Western blotting results in each group.

Effect of different frequency with same amount of treadmill exercise on the expression of MMP-13, TIMP-1, NF-κB p65, IκB-β, and COL2A1 expression in knee joint cartilage of rats with MIA-induced OA. Protein expression was determined in western blots of total protein extracted from cartilage tissues as described in Materials and Methods. The data was obtained in three separate experiments β-actin as an internal standard. Differences between CG and the OAG group were significant (*P < 0.001), and differences between the OAG and the treadmill frequency groups were significant (+P<0.001, +aP = 0.030, +bP = 0.001, +cP = 0.039, +dP = 0.010, +eP = 0.038, +fP = 0.002,). One-way ANOVA, n = 3 rats for each group, means with 95% confidence interval.