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

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. Randomised Controlled Trial. Institutional physiotherapy clinic. 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. 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 (SLSS, SLSD), and step-down test (SDT). Significant immediate pain reduction was found in LLRT-BFR group in SLSS, SLSD 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 SLSS (d = 0.56). No significant between-group differences were observed. The pain reduction induced by LLRT-BFR could indicate this intervention as a preconditioning process prior to the rehabilitation of AKP.