Trial Outcomes & Findings for Blood Flow Restriction Training in Individuals Awaiting Total Knee Replacement (NCT NCT06111690)

NCT ID: NCT06111690

Last Updated: 2026-03-24

Results Overview

Quadricep Muscle Strength will be measured using an isokinetic dynamometer. Quadriceps femoris maximum voluntary isometric contraction (MVIC) as torque output (Nm) will be measured. Subjects will be seated in the dynamometer's chair with their knee at 60 degrees of flexion.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

16 participants

Primary outcome timeframe

Baseline, 8 weeks and 16 weeks

Results posted on

2026-03-24

Participant Flow

16 recruited; 2 did not meet in-person screening; 14 participated in the study.

The 2 participants that did not meet in-person screening had a high Ankle-brachial Index (ABI \> 1.5), which makes it unsafe to participate in blood-flow restriction training.

Participant milestones

Participant milestones
Measure
Preoperative Exercises
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Overall Study
STARTED
16
Overall Study
COMPLETED
14
Overall Study
NOT COMPLETED
2

Reasons for withdrawal

Reasons for withdrawal
Measure
Preoperative Exercises
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Overall Study
Failed in-person screening
2

Baseline Characteristics

Blood Flow Restriction Training in Individuals Awaiting Total Knee Replacement

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Preoperative Exercises
n=14 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Age, Categorical
<=18 years
0 Participants
n=138 Participants
Age, Categorical
Between 18 and 65 years
4 Participants
n=138 Participants
Age, Categorical
>=65 years
10 Participants
n=138 Participants
Age, Continuous
70.57 years
STANDARD_DEVIATION 7.56 • n=138 Participants
Sex: Female, Male
Female
9 Participants
n=138 Participants
Sex: Female, Male
Male
5 Participants
n=138 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=138 Participants
Race (NIH/OMB)
Asian
0 Participants
n=138 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=138 Participants
Race (NIH/OMB)
Black or African American
1 Participants
n=138 Participants
Race (NIH/OMB)
White
13 Participants
n=138 Participants
Race (NIH/OMB)
More than one race
0 Participants
n=138 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=138 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
1 Participants
n=138 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
13 Participants
n=138 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=138 Participants
Region of Enrollment
United States
14 Participants
n=138 Participants

PRIMARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

Quadricep Muscle Strength will be measured using an isokinetic dynamometer. Quadriceps femoris maximum voluntary isometric contraction (MVIC) as torque output (Nm) will be measured. Subjects will be seated in the dynamometer's chair with their knee at 60 degrees of flexion.

Outcome measures

Outcome measures
Measure
Preoperative Exercises
n=14 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Quadricep Muscle Strength
8-week assessment (non-surgical side)
91.03 torque newton-meter
Standard Deviation 29.13
Quadricep Muscle Strength
8-week assessment (surgical side)
80.32 torque newton-meter
Standard Deviation 36.94
Quadricep Muscle Strength
Baseline assessment (non-surgical side)
86.15 torque newton-meter
Standard Deviation 28.39
Quadricep Muscle Strength
Baseline assessment (surgical side)
76.55 torque newton-meter
Standard Deviation 37.23
Quadricep Muscle Strength
16-week assessment (non-surgical side)
85.24 torque newton-meter
Standard Deviation 20.86
Quadricep Muscle Strength
16-week assessment (surgical side)
55.49 torque newton-meter
Standard Deviation 17.57

PRIMARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

Population: The discrepancy in number of participants included (N=14) versus the number of participants analyzed in this outcome (n=7) is due to unavailability of the DXA scanner in the beginning of the study. Of note, all missed measures were reported to the IRB.

Leg muscles % fat mass will be measured using a DXA scan.

Outcome measures

Outcome measures
Measure
Preoperative Exercises
n=7 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Leg Muscles Percentage of Fat Mass
Baseline %Fat (non-surgical side)
47.88 Percentage
Standard Deviation 3.42
Leg Muscles Percentage of Fat Mass
Baseline %Fat (surgical side)
47.28 Percentage
Standard Deviation 3.31
Leg Muscles Percentage of Fat Mass
8-week %Fat (non-surgical)
46.64 Percentage
Standard Deviation 7.27
Leg Muscles Percentage of Fat Mass
8-week %Fat (surgical)
45.94 Percentage
Standard Deviation 7.53
Leg Muscles Percentage of Fat Mass
16-week %Fat (non-surgical side)
47.00 Percentage
Standard Deviation 6.92
Leg Muscles Percentage of Fat Mass
16-week %Fat (surgical side)
47.03 Percentage
Standard Deviation 6.90

PRIMARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

Population: The discrepancy in number of participants included (N=14) versus the number of participants analyzed in this outcome (n=7) is due to unavailability of the DXA scanner in the beginning of the study. Of note, all missed measures were reported to the IRB.

Leg muscles lean mass in kilograms will be measured using a DXA scan.

Outcome measures

Outcome measures
Measure
Preoperative Exercises
n=7 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Leg Muscles Lean Mass in Kilograms
Baseline_LeanMass (non-surgical)
5.47 Kilograms
Standard Deviation 4.08
Leg Muscles Lean Mass in Kilograms
Baseline_LeanMass (surgical)
5.63 Kilograms
Standard Deviation 4.13
Leg Muscles Lean Mass in Kilograms
8-week_LeanMass (non-surgical)
7.92 Kilograms
Standard Deviation 1.36
Leg Muscles Lean Mass in Kilograms
8-week_LeanMass (surgical)
7.98 Kilograms
Standard Deviation 1.15
Leg Muscles Lean Mass in Kilograms
16-week_LeanMass (non-surgical)
7.78 Kilograms
Standard Deviation 1.31
Leg Muscles Lean Mass in Kilograms
16-week_LeanMass (surgical)
7.85 Kilograms
Standard Deviation 1.10

SECONDARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

Subject will walk a 4-meter walkway at a self-selected pace. Time to complete task will be recorded.

