The influence of shock-pad density and footwear cushioning on heel impact and forefoot loading during running and turning movements

This investigation explored how shock-pad density and footwear cushioning influences soccer players' biomechanics. Ten participants (20.9 ± 2.5 yrs, 83.2 ± 7.1 kg, UK footwear size 10-11) wore three footwear cushioning conditions (soccer boot, soccer boot with cushioning insole and soccer boot with heel insert). Each footwear condition was tested on two shock-pad densities (55 g/litre and 65 g/litre) beneath a third generation carpet. For each footwear-shock-pad combination, eight running trials (3.81 m/s) and eight turning trials (consistent self-selected speeds) were collected. Pressure insole data were collected to provide a measure of player loading at impact and propulsion. Repeated measures ANOVAs demonstrated no main effects of footwear. The greater surface density did however, significantly increase (p < 0.05) measurements associated with loading during running (first metatarsal peak pressure) and turning (peak impact force, lateral heel and first metatarsal peak pressure). These findings suggest that shock-pad density is important in the regulation of player loading.