Razi Journal of Medical Sciences

Background: Shoes is the first point of contact between the foot and the ground in walking.Any change in that could affect the balance and postural stability. The risks associated with slipping and falling is related to the materials of footwear, surface condition, and geometric design of the shoe sole. The aim of this study was to measure the effect of different shoe sole tread groove depths on the stability during walking on dry and slippery surfaces.

Methods: In this semi-experimental study, 22 healthy young men with average age 24.5±3.43 years wore the oxford standard shoe and walked on two different surfaces (dry and slippery) with three different groove depths (1, 2.5 and 5 mm). In fact, there were six different test conditions. Data was collected by the VICON Motion Analysis system and Force plate set. The Paired T-test was performed to study the effects of groove depth and surface contamination on the Coefficient of Friction (COF) and Fluctuations Rate of Ankle (FRA).

Results: The results showed that on slippery and dry surfaces, increase in groove depths leads to increase of COF and decrease of FRA (p<0.05). Also values of COF on slippery surface were less than dry surface significantly (p<0.01).

Conclusion: The aim of this study was to find the groove depth which has the optimal stability. In our study, the deepest groove (5 mm) was better for reduction of FRA and increase of COF during walking on slippery and dry surfaces.