1037 - Efficacy of blood flow restriction with low-load resistive exercise in irregular exercise adults who have risk factors for symptomatic knee osteoarthritis: Double-blind randomized controlled trial.

Objectives: To assess the efficacy of blood flow restriction (BFR) to improve knee extensor strength in an irregular exercise of adults with risk factors of symptomatic knee osteoarthritis (OA).

Design: Double-blind randomized controlled trial (January 2022 – July 2022)
Participants: Irregular exercise adults aged ≥ 40 years old who had at least one of the risk factors for symptomatic knee OA.

Methods: 44 paticipants were randomly assigned into intervention (BFR) and control groups using stratified and mixed block randomization. The BFR group exercised 2 times/week for 4 weeks in leg extension exercises at 30% of 1 repetition maximum (1RM) (15 reps×4 sets) with cuff pressure according to the protocol of this study, while the control group exercised without using the cuff protocol. Both groups were given the diary book to record any possible confounding factors. The outcomes of interest included 1RM isotonic knee extension, 1RM isotonic leg press, 30-second chair stand test, and knee pain outcome score (KOOS). Pre-exercise and post-exercise tests were recorded. Compare the differences in results between groups using the linear regression test.

Results: Result: The posttestmean differences of 1RM isotonic knee extensor, 1RM leg press, 30 second chair stand test, and KOOS after 4 weeks of exercise between groups (adjusted mean difference, AMD) were 14.74 kg (95% CI: 4.00, 19.29; p< 0.001), 30.83 kg (95% CI: 18.00, 43.66; p< 0.001), 7.11 times (95% CI: 4.16, 10.07; p< 0.001) and 1.42 points (95% CI: 0.34, 2.50; p=0.01) respectively, which were significantly different in statistics.

Conclusions:

Conclusion: A 4-week, low-load resistive training program with concurrent application of BFR improves knee extensor strength in irregular exercise of adults who have risk factors of symptomatic knee OA when compared and no further worsened knee symptoms.