Blood Flow Restriction Training (BFR) in an Adolescent Population

A Determination of Efficacy and Therapeutic Benefits of Blood Flow Restriction Training in an Adolescent Population

While there are a number studies that have reported on the use of BFR in the adult population, there is limited information about the use of BFR in the adolescent population. This study aims to evaluate the use of BFR training in conjunction with traditional ACL (anterior cruciate ligament) reconstruction rehabilitation in adolescents. The purpose of this study is to evaluate the addition of BFR-based exercise to traditional methods of physical therapy. Does the use of BFR-based exercise improve strength, hypertrophy, functional and patient reported outcomes after ACL Reconstruction in the adolescent population?

The planned pilot study is a prospective case control study utilizing retrospective controls. The investigators will compare the use of exercises augmented with BFR with quantitative measurements of strength and patient reported outcomes. A total of 20 youth and adolescent patients undergoing a surgical procedure for ACL reconstruction at Connecticut Children's Elite Sports Medicine and completing physical therapy at Connecticut Children's Sports Physical Therapy will be recruited for this study. A review of data from 20 previous patients, matched for age, sex, BMI and surgical procedure that completed physical therapy at Connecticut Children's Sports Physical Therapy will be used as a comparison. As part of this pilot study, the investigators will additionally collect prospective controls. This population will be patients not participating in physical therapy at Connecticut Children's, but underwent ACL reconstruction by Elite Sports Medicine. The investigators are unsure of the ability for us to collect prospective controls in a timely manner, hence the investigators will use the above described retrospective cohort as controls if the prospective controls prove difficult to recruit. Identification and Recruitment: All potential patients undergoing ACL reconstruction at Elite Sports Medicine will be approached for participation for this study. Eligible patients will be identified at their initial pre-operative appointment with the Sports Medicine Physician, Athletic Trainer, and Sports Physical Therapy Physical Therapist. Subject selection will be completed by those patients meeting the above outlined inclusion and exclusion criteria. At this time, the study purpose and protocol will be explained and a brief summary of the study will be provided. Consent: Consent will take place at the pre-operative visit. The patient/parent will be given a detailed description of the purpose and methodology for this study. The participants will have the opportunity to read the consent forms and ask any questions they may have about the research. If the patients agree to participate, they will be asked to sign the consent form and a copy will be provided. Retention: Eligible patients will be required to be seen for a minimum of 90% of patient visits to be included in this study. In addition to the standard ACL protocol, patients in this study will utilize the Owen Recovery Science exercise protocol for BFR [18]. The following guidelines will be followed concerning exercise progression, occlusion pressure and difficulties with volume achievement. To determine the appropriate resistance for each exercise, the patient's 1 repetition maximum (1RM) will be attained using a repetition test [19]. This test will use a previously validated algorithm to determine the 1RM based on the weight used to perform a 7-10 repetition test [20]. Patient will perform the exercise with a weight they can comfortably lift for several repetitions. Based on the weight or resistance used, and the patient's perceived exertion a 1RM will be estimated using the modified OMNI-RES (OMNI perceived exertion scale for resistance). The starting load for each exercise will be 20-30% of their 1RM , or bodyweight resistance will be used when loading is not feasible. Proposed Protocol Phase 1- Weeks 1 to 2 Quad Set: 10 second on, 10 second rest at 100% occlusion x10' o progress to isometrics at the edge of the table 60 degrees as clinically appropriate Side Lying Hip Abduction, 30/15/15/15, at 80% occlusion Hip Extension from prone 30/15/15/15, at 80% occlusion Re-check load at the start of each Phase, to determine 1 RM (7-10 RM (repetition maximum) test on leg press) Total BFR time approximately 24 minutes per session, with 2 sessions per week Phase 2- Weeks 3 to 4 Replace Quad Set with Long Arc Quad (90-30deg), 30/15/15/15 at 80% occlusion Replace Hip Extension with Leg Press (shuttle), 30/15/15/15 at 80% occlusion Hip Abduction, 30/15/15/15 at 80% occlusion Total BFR time approximately 24 minutes per session with 2 sessions per week Phase 3- Weeks 5 to 6 Long Arc Quad (90-30deg), 30/15/15/15 at 80% occlusion Leg Press (shuttle), 30/15/15/15 at 80% occlusion Replace Hip Abduction with Bilateral Hip Bridge, 30/15/15/15 at 80% occlusion Total BFR time approximately 24 minutes per session, with 2 sessions per week Phase 4- Weeks 7 to 8 Leg Press (shuttle), 30/15/15/15 at 80% occlusion Replace Long Arc Quad with Step Up 30/15/15/15 at 80% occlusion Bilateral Hip Bridge, 30/15/15/15 at 80% occlusion Total BFR time approximately 24 minutes per session, with 2 sessions per week Phase 5- Weeks 9 to 12 Replace Bilateral Hip Bridge with Medial Step Down, 30/15/15/15 at 80% occlusion Replace Step up with Split Squat, 30/15/15/15 at 80% occlusion Leg Press (shuttle), 30/15/15/15 at 80% occlusion Total BFR time approximately 24 minutes per session, with 2 sessions per week Phase 6- Weeks 11 to 12 Progressively load exercises from phase 5 Total BFR time approximately 24 minutes per session, with 2 sessions per week

The investigators will compare the use of exercises augmented with BFR with quantitative measurements of strength and patient reported outcomes. A total of 20 youth and adolescent patients undergoing a surgical procedure for ACL reconstruction at Connecticut Children's Elite Sports Medicine and completing physical therapy at Connecticut Children's Sports Physical Therapy will be recruited for this study. A review of data from 20 previous patients, matched for age, sex, BMI and surgical procedure that completed physical therapy at Connecticut Children's Sports Physical Therapy will be used as a comparison. As part of this pilot study, the investigators will additionally collect prospective controls. This population will be patients not participating in physical therapy at Connecticut Children's but underwent ACL reconstruction by Elite Sports Medicine.

