Blood Flow Restriction Training in knee rehab – It’s not if, It’s when!

November 16th, 2023

As you know, you should begin high-quality rehabilitation immediately after an injury. Everyone with an acute knee injury (e.g. ACL rupture, MCL injury, meniscal tear…) experiences early loss in muscle mass and muscle strength. So the first phase is crucial!
Overuse injuries also require adequate load management to reduce pain and increase load capacity.  

Can we reduce these losses and restore them more early with Blood Flow Restriction Training (BFRT)? Can we reduce pain with BFRT?

credits to The BFR Pros

Yes you heard that right! Blood Flow Restriction Training is able to increase muscle mass and strength with much less weights or NO weights at all. Which is absolutely important to maintain and improve post knee injury to restore daily functioning and participation to sports!

Experts Agree on the Recommendation to Use BFR in ACL Rehab

(Practice guideline Kotsifaki et al., 2023)

Based on the scientific evidence, high intensity strength training is necessary to get these improvements. But all of you know that training with heavy loads is far from possible after an acute knee injury. We need to protect tissue healing and respect the reduced load capacity of the knee! Especially when there are weight bearing restrictions given by the surgeon because of for example a meniscal repair.
So we have no other choice than applying low intensity training in these cases. But almost always muscles aren’t getting into fatigue and thus you aren’t experiencing the feeling of the pump, because of the very high amount of repetitions needed. The pump is actually very important to achieve because we then know that mechanisms are taking place and we are reducing the loss or even gaining muscle mass and strength.  

Typically with overuse injuries, patients or athletes experience pain and are unable to tolerate the loading that occurs during training or high intensity strength exercises. Current research is suggesting that BFRT could reduce knee pain (e.g. anterior knee pain, patella femoral pain, patellar tendinopathy). This isn’t the only advantage of BFRT. Imagine your patient or athlete is already able to experience the physiological benefits associated with training at a higher intensity, meaning they are already building muscle mass and strength, or at least maintaining them without performing high intensity strength training.

Researchers found that BFRT can improve cross-sectional area and stiffness of the patellar tendon in healthy individuals. This is interesting to consider regarding the rehab of patellar tendinopathies, but should be further investigated!

BFR is no Magic! It's Pure Exercise Physiology

Besides that, BFR could:

  • Reduce loss in bone mineral density and bone mass
  • Possibly reduce swelling
  • Possibly resolve activation problems
  • Maintain or improve aerobic capacity, muscle mass and muscle strength with Aerobic BFRT
  • Improve physical functioning and quality of life
  • Be used safe in adolescents

LL-BFR Outperforms LL Training without BFR


How should BFRT be applied?

Step 1: is there an indication?

Who is likely an appropriate BFR training candidate? The evidence strongly supports BFR’s use in those patients with either a loading problem or a pain problem.

There is no discussion that there is an indication after for example ACLR or other serious knee injuries. Because load capacity is suppressed and pain is a major factor influencing the knee function.

 Step 2: is it safe?

The evidence does not support the assertion that BFR creates blood clots! It seems to reduce the possibility of a blood clot.
BFR is safe if the following requirements are met:

  • Medical screening passed
    • Rule out absolute contra-indications
    • Take into account relative contra-indications
    • Blood pressure assessment
    • Consult with doctor or expert (when in doubt)
  • Applied by an experienced and trained therapist
  • Correct protocols and techniques applied
  • Use of objective LOP (limb occlusion pressure) assessment and pneumatic cuffs or validated automatic devices
      • Choose your cuffs wisely!

Stop Guessing! Start Assessing!

Step 3: write a BFR training program!

Writing a BFR training program includes taking into account medical screening and patient characteristics. Determining the training pressure based on a LOP assessment and prescribing based on the pressure/load continuum are crucial! When necessary, implement strategies to reduce perceptual demands to maintain long-term compliance. Last but not least, think about The Pillars of BFR Training throughout your training and within each session. Use them as a progressive framework/ continuum to applying BFRT from very easy to harder and select the right exercises.

