Why Exercise Can Benefit Arthritis Pain
Why Is Arthritis So Painful?
There is a sling of tissue made up of ligaments and muscles that surround a joint: as the joint space narrows, the surrounding tissue stays the same length, and the sling of what was once supportive tissue now becomes loose, which allows the bones to shift, shear, and wear down the cartilage on the joint surfaces. It is this extra shearing that typically causes inflammation and joint pain. Over the years or even decades, our body will naturally tighten up the joint by laying down layers of inelastic scar tissue, which act to restrict the flexibility of the joint (Andriacchi,2004). This would explain why people describe arthritis as stiffness, when actually this condition begins with the joint being too loose!
Exercise Can Help For 3 Reasons
First, when you strengthen a muscle, it tightens and shortens in length. By strengthening the muscles that surround the joint (ex. for the knee- quad, hamstrings, calf), the tightness will cradle the joint, which stops the bones from shearing against each other. Less shearing equals less joint pain. (Irrgang & Pezzullo, 1998)
Secondly, cartilage unlike other tissues in the body, has a poor blood supply; it receives nutrition only from the synovial fluid that is normally found in the joint. Exercise helps by moving the nutritious fluid to every part of the joint, and the impact of exercise squeezes the nutrients into the cartilage. (Andriacchi,2004).
Thirdly, research has recently shown that exercise can increase glycosaminoglycans, which are part of the building block to cartilage. In a Swedish study, people with osteoarthritis skipped rope, jogged on treadmills, and performed strengthening exercises, three times a week for four months. At the end of the study, there was a significant improvement in their pain levels and the structure of the cartilage in those people who had exercised versus the control group. (Roos & Dahlberg, 2005)
Where to Start
Strengthening exercises that are non-weight bearing are the best place to start; Pool workouts, biking, tubing exercises, and balance training can all be helpful. There is an optimal amount of exercise load and repetitions that result in good cartilage health, and if the load or repetitions exceeds this zone, injury can occur. This is why it is best to consult with a Physiotherapist who is trained to assess muscle strength, joint stability and mobility, use manual therapy and needling techniques to reduce pain, and instruct an exercise program tailored to the patient. (American College of Rheumatology Subcommittee on Osteoarthritis Guidelines, 2000)
References:
- American College of Rheumatology Subcommittee on Osteoarthritis Guidelines. (2000) Recommendations for the medical management of osteoarthritis of the hip and knee: 2000 update. Arthritis &Rheumatology. Volume 43, pp 1905–15.
- Andriacchi, T. P., Mündermann, A., Smith, R.L., Alexander, E.J., Dyrby, C., Koo, S. (2004) A Framework for the in Vivo Pathomechanics of Osteoarthritis at the Knee. Annals of Biomedical Engineering, Volume 32, Issue 3, pp 447-457
- Irrgang,J.J, and Pezzullo, D. (1998) Rehabilitation Following Surgical Procedures to Address Articular Cartilage Lesions in the Knee. Jounal of Orthopaedics Sports Physical Therapy. Volume 28, Issue, pp 232-240
- Roos, E. M., Dahlberg, L. (2005) Positive effects of moderate exercise on glycosaminoglycan content in knee cartilage: A four-month, randomized, controlled trial in patients at risk of osteoarthritis.Arthritis & Rheumatism, Volume 52, Issue 11,pp 3507–3514