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.

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.

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

Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures, and appendices) may be available upon reasonable request.

Requests should be directed to Jordan.Fried@nyulangone.org. To gain access, data requestors will need to sign a data access agreement.

Beginning 9 months and ending 36 months following article publication or as required by a condition of awards and agreements supporting the research.

The investigator who proposed to use the data.

double blind