Low load resistance training with blood flow restriction decreases anterior knee pain more than resistance training alone. A pilot randomised controlled trial.

Abstract Objectives To evaluate if application of blood flow restriction (BFR) combined with low-load resistance training (LLRT) would induce significant anterior knee pain (AKP) reduction compared to LLRT alone. Design Randomised Controlled Trial. Setting Institutional physiotherapy clinic. Participants Forty males suffering from AKP were randomly allocated in the LLRT-BFR or LLRT group. BFR was applied at 80% of complete vascular occlusion. Four sets of open kinetic chain knee extensions were implemented in both groups using a pain monitoring model. Main outcome measures Pain (0–10) was assessed immediately after LLRT-BFR or LLRT application and after a physiotherapy session (45 min) during shallow and deep single-leg squat (SLS S , SLS D), and step-down test (SDT). Results Significant immediate pain reduction was found in LLRT-BFR group in SLS S , SLS D and SDT (d = 1.32, d = 1.12, d = 0.88 respectively), but no difference was found in LLRT group. Following the physiotherapy session pain reduction was sustained in LLRT-BFR group in both SLSs and SDT (d = 1.32, d = 0.78, d = 0.89 respectively). For the control group significant pain reduction was only found in SLS S (d = 0.56). No significant between-group differences were observed. Conclusions The pain reduction induced by LLRT-BFR could indicate this intervention as a preconditioning process prior to the rehabilitation of AKP. Highlights What are the findings? • LLRT-BFR significantly reduced pain in functional activities immediately post-intervention, and this was sustained for at least 45 min, with large effect sizes, an effect not seen in the LLRT group. • There were no non-responders in the LLRT-BFR group in contrast to the LLRT group where 20% of the participants reported symptoms worsening post-intervention. How might this impact on clinical practice in the future? • LLRT-BFR may be used to reduce knee pain before rehabilitation, providing clinicians a window of opportunity for knee loading exercises, which are typically otherwise associated with symptoms. [ABSTRACT FROM AUTHOR]