Girth, strength, and flexibility of the calf muscle in patients with knee osteoarthritis: A case–control study

OBJECTIVES: Reduced strength and girth in thigh muscles such as the quadriceps and the hamstrings have been observed in patients with knee osteoarthritis (OA). However, studies on the characteristics of calf muscles in these patients are lacking. This study aimed to evaluate the girth, strength, and flexibility of the calf muscle of patients with knee OA. METHODS: In this case–control study, we recruited 15 patients with knee OA and 15 healthy control participants. The girth, strength, and flexibility of the calf muscle were evaluated in one session using a flexible non-elastic tape measure (centimetre), a handheld dynamometer (Newton), and a standard goniometer (degree) to measure ankle dorsiflexion. RESULTS: Strength of the calf muscle strength was significantly lower in the patients with knee OA comapred with the control group (−42.03; 95% CI: −73.9, −10.1; p = .012). No significant differences in calf muscle girth (.27; 95% CI: −2.63, 3.16; p = .852) or flexibility (−1.93; 95% CI: −4.8, .93; p = .177) were found between the two groups. CONCLUSION: In our study, patients with knee OA demonstrated reduced calf muscle strength. We recommend that the management of patients with knee OA include strengthening the calf muscles.