Evaluation of Muscle Oxygenation and Recovery Dynamics in Individuals With Knee Osteoarthritis

Knee osteoarthritis (OA) is a degenerative joint disease characterized by pain, muscle weakness, and functional limitations that significantly affect lower limb muscle performance. Structural and physiological alterations in the quadriceps muscle, particularly in the vastus medialis obliquus (VMO), have been reported in individuals with knee OA, including reductions in muscle cross-sectional area, intramuscular fat infiltration, vascular changes, and impaired neuromuscular activation. Muscle oxygenation (SmO₂) is an objective indicator of the metabolic status and circulatory capacity of skeletal muscle. However, the oxygenation dynamics of the quadriceps muscle before and after exercise in individuals with knee OA have not been sufficiently investigated. The aim of this study is to evaluate VMO muscle oxygenation at rest, during exercise, and during the recovery period in individuals with knee OA and to compare these parameters with age- and sex-matched healthy individuals. In addition, the study will examine the relationship between muscle oxygenation parameters, muscle strength, functional performance, and pain levels. Understanding these physiological responses may provide insight into the metabolic mechanisms underlying muscle dysfunction in knee OA and may contribute to the development of more individualized rehabilitation strategies.