Table 1. Study characteristics.

Author	Year	Study type	Sample size	Measured Parameters (angular velocity)	Measured time points
Anchuela et al.[21]	2001	PCS	28	Q(60°/sec), H(60°/sec)	Preop, 6 Mo, 1 yr
Berman et al.[22]	1991	PCS	68	Q(60°/sec), H(60°/sec)	Preop, 3 Mo, 6 Mo, 1 yr
Lee et al.[23]	1999	PCS	34	Q (90°/sec, 180°/sec), H(90°/sec, 180°/sec)	Preop, 3 Mo, 6 Mo, 1 yr
Lorentzen et al.[24]	1999	PCS	30	Q (30°/sec, 120°/sec), H(30°/sec, 120°/sec)	Preop, 3 Mo, 6 Mo
Schroer et al.[25]	2010	PCS	50	Q(60°/sec), H(60°/sec)	Preop, 3 Mo, 6 Mo, 1 yr

Abbreviations: PCS, prospective comparison study; Q, quadriceps; H, hamstring; Preop, preoperative level