How Do Muscle Function and Quality Affect the Progression of KOA? A Narrative Review

Knee osteoarthritis (KOA) is widely recognized as a chronic joint disease characterized by degeneration of knee cartilage and subsequent bone hyperplasia. However, it is important to acknowledge the significant role of muscles in the development and progression of KOA. Muscle function (MF) and muscle quality (MQ) are key factors in understanding the involvement of muscles in KOA. Quantitative indices such as muscle mass, muscle strength, muscle cross-sectional area, muscle thickness, and muscle fatigue are crucial in assessing MF and MQ. Despite the growing interest in KOA, there is a scarcity of studies investigating the relationship between muscles and this condition. This review aims to examine the commonly used indices and measurement methods for assessing MF and MQ in clinical settings, while also exploring the association between muscles and KOA. Furthermore, this article highlights the importance of restoring MF and MQ to enhance symptom management and improve the quality of life for patients with KOA.