In addition to the standard ACL protocol, patients in this study will utilize the Owen Recovery Science exercise protocol for BFR [18]. The following guidelines will be followed concerning exercise progression, occlusion pressure and difficulties with volume achievement. A total of 20 youth and adolescent patients undergoing a surgical procedure for ACL reconstruction at Connecticut Children's Elite Sports Medicine and completing physical therapy at Connecticut Children's Sports Physical Therapy will be recruited for this study.

As part of this pilot study, the investigators will additionally collect prospective controls. This population will be patients not participating in physical therapy at Connecticut Children's but underwent ACL reconstruction by Elite Sports Medicine

FDA Establishment Registration Number 9681444. Device Listing Number E127474. Classification Number 878.5910. Product Code KCY. 510(k) Exempt. MID: XCDELMED1099VAN

The Delfi Tourniquet System is designed to be used in conjunction with exercise. The system automatically determines the degree of occlusion and allows for safe regulation of pressure. Patients will then complete exercises with the use of this device following the Owens Recovery Science Protocol

Isometric strength testing to measure peak torque quadriceps strength (unit: ft-lbs) as reported by isokinetic dynamometer on involved and uninvolved limb.

Quadriceps limb symmetry index is calculated by taking the values from outcome 1. [ ( peak torque quadriceps involved limb (ft/lbs)/ peak torque quadriceps uninvolved limb (ft-lbs))*100] as reported by isokinetic dynamometer. This value is expressed as a percentage. 100% would equal perfect symmetry.

Isometric strength testing to measure peak torque hamstsring strength (unit: ft-lbs) as reported by isokinetic dynamometer on involved and uninvolved limb.

Hamstring limb symmetry index is calculated by taking the values from outcome 3 [ ( peak torque hamstring involved limb (ft/lbs) / peak torque hamstring uninvolved limb (ft-lbs))*100] as reported by isokinetic dynamometer. This value is expressed as a percentage.100% would equal perfect symmetry.

Isometric strength testing to measure peak torque hip extension in foot pounds as reported by isokinetic dynamometer

Hip Extension limb symmetry index is calculated by taking the values from outcome 5 [ ( peak torque hip extension involved limb peak torque (ft/lbs) /hip extension uninvolved limb peak torque (ft-lbs))*100] as reported by isokinetic dynamometer. This value is expressed as a percentage.100% would equal perfect symmetry.

Anterior step down test measured in number of repetitions comparing involved to uninvolved lower extremity

Y balance test measuring distance of excursion in cm compared comparing involved to uninvolved lower extremity

Single Leg Hop Test measured in cm for involved and uninvolved limbs. Limb symmetry index is calculated by using the distance for involved and uninvolved [ ( involved limb distance / uninvolved limb distance)*100]. this value is expressed as a percentage. 100% would equal perfect symmetry.

Timed 6m single leg hop calculating limb symmetry index [ ( involved limb single leg hop time/ uninvolved single leg hop time)*100]. This value is expressed as a percentage. 100% would equal perfect symmetry.

Single Leg Triple hop calculating limb symmetry index [ ( involved limb triple hop distance/ uninvolved triple hop distance)*100]. This value is expressed as a percentage. 100% would equal perfect symmetry.

Single Leg Crossover Hop calculating limb symmetry index [ ( involved limb crossover hop distance/ crossover triple hop distance)*100]. This value is expressed as a percentage. 100% would equal perfect symmetry.

Thigh Circumference measured at location 10cm superior to patella and measured in cm comparing involved to uninvolved lower extremity

Patient Reported Outcome Measure- Scores range from 0 points (lowest level of function or highest level of symptoms) to 100 points (highest level of function and lowest level of symptoms).

Patient Reported Outcome Measure- The score is a percentage score from 0 to 100, with 0 representing extreme problems and 100 representing no problems. This scoring direction, 100 indicating no problems

Patient Reported Outcome Measure- ACL-RSI scores range from 0 to 100, with higher scores representing patients who are more ready to return to sport

Patient Reported Outcome Measure- This determines a patient's activity level as it pertains to running, cutting, deceleration and pivoting. A higher score indicates a higher activity level (0-16 max)

Inclusion Criteria: Patients between the age of 12 and 18 years at the time of surgery. Post-primary ACL reconstruction Orthopaedic surgical intervention (including all additional procedures at the knee) completed by one of the Elite Sports Medicine physicians. Patient completed postoperative rehabilitation following standard protocols No contraindications to performing BFR, as outlined in the Owens Recovery[18] Science 2018 Personal Blood Flow Restriction manual. Exclusion Criteria: Patients older than 18 and younger than 12 at the time of surgery Any additional diagnoses or deformity not related to knee injury that could affect knee strength Additional lower extremity injury at time of knee injury (e.g., ankle injury) requiring treatment Previous surgical intervention on the knee (ipsilateral and contralateral) Patients with weight bearing restrictions for greater than two weeks after surgery due to concomitant pathology such as meniscal root/radial repair, chondral pathology, or multi-ligament pathology. . Generic exclusion: "Subjects not meeting all inclusion criteria."