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CompletedNCT04635579Updated Feb 28, 2022Results posted

Personalized Blood Flow Restriction for Anterior Cruciate Ligament Rehabilitation

An interventional study of Blood flow restriction in Anterior Cruciate Ligament Tear, sponsored by University of Washington. Completed at 1 site in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2022-02-28.

Sponsored by University of Washington · Not applicable, Interventional, and Basic science

From the registry’s dates

  • Registered 2 years 5 months after the study started (first participant enrolled May 2018, registered Nov 2020).
Phase
Not applicable
Study type
Interventional
Enrollment
40
Allocation
Non-randomized
Ages
18 Years and older
Sex
All
01

Study summary

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

Read the detailed description

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.

02

Conditions studied

  • Anterior Cruciate Ligament Tear
03

In context

Anterior Cruciate Ligament Injuries

512 studies on the registry are indexed under Anterior Cruciate Ligament Injuries; 163 are open to participants now.

This study's enrollment of 40 is below the median of 56 across 372 interventional studies indexed under Anterior Cruciate Ligament Injuries.

Browse Anterior Cruciate Ligament Injuries studies →

Lead sponsor

University of Washington is the lead sponsor of 1,397 studies on the registry; 225 are open to participants now.

Of its 154 completed or terminated interventional studies of FDA-regulated products, 132 (86%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • 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

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
05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
40 participants (actual)

Study arms

  • Experimental
    Anterior cruciate ligament reconstruction group

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

    Device: Blood flow restriction

  • Active comparator
    Control group

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

    Device: Blood flow restriction

Interventions

  • DeviceBlood flow restriction

    Intervention restricts blood flow to the lower limb as a percentage of the limb occlusion pressure

06

What researchers measure

Primary outcomes

  1. Knee Flexion

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

    Time frame: 6 minutes

  2. Knee Internal Rotation

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

    Time frame: 6 minutes

  3. Knee Varus

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

    Time frame: 6 minutes

  4. Hip Flexion

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

    Time frame: 6 minutes

  5. Hip Adduction

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

    Time frame: 6 minutes

  6. Hip Internal Rotation

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

    Time frame: 6 minutes

  7. Knee Extension Moment

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

    Time frame: 6 minutes

  8. Knee Internal Rotation Moment

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

    Time frame: 6 minutes

  9. Knee Adduction Moment

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

    Time frame: 6 minutes

  10. Hip Extension Moment

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

    Time frame: 6 minutes

  11. Hip Adduction Moment

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

    Time frame: 6 minutes

  12. Hip Internal Rotation Moment

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

    Time frame: 6 minutes

Secondary outcomes

  1. Exercise Difficulty Score

    Numerical Analogue Scale, 0-10, higher scores indicate greater difficulty

    Time frame: 6 minutes

  2. Exercise Discomfort Score

    Numerical Analogue Scale, 0-10, higher scores indicate greater discomfort

    Time frame: 6 minutes

07

Results

Posted Feb 28, 2022

Participant flow

Participant flow — Overall Study
MilestoneAnterior Cruciate Ligament Reconstruction GroupControl Group
Started2020
Completed2020
Not completed00

Outcome measures

PrimaryKnee Flexion

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

Time frame:
6 minutes
Reported as:
Mean · Degrees
Knee Flexion
DegreesAnterior Cruciate Ligament Reconstruction GroupControl Group
Knee Flexion-0.05 ± 2.00.01 ± 5.14
PrimaryKnee Internal Rotation

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

Time frame:
6 minutes
Reported as:
Mean · Degrees
Knee Internal Rotation
DegreesAnterior Cruciate Ligament Reconstruction GroupControl Group
Knee Internal Rotation1.19 ± 1.4-0.03 ± 1.97
PrimaryKnee Varus

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

Time frame:
6 minutes
Reported as:
Mean · Degrees
Knee Varus
DegreesAnterior Cruciate Ligament Reconstruction GroupControl Group
Knee Varus0.12 ± 1.25-0.36 ± 2.61
PrimaryHip Flexion

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

Time frame:
6 minutes
Reported as:
Mean · Degrees
Hip Flexion
DegreesAnterior Cruciate Ligament Reconstruction GroupControl Group
Hip Flexion-1.73 ± 2.27-2.9 ± 8.15
PrimaryHip Adduction

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

Time frame:
6 minutes
Reported as:
Mean · Degrees
Hip Adduction
DegreesAnterior Cruciate Ligament Reconstruction GroupControl Group
Hip Adduction0.61 ± 1.91.52 ± 2.6
PrimaryHip Internal Rotation

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

Time frame:
6 minutes
Reported as:
Mean · Degrees
Hip Internal Rotation
DegreesAnterior Cruciate Ligament Reconstruction GroupControl Group
Hip Internal Rotation1.49 ± 2.371.05 ± 2.6
PrimaryKnee Extension Moment

