Effect of blood flow restriction on knee joint position sense in healthy recreationally active adults: A randomized pilot trial

Objectives: The present pilot randomized trial aimed to assess the feasibility of conducting a future definitive randomized controlled trial (RCT) investigating the effect of blood flow restriction (BFR) on knee joint position sense (JPS) in healthy recreationally active adults and to obtain preliminary estimates of the potential effect to inform the design of such a trial. Materials and Methods: Thirty participants were randomly allocated to a BFR, Placebo, or Control groups. JPS was assessed twice with a 90-min break, using an active joint position reproduction test at two target positions (60° and 30° of knee flexion). In the BFR Group, occlusion was implemented during the 2 nd assessment. The primary outcomes were feasibility-related measures, including participant recruitment, successful randomization, completion of the study protocol, and procedural safety. Exploratory outcomes included changes in absolute angular error (AAE) between the 1 st and 2 nd assessments. Results: All 30 participants were randomized and completed the study, with no missing data or adverse events. All pre-defined feasibility criteria were met. Exploratory analyses suggested a tendency for increased AAE in the BFR Group, whereas the Placebo and Control groups showed stable or improved performance. Although some between-group differences reached statistical significance, these findings should be interpreted with caution, given the study’s pilot nature and the limited statistical power for efficacy testing. Conclusion: The study supports the feasibility of conducting a future definitive RCT. Exploratory findings suggest that knee JPS may be transiently impaired during occlusion; however, these results are hypothesis-generating and require confirmation in a larger, adequately powered study.