News

The immediate effects of exercise on pain are not clearly understood

Lateral epicondylalgia, which is commonly referred to as tennis elbow, is a painful condition that affects about 1-3% of the general population. Tennis elbow is the result of inflammation of tendons at the elbow that travels to the wrist, and it develops from overuse in sports and other activities. Individuals who play tennis and other racquet sports are at the greatest risk for tennis elbow, but it can also develop in anyone else that performs activities requiring the use of the elbow and wrist on a regular basis. Patients with tennis elbow typically experience pain on the outside of their elbow that becomes worse with certain movement and gripping motions, and exercise is considered an important part of treatment to address these symptoms. Although the benefits of exercise for treating tennis elbow have been well established, its immediate effects on patients' perception of pain are not known. Therefore, a study was conducted to determine how patients' perception of pain is affected by certain exercises, which can help physical therapists better cater exercises specifically to each patient.

Three measures used to evaluate patients' pain

Patients with tennis elbow for at least six weeks were invited to participate in the study and screened to determine if they were eligible. This led to a total of 24 individuals with an average age of 52 years being accepted. The experiment was conducted by having each participant perform two different exercises for the wrist and measuring their pain levels before and afterward. Each wrist exercise was performed 10 times and held for 15 seconds each with a 15-second rest, and patients also completed a control condition to compare to the exercises in which they remained seated with the arm resting. Participants were evaluated with the following three pain measurements before, immediately after and 30 minutes after each exercise: pain intensity, pressure pain threshold (the minimum force applied that leads to pain) and pain-free grip force (the amount of force a patient can generate to the onset of pain).

Exercises performed above patients' pain threshold increase pain intensity

The results of these measurements showed when the patients performed the exercises at 20% above their pressure pain threshold, it increased the intensity of their pain immediately after the exercise. When the same exercise was performed at 20% below their pain threshold, though, it did not have the same effect. This pain intensity was also found to remain significantly higher 30 minutes after performing the exercise above their pain threshold. Finally, the patients with greater pain and disability or fear of movement unsurprisingly reported greater pain intensity during these exercises as well. These findings show that certain exercises performed beyond a patient's pain threshold can cause pain that lasts for at least 30 minutes afterward and that it may be worse in those that already have higher pain and disability levels. Although further research is necessary, this study may help to better shape exercise programs for patients with tennis elbow, as physical therapists can take account of their pain threshold and cater their exercises accordingly. Doing so will help to improve treatment for this condition while avoiding any unnecessary pain for patients.