Effect of Blood Flow Restriction in Low-Intensity Resistance Training of Quadriceps Femoris on Lower Extremity Strength in Patients with Knee Osteoarthritis

Background: Strengthening exercises on the quadriceps muscles can improve the physical function of people with knee OA (KOA). Low-intensity resistance training (LI-RT) with Blood Flow Restriction (BFR) increases muscle strength, equivalent to high-intensity resistance training (HI-RT). However, little is known regarding the effect of BFR exercises on lower extremity strength in patients with KOA measured by 30STS test and the prescriptions are still very diverse. This study aim determine the BFR effect in LI-RT of the quadriceps femoris muscle on lower extremity strength in patients with KOA measured by 30 Seconds Sit to Stand (30STS) test. Methods: Twenty-eight patients with Kellgren Lawrence grades 2 and 3 KOA. The intervention group (n=14) received LI-RT with BFR, while the control group (n=14) only received LI-RT. Lower extremity strength was measured by 30STS test before and after 6 weeks of exercise. Results: There was a significant difference in each group's 30STS score before and after training (p < 0,05). There was a significantly higher 30STS score after the exercise and the delta value (p < 0,05) in the intervention group compared to the control group. Conclusions: The BFR addition in LI-RT for 6 weeks increases lower extremity strength in patients with KOA.