Massage for arthritis: THE PERLMAN STUDY

A more recent study by Perlman et al. consisted of a randomized controlled trial (RCT) specifically focused on massage therapy as an intervention for osteoarthritis of the knee, and serves as a good example of the strengths of this type of research design.8 In this study, adults who had been diagnosed with osteoarthritis by their physician—and had scores above 40 on two different measures of pain—were considered eligible. Patients with other conditions resulting in knee pain or those receiving corticosteroid medications were excluded from participation. Demographic characteristics of the sample were primarily older white women, with a body mass index of 28.5. Sixty-eight patients were then randomly assigned to one of two groups: eight weeks of massage therapy performed by licensed therapists who were NCBTMB certified or to a usual care waiting list, which served as the control group. Sixty-minute sessions were given twice a week for the first four weeks, and then once a week for the remainder of the study. The massage techniques used were Swedish techniques of effleurage, petrissage and tapotement, chosen for their wide availability and applied at the therapist’s discretion. Usual care consisted of pain medications, exercise and application of heat and ice. At the end of the eight weeks, patients on the waiting list crossed over and began receiving massage. Patients in the original treatment group were simply followed for another eight weeks. The primary outcome measures selected included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), a commonly used measure in arthritis studies, and the visual analog scale (VAS) for pain. Both measures use a 0 to 100 scale. The sample size of 68 participants (34 per group) allowed the investigators an 80 percent chance of a clinically meaningful difference of 20 points between the two groups in terms of any changes from baseline scores. Data analysis was based on the intent to treat design, which takes into account the number of participants who didn’t complete the study. Using the number of participants who enter the study as the basis for statistical analysis instead of the number who complete the study, results in a more conservative estimate of the true results—this method makes it harder to reach statistical signifi-cance. Therefore, positive results are more credible. Another feature that increases the credibility of this study is the use of trained practitioners. While the techniques used were limited to the specific Swedish massage strokes, the therapists were allowed to use clinical judgment in their application. This mimics the way that massage is practiced in the real world, and increases the generalizability of the study results. The results of the study were impressive. The mean WOMAC scores in the massage group improved by as much as 12 to 15 points, while the usual care group improved by only three to four points. Pain scores in the massage group improved by 17 points, compared to two in the usual care group. The original intervention group was followed and re-evaluated at the end of the 16-week study period, and these improvements in pain, disability and range of motion were maintained. Massage also appears to be a safe intervention for osteoarthritis. Only one participant withdrew from the study after reporting increased discomfort following the massage. Overall, the results of this study indicate that massage is a safe and effective therapy for osteoarthritis of the knee. The study’s strongest element is its design—the RCT.