Blood Flow Restriction Research Articles

The Effect of Exercises with Blood Flow Restriction in the Limbs on the Development of Muscle Strength and Hypertrophy: A Pilot Study

Weight training with regulated blood flow in the limbs is characterized by low load intensity ranging from 30-50% of the one repetition maximum. The aim of the study was to assess the effect of weight training with regulated blood flow in the limbs on changes in muscle strength and hypertrophy. The research sample consisted of 5 participants aged 26.40±7.16 years who performed 10-week intervention program. The weekly microcycle consisted of three training sessions, which intensity was regulated by inflatable cuffs placed on proximal parts of upper and lower limbs. Body composition was assessed with InBody 720. Muscle strength of knee and elbow flexors and extensors was assessed with Cybex HUMAC NORM isokinetic dynamometer at four speeds ranging from 60-240°·s-1, supplemented by front squat and bench press with emphasis on speed during the concentric phase of the movement. The results showed an increase in knee flexor muscle strength that was not statistically significant. The present pilot-study points to the need for further verification of methods how to use regulated blood flow in training related to muscle strength and hypertrophy.

Application of blood flow restriction training in lower limb rehabilitation

With the popularity of national fitness campaigns, sports injuries, especially lower limb injuries such as anterior cruciate ligament tears and ankle sprains, are increasing year by year. There are limitations in traditional treatment such as muscle atrophy. In recent years, the blood flow restriction training method (BFRT) which simulates high-intensity exercise with low intensity and limits arterial and venous blood flow to promote muscle growth and strength enhancement, has drawn attention as a novel approach to rehabilitation. This article reviews the application of BFRT in the rehabilitation of lower limb injuries, discusses its effects on muscle function, pain management and quality of life, and evaluates its safety and prospects for clinical application. BFRT reduces mechanical stress, relieves pain, improves endurance and aerobic capacity, and improves cardiovascular function. However, there are discomfort and potential risks, such as muscle injury and thrombosis, which require individualised adjustments and standardised training. BFRT has shown positive result(reducing pain &oedema and improving function)s in rehabilitation of ACL reconstruction (ACLR) and chronic ankle instability (CAI). In addition, BFRT has been shown to aid in the functional recovery of the lower extremity in patients with Achilles tendon injuries and strokes. Despite the positive effects of BFRT, relevant studies have problems such as small sample sizes and non-uniform parameters. BFRT is considered a safe training modality, but contraindications should be examined before clinical application. Future research endeavours should investigate the impact of BFRT in many rehabilitation contexts and enhance tailored rehabilitation strategies. In order to maximize the therapeutic benefit, a rehabilitation training program should be developed and refined with a minimum effective dose based on the quantification of the in vivo physiological response to BFRT. The identification of the optimal prognostic approach will help to advance the standardisation of BFR treatment methods.

Feasibility and safety of two weeks of blood flow restriction exercise in individuals with spinal cord injury

Context Reduced muscle strength and function are common after spinal cord injury (SCI). While low-load blood flow restriction exercise (BFRE) enhances muscle strength in healthy and clinical populations, its safety and feasibility in individuals with SCI remain underexplored. Objectives To investigate the feasibility and safety of low-load BFRE in individuals with incomplete SCI. Study Design Case series. Setting SCI rehabilitation center. Participants Six participants with motor incomplete SCI were enrolled in the study. Intervention A two-week BFRE intervention for the lower limbs was conducted twice weekly at 40% total arterial occlusion pressure, using 30-40% of 1-repetition maximum loads. Outcome Measures Feasibility measures, specifically recruitment and eligibility rates and intervention acceptability, were collected. Blood pressure (BP) responses and specific coagulation markers for deep vein thrombosis (DVT) were assessed as safety measures. Results Recruitment and eligibility rates were 2.8% and 6.6% for individuals admitted for first-time rehabilitation (subacute SCI) and 8.3% and 13.9% for 4-week readmission rehabilitation stays (chronic SCI), respectively. Intervention acceptability was high, characterized by 95.8% training adherence and low-to-moderate self-reported pain levels. BP responses and changes in C-reactive protein, Fibrinogen, and D-dimer during the intervention remained within clinically acceptable levels. Conclusion BFRE was feasible in an SCI rehabilitation setting despite a low recruitment rate. BFRE imposed no heightened risk of DVT or severe BP fluctuations in the present case series. Additionally, no severe adverse events occurred, and only mild complaints were reported. More extensive safety considerations warrant larger-scale exploration. Trial registration ClinicalTrials.gov identifier: NCT03690700.

