Personalized Blood Flow Restriction for Anterior Cruciate Ligament Rehabilitation

This is a cross-sectional study on the use of personalized blood flow restriction during rehabilitation exercises and its effects on biomechanics on people who have had an anterior cruciate ligament reconstruction and healthy controls

Rehabilitation after surgical reconstruction of the anterior cruciate ligament (ACL) aims to reestablish the function of the knee. However, regaining previous levels of strength is challenging, with long-term muscle weakness frequently reported and thought to play a key role in the increased risk of knee osteoarthritis for individuals with a history of ACL damage. Effectively building muscle strength requires exercises with high resistance loads, however the joint stress and risk of further injury makes these types of activities inappropriate and unsafe for those rehabilitating after ACL reconstruction surgery and other injuries. Personalized blood flow restriction (BFR) training is a technique where the blood flow to the muscles being exercised is controlled by a pressure cuff to a predefined level, and has been shown to increase strength while exercising with significantly lower loads. Early results have been promising, however the effects of BFR on the biomechanics of the exercise as well as the acceptability in the ACL reconstruction population have not been explored. In this application, we propose a cross-sectional study designed to test the acceptability of BFR training for those undergoing rehabilitation from ACL reconstruction surgery and healthy controls during free standing exercises. We will also investigate the biomechanical effects of this rehabilitation technique. This application is part of a larger program of musculoskeletal research in this area being developed by the team. The results from the proposed project will inform the design of a clinical trial of personalized BFR after ACL reconstruction.

Single session blood flow restriction of lower limb to individuals who have undergone anterior ligament reconstruction surgery

Single session blood flow restriction of lower limb to individuals who have no musculoskeletal injuries

Maximum difference in flexion motion of knee while performing exercise between baseline and blood flow restriction condition. Measured in degrees

Maximum difference in internal rotation of knee while performing exercise between baseline and blood flow restriction condition. Measured in degrees

Maximum difference in varus motion of knee while performing exercise between baseline and blood flow restriction condition. Measured in degrees

Maximum difference in flexion motion of hip while performing exercise between baseline and blood flow restriction condition. Measured in degrees

Maximum difference in adduction motion of hip while performing exercise between baseline and blood flow restriction condition. Measured in degrees

Maximum difference in internal rotation motion of hip while performing exercise between baseline and blood flow restriction condition. Measured in degrees

Maximum difference in extension moment of knee while performing exercise between baseline and blood flow restriction condition. Measured in Newton meters per kilogram

Maximum difference in internal rotation moment of knee while performing exercise between baseline and blood flow restriction condition. Measured in Newton meters per kilogram

Maximum difference in adduction moment of knee while performing exercise between baseline and blood flow restriction condition. Measured in Newton meters per kilogram

Maximum difference in extension moment of hip while performing exercise between baseline and blood flow restriction condition. Measured in Newton meters per kilogram.

Maximum difference in adduction moment of hip while performing exercise between baseline and blood flow restriction condition. Measured in Newton meters per kilogram

Maximum difference in internal rotation moment of hip while performing exercise between baseline and blood flow restriction condition. Measured in Newton meters per kilogram

Inclusion Criteria (ACL-R group): Must be undergoing rehabilitation for anterior cruciate ligament reconstruction surgery Must be at least 3 months post surgery. Attending clinician should confirm that they are able to take part in the trial Exclusion Criteria: Any other orthopaedic, neurological, or other condition within the last 12 months that would affect ability to carry out the required exercises Any medical conditions that may affect circulation including, but not limited to, deep vein thrombosis, high blood pressure, and cardiac disease

Data will be made available to researchers on request. Dataset includes all kinematic, kinetic and patient reported data.