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

Time frame:
6 minutes
Reported as:
Mean · Newton meters per kilogram
Knee Extension Moment
Newton meters per kilogramAnterior Cruciate Ligament Reconstruction GroupControl Group
Knee Extension Moment0.31 ± 0.210.6 ± 0.26
PrimaryKnee Internal Rotation Moment

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

Time frame:
6 minutes
Reported as:
Mean · Newton meters per kilogram
Knee Internal Rotation Moment
Newton meters per kilogramAnterior Cruciate Ligament Reconstruction GroupControl Group
Knee Internal Rotation Moment-0.01 ± 0.05-0.02 ± 0.07
PrimaryKnee Adduction Moment

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

Time frame:
6 minutes
Reported as:
Mean · Newton meters per kilogram
Knee Adduction Moment
Newton meters per kilogramAnterior Cruciate Ligament Reconstruction GroupControl Group
Knee Adduction Moment0.06 ± 0.050.12 ± 0.07
PrimaryHip Extension Moment

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

Time frame:
6 minutes
Reported as:
Mean · Newton meters per kilogram
Hip Extension Moment
Newton meters per kilogramAnterior Cruciate Ligament Reconstruction GroupControl Group
Hip Extension Moment0.09 ± 0.160.2 ± 0.14
PrimaryHip Adduction Moment

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

Time frame:
6 minutes
Reported as:
Mean · Newton meters per kilogram
Hip Adduction Moment
Newton meters per kilogramAnterior Cruciate Ligament Reconstruction GroupControl Group
Hip Adduction Moment-0.01 ± 0.1-0.07 ± 0.14
PrimaryHip Internal Rotation Moment

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

Time frame:
6 minutes
Reported as:
Mean · Newton meters per kilogram
Hip Internal Rotation Moment
Newton meters per kilogramAnterior Cruciate Ligament Reconstruction GroupControl Group
Hip Internal Rotation Moment-0.02 ± 0.130.05 ± 0.05
SecondaryExercise Difficulty Score

Numerical Analogue Scale, 0-10, higher scores indicate greater difficulty

Time frame:
6 minutes
Reported as:
Mean · units on a scale
Exercise Difficulty Score
units on a scaleAnterior Cruciate Ligament Reconstruction GroupControl Group
Exercise Difficulty Score4.0 (3 to 5.5)5.0 (4.5 to 6)
SecondaryExercise Discomfort Score

Numerical Analogue Scale, 0-10, higher scores indicate greater discomfort

Time frame:
6 minutes
Reported as:
Mean · units on a scale
Exercise Discomfort Score
units on a scaleAnterior Cruciate Ligament Reconstruction GroupControl Group
Exercise Discomfort Score4.0 (3.5 to 5.5)4.5 (3 to 5)

Adverse events

Collected over 1 year. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Anterior Cruciate Ligament Reconstruction Group0/20 (0%)0/20 (0%)0/20 (0%)
Control Group0/20 (0%)0/20 (0%)0/20 (0%)

Baseline characteristics

Age, Continuous
Age, Continuous(years)Anterior Cruciate Ligament Reconstruction GroupControl GroupTotal
Mean30.6 (21 to 50)28 (19 to 48)29.3 (19 to 50)
Sex: Female, Male
Sex: Female, Male(Participants)Anterior Cruciate Ligament Reconstruction GroupControl GroupTotal
Female121123
Male8917
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Anterior Cruciate Ligament Reconstruction GroupControl GroupTotal
American Indian or Alaska Native000
Asian213
Native Hawaiian or Other Pacific Islander000
Black or African American112
White171835
More than one race000
Unknown or Not Reported000
Region of Enrollment
Region of Enrollment(participants)Anterior Cruciate Ligament Reconstruction GroupControl GroupTotal
United States202040
08

Study locations

1 site
  • University of Washington Medical Center
    Seattle, Washington 98195, United States
09

References and documents

Study documents

  • Study protocol · Apr 24, 2018
  • Statistical analysis plan · Apr 24, 2018
  • Informed consent form · Apr 24, 2018

Documents are hosted by the registry — open the source record to download them.

Individual participant data

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

Supporting information: Study protocol, Analytic code

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Feb 28, 2022, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT04635579
Lead sponsor
University of Washington
Collaborators
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Responsible party
Scott Telfer, EngD (Assistant Professor: School of Medicine, University of Washington) — Principal investigator
First posted
Nov 19, 2020
Start date
May 8, 2018
Primary completion
Nov 2, 2020
Completion
Nov 2, 2020
Results posted
Feb 28, 2022
Last update
Feb 28, 2022

Study contacts

Scott Telfer, EngD
principal investigator · University of Washington

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
View the source record on ClinicalTrials.gov ↗

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