Table 1.

The mean ± standard deviation and P values of independent sample t-test between OA and asymptomatic groups in mean muscle forces and peak 3D knee joint forces as well as mean knee extensor/flexor muscle forces, torques, and ratios (EFAR and EFTR), where the muscle forces and the joint forces were normalized to the maximum isometric muscle forces and the body weight (BW), respectively.

	OA (n = 11)	Asymptomatic (n = 10)	P value
Mean muscle forces
VINT	0.051 ± 0.020	0.020 ± 0.005	0.001*
VLAT	0.140 ± 0.070	0.057 ± 0.016	0.002*
VMED	0.130 ± 0.065	0.051 ± 0.014	0.002*
RF	0.220 ± 0.110	0.100 ± 0.047	0.006*
SM	0.027 ± 0.016	0.020 ± 0.010	0.230
ST	0.022 ± 0.012	0.015 ± 0.005	0.095
BFLH	0.043 ± 0.012	0.020 ± 0.008	<0.001*
BFSH	0.016 ± 0.004	0.025 ± 0.011	0.033*
GASM	0.088 ± 0.022	0.110 ± 0.025	0.053
GASL	0.064 ± 0.010	0.072 ± 0.019	0.300
SAR	0.028 ± 0.014	0.038 ± 0.015	0.170
GRA	0.069 ± 0.026	0.039 ± 0.017	0.006*
Peak 3D knee joint forces (BW)
Compressive force	2.72 ± 0.21	2.47 ± 0.21	0.047*
ML shear force	0.43 ± 0.03	0.10 ± 0.01	0.001*
AP shear force	0.55 ± 0.12	0.70 ± 0.04	0.140
Mean extensor/flexor values
Flexor activation	0.05 ± 0.02	0.05 ± 0.01	0.250
Flexor torque	0.22 ± 0.07	0.28 ± 0.03	0.057
Extensor activation	0.13 ± 0.05	0.05 ± 0.01	0.026*
Extensor torque	0.25 ± 0.08	0.19 ± 0.04	0.043*
EFAR	3.67 ± 1.14	2.00 ± 0.63	0.040*
EFTR	1.82 ± 0.40	1.27 ± 0.34	0.048*

*Significant differences between the OA patients and the asymptomatic group (P < 0.05).