Introduction

Knee osteoarthritis is a common condition affecting millions worldwide, especially older adults. It often causes pain, stiffness and reduced mobility, affecting everyday life. Thankfully, targeted exercise is a powerful way to ease symptoms and improve knee function. This article outlines safe, effective knee-strengthening exercises, highlights movements to avoid, and offers practical tips for doing these exercises at home or in the gym.

Understanding Knee Osteoarthritis and Why Exercise Matters

Knee osteoarthritis is a degenerative condition where the cartilage cushioning the bones gradually wears down. This leads to pain, swelling, stiffness and a reduced range of movement, making simple tasks like walking or climbing stairs difficult. Research shows that exercise plays a vital role in managing knee osteoarthritis. Moving regularly helps strengthen the muscles around the knee, which supports the joint and reduces strain. Exercise also helps ease pain and improve function by keeping the joint flexible and well-lubricated. As one recent study highlights, “Previous research has demonstrated the therapeutic potential of aerobic exercise in alleviating symptoms of knee osteoarthritis (KOA)” (Luo et al., 2025). Another review found that “closed kinetic chain exercise (CKCE) shows promise in reducing pain and improving function in individuals with knee OA” (Fadil et al., 2025). Moreover, new research supports the use of “nonimmersive virtual reality (VR) applications” to boost muscle activity, balance and pain relief in people with knee osteoarthritis (Sönmez et al., 2025). It’s important, however, to choose exercises carefully and maintain good technique to avoid making symptoms worse.

Essential Knee Strengthening Exercises: Home and Gym Solutions

Strengthening the muscles around the knee — including the quadriceps, hamstrings and calves — helps take pressure off the joint and improve movement. Among aerobic exercises, Pilates stands out: research shows it “appears to be the most effective aerobic exercise modality for managing knee osteoarthritis (KOA), particularly in enhancing overall functional outcomes” (Luo et al., 2025). Closed kinetic chain exercises like sit-to-stand and step-ups are also very effective. In fact, studies show that “CKCE treatment led to greater improvements in pain and function compared to no treatment” (Fadil et al., 2025). Here are five key exercises to include, which you can easily adapt for home or gym:

Sit-to-Stand (Home)

• Sit on a firm chair with your feet flat on the floor, hip-width apart.
• Lean slightly forward and tighten your tummy muscles.
• Stand up slowly without using your hands, then sit back down with control.
• Repeat 10–15 times.

This exercise mirrors everyday movements and strengthens the quadriceps, making daily activities easier. It is also a safe type of closed kinetic chain exercise.

Straight Leg Raises (Home)

• Lie on your back with one leg bent and the other straight.
• Tighten your thigh muscle on the straight leg and raise it to the height of your bent knee.
• Hold for a few seconds, then lower slowly.
• Repeat 10–15 times on each leg.

This movement strengthens the quadriceps without putting undue pressure on the knee.

Pilates-Based Knee Strengthening (Home or Gym)

• Pilates exercises focusing on core control, gentle leg movements and modified bridges activate key muscles without stressing the joint.
• Pilates can be adjusted for all fitness levels, focusing on slow, low-impact movement and mindful muscle use.
• Data show “Pilates demonstrated the highest probability of being optimal for pain, stiffness, physical function and total symptom improvement” (Luo et al., 2025).

Including Pilates in your routine can be especially helpful for reducing pain and restoring knee function.

Hamstring Curls (Gym or Home with Resistance Bands)

• Stand holding onto support for balance.
• Slowly bend one knee, bringing your heel towards your bottom.
• Hold briefly and lower gently.
• Do 10–15 repetitions per leg.

This strengthens the hamstrings, which play a vital role in stabilising the knee.

Calf Raises (Home or Gym)

• Stand near a sturdy support, feet hip-width apart.
• Raise your heels off the floor and slowly lower them back down.
• Repeat 15–20 times.

Strong calf muscles help absorb shocks when walking or running, supporting the knee joint.

Virtual Reality-Based Balance and Functional Exercises (Clinic Setting)

• Guided, nonimmersive virtual reality exercises under professional supervision can boost balance and muscle endurance.
• One study found “significant improvement in endurance, pain levels and independence in daily activities” for patients using VR-based training (Sönmez et al., 2025).

These innovative approaches may enhance engagement and improve outcomes when available.

These exercises are all aligned with NHS and physiotherapy recommendations, underscoring the importance of progressing gradually and being consistent to see benefits.

Exercises and Movements to Approach with Caution

Some movements can strain osteoarthritic knees and should be avoided or adapted. Deep squats and high-impact activities like jumping or running may worsen pain or cause further joint damage by increasing compression inside the knee. Gentler alternatives like partial squats or step-ups onto a low platform are safer and still build muscle strength. Tai Chi is also beneficial; research shows “Tai Chi had the highest likelihood of reducing pain measured by the Visual Analog Scale” (Luo et al., 2025). Always consult a physiotherapist to ensure your chosen exercises suit your condition.

Supporting Your Knee Health: Extra Tips and Resources

Consistency is key to improving knee health. Combine regular exercise with warming up before and cooling down after sessions to reduce injury risk and improve results. It’s important to listen to your body – if an exercise causes increased pain, adjust or stop and seek professional advice if necessary. Bear in mind that, despite promising results, some evidence quality is still considered low. For example, “the quality of evidence is considered low according to the GRADE system” for closed kinetic chain exercises in knee osteoarthritis (Fadil et al., 2025). If you are elderly or have advanced symptoms, personalised rehabilitation plans are advisable. Useful resources, such as printable guides and advanced physiotherapy programmes, are freely available on the NHS website and can help you stay on track.

Conclusion

Targeted knee exercises are a practical and effective way to manage osteoarthritis. By strengthening key muscles, enhancing joint function, and avoiding harmful movements, you can take positive steps towards stronger, healthier knees. Following these expert, science-backed strategies will help you live more comfortably and maintain your mobility for years to come.

References

• Luo, Y., Chen, X., Gong, H., Chen, L., Zhang, L., & Li, S. (2025). Efficacy of aerobic exercises for knee osteoarthritis: a network meta analysis of randomized clinical trials. Journal of Orthopaedic Surgery and Research. https://doi.org/10.1186/s13018-025-05973-z
• Fadil, A., Muaidi, Q., Alayat, M., Almatrafi, N., Subahi, M., & Alshehri, M. (2025). The Effectiveness of closed kinetic chain exercises in individuals with knee osteoarthritis: A systematic review and meta-analysis. PLOS ONE. https://doi.org/10.1371/journal.pone.0322475
• Sönmez, M., Avcı, Ş., Şimşek, F., & Baygutalp, F. (2025). Nonimmersive Virtual Reality-Based Exercises Improve Muscle Excitability and Balance in Patients with Knee Osteoarthritis: A Sham-Controlled Study. Journal of Clinical and Translational Science. https://doi.org/10.1177/2161783X251360443