Blood flow restriction training for U.S. Veterans with knee osteoarthritis: A pilot randomized controlled trial

Introduction: Knee osteoarthritis (KOA) is a burdensome disease among Veterans. Strength training (ST) can improve pain and function in KOA; however, increases in exercise load often result in increased pain. ST with blood flow restriction (ST+BFR) can use less exercise load and increase strength and function, but few studies have examined these effects among Veterans with KOA. This study explored the feasibility, acceptability, and safety of a ST+BFR intervention and explored differences in function, strength, and self-reported outcomes between groups of Veterans with KOA. Methods: This pilot randomized controlled trial compared ST+BFR with ST only among U.S. Veterans with mild to moderate KOA. Measures of feasibility and acceptability were collected. Safety was monitored via adverse events. Clinical outcome measures included physical function (six-minute walk distance, 30-second sit to stand, and 40-metre walk test), knee muscle strength (extensor and flexor), and self-reported pain and function. These outcomes were compared 10 weeks and six months from baseline using mixed-effects regression. Results: Of 33 Veterans, 29 completed the study (94% men). Nine mild adverse events occurred. Participants reported that the ST+BFR intervention helped improve functional strength and mobility and encouraged them to be more physically active. Both groups made significant improvements in physical function, knee muscle strength, and self-reported pain and function compared with baseline; however, no between-groups differences were observed. Discussion: A ST+BFR intervention was feasible, safe, and acceptable among mostly men U.S. Veterans with KOA. No differences were observed between groups. A larger randomized trial of this intervention appears justified.