Blood Flow Restriction Training in Rehabilitation Following Anterior Cruciate Ligament Reconstructive Surgery: A Review

Abstract

Anterior cruciate ligament (ACL) rupture is a highly prevalent orthopaedic injury, resulting in substantial skeletal muscle atrophy due to changes in muscle protein balance and satellite cell abundance. Neural activation problems also contribute to strength loss, impacting upon a patients' physical function and rehabilitative capacity. Heavy loads typically required for muscle hypertrophy and strength adaptations are contraindicated due to graft strain and concomitant cartilage, meniscal and bone pathologies associated with ACL reconstruction. Strength of the quadriceps is a fundamental component for the ability to reduce shearing and torsional strains on the ACL with ground contact, and forms a critical component of ACL rehabilitation. Given the dangers of early post-operative heavy-loading, low-load blood flow restriction (BFR) training may provide an alternative rehabilitation tool for practitioners. Passive BFR can attenuate early muscle atrophy and strength loss, and may be more effective with the addition of novel, complementary therapies such as neuromuscular electrical stimulation. Upon ambulation, aerobic and resistance exercise with BFR can stimulate muscle hypertrophy and strength adaptations and resolve activation problems. This may occur through increasing muscle protein synthesis and satellite cell proliferation, decreasing muscle protein breakdown and improving muscle activation via altered recruitment patterns. Thus, BFR training may provide an effective rehabilitation tool that does not place heavy loads and force through the tibiofemoral joint. This may reduce the risk of damaging the graft, cartilage, meniscus or other intra-articular structures, providing thorough screening prior to use is followed by correct, evidenceinformed application.

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

“…The end goal of ACLR rehabilitation is for patients to be able to return to heavy loading and their preinjury strength and activity level [11]. The application of BFR passively or in combination with electrical stimulation and aerobic exercise during the early post-surgery phases of ACLR rehabilitation has been discussed previously [11].…”

“…The end goal of ACLR rehabilitation is for patients to be able to return to heavy loading and their preinjury strength and activity level [11]. The application of BFR passively or in combination with electrical stimulation and aerobic exercise during the early post-surgery phases of ACLR rehabilitation has been discussed previously [11]. The present study shows that during the progressive limb loading phase of rehabilitation, the advantages of BFR-RT over HL-RT is that it can be used to allow a greater reduction in pain and effusion and improve physical function to a superior extent than HL-RT, importantly without any detrimental effect on muscle hypertrophy and strength improvements.…”

“…Muscle weakness can persist for years after ACLR surgery [6] and is associated with chronic reductions in function [7,8], a high re-injury risk [9] and joint degeneration [10]. Therefore, targeting muscle weakness early in the rehabilitation process is imperative [11].…”

“…Heavy load resistance training (HL-RT) using external loads of 65-70% of an individual's one repetition maximum (1RM) are recommended to stimulate skeletal muscle hypertrophy and strength adaptations [15,16]. Whilst these loads may be required to increase strength to a satisfactory level [17], issues such as meniscal damage and bone bruising may contraindicate HL-RT in load compromised ACLR patients [11].…”

“…Importantly there were no differences in knee ROM or reduction in knee laxity from pre-surgery to post-training, supporting the use of BFR-RT without compromising graft healing. The hemodynamic and perceptual responses to BFR-RT in ACLR patients may not limit its application and may reduce knee pain [28], possibly providing a useful rehabilitation tool for ACLR patients [11]. However, the effectiveness of BFR-RT for stimulating muscle strength and hypertrophy during ACLR rehabilitation has not been directed compared to HL-RT.…”