Knee osteoarthritis is one of the most prevalent musculoskeletal conditions in the world, causing pain, functional limitation and a significant impact on quality of life. Although there is still no definitive cure, physical exercise has been shown to lead to benefits in both pain control and improved functionality. We highlight some studies that have revealed the positive impact of physical exercise programmes on the management of knee osteoarthritis.
Benefits of physical exercise in pain control
A study conducted by Henriksen et al. (2014) demonstrated that a 12-week muscle strengthening and motor control exercise programme supervised by physiotherapists significantly reduced pain sensitivity in patients with knee osteoarthritis. In addition to relieving the pain reported by patients, physical exercise helped to improve the underlying mechanisms of pain, such as reducing pressure sensitivity and decreasing pain amplification after the application of a series of nociceptive (painful) stimuli, a process known as ‘temporal summation’.
Also noteworthy is the study by Helmark et al. (2010), which demonstrated that a single session of physical exercise was sufficient to induce an intra-articular anti-inflammatory response in patients with knee osteoarthritis. It is known that the inflammatory process that characterises this condition can also contribute to pain symptoms, so the acute effects of physical exercise may be relevant for better control of this symptom in patients with knee osteoarthritis.
The results thus suggest that exercise not only relieves symptoms but also positively influences the neurophysiological and inflammatory processes associated with the pain experienced by these patients, making it an essential approach to the rehabilitation of patients with osteoarthritis.
Strength Training: High or Low Intensity?
One of the most effective types of exercise for reducing pain and improving quality of life and functionality in patients with knee osteoarthritis is strength training. A study conducted by de Zwart et al. (2022) compared the effects of high- and low-intensity strength training in patients with knee osteoarthritis. Both groups performed physical exercise supervised by physiotherapists for 12 weeks, focusing on strengthening the lower limb muscles.
The results showed that both high-intensity training (70-80% of maximum strength) and low-intensity training (40-50% of maximum strength) provided significant increases in muscle strength and functionality. There was no significant difference in pain reduction between the two groups, suggesting that both methods may be effective, depending on the individual preferences and conditions of the patient. It is important to note that both programmes were well tolerated by the participants, indicating the safety of this approach.
Practical Recommendations
Based on these studies, it can be said that physical exercise is a very important intervention in the treatment of knee osteoarthritis, and the following recommendations should be considered.
Supervision: Programmes supervised by physiotherapists are essential to ensure the safety and effectiveness of the exercises.
Consistency: For best results, patients should follow a regular exercise programme, with sessions two to three times a week.
Personalised Approach: The selection of the exercise dose to be performed should consider the patient's pain level, functional capacity and goals.
Pedro Machado
Physiotherapist and researcher
