Mechanical stress is an important factor that regulates cartilage metabolisms . Appropriate mechanical stress maintains or increases the amount of sGAG, while excessive mechanical stress decreases it. MIA induces inflammation, inhibits glycolytic system, reduces viability of chondrocytes, and results in degeneration of the cartilage . In this low dosage of the MIA-induced model, forced running further progressed cartilage degeneration in an inflammatory condition. Both mechanical stress and inflammation are the most important factors affecting OA progression, and even though some modifications are required, this is a good model for mimicking OA in rats.