Table 4.

Results of stepwise multiple regression analysis for the WOMAC stiffness.

WOMAC Stiffness	K/L < 2			K/L ≥ 2
	95% CI for Estimate		p	95% CI for Estimate		p
	Lower	Upper		Lower	Upper
Spouse (presence/absence)	0.004	0.578	0.047
Nutrition status (risky/well nourished)				0.546	1.778	<0.001
Grip strength (low/robust)	0.257	0.894	<0.001
Knee extension 60 peak torque (Nm/kg)	−0.015	−0.006	<0.001	−0.027	−0.007	<0.001

K/L, Kellgren–Lawrence grade; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index; 95% CI, 95% confidence interval. p-values were determined by stepwise multiple regression analysis. Knee extension 60 peak torque was a continuous variable. Spouse (reference group: no), nutrition status (reference group: well nourished), and grip strength (reference group: robust) were categorical variables.