It is well accepted that the main aim of an ACL reconstruction (ACLR) rehabilitation programme is to return patients to their pre-injury level of function with the lowest risk of re-injury. Post-surgery, players will usually experience a significant loss of lower limb strength due to muscle atrophy and inhibition mechanisms. This FastFact highlights a blinded, randomised controlled trial comparing the use of blood flow restriction training (BFR-RT) with standard therapy (HL-RT) for the rehabilitation of patients following ACLR1.
ACL rehabilitation protocols generally involve heavy load resistance training (HL-RT) to stimulate skeletal muscle hypertrophy and strength adaptations. Unfortunately, this type of rehabilitation can be poorly tolerated by some patients, especially those with concomitant meniscal, chondral or bone injuries. Blood flow restriction (BFR) resistance training (BFR-RT) has been proposed as a possible alternative option for these patients. This type of training has been shown to elicit muscle hypertrophy and strength adaptations in load-compromised populations using much lighter loads. In addition, BFR-RT can reduce pain and improve general physical function.
This study highlighted in this FastFact is a blinded randomized controlled trial comparing the use of BFR-RT vs. HL-RT in 28 subjects who underwent ACLR surgery with hamstring autograft. The intervention included an 8-week programme of unilateral leg press within a standardised rehabilitation programme. The HL-RT group trained at 70% of 1 repetition maximum (RM) while the BFR-RT group trained at only 30% of 1RM. Results at nine weeks showed that both BFR-RT and HL-RT elicited comparable increases in skeletal muscle hypertrophy and strength. Interestingly, BFR-RT resulted in greater improvements in physical function, range of motion and greater reduction in pain and effusion. Of note, there were no adverse events or effects with either intervention.
This study highlights the potential value of BFR and its role as a tool in post-operative rehabilitation after ACL reconstruction surgery. While this study focused on BFR allowing therapists to work with patients who are “knee load compromised” after ACL reconstruction, it is possible that applying BFR therapies with different protocols and regimens can introduce many more benefits. It is important to highlight the relatively small number of participants in this study and the need to confirm the study’s findings in a larger cohort of patients.
11. Hughes L, Rosenblatt B, Haddad F, et al: Comparing the Effectiveness of Blood Flow Restriction and Traditional Heavy Load Resistance Training in the Post-Surgery Rehabilitation of Anterior Cruciate Ligament Reconstruction Patients: A UK National Health Service Randomised Controlled Trial. Sports Med. 2019 Jul 12 [Epub ahead of print].