Topical pain reliever reduces pain during functional activities in knee osteoarthritis (OA)

November 20, 2012 — Researchers in Louisville, Ky., recently studied the effects of Biofreeze Pain Reliever on patients with knee osteoarthritis (OA) and found the decline in pain during functional tasks to be clinically significant.

OA is a common health problem with symptoms including reduced functioning and joint pain. Prolonged pharmacological management of knee OA is associated with side effects including gastrointestinal, renal, and neurological dysfunction. The results of the study were published in September ahead of print in the Journal of Geriatric Physical Therapy.

The purpose of this study, led by Dr. Robert Topp, was to evaluate the ability to complete functional tasks among patients with knee OA pain after a topical application of either 3.5 percent menthol gel (Biofreeze Pain Reliever) or an inert placebo gel. Topp had previously published studies on the mechanisms of Biofreeze topical analgesic, as well as exercise interventions using Thera-Band resistance products in knee osteoarthritis patients.

Twenty knee arthritis patients performed five functional tasks after applying Biofreeze Pain Reliever or a placebo gel on separate days. The researchers recorded changes in performance and pain with each functional task in both conditions. The subjects performed the following functional tasks: six minute walk, timed get up and go, 30-second timed chair stand, and time to ascend and descend a flight of stairs.

Biofreeze Pain Reliever significantly decreased pain in four of five functional tasks, whereas the placebo did not reduce pain in any of the functional tasks. Also, applying Biofreeze to the arthritic knee resulted in improved performance in three out of five functional tasks, whereas the placebo improved only one of the five functional tasks.

Statistically, there were no significant differences between the Biofreeze and placebo in pain or performance; however, according to the researchers, “The declines in pain during the functional tasks appear to be clinically significant ranging from 27 percent to 37 percent decline in pain following the application (of Biofreeze).”

Menthol, the active ingredient in Biofreeze, is thought to reduce pain through biochemical mechanisms by stimulating cold receptors. The study’s authors concluded, “Using topical menthol to compliment standard pharmacological treatment of knee OA may contribute to enhanced pain relief and improve functional ability, particularly during pain-evoking activities.”

Source: Performance Health, performancehealth.com

Reference

Topp R, Brosky JA Jr, Pieschel D. The Effect of Either Topical Menthol or a Placebo on Functioning and Knee Pain Among Patients With Knee OA. J Geriatr Phys Ther. 2012 Sep 12. [Epub ahead of print]