Effects of Blood Flow Restriction Training on Strength and Functionality in People With Knee Arthropathies: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials.

Previous meta-analyses show contrasting findings regarding the effects of blood flow restriction training (BFRT) in different knee conditions. Furthermore, no previous dose-response analysis has been conducted to determine the dose of BFRT required for maximal strength and functionality adaptations. To analyze the evidence on the effects of BFRT on strength and functionality in patients with knee osteoarthritis or rheumatoid arthritis through a systematic review with dose-response meta-analysis. Included studies met the following criteria: participants with knee osteoarthritis or rheumatoid arthritis; low-load resistance BFRT as intervention; control group with traditional moderate or high intensity resistance training (MIRT and HIRT); include muscle strength and functionality as primary and secondary outcome measures, respectively; and only randomized controlled trials. A random-effects and a dose-response model estimated strength and functionality using estimates of the total repetitions performed. We included five studies with a sample of 205 participants. No statistically significant differences were found between BFRT and MIRT or HIRT for strength (SMD = -0.06; 95% CI = -0.78-0.67; and > 0.05) and functionality (SMD = 0.07; 95% CI = -0.23-0.37; and > 0.05). We found an inverted U-shaped association between the increase in total repetitions and strength gain and between the increase in total repetitions and functional improvement. People with knee osteoarthritis or rheumatoid arthritis can use low-load BFRT for strength and functionality as a similarly effective alternative to MIRT and HIRT. A total of 2000 repetitions per BFRT program are necessary to maximize strength gains in these patients, while functional improvement requires 1800 total repetitions.