Thrombotic complications in pregnancy: a case-based review of the evidence

Pregnancy is a prothrombotic state due to an estrogen-driven shift in the coagulation system, increased venous stasis, and external restriction of blood flow caused by the gravid uterus. Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in pregnancy. Preventing, recognizing, and treating thrombosis in pregnancy, as well as the postpartum period, often challenges decision making in the clinical setting. In early pregnancy, guidance with respects to thrombophilia testing and anticoagulation in increasing the likelihood of live birth among patients with recurrent miscarriages is evolving. This review explores emerging data that support clinical decision making in thrombosis care in women with common thrombotic complications in pregnancy. The first case outlines VTE diagnosis in pregnancy, initial anticoagulation management, management around delivery and postpartum, and subsequent long-term anticoagulation treatment. The second case examines testing for inherited and acquired thrombophilia in the setting of recurrent miscarriage and the management of obstetric antiphospholipid syndrome. Lastly, the third case reviews VTE risk assessment and prevention in pregnancy and the postpartum period, as well as duration and dose of postpartum thromboprophylaxis. Review of these common clinical scenarios surrounding thrombotic complications in pregnancy demonstrates recent advances in high-quality data, current gaps in knowledge, and variation in expert opinion. Ultimately, multidisciplinary discussion and teamwork remain key to optimal, safe care. Clinicians must prioritize collaborative, high-quality trials and prospective clinical management studies to better understand and define best practice in this population.

Inhaled Argon Dilates Pulmonary Vasculature in Rat Isolated Lungs.

During cardiopulmonary resuscitation, pulmonary vasoconstriction due to hypoxia and hypercarbia restricts blood flow from the right to the left heart, resulting in reduced cardiac output that further inhibits adequate oxygenation and the ability to distribute oxygenated blood and medications. An inhaled pulmonary vasodilator could attenuate vasoconstriction and, therefore, increase cardiac output. We used rat isolated lungs to test if inhaled Argon leads to pulmonary vasodilation in phenylephrine-treated lungs. Lungs of 13 adult male Sprague Dawley rats were isolated, ventilated, and perfused. Pulmonary artery and left atrium were cannulated and lungs perfused at constant flow with 4% albumin physiological saline solution. Controls (n=6) were ventilated with 65% N2, 5% CO2, 30% O2 and Argon lungs (n=7) with 65% Argon, 5% CO2, 30% O2. Pulmonary mean arterial pressure (pMAP) and airway pressure (AWP) were recorded continuously, and pulmonary vascular resistance (PVR) was calculated. Following baseline readings, phenylephrine, a pulmonary vasoconstrictor, was perfused at increasing concentrations from 10-7 M to 10-3 M every 5 min. Statistics: Student's t-Test, α=0.05. Argon led to significantly lower pMAPs and PVRs, independent of AWP. Thus, it significantly dilated pre-constricted pulmonary vessels in an ex-vivo lung model. When given during resuscitation, this might aid to increase cardiac output.

Effect of Blood Flow Restriction on Gait and Mobility in Older Adults: A Systematic Review and Meta-Analysis.

Older adults demonstrate gait impairments that increase their risk for falls. These age-related mobility impairments are in part due to declines in muscle mass and strength. High-intensity exercise can improve muscle strength and mobility but may not be tolerable for older adults due to musculoskeletal injury and pain. Blood flow restriction (BFR) with lower-intensity exercise offers a strategy that may be more tolerable for older adults, but whether BFR improves gait and mobility in older adults is unclear. The purpose of this systematic review and meta-analysis was to determine the effect of BFR on gait and mobility in healthy older adults. PubMed, Embase, Cochrane Library, and CINAHL were systematically searched for articles utilizing BFR in older adults. Articles were included if adults were over 60 years, did not have chronic health conditions, had undergone randomized controlled trials, and presented objectively measured gait outcomes. The search identified 1501 studies, of which 9 were included in the systematic review and 8 studies in the meta-analysis. Outcome measures included the Timed Up and Go (TUG), 6-Minute Walk Test (6MWT), 400 m walk test, Short Physical Performance Battery (SPPB), and 10 m walk test. Meta-analyses found improvements in the TUG (mean difference (MD) = -0.71; 95% CI = -1.05, -0.37; p < 0.001) and SPPB (MD = -0.94; 95% CI = -1.48, -0.39; p < 0.001) in BFR compared to no BFR. There were no differences in gait speed (MD = 0.59; 95% CI = -0.22, 1.41; p = 0.16). BFR may be effective for gait and mobility tasks over shorter distances. Clinicians may consider incorporating BFR to improve mobility and gait function in older adults.

