Blood Flow Restriction Therapy in Lower Limb Extensor Injuries

Study Overview
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Brief Summary
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The primary objective of the study is to determine the efficacy of blood flow restriction therapy on patients with lower limb extensor injuries by measuring pre and post blood flow restriction therapy strength and muscle mass.

Detailed Description
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The purpose is to restrict venous outflow with an inflatable cuff to create a high intensity environment increases muscle hypertrophy, thus promoting a more efficient form of rehabilitation. Blood flow restriction therapy is a blood pressure cuff placed around the desired limb with a handheld device that controls the pressure exerted by the cuff. The cuff is placed around the desired limb before a specific exercise, the physical therapist determines the appropriate pressure and time, and the patient completes the exercise as they normally would. The monitor determines the limb occlusion pressure and has an automatic timer that will deflate after the specified time has elapsed. There are also audio and visual alarms that alert the user of under or over pressurization. The specific pressure will vary based on patient's tolerance and will stay consistent through each exercise. Thus far blood flow restriction therapy has been tested in patients with several pathologies but there is limited literature on its effect on lower limb extensor injuries.

Official Title
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Blood Flow Restriction Therapy in Lower Limb Extensor Injuries: A Randomized Controlled Double-Blind Study

Conditions
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Lower Limb Injury

Intervention / Treatment
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* Behavioral: Physical Therapy with pressure cuff
* Behavioral: Physical Therapy with placebo pressure cuff


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Must be at least 18 years of age and younger than 65 years of age ASA class I-II Diagnosed with a lower limb extensor injury (quadriceps tendon rupture, patella tendon rupture, patella fracture) Intention to receive physical therapy as standard of care Exclusion Criteria: Legally incompetent or mentally impaired (e.g. minors, Alzheimer's subjects, dementia, etc.) Younger than 18 years of age or older than 65 Any patient considered a vulnerable subject Patients with impaired circulation, peripheral vascular compromise, previous revascularization of the extremity, or severe hypertension Concomitant lower extremity traumatic injuries, delaying or precluding the subject's ability to participate in the therapy Immobile or use of mobile assistive device prior to injury No prior extensor injuries Patients with Sickle cell anemia or venous thromboembolism Patients with cancer or Lymphectomies Patients with increased intracranial pressure Patients with intention to receive standard therapy and not the study therapy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: blood flow restriction therapy (pressure cuff)<br>The cuff will be placed around the upper thigh of the injured leg and set at a pressure that will prevent approximately 80% arterial blood flow. The machine will determine what pressure is required to reach that 80%, when placed on the leg and turned on. | Behavioral: Physical Therapy with pressure cuff<br>* 6 weeks of physical therapy will have similar exercises to standard therapy however the patients will use a cuff around the affected leg during the exercises.<br>|
| Placebo Comparator: blood flow restriction therapy (placebo)<br>Patients with a placebo pressure will have a pressure setting, 50% lower than the effective setting as stated in the experimental arm | Behavioral: Physical Therapy with placebo pressure cuff<br>* 6 weeks of physical therapy will have similar exercises to standard therapy however the patients will use a pressure cuff around the affected leg during the exercises. The pressure cuff will have 50% of the pressure that will be considered effective.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in extensor strength of both legs | Isokinetic strength testing with a Biodex dynamometer to measure peak torque | Visit 1 Day 0 | 
| Change in extensor strength of both legs | Isokinetic strength testing with a Biodex dynamometer to measure peak torque | Visit 3 week 6 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in recovery, muscle strength | Having bilateral thigh circumference measured | Visit 1 Day 0 | 
| Change in recovery, muscle strength | Having bilateral thigh circumference measured | Visit 1 Week 6 | 
| Change in Knee function | The IKDC subjective knee evaluation form is a self-administered questionnaire which contains 18 items divided into 3 subgroups. These subgroups are symptoms, sports and daily activities and the patients current and previous levels of knee function. | Visit 1 Day 0 | 
| Change in Knee function | The IKDC subjective knee evaluation form is a self-administered questionnaire which contains 18 items divided into 3 subgroups. These subgroups are symptoms, sports and daily activities and the patients current and previous levels of knee function. | Visit 3 week 6 |