The effect of stud shape on penetration characteristics through synthesized natural turf in football

The aim of this study was to provide information to footwear manufacturers to assist improvements in player performance and injury rates. Custom-made studs were dropped onto a synthesised natural turf surface using a bespoke instrument drop-rig. Ten drops were performed with each stud and the acceleration profile from contact to a depth of 30 mm was recorded. Theoretical predictions were made based on the soil mechanics used in civil engineering. A difference/reverse Helmert contrast ANOVA revealed two significant differences in the rate of penetration and a regression analysis indicated that perimeter length made a significant contribution (p < 0.01) to predicting the negative jerk of the studs. There were no significant differences or relationships associated with time taken to reach a depth of 30 mm. This study provides a plausible explanation for the somewhat expected differences in penetration behaviour. It also highlights a key development in establishing a methodology for this type of work.