Understanding the influence of surface roughness on the tribological interactions at the shoe–surface interface in tennis

Abstract

The traction provided by shoe-surface interactions in tennis can have an impact on player safety, performance and overall enjoyment of the sport. There is a requirement for an improved scientific understanding of the tribological interactions at the shoe-surface interface and the effects that footwear and surface characteristics have on the traction developed. The aim of this study was to investigate the influence surface roughness has on traction present during a sliding contact between a shoe and an acrylic hard court tennis surface. The substrate of acrylic hard court tennis surfaces are formed from a coating of a silica sand and acrylic paint mix, giving them variations in surface roughness characteristics. Mechanical traction tests were performed on five surfaces of varying roughness at normal forces of between 400 N and 800 N with a commercially available acrylic hard court tennis shoe (with a herringbone outsole pattern) and a shoe with a flat outsole. Significant linear relationships were found between dynamic traction force and normal force. A trend for decreased dynamic traction with increased roughness was found. When examined under a microscope after testing evidence of contact between the shoe and the surface decreasing with increased surface roughness was found. With the flat shoe, surface roughness affected the relationship between the coefficient of traction and the normal load. As roughness increased the coefficient of dynamic traction becomes less dependent on normal force. Evidence of a sudden increase in traction with the flat shoe when tested on the roughest surface suggests other friction mechanisms caused by the outsole overcoming the roughness of the surface, such as abrasive wear, had a significant effect on dynamic traction force.

Tennis shoe–court interactions: examining relationships between contact area, pressure and available friction

“…The vertical loads ranged from 600 to 1600 N in intervals of 200 N. Three commercially available hard court tennis shoes of the same design but ranging in size (EU sizes 31, 39 and 49) were tested. The shoe-surface contact area of the forefoot segments was calculated using an ink print protocol developed previously (Clarke et al, 2012). Blank paper was rigidly attached onto a smooth acrylic sheet under the shoes before they were loaded.…”

“…The magnitude of these forces in combination with other variables, e.g. surface roughness (Clarke et al 2012) and shoe orientation (Ura et al, 2013) affects the friction generated between the shoe and surface. Previous tennis studies have reported peak vertical forces of 1243.9 ± 99.1 and 1680.5 ± 483.7 N on hard court for a side jump and running forehand movements respectively (Damm et al, 2013).…”

The development of an apparatus to understand the traction developed at the shoe–surface interface in tennis

“…the addition of computer-controlled valves allowing a range of dynamic load patterns). A number of studies have used velocity controlled motor-driven mechanical test devices when investigating the traction of shoesurface interactions in sport [35][36][37]. It is argued that velocity-driven traction test devices are not suitable for classifying the traction developed during the initial movement of a shoe relative to a surface.…”

Effect of shoe orientation on shoe-surface traction in tennis

“…For example, the execution of a deliberate sliding movement will depend on the dynamic traction developed (Driscoll et al 2012). In tennis an understanding of translational traction for varying shoes, surfaces and loading conditions via mechanical testing has been reported (Clarke et al 2011(Clarke et al , 2012a(Clarke et al , 2012b(Clarke et al , 2013. In tennis, players continuously perform sideways movements yet there is little reported literature to date that examines the influence the shoe orientation has on traction (Driscoll et al 2012).…”