Training with blood flow restriction increases femoral artery diameter and thigh oxygen delivery during knee‐extensor exercise in recreationally trained men

Clinical Scenario: Knee pathologies often require rehabilitation to address the loss of knee-extensor (KE) strength, function, and heightened pain. However, in the early stages of rehabilitation, higher loads may be contraindicated. Blood flow restriction (BFR) resistance training does not require high loads and has been used clinically to promote strength improvements in a variety of injured populations. BFR resistance training may be an effective alternative to high-intensity resistance training during early rehabilitation of knee pathologies. Clinical Question: Following a knee injury, does BFR resistance training improve KE strength and function, and reduce patient-reported pain? Summary of Key Findings: Four randomized controlled trial studies met the inclusion criteria. Each included study evaluated the use of BFR resistance training on knee pathologies and the effects on KE strength, functional outcomes, and pain compared with high- or low-load resistance training. All 4 studies reported significant improvements in KE strength, function, and pain through a variety of outcome measures, following BFR resistance training use as the treatment. Clinical Bottom Line: There is consistent evidence to support the use of BFR resistance training as a treatment intervention following knee injury and as a means to improve KE strength and function and to reduce pain. Strength of Recommendation: Grade A evidence supporting the use of BFR resistance training for improvement in KE strength and function, and the reduction of patient-reported pain following an acute or chronic knee pathology.

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Insights for Blood Flow Restriction and Hypoxia in Leg Versus Arm Submaximal Exercise

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2019-0168 ◽

2020 ◽

Vol 15 (5) ◽

pp. 714-719

Author(s):

Sarah J. Willis ◽

Grégoire P. Millet ◽

Fabio Borrani

Keyword(s):

Blood Flow ◽

Oxygen Delivery ◽

Vascular Reactivity ◽

Near Infrared ◽

Biceps Brachii ◽

Submaximal Exercise ◽

Blood Flow Restriction ◽

Arterial Oxygen ◽

Flow Restriction ◽

Arm Cycling

Purpose: To assess tissue oxygenation, along with metabolic and physiological responses during blood flow restriction (BFR, bilateral vascular occlusion) and systemic hypoxia conditions during submaximal leg- versus arm-cycling exercise. Methods: In both legs and arms, 4 randomized sessions were performed (normoxia 400 m, fraction of inspired oxygen [FIO2] 20.9% and normobaric hypoxia 3800 m, FIO2 13.1% [0.1%]; combined with BFR at 0% and 45% of resting pulse elimination pressure). During each session, a single 6-minute steady-state submaximal exercise was performed to measure physiological changes and oxygenation (near-infrared spectroscopy) of the muscle tissue in both the vastus lateralis (legs) and biceps brachii (arms). Results: Total hemoglobin concentration ([tHb]) was 65% higher (P < .001) in arms versus legs, suggesting that arms had a greater blood perfusion capacity than legs. Furthermore, there were greater changes in tissue blood volume [tHb] during BFR compared with control conditions (P = .017, F = 5.45). The arms elicited 7% lower tissue saturation (P < .001) and were thus more sensitive to the hypoxia-induced reduction in oxygen supply than legs, no matter the condition. This indicates that legs and arms may elicit different regulatory hemodynamic mechanisms (ie, greater blood flow in arms) for limiting the decreased oxygen delivery during exercise with altered arterial oxygen content. Conclusions: The combination of BFR and/or hypoxia led to increased [tHb] in both limbs likely due to greater vascular resistance; further, arms were more responsive than legs. This possibly influences the maintenance of oxygen delivery and enhances perfusion pressure, suggesting greater vascular reactivity in arms than in legs.

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Differences in Femoral Artery Occlusion Pressure between Sexes and Dominant and Non-Dominant Legs

Medicina ◽

10.3390/medicina57090863 ◽

2021 ◽

Vol 57 (9) ◽

pp. 863

Author(s):

Nicole D. Tafuna’i ◽

Iain Hunter ◽

Aaron W. Johnson ◽

Gilbert W. Fellingham ◽

Pat R. Vehrs

Keyword(s):

Blood Flow ◽

Femoral Artery ◽

Superficial Femoral Artery ◽

Arterial Occlusion ◽

Artery Occlusion ◽

Blood Flow Restriction ◽

Occlusion Pressure ◽

Flow Restriction ◽

Significant Difference ◽

Arterial Occlusion Pressure

Background and Objectives: Blood flow restriction during low-load exercise stimulates similar muscle adaptations to those normally observed with higher loads. Differences in the arterial occlusion pressure (AOP) between limbs and between sexes are unclear. We compared the AOP of the superficial femoral artery in the dominant and non-dominant legs, and the relationship between blood flow and occlusion pressure in 35 (16 males, 19 females) young adults. Materials and Methods: Using ultrasound, we measured the AOP of the superficial femoral artery in both legs. Blood flow at occlusion pressures ranging from 0% to 100% of the AOP was measured in the dominant leg. Results: There was a significant difference in the AOP between males and females in the dominant (230 ± 41 vs. 191 ± 27 mmHg; p = 0.002) and non-dominant (209 ± 37 vs. 178 ± 21 mmHg; p = 0.004) legs, and between the dominant and non-dominant legs in males (230 ± 41 vs. 209 ± 37 mmHg; p = 0.009) but not females (191 ± 27 vs. 178 ± 21 mmHg; p = 0.053), respectively. Leg circumference was the most influential independent predictor of the AOP. There was a linear relationship between blood flow (expressed as a percentage of unoccluded blood flow) and occlusion pressure (expressed as a percentage of AOP). Conclusions: Arterial occlusion pressure is not always greater in the dominant leg or the larger leg. Practitioners should measure AOP in both limbs to determine if occlusion pressures used during exercise should be limb specific. Occlusion pressures used during blood flow restriction exercise should be chosen carefully.

