Understanding Limb Occlusion Pressure (LOP) for Safe and Effective BFR Rehabilitation

Limb Occlusion PressureSafetyLOP
Written By Michael .

What Is Limb Occlusion Pressure (LOP) and Why Is It Important?

Limb occlusion pressure (LOP), also referred to as arterial occlusion pressure (AOP), is defined as the minimum external pressure needed to fully occlude arterial inflow into a limb (4, 5, 6). At 100% LOP, arterial blood flow is completely stopped distal to the cuff. It is important to clarify a common misunderstanding: while 100% LOP represents full arterial occlusion, venous outflow is typically occluded at much lower pressures. In most individuals, venous return (outflow) begins to be restricted at 30–50% LOP, depending on cuff width, limb characteristics, and vascular health (2, 3, 5, 6, 7, 9).

This occurs because veins and arteries differ structurally and functionally. Veins are thin-walled, low-pressure, highly compliant vessels located more superficially within the limb. Venous pressure is low, so it does not take much external pressure from the cuff to compress the veins and slow or stop blood from leaving the limb. Arteries have thicker muscular walls, are positioned deeper within the limb, and operate under significantly higher internal pressures (systolic pressures commonly 110–140+ mmHg). As a result, substantially greater external pressure is required to overcome arterial pressure and fully occlude inflow (3).

When a cuff is placed at the top of the limb and inflated, it compresses the veins first, causing blood to pool below the cuff and muscle cells to swell. As pressure increases toward 100% LOP, arterial inflow progressively diminishes until complete occlusion occurs. This distinction is central to understanding how BFR works. Properly prescribed BFR (typically 40–80% LOP) partially restricts arterial inflow while effectively occluding venous outflow (4, 5). The partial restriction of arterial inflow and complete occlusion of venous outflow creates a hypoxic, metabolically and mechanically stressful environment similar to the muscular environment created with high-intensity, heavy-load resistance training.

During BFR training we apply a percentage of LOP often between 40–80% depending on the limb, the patient, and the training goal. At these sub-maximal pressures:

  • Arterial inflow is partially restricted (blood entering the limb)

  • Venous outflow is largely occluded (blood leaving the limb)

For example:

  • At 40% LOP roughly 40% of arterial inflow is restricted and 100% of venous outflow is restricted.

  • At 60% LOP roughly 60% of arterial inflow is restricted and 100% of venous outflow is restricted.

  • At 80% LOP roughly 80% of arterial inflow is restricted and  100% of venous outflow is restricted.

This creates a hypoxic and metabolically and mechanically stressful environment within the muscle while allowing some arterial inflow to continue. The result is a powerful stimulus for strength and hypertrophy adaptations using low loads.

Why Fixed Pressures (150–200 mmHg) Are Not Evidence-Based  

Historically, some practitioners applied arbitrary pressures, such as 150 mmHg for the upper extremity or 200 mmHg for the lower extremity, when performing blood flow restriction (BFR). While simple, this approach fails to account for substantial individual variability in limb occlusion pressure (LOP).

LOP differs significantly between individuals and even between limbs of the same individual. It is influenced by limb circumference, underlying tissue composition (muscle and adipose thickness), vascular characteristics, cuff width, and cuff material (2, 3, 5, 6, 7, 9). The three most significant physiological factors influencing LOP are limb circumference, tissue composition, and individual vascular characteristics (5, 6, 7). Arbitrary fixed pressures do not account for these differences.

Modern BFR practice is grounded in individualized LOP determination. Current best practice recommends measuring each person’s LOP and prescribing exercise pressures as a percentage of that value, commonly 40–50% LOP for the upper extremity and 40–80% LOP for the lower extremity, depending on the goal and population (8). This percentage-based model standardizes the physiological stimulus across individuals while improving safety and reproducibility.

When LOP is not measured, pressure selection becomes estimation rather than calibration. A fixed pressure will not create the same relative stimulus in different individuals. For example, 150 mmHg may represent:

  • ~70% LOP in one individual

  • ~40% LOP in another

  • Or potentially exceed 80–100% LOP in a smaller, leaner, or older limb

Because BFR adaptations are pressure-dependent, this variability directly affects both safety and effectiveness. Pressures that are too low may fail to generate sufficient arterial restriction and metabolic stress, while pressures that are too high may approach full arterial occlusion, increasing discomfort and unnecessary ischemic stress.

Cuff characteristics further complicate the use of fixed pressures. Wider cuffs occlude arterial flow at lower pressures, whereas narrower cuffs require higher pressures to achieve the same effect (3, 5, 6). Cuff material also alters the applied stimulus and resulting vascular response (2). Identical absolute pressures applied with different cuffs can produce markedly different physiological outcomes.

The importance of individualized occlusion pressure extends beyond exercise settings. In surgical practice, limb occlusion pressure–based tourniquet systems have been shown to reduce excessive inflation pressures compared to standard fixed-pressure approaches, supporting greater precision and reduced unnecessary compression (1).

