Table 4 Pearson's correlation coefficients between knee flexion angles at the time of peak vertical ground reaction force (VGRF) and peak VGRF and loading rate (LR) VGRF.

Group	DJ height (cm)	Knee flexion angle
		Peak VGRF	LR VGRF
CON	30	–0.78**	–0.82**
	50	–0.90**	–0.89**
	70	–0.88**	–0.89**
PJK	30	–0.92**	–0.82*
	50	–0.81*	–0.89**
	70	–0.83*	–0.97**
RJK	30	–0.92**	–0.92**
	50	–0.96**	–0.96**
	70	–0.43	–0.57

CON, control; DJ, drop jump; LR VGRF, loading rate vertical ground reaction force; PJK, previous jumper's knee; RJK, recent jumper's knee.

*Significant at p<0.05.

**Significant at p<0.01.