Description

Knee osteoarthritis (KOA) is a chronic, progressive degenerative condition commonly affecting older adults and is a major cause of disability. It is characterized by degeneration of articular cartilage, subchondral bone changes, and synovial inflammation. KOA results in pain, stiffness, impaired balance, reduced physical function, and diminished quality of life, leading to significant psychological and socioeconomic burden. Knee osteoarthritis (KOA) develops due to several factors including mechanical stress, obesity, joint injury, aging-related cartilage wear and tear, genetic predisposition, and low-grade inflammation that damages the cartilage.

Physical therapy is a key component of KOA management and focuses on pain reduction, restoration of joint mobility, and improvement in functional ability and quality of life through exercises such as quadriceps strengthening, gait and balance training, and aerobic or aquatic exercises. Quadriceps strengthening helps stabilize the knee joint, reduce abnormal loading, and improve shock absorption, thereby decreasing joint stress during daily activities.

In addition to quadriceps weakness, patients with KOA commonly exhibit reduced calf muscle strength compared to healthy individuals. The calf muscles, particularly the gastrocnemius, play an important role in knee stabilization, load absorption, and functional movements such as walking. Altered gastrocnemius activation during weight-bearing activities can negatively affect knee biomechanics and contribute to disease progression. Muscle strengthening exercises have been shown to improve muscle strength, balance, and reduce joint inflammation in KOA patients.

Literature review: In a study carried out by Paul DeVita et al in 2018 weaker quadriceps increased the risk and progression of KOA, while strengthening the quadriceps improves pain, physical function, and quality of life by providing better knee stability and reducing joint stress.

A 2020 study by Ali M. Alshami et al. reported that compared to healthy adults, calf muscle weakness and atrophy is common in patients with KOA, with muscle strength notably decreased despite flexibility and girth not being significantly affected to be.

Zhanliang Tan et al in 2025 stated that HKE targeting gastronomies muscle effectively and safely alleviated knee pain and restored function.

A systemic review by Disha D hedge et al in 2025 states that Quadriceps strengthening as a part of lower extremity strengthening is effective in reducing pain in KOA. Emine Kiyak (2018) reported that about 81% of KOA patients significant difficulties in maintaining sleep. Patients with KOA suffered from night pain, which significantly disrupted sleep and contributed to poorer overall sleep quality, ultimately diminishing quality of life.