Kaycee Glattke

Low-Intensity Blood Flow Restriction training (LI-BFR) involves the use of inflatable cuffs placed proximally around the extremities with the aim of occluding venous return while maintaining arterial blood flow during low-intensity exercise. LI-BFR has been shown to result in increased muscular strength and hypertrophy compared to training done without moderate BFR intervention1 ; however, many knowledge gaps exist in the scientific literature. In this study, we aim to determine whether the use of lowintensity (LI) resistance training combined with blood flow restriction (BFR) of the lower extremities employed pre-operatively will improve post-operative outcomes in individuals who have undergone reconstruction of the anterior cruciate ligament (ACL-R). Currently, there is evidence in literature supporting the use of LI-BFR and its safety; however, there is minimal evidence for its use in operative populations as well as in regard to certain population characteristics including gender, age, and preoperative activity levels. The proposed study will serve as a foundation to develop future study phases to investigate the intervention’s efficacy in certain population characteristics and further develop a standardized protocol to clinically implement LI-BFR. In this proposed study, 36 subjects will be recruited from a population of Mayo Clinic patients who have been identified as those with an ACL injury that requires surgical reconstruction. Subjects will be randomized into one of two groups: a group receiving the LI-BFR intervention, and a group that will receive a sham BFR intervention. Subjects will undergo two weeks of pre-operative rehabilitation, where they will complete a low-intensity training protocol developed by licensed physical therapists with their assigned intervention twice per week. At the first and last pre-operative training sessions, we will conduct a series of measures to quantify quadriceps strength (with a handheld dynamometer and leg press test), quadriceps hypertrophy (with musculoskeletal ultrasound), range of motion, static and dynamic stability (with the Lockhart Monitor phone application), extension lag, and effusion. Subjects will also complete a series of patient-reported outcome measures questionnaires including the Lower Extremity Functional Scale, Lysholm Knee Scoring Scale, Visual Analog Scale for Pain, Activities-Specific Balance Confidence Scale, and ACL-Return to Sport Index. After each subject’s reconstruction surgery is completed, they will return for five post-operative data collection sessions at 8-10 days, 4 weeks, 8 weeks, 14 weeks, and 24 weeks post-op for re-evaluation of the measures listed above. At least one journal paper and one doctoral dissertation are expected from this project.

Last updated February 2020.