Outcome measures

Outcome measures
Measure
Preoperative Exercises
n=14 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Self-selected Gait Speed
Baseline assessment
0.91 meters per second
Standard Deviation 0.21
Self-selected Gait Speed
8-week assessment
0.93 meters per second
Standard Deviation 0.19
Self-selected Gait Speed
16-week assessment
0.88 meters per second
Standard Deviation 0.21

SECONDARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

Subject will get up from a chair, walk 3 meters, turn around and walk back to and sit on the chair. Time to complete task will be recorded.

Outcome measures

Outcome measures
Measure
Preoperative Exercises
n=14 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Timed up and go Test
Baseline assessment
13.90 Seconds
Standard Deviation 6.61
Timed up and go Test
8-week assessment
12.47 Seconds
Standard Deviation 4.03
Timed up and go Test
16-week assessment
12.83 Seconds
Standard Deviation 4.25

SECONDARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

Subject will perform sit-to-stand from a standard chair for 30 seconds. Number of times of completed sit-to-stand in 30 seconds will be recorded.

Outcome measures

Outcome measures
Measure
Preoperative Exercises
n=14 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
30-second Chair Stand Test
Baseline assessment
7.50 Units (number of times standing up)
Standard Deviation 3.06
30-second Chair Stand Test
8-week assessment
9.07 Units (number of times standing up)
Standard Deviation 3.79
30-second Chair Stand Test
16-week assessment
7.86 Units (number of times standing up)
Standard Deviation 3.53

SECONDARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

Subject will climb up and down a flight of stairs (11 steps). Time to complete task will be recorded.

Outcome measures

Outcome measures
Measure
Preoperative Exercises
n=14 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Stair Climb Test
Baseline assessment
34.36 Seconds
Standard Deviation 32.09
Stair Climb Test
8-week assessment
28.34 Seconds
Standard Deviation 23.13
Stair Climb Test
16-week assessment
37.15 Seconds
Standard Deviation 27.85

SECONDARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

Subjects will cover as much as they can while walking on a flat, unobstructed path for 6 minutes.

Outcome measures

Outcome measures
Measure
Preoperative Exercises
n=14 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
6-minute Walk Test
8-week assessment
395.87 meters
Standard Deviation 108.73
6-minute Walk Test
16-week assessment
346.59 meters
Standard Deviation 110.13
6-minute Walk Test
Baseline assessment
369.43 meters
Standard Deviation 119.00

SECONDARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

Patient-Reported Physical Outcome will be assessed using PROMIS® (Patient-Reported Outcomes Measurement Information System), which is used to evaluate and monitor physical, mental, and social health in persons with several conditions. This is a 20 item survey with each item scored from 1-5. Total possible scores range from 5-100 with a higher score indicating better physical function.

Outcome measures

Outcome measures
Measure
Preoperative Exercises
n=14 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Patient-Reported Physical Outcomes Measurement Information System (PROMIS
Baseline assessment
60.00 Score
Standard Deviation 22.19
Patient-Reported Physical Outcomes Measurement Information System (PROMIS
8-week assessment
57.50 Score
Standard Deviation 19.78
Patient-Reported Physical Outcomes Measurement Information System (PROMIS
16-week assessment
56.15 Score
Standard Deviation 25.51

SECONDARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

The RAND-36 Questionnaire is comprised of 36 items that assess eight health concepts: physical functioning, role limitations caused by physical health problems, role limitations caused by emotional problems, social functioning, emotional well-being, energy/fatigue, pain, and general health perceptions. All questions are scored on a scale from 0 (worst) to 100 (best), with 100 representing the highest level of functioning possible. Aggregate scores are calculated between 0-100 with higher scores representing better quality of life.

Outcome measures

Outcome measures
Measure
Preoperative Exercises
n=14 Participants
Intervention is blood flow restriction training (BFRT) Blood Flow Restriction Training (BFRT): Participants will be performing low-resistance exercise with (BFRT). Intervention will start at least seven days after initial evaluation, so it does not influence measures of real-time physical activity. We will use a log to register exercise completion and to record bilateral knee pain before, during and after each intervention session
Health Related Quality of Life (RAND-36)
Baseline assessment
71.79 Score
Standard Deviation 16.01
Health Related Quality of Life (RAND-36)
8-week assessment
71.07 Score
Standard Deviation 16.78
Health Related Quality of Life (RAND-36)
16-week assessment
76.54 Score
Standard Deviation 15.99

SECONDARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

An activity monitor will be worn for 7 days and physical activity (i.e., daily number of steps) will be tracked.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Baseline, 8 weeks and 16 weeks

Change in 'MILLIPLEX® MAP Human High Sensitivity T Cell Magnetic Bead Panel' to assess a panel of 8 inflammatory biomarkers: Interleukin (IL)-1β, IL-2, IL-5, IL-6, IL-10, IL-12p70, IL-13 and Interferon-γ.

Outcome measures

Outcome data not reported

Adverse Events

Preoperative Exercises

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Gustavo Almeida

University of Texas at San Antonio, Health Sciences Center

Phone: 4123781951

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place