Blood flow modulation to improve motor and neurophysiological outcomes in individuals with stroke: a scoping review.

Ischemic Conditioning (IC) is a procedure involving brief periods of occlusion followed by reperfusion in stationary limbs. Blood Flow Restriction with Exercise (BFR-E) is a technique comprising blood flow restriction during aerobic or resistance exercise. Both IC and BFR-E are Blood Flow Modulation (BFM) strategies that have shown promise across various health domains and are clinically relevant for stroke rehabilitation. Despite their potential benefits, our knowledge on the application and efficacy of either intervention in stroke is limited. This scoping review aims to synthesize the existing literature on the impact of IC and BFR-E on motor and neurophysiological outcomes in individuals post-stroke. Evidence from five studies displayed enhancements in paretic leg strength, gait speed, and paretic leg fatiguability after IC. Additionally, BFR-E led to improvements in clinical performance, gait parameters, and serum lactate levels. While trends toward motor function improvement were observed post-intervention, statistically significant differences were limited. Neurophysiological changes showed inconclusive results. Our review suggests that IC and BFR-E are promising clinical approaches in stroke, however high-quality studies focusing on neurophysiological mechanisms are required to establish the efficacy and underlying mechanisms of both in stroke. Recommendations regarding future directions and clinical utility are provided.

Respiratory Muscle Strength as a Predictor of VO2max and Aerobic Endurance in Competitive Athletes

This study explores the association of respiratory muscle strength with aerobic endurance kinetics among athletes, with a specific focus on maximal oxygen consumption (VO2max). Previous research has elucidated the complex interactions between respiratory and skeletal muscles during exercise, highlighting the critical role of efficient respiration in maximizing athletic performance. The interplay between active skeletal muscles and respiratory muscles, especially the influence of respiratory muscle fatigue on exercise capacity, is well-documented. High-intensity exercise has been shown to activate the respiratory muscle metaboreflex, which can restrict blood flow to working muscles, thereby impacting the energy required for respiration. A total of 41 athletes, drawn from the disciplines of biathlon, judo, and cross-country, participated in this study. Respiratory function tests (RFTs) were administered to assess various respiratory parameters, including changes in chest circumference. Additionally, maximal oxygen consumption (VO2max) and heart rate were measured during a treadmill test. To explore the associations between VO2max and ventilatory parameters—namely, ventilation (VE), oxygen consumption (VO2), carbon dioxide production (VCO2)—as well as respiratory metrics, linear regression analysis was employed. Based on the standardized regression coefficients (β), it was found that maximum expiratory pressure (MEP) (mean ± SD: 130.95 ± 42.82) and inspiratory diaphragmatic circumference values were significantly associated with VE, VO2, and VCO2. Conversely, the other predictor variables did not exhibit a significant effect on VE (mean ± SD: 134.80 ± 36.69), VO2 (mean ± SD: 3877.52 ± 868.47 mL), and VCO2 (mean ± SD: 4301.27 ± 1001.07 mL). Similarly, measurements of chest circumference (mean ± SD: 91.40 ± 10.72 cm), MEP, and diaphragmatic circumference during inspiration (mean ± SD: 95.20 ± 10.21 cm) were significantly associated with VO2max (mean ± SD: 58.52 ± 10.74 mL/kg/min), while the remaining predictor variables did not demonstrate a significant effect on VO2max. Additionally, a multiple linear regression analysis was conducted to examine the combined effects of respiratory muscle strength and ventilatory factors on VO2max. The model, which included interaction terms, explained 89.9% of the variance in VO2max (R2 = 0.899, adjusted R2 = 0.859). Significant interactions were found between MIP and VE (B = −0.084, p = 0.006), as well as MEP and VE (B = 0.072, p = 0.012). These findings suggest that respiratory muscle strength plays a more substantial role in determining VO2max in individuals with higher ventilatory efficiency, highlighting the importance of both respiratory strength and breathing efficiency in aerobic performance. Our findings underscore the importance of considering respiratory muscle strength in assessing and enhancing athletes’ aerobic performance. Integrating objective measurements such as maximal inspiratory and expiratory pressure assessments into routine performance evaluations allows coaches and sports scientists to monitor changes in respiratory function over time and adjust training protocols accordingly.

