Effect of low-intensity resistance training with blood flow restriction on functional status in knee osteoarthritis

Abstract

Background: Knee osteoarthritis is a joint pathology with high prevalence, resulting from the increase of aging and obesity in the world population. Articular cartilage destruction can cause pain and eventually reduces activities of daily living and affects functional status in subjects with knee osteoarthritis. Exercise interventions in knee-OA aimed at increasing knee extensor muscle strength involve high-intensity resistance training but may result in joint pain due to high-compressive forces. Other alternative method includes low-intensity resistance training performed with blood flow restriction, a potential intervention for a patient who does not tolerate high loads due to lower mechanical stress. This study aims to determine the effects of blood flow restriction with low-intensity resistance training on the quadriceps for six weeks on functional status in knee-OA patients. Methods: Twenty-eight patients aged 50-70 years old with knee-OA in Physical Medicine and Rehabilitation Outpatient Clinic Soetomo Hospital Surabaya were randomized into control and treatment groups. Both groups underwent a 6-week supervised training program consisting of LI-RT (30% 1-RM) two sessions/week. The treatment group received an additional application of blood flow restriction using a cuff on 1/3 of the upper thigh with 50 mmHg occlusion pressure. Both groups were assessed for functional status by self-reported WOMAC questionnaire before and after the protocol. Results: Both training methods were able to reduce WOMAC pain and improve physical function subscales significantly, but WOMAC stiffness subscales only reduced significantly in low-intensity resistance training with blood flow restriction. There were no significant differences between groups for any domain from WOMAC, nor any significant differences between delta scores (all P > 0.05). Conclusion: Low-intensity resistance training with and without blood flow restriction was similarly effective in enhancing functional status in subjects with knee osteoarthritis.