The therapeutic effect of a flexible and non-heeled shoe on the clinical, functional and gait biomechanical aspects of elderly women with knee osteoarthritis: a randomized clinical trial

Author(s)

Francis Trombini de Souza

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD)
• Defense date: 2013-12-11

Examining board members

Isabel de Camargo Neves Sacco; Marcos Duarte; Silvia Maria Amado João; Jefferson Fagundes Loss

• Advisor: Isabel de Camargo Neves Sacco; Ricardo Fuller

Abstract

Osteoarthritis (OA) is the most common disorder of the musculoskeletal system, and contributes to the incapacity for work of about 15% of the adult population worldwide. Mechanical stress is a major cause of the initiation and progression of OA, especially in joints that are in constant overload and motion, such as the knee. Therefore, reduction of intra-articular overload has been one of the main treatments for this disease. Recent studies have demonstrated that the short-term use of a low cost flexible shoe (Moleca®) can minimize the joint overload. The aim of the current study was to evaluate the therapeutic effect of a low cost, flexible non-heeled shoe on the clinical, functional and gait biomechanical aspects of elderly women with knee OA. A randomized, parallel and controlled clinical trial, with blind assessor was carried out. Fifty-six elderly women with knee OA graded 2 or 3 (Kellgren and Lawrence), assessed at baseline, after three and after six months, were randomly allocated into the intervention group (IG, n = 28) or the control group (CG, n = 28). The use of the Moleca® shoes for six months, for at least six hours a day, seven days a week (42 hours weekly) was adopted as intervention. For both groups, a rescue analgesic medication (acetaminophen) was allowed, only if necessary, in a maximum of 2 grams daily. We adopted the pain subscale of the WOMAC questionnaire as the primary outcome, and the stiffness, function and total score of the same questionnaire, as well as the Lequesne questionnaire score, the distance walked in six minutes, the clinical aspects (edema and joint effusion), the general health condition of the patient, the knee adduction moment and the paracetamol 500 milligrams intake as the secondary outcome. The time effects (baseline, 3 and 6 months) of group (IG and CG) and interaction (time and group) were calculated by two-way casewise ANOVA. We adopted an alfa of 5% for statistical differences and Cohen\'s d coefficient to describe the effect size of the intervention. The results, with large effect sizes for the IG, showed improvement in pain (effect size of 1.41) and function (effect size of 1.22) in WOMAC and Lequesne questionnaires. The CG (to a lesser extent) also showed pain reduction and function improvement. However, this group, unlike the IG, showed higher rescue medication intake throughout the clinical trial, which possibly has provided improvement in its pain and function. No significant difference was observed in clinical aspects, such as edema, joint effusion, or the general health condition of the patient (global assessment of physician and patient). Knee adduction moment impulse reduction was noted in the IG at the end of six months, although not significant. The results of the current study allow us to recommend the use of this low cost minimalist footwear as another conservative mechanical treatment that aims to minimize pain, improve functional aspects, reduce the rescue medication intake, and keep constant the clinical characteristics and knee joint loading in elderly women with knee OA (AU)

• FAPESP's process: 11/01640-8 - Therapeutic effect of a flexible and non-heeled footwear on the clinical, functional feature and gait biomechanics in elderly women with knee osteoarthritis: a randomized clinical trial
• Grantee: Francis Trombini de Souza
• Support type: Scholarships in Brazil - Doctorate