Pillar 1: cell swelling/ passive BFR

Goals of Pillar 1:

  • Short familiarization period
  • Reduction in atrophy and muscle strength loss

Pillar 2: cardiovascular training

Goals of Pillar 2:

  • Increase in muscle mass and strength
  • Maintenance or improvement of aerobic capacity
  • Pain relief
  • Bridge towards pillar 3

Pillar 3: resistance training

Goals of Pillar 3:

  • Pursue the same benefits as with traditional high load strength training without all the external mechanical stress
  • Attenuate atrophy
  • Increase muscle hypertrophy
  • Increase muscle strength and endurance
  • Resolve activation problems
  • Pain relief
  • Facilitate bone metabolism

Pillar 4: performance training

Not often used in knee rehab

Individuals can skip pillar 1 and/or 2 if your evaluation suggests that they are able to tolerate the stress of later pillars.

BFR Training as a Bridge Towards High Load Training

BFRT is already being used all over the world to accelerate fatigue and rehab. Not only with elite athletes, but also with the recreational athlete and non-sporter with knee injuries. Doctors and surgeons are already referring to the use of BFR in their patients rehab! Don’t stay behind. It’s not IF, it’s WHEN!

Are you a doctor or a patient and do you want to find a BFR certified physio? LOOK AT www.bfrproviders.com

Find your BFR specialist


Mathias Thoelen
The BFR Pros

If you have any questions, Mathias Thoelen and The BFR Pros are ready for you!

The BFR Pros are a team of clinicians, coaches and athletes who have combined forces to bring you the real science and tools behind Blood Flow Restriction.


Abe, T., Kearns, C. F., & Sato, Y. (2006). Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training. Journal of applied physiology, 100(5), 1460-1466.

Abe, T., Fujita, S., Nakajima, T., Sakamaki, M., Ozaki, H., Ogasawara, R., ... & Ishii, N. (2010). Effects of low-intensity cycle training with restricted leg blood flow on thigh muscle volume and VO2max in young men. Journal of sports science & medicine, 9(3), 452.

Bond, C. W., Hackney, K. J., Brown, S. L., & Noonan, B. C. (2019). Blood flow restriction resistance exercise as a rehabilitation modality following orthopaedic surgery: a review of venous thromboembolism risk. journal of orthopaedic & sports physical therapy, 49(1), 17-27.

Centner, C., Jerger, S., Lauber, B., Seynnes, O. R., Friedrich, T., Lolli, D., ... & König, D. (2022). Low-load blood flow restriction and high-load resistance training induce comparable changes in patellar tendon properties.

Constantinou, A., Mamais, I., Papathanasiou, G., Lamnisos, D., & Stasinopoulos, D. (2022). Comparing hip and knee focused exercises versus hip and knee focused exercises with the use of blood flow restriction training in adults with patellofemoral pain. European Journal of physical and rehabilitation Medicine, 58(2), 225.

Cuddeford, T., & Brumitt, J. (2020). In‐season rehabilitation program using blood flow restriction therapy for two decathletes with patellar tendinopathy: A case report. International journal of sports physical therapy, 15(6), 1184.

Formiga, M. F., Fay, R., Hutchinson, S., Locandro, N., Ceballos, A., Lesh, A., ... & Cahalin, L. P. (2020). EFFECT OF AEROBIC EXERCISE TRAINING WITH AND WITHOUT BLOOD FLOW RESTRICTION ON AEROBIC CAPACITY IN HEALTHY YOUNG ADULTS: A SYSTEMATIC REVIEW WITH META-ANALYSIS. International Journal of Sports Physical Therapy, 15(2).

Giles, L., Webster, K. E., McClelland, J., & Cook, J. L. (2017). Quadriceps strengthening with and without blood flow restriction in the treatment of patellofemoral pain: a double-blind randomised trial. British journal of sports medicine, 51(23), 1688-1694.

