Effects of Blood‐Flow Restricted Resistance Exercise Versus Neuromuscular Exercise on Self‐Perceived Knee Pain, Function, Quality of Life, and Objective Measures of Functional Performance and Pain Sensitization in Adults With Knee Osteoarthritis—A Randomized Controlled Trial

Standard rehabilitation for knee osteoarthritis (knee‐OA) combines patient education and neuromuscular exercises (NEMEX). Heavy‐load resistance training (HLRT) has shown positive effects on pain, functionality, and muscle mass, but can be painful with knee‐OA. Low‐load blood‐flow restricted resistance exercise (BFR‐RE) has shown comparable effects to HLRT without promoting exercise‐induced pain. Therefore, the present study examined the effect of BFR‐RE vs. NEMEX on self‐perceived knee pain, functional performance, and pain sensitization in knee‐OA individuals. Ninety‐six participants (age 56.7 ± 7.6; 49 females, 47 males) with symptomatic knee‐OA were randomized to 12 weeks biweekly BFR‐RE or NEMEX. BFR‐RE was performed at 60%–80% of total arterial occlusion pressure. Control participants completed a 12‐week NEMEX program. Both groups also attended patient education. Primary outcome : Change in the Knee injury and Osteoarthritis Outcome Score (KOOS) pain subscale from baseline to 12 weeks. Secondary outcomes : Remaining KOOS subscales, Oxford Knee Score (OKS), 30‐s sit‐to‐stand (STS), STS power, 4 × 10 m fast‐paced walking (4 × 10 m‐FWT), stair climb test (SCT), spreading and local pain sensitization measured as pressure pain thresholds (PPT). No significant between‐group difference in the change in KOOS‐Pain was observed (+6.4 points, 95% CI = −1.0–13.7, effect size (ES) = 0.35, p = 0.07) or the remaining KOOS subscales and OKS (ES = 0.05–0.20, p > 0.05). BFR‐RE demonstrated greater improvements than NEMEX for all functional outcomes (STS, STS power, 4 × 10 m FWT, SCT) (ES = 0.89–1.56, p < 0.01) and spreading sensitization (ES = 0.43–0.55, p < 0.05). BFR‐RE and NEMEX were equally effective in reducing knee pain, while BFR‐RE achieved greater statistical gains in functional performance and improved spreading sensitization in persons with moderate knee‐OA. The enhanced improvements with BFR‐RE compared to NEMEX represent novel insights that should be considered in future treatments of knee‐OA.