Effects of nail softness and stiffness with distance running shoes on ground reaction forces and vertical loading rates in male elite long-distance runners with pronated feet

Table 2 Ground reaction forces and their time to peak at heel contact during running in single-stiffness and dual-stiffness spike running shoes

Variables	Components	Means ± SDs Single-stiffness spike shoes (Control)	Means ± SDs Dual-stiffness spike shoes	t	Sig	Effect size (d)
GRF (% BW)	Fx_HC	13.76 ± 8.57	7.57 ± 4.42	2.578	0.021	0.95
GRF (% BW)	Fz_HC	159.92 ± 19.83	129.48 ± 24.49	−2.874	0.010	1.40
TTP (% Stance time)	Fz_HC	18.06 ± 6.36	23.75 ± 1.73	−3.405	0.004	1.40

Fx_HC peak lateral ground reaction force during heel contact, Fz_HC peak vertical ground reaction force during heel contact, SD standard deviation, TTP time to peak

ISSN: 2052-1847