Hughes, L., Grant, I., & Patterson, S. D. (2021). Aerobic exercise with blood flow restriction causes local and systemic hypoalgesia and increases circulating opioid and endocannabinoid levels. Journal of Applied Physiology, 131(5), 1460-1468.

Hughes, L., Paton, B., Haddad, F., Rosenblatt, B., Gissane, C., & Patterson, S. D. (2018). Comparison of the acute perceptual and blood pressure response to heavy load and light load blood flow restriction resistance exercise in anterior cruciate ligament reconstruction patients and non-injured populations. Physical Therapy in Sport, 33, 54-61.

Hughes, L., & Patterson, S. D. (2020). The effect of blood flow restriction exercise on exercise-induced hypoalgesia and endogenous opioid and endocannabinoid mechanisms of pain modulation. Journal of Applied Physiology, 128(4), 914-924.

Hughes, L., Patterson, S. D., Haddad, F., Rosenblatt, B., Gissane, C., McCarthy, D., ... & Paton, B. (2019a). Examination of the comfort and pain experienced with blood flow restriction training during post-surgery rehabilitation of anterior cruciate ligament reconstruction patients: A UK National Health Service trial. Physical Therapy in Sport, 39, 90-98.

Hughes, L., Rosenblatt, B., Haddad, F., Gissane, C., McCarthy, D., Clarke, T., ... & Patterson, S. D. (2019b). Comparing the effectiveness of blood flow restriction and traditional heavy load resistance training in the post-surgery rehabilitation of anterior cruciate ligament reconstruction patients: a UK National Health Service Randomised Controlled Trial. Sports Medicine, 49(11), 1787-1805.

Hughes, L., Rosenblatt, B., Paton, B., & Patterson, S. D. (2018). Blood flow restriction training in rehabilitation following anterior cruciate ligament reconstructive surgery: A review. Techniques in Orthopaedics, 33(2), 106-113.

Jack, R. A., Lambert, B. S., Hedt, C. A., Delgado, D., Goble, H., & McCulloch, P. C. (2022). Blood Flow Restriction Therapy Preserves Lower Extremity Bone and Muscle Mass After ACL Reconstruction. Sports Health, 19417381221101006.

Korakakis, V., Whiteley, R., & Epameinontidis, K. (2018). Blood flow restriction induces hypoalgesia in recreationally active adult male anterior knee pain patients allowing therapeutic exercise loading. Physical Therapy in Sport, 32, 235-243.

Kotsifaki, R., Korakakis, V., King, E., Barbosa, O., Maree, D., Pantouveris, M., ... & Whiteley, R. (2023). Aspetar clinical practice guideline on rehabilitation after anterior cruciate ligament reconstruction. British Journal of Sports Medicine, 57(9), 500-514

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Rolnick, N., Kimbrell, K., Cerqueira, M. S., Weatherford, B., & Brandner, C. (2021). Perceived Barriers to Blood Flow Restriction Training. Frontiers in Rehabilitation Sciences, 14.

Skovlund, S. V., Aagaard, P., Larsen, P., Svensson, R. B., Kjaer, M., Magnusson, S. P., & Couppé, C. (2020). The effect of low‐load resistance training with blood flow restriction on chronic patellar tendinopathy—A case series. Translational Sports Medicine, 3(4), 342-352.

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About the Author

Mathias Thoelen
Instructor/ Lecturer Blood Flow Restriction Training (BFRT)

Mathias Thoelen is a Belgian Sports Physical Therapist working at Sports Medical Center Anna TopSupport Eindhoven in The Netherlands. Mathias currently teaches BFR Workshops in Europe for the BFR Pros. His ambition is to make Blood Flow Restriction Training great in Europe and beyond by providing evidence-based workshops about the safe and objective application of BFRT in different populations. In addition, he is engaged in research on training with BFR in post operative patients.

“The lack of knowledge and experience is a major problem as the demand for BFR is increasing worldwide.
My goal is to provide a safe, objective and evidence-based worldwide application of BFRT!” If you have any questions, Mathias Thoelen and The BFR Pros are ready for you!

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