Physical exercises are strongly recommended for the treatment of knee osteoarthritis (KOA). However, when subjected to loads that overload the joint, these individuals may experience worsened symptoms and low adherence to treatment. Evidence shows that exercises combined with Blood Flow Restriction (BFR) allow for strength and muscle endurance gains using lighter loads. Therefore, it is necessary to investigate whether this method can help patients reduce pain and joint discomfort as effectively as exercises with heavier loads.

To assess the efficacy of 40% occlusion with blood flow restriction in improving pain in patients with knee osteoarthritis.

Clinical study with 16 patients (12 women, 4 men; average age 51.31 ± (9.1) years), divided into three groups: 40% BFR + Rest (n = 4), 40% BFR + Low Load (n = 6), and HIRE (High Intensity Resistance Exercise) + Placebo (n = 6). Pain was assessed before and after one month using the Visual Analog Scale (VAS).

Regarding the initial pain scale, the averages were: 3.5 ± 3.3 for the 40% BFR + Rest group, 6 ± 3.16 for the 40% BFR + Low Load group, and 3.83 ± 3.25 for the HIRE + Placebo group. Regarding the final pain scale, the averages were: 3 ± 3.4 for the 40% BFR + Rest group, 4 ± 3.87 for the 40% BFR + Low Load group, and 0.6 ± 1.21 for the HIRE + Placebo group. Thus, when evaluating pain levels before and after one month of treatment, the 40% BFR + Rest group showed a pain reduction of approximately 14% on average, while the 40% BFR + Low Load group demonstrated a reduction of around 33%, and the HIRE + Placebo group reduced the average by about 84%, indicating a greater improvement in pain compared to the 40% BFR + Rest and 40% BFR + Low Load groups.

Thus, it is concluded that all groups showed improvement in the investigated outcome, but the group using high loads (HIRE + Placebo) still appears to be more effective in reducing knee pain in patients with osteoarthritis.

It is expected that the results of this clinical study will clarify the applicability and implementation of 40% BFR in the rehabilitation of OA.