In summary, fixed pressures (150–200 mmHg) are not evidence-based when individualized LOP measurement is available. BFR is a pressure-dependent intervention, and proper dosing requires individualized assessment to ensure consistent stimulus, maximize safety, and optimize adaptation.

Why Individualized LOP Matters

Limb occlusion pressure (LOP) is the foundation of safe and effective BFR training. Arterial occlusion pressure varies significantly between individuals based on limb size, tissue composition, vascular characteristics, and cuff design, BFR must be prescribed as a percentage of each person’s measured LOP rather than as a fixed pressure. Properly dosed BFR (typically 40–80% LOP depending on the limb and goal) partially restricts arterial inflow while substantially limiting venous outflow, creating the hypoxic, metabolically and mechanically stressful intramuscular environment necessary to stimulate strength and hypertrophy adaptations with low loads. Using an individualized LOP ensures the correct physiological stimulus is delivered consistently and safely for each individual. When LOP is measured and applied appropriately, BFR becomes a precise, scalable, and evidence-based intervention rather than a generalized compression strategy.

Frequently Asked Questions About LOP in BFR Therapy

Is 100% LOP used during rehabilitation?

No. 100% LOP fully occludes arterial inflow and is not used during therapeutic exercise (only passive BFR)

Why is individualized LOP necessary in clinical populations?

LOP varies significantly based on limb size, tissue composition, cuff width, and patient characteristics.

Can fixed pressures compromise safety?

Yes. Fixed pressures may underdose or overdose patients depending on individual physiology.

How often should LOP be reassessed?

LOP should be reassessed when there are meaningful changes in limb size, healing stage, or clinical status.

References

  1. Aflatooni, J., Goble, H., Lambert, B., Liberman, S., & McCulloch, P. C. (2025). Limb Occlusion Pressure Versus Standard Pneumatic Tourniquet Pressure in Anterior Cruciate Ligament Surgery: A Randomized Controlled Trial. Journal of the American Academy of Orthopaedic Surgeons. Global research & reviews, 9(5), e24.00282. https://doi.org/10.5435/JAAOSGlobal-D-24-00282

  2. Buckner, S. L., Dankel, S. J., Counts, B. R., Jessee, M. B., Mouser, J. G., Mattocks, K. T., & Loenneke, J. P. (2017). Influence of cuff material on blood flow restriction stimulus in the upper body. Journal of Applied Physiology, 122(6), 1445–1452. https://doi.org/10.1152/japplphysiol.00145.2017

  3. Crenshaw, A. G., Hargens, A. R., Gershuni, D. H., & Rydevik, B. (1988). Wide tourniquet cuffs more effective at lower inflation pressures. Acta Orthopaedica Scandinavica, 59(4), 447–451. https://doi.org/10.3109/17453678809149394

  4. Evin, H. A., Mahoney, S. J., Wagner, M., Bond, C. W., MacFadden, L. N., & Noonan, B. C. (2021). Limb occlusion pressure for blood flow restricted exercise: Variability and relations with participant characteristics. Physical therapy in sport : official journal of the Association of Chartered Physiotherapists in Sports Medicine, 47, 78–84. https://doi.org/10.1016/j.ptsp.2020.11.026

  5. Graham, M. M., Mouser, J. G., Buckner, S. L., Dankel, S. J., Jessee, M. B., & Loenneke, J. P. (2019). Relationships between limb circumference and arterial occlusion pressure at rest. Clinical Physiology and Functional Imaging, 39(1), 46–51. https://doi.org/10.1111/cpf.12531

  6. Jessee, M. B., Buckner, S. L., Mouser, J. G., Mattocks, K. T., Dankel, S. J., Counts, B. R., & Loenneke, J. P. (2016). Determining the optimal cuff width for blood flow restriction training. European Journal of Applied Physiology, 116(10), 2079–2088. https://doi.org/10.1007/s00421-016-3453-5

  7. Loenneke, J. P., Fahs, C. A., Rossow, L. M., Thiebaud, R. S., Mattocks, K. T., Abe, T., & Bemben, M. G. (2012). Effects of cuff width on arterial occlusion: Implications for blood flow restricted exercise. European Journal of Applied Physiology, 112(8), 2903–2912. https://doi.org/10.1007/s00421-011-2266-8

  8. Patterson, S. D., Hughes, L., Head, P., Warmington, S., Brandner, C., Bloodworth, A., … Loenneke, J. P. (2019). Blood flow restriction exercise: Considerations of methodology, application, and safety. Frontiers in Physiology, 10, 533. https://doi.org/10.3389/fphys.2019.00533

  9. Weatherholt, A. M., Vanwye, W. R., Lohmann, J., & Owens, J. G. (2019). The Effect of Cuff Width for Determining Limb Occlusion Pressure: A Comparison of Blood Flow Restriction Devices. International journal of exercise science, 12(3), 136–143. https://doi.org/10.70252/RWVU7100

Michael . https://GreatLakesSportsPerformance.com