structures of the foot, ankle and lower leg high compressive and rotational forces are transmitted resulting in injuries in these regions.

Conclusions:
Each surface has its own advantages and disadvantages, changing the biomechanics of the lower extremity and particularly the ankle. According to the purpose that one wants to achieve they can choose a suitable surface. To prevent injuries and falls, we must choose shoes that fit well, are comfortable with cushioning, and have a feeling neither too hard nor too soft, with laces and low collar.