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Low-Intensity Resistance Training with Moderate Blood Flow Restriction Appears Safe and Increases Skeletal Muscle Strength and Size in Cardiovascular Surgery Patients: A Pilot Study

Journal of Clinical Medicine ◽

10.3390/jcm10030547 ◽

2021 ◽

Vol 10 (3) ◽

pp. 547

Author(s):

Hironaga Ogawa ◽

Toshiaki Nakajima ◽

Ikuko Shibasaki ◽

Takahisa Nasuno ◽

Hiroyuki Kaneda ◽

...

Keyword(s):

Skeletal Muscle ◽

Blood Flow ◽

Muscle Strength ◽

Cardiovascular Surgery ◽

Knee Extensor ◽

Blood Flow Restriction ◽

Flow Restriction ◽

Low Intensity ◽

Knee Extensor Strength ◽

Skeletal Muscle Strength

We examined the safety and the effects of low-intensity resistance training (RT) with moderate blood flow restriction (KAATSU RT) on muscle strength and size in patients early after cardiac surgery. Cardiac patients (age 69.6 ± 12.6 years, n = 21, M = 18) were randomly assigned to the control (n = 10) and the KAATSU RT group (n = 11). All patients had received a standard aerobic cardiac rehabilitation program. The KAATSU RT group additionally executed low-intensity leg extension and leg press exercises with moderate blood flow restriction twice a week for 3 months. RT-intensity and volume were increased gradually. We evaluated the anterior mid-thigh thickness (MTH), skeletal muscle mass index (SMI), handgrip strength, knee extensor strength, and walking speed at baseline, 5–7 days after cardiac surgery, and after 3 months. A physician monitored the electrocardiogram, rate of perceived exertion, and the color of the lower limbs during KAATSU RT. Creatine phosphokinase (CPK) and D-dimer were measured at baseline and after 3 months. There were no side effects during KAATSU RT. CPK and D-dimer were normal after 3 months. MTH, SMI, walking speed, and knee extensor strength increased after 3 months with KAATSU RT compared with baseline. Relatively low vs. high physical functioning patients tended to increase physical function more after 3 months with KAATSU RT. Low-intensity KAATSU RT as an adjuvant to standard cardiac rehabilitation can safely increase skeletal muscle strength and size in cardiovascular surgery patients.

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Exercise with Blood Flow Restriction to Improve Quadriceps Function Long After ACL Reconstruction

International Journal of Sports Medicine ◽

10.1055/a-0961-1434 ◽

2019 ◽

Vol 40 (10) ◽

pp. 650-656 ◽

Cited By ~ 4

Author(s):

Matthew A. Kilgas ◽

Lydia L.M. Lytle ◽

Scott N. Drum ◽

Steven J. Elmer

Keyword(s):

Blood Flow ◽

Vastus Lateralis ◽

Knee Extensor ◽

Rectus Femoris ◽

Blood Flow Restriction ◽

Flow Restriction ◽

Post Surgery ◽

Knee Extensor Strength ◽

Quadriceps Function ◽

At Home

AbstractQuadriceps atrophy and weakness can persist for years after anterior cruciate ligament reconstruction (ACLR). We evaluated the effectiveness of a home-based blood flow restriction (BFR) exercise program to increase quadriceps size and strength several years after ACLR. Nine adults with ACLR (5±2 yrs post-surgery, ≤90% symmetry in quadriceps size and strength) and nine uninjured controls volunteered. ACLR participants exercised at home for 25 min, 5×/wk for 4 wks (single-leg knee extension, bodyweight half-squats, walking). Blood flow in only the involved leg was restricted using a thigh cuff inflated to 50% of limb occlusion pressure. Rectus femoris and vastus lateralis thickness and knee extensor strength were measured before and after training. Baseline and post-training symmetry (involved leg/uninvolved leg) indices were compared to uninjured controls. Rectus femoris and vastus lateralis thickness and knee extensor strength in the involved leg increased by 11±5%, 10±6%, and 20±14%, respectively (all P<0.01). Compared to baseline, post-training knee extensor strength symmetry increased from 88±4 to 99±5% (P<0.01) and did not differ from uninjured controls (99±5%, P=0.95). Implementation of BFR exercise at home was feasible, safe and effective. Results extend upon early post-operative application of BFR exercise for ACLR recovery and demonstrate that BFR can improve quadriceps function long after ACLR.

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