The Effect of Medical Exercise Therapy on Pressure Sensitivity in Patients with Knee Osteoarthritis: A Cohort Pilot Study

INTRODUCTION: While continued research into pain and exercise may address the underlying mechanisms, the mechanisms through which exercise may act are still poorly understood. The purpose of this study was to examine the effects of medical exercise therapy on pressure sensitivity in knee osteoarthritis patients, and to assess whether the decreased pain perception after medical exercise therapy can be explained by changes in pressure sensitivity. METHODS: We adopted acohort design in which 16 patients with long term pain were tested before and after 3 months of medical exercise therapy intervention. Pain was detected by visual analogue scale (VAS) and a digital pressure algometer, which also assessed pressure sensitivity. Function (Knee Osteoarthritis Outcome Score, KOOS), anxiety and depression (HAD) and kinesiophobia (Tampa Scale of Kinesiophobia, TSK) were also measured. RESULTS: The VAS showed a statistically significant reduction of perceived pain, from 5.19 (SD 2.04) to 4.12 (SD 2.09) from pre- to post-test (p < 0.05). There was no significant change in pressure algometry on either the painful side or the non-painful side. CONCLUSION: As there were no significant correlations between the reduced pain perception and pressure sensitivity in knee osteoarthritis patients, we suggest that local knee pain does not necessarily alter generalized sensitivity. These findings should be further investigated in a randomized trial in the future. TRIAL REGISTRATION: Clinicaltrials.gov, identifier NCT02905747.