The influence of footwear tread groove parameters on available friction

•The available friction provided by a shoe outsole is influenced by many factors, including the design of tread grooves.•We investigated the influence of three tread groove parameters (width, depth, and orientation) on available friction.•Groove orientation had the greatest impact on available friction.

The purpose of this study was to determine how footwear tread groove parameters influence available friction (COF). Utilizing a whole shoe tester (SATRA STM 603), 3 groove parameters (width, depth and orientation) were evaluated. Groove orientation had 3 levels (parallel, oblique and perpendicular), width had 3 levels (3, 6 and 9 mm) and depth had 3 levels (2, 4 and 6 mm). In total, the COF of 27 shoes, each with a distinct groove combination, was assessed on wet porcelain tile. The 27 groove combinations produced a wide range of COF values (0.080–0.344). Groove orientation had the greatest impact on COF, explaining the greatest variance in observed COF values (ŋ2 = 0.81). The most slip resistant groove combination was an oblique orientation, with 3 mm width and 2 mm depth. The least slip resistant groove combination was a parallel orientation, with a 6 mm width and 6 mm depth.