Effects of a strengthening program for foot-ankle muscles in clinical aspects and gait biomechanics of people with knee osteoarthritis: a randomized blinded clinical trial

Abstract

Strengthening the muscles of the trunk and lower limbs causes a number of benefits to patients with knee osteoarthritis (OAJ) but does not reduce the internal load of the knee during gait, being the major responsible for the progression of the disease. Recent studies have shown that strengthening the ankle and foot muscles improved impact absorption during gait in the elderly, function in diabetics and reduced patellofemoral pain. However, it is not yet known if they would also reduce the internal knee load in OAJ patients. Reducing knee overload in individuals with OAJ could improve pain and slow disease progression, benefiting this population. Objective: To evaluate the effect of an ankle and foot muscle strengthening program on pain, analgesic consumption, functionality, and lower limb biomechanics during gait in individuals with OAJ. Methods: Individuals diagnosed with OAJ will be recruited based on the criteria of the American College of Rheumatology and randomly assigned to two groups: OAJ-Control (without intervention) and OAJ-Exercise (submitted to an ankle and program of exercise, foot for 8 weeks). Pain, analgesic consumption, functionality and lower limb biomechanics during gait will be evaluated. Three evaluations will be performed in both groups: before and immediately after the end of the intervention and 8 weeks after the end of the intervention (follow-up). The interventions (3x / week, alternate days, for 8 weeks) will be in person and supervised. The analysis of the results will be by intention to treat using 2 x 3 mixed model ANOVAs (group x time), with significance level of ± = 0.05 and 95% confidence interval. The hypothesis of the study is that strengthening the ankle and foot muscles decreases pain and improves knee biomechanics while walking in OAJ patients. (AU)