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

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 (SLSS , SLSD ), and step-down test (SDT).

RESULTS: 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.

CONCLUSIONS: The pain reduction induced by LLRT-BFR could indicate this intervention as a preconditioning process prior to the rehabilitation of AKP.