The Role of Knee Positioning and Range-of-Motion on the Closed-Stance Forehand Tennis Swing

Table 4. Hip and trunk rotations and correlations with knee positions and ROM.

Hip Trunk Rotat	Mean (Nm)	SD (±) (Nm)	Rear Knee IP: Setting (R²)	Rear Knee ROM: Setting (R²)	Front Knee IP: Swing (R²)	Rear Knee IP: Swing (R²)	Front Knee ROM: Swing (R²)	Rear Knee ROM: Swing (R²)
Hip: Setting	-7.8	2.8	----	.338	----	----	----	----
Trunk:Setting	-17.4	4.6	----	.244	----	----	----	----
Hip: Swing	72.4	9.4	----	----	.132*	.179*	----	.652
Trunk:Swing	97.8	12.7	----	----	----	----	.374#	.414

All variables are significant at p<0.05 unless indicated by*.# This correlation is only for subjects that extended their front knee during the swing phase. There was no correlation found for those subjects that flexed their front knee during the swing phase.