Isometric exercise for knee osteoarthritis: A systematic review and meta-analysis

Abstract

Knee osteoarthritis (KOA) is a common degenerative disease that severely affects patients' quality of life and imposes a heavy economic burden. Exercise therapy is widely applied due to its minor side effects and significant efficacy. Isometric exercise, a form of strength training that involves muscle contractions at a fixed joint angle, has shown positive effects on KOA, while existing studies still show some controversy. This study evaluated the effectiveness of isometric exercise for KOA through a systematic review and meta-analysis, following PRISMA reporting guidelines and registered in PROSPERO (ID: CRD42024551748). Nine studies involving 688 participants were included in the systematic review and meta-analysis. Results demonstrated that isometric exercise significantly reduced pain (SMD = 0.69, 95 % CI: 0.46–0.92, P < 0.001), improved physical function (SMD = 0.63, 95 % CI: 0.40–0.87, P < 0.001), and enhanced muscle strength (SMD = 0.44, 95 % CI: 0.12–0.76, P = 0.007) compared to control groups. Subgroup analysis results showed that the therapeutic effects of isometric exercise varied under different intervention types and frequencies. However, when compared with isotonic exercise, isometric exercise did not show significant advantages in pain relief, functional improvement, or muscle strength enhancement. These findings suggest that isometric exercise is a viable and effective option for managing KOA. Clinically, the appropriate exercise regimen should be selected based on the specific conditions of patients. Despite some limitations, the study results still provide valuable references for clinical practice.

Keywords

• Isometric exercise
• Knee osteoarthritis
• Meta-analysis