Blood Flow Restriction Training: A Tool to Enhance Rehabilitation and Build Athlete Resiliency

Blood flow restriction training (BFRT) is a tool utilized in rehabilitation and injury prevention to improve muscle strength and size, particularly in load-compromised individuals. BFRT facilitates gains in muscular strength and hypertrophy at lower loads, allowing for accelerated recovery and less disuse atrophy. BFRT must be applied appropriately and with caution, particularly in individuals with cardiovascular concerns. There are applications for BFRT across a wide spectrum of human performance training and in rehabilitation of both lower and upper extremity conditions, providing a high-quality adjunct to improve muscle strength, power, and endurance. Level of EvidenceLevel V, expert opinion.

The Efficacy of Blood Flow Restriction Training to Improve Quadriceps Muscle Function after ACL Reconstruction.

Blood flow restriction training (BFRT) is a popular rehabilitation intervention after anterior cruciate ligament reconstruction (ACLR). However, there are a lack of clinical trials establishing the efficacy of using BFRT during rehabilitation to improve quadriceps muscle function. To evaluate the efficacy of blood flow restriction training to improve quadriceps muscle strength, morphology, and physiology, and knee biomechanics in individuals after ACLR in a double-blind, randomized, placebo-controlled clinical trial (NCT03364647). 48 athletes (20 females/28 males) were randomly assigned to low-load strength training with active BFRT or standard of care strength training with a sham unit. Treatment occurred for 1-month pre-surgery and 4-5 months post-surgery with both groups following the same standard rehabilitation protocol. Outcome variables were measured at baseline and 4-5 months post-surgery. Quadriceps muscle strength (isometric and isokinetic peak torque and rate of torque development) was measured on an isokinetic dynamometer. Quadriceps muscle morphology (physiological cross-sectional area, fibrosis) was determined using magnetic resonance imaging. Quadriceps muscle physiology (fiber type, fiber cross-sectional area, satellite cell abundance, collagen content, fibro-/adipo-genic progenitor cells) was evaluated with muscle biopsies of the vastus lateralis. Knee extensor moment and knee flexion angle were measured via three-dimensional gait analysis. Change scores were calculated as: post-intervention-baseline. Two sample t-tests were then used to assess between-group differences for each outcome variable. No significant between-group differences were found for any outcome variable. The addition of BFRT to a rehabilitation program for athletes pre- and post- ACLR was no more effective than standard rehabilitation for improving quadriceps muscle function. Clinicians should consider the value of BFRT relative to the cost, time, and discomfort for patients in light of these results.

Contralateral Comparison Of Beta-band Oscillations In The Motor Cortex Following Blood Flow Restriction Training

Contralateral Comparison Of Beta-band Oscillations In The Motor Cortex Following Blood Flow Restriction Training

Effects Of Acute Upper And Lower Resistance Exercise On Cardiovascular Response Through Blood Flow Restriction

Effects Of Acute Upper And Lower Resistance Exercise On Cardiovascular Response Through Blood Flow Restriction

Contribution of the arterial cells to atherosclerosis and plaque formation.

Atherosclerosis is commonly known as an inflammatory disease that is characterized by lipid deposition in the arterial wall, causing gradual restriction or complete blockade of blood flow, which can cause complications such as myocardial infarction, stroke, or peripheral artery disease. Several factors contribute to initiation and progression of atherosclerotic plaque formation. The role of macrophages and leukocytes in atherosclerosis has been well explored. Here, we provide an overview of what has been reported on the role and impact of the arterial cells on plaque formation, and vice versa. The atherogenic environment can trigger transformation and dedifferentiation of the endothelial cells (ECs), smooth muscle cells, and fibroblasts (FBs) whereby they can either directly contribute to plaque formation or influence its composition. Recent studies have demonstrated the plasticity in the identity of the arterial cells, the formation of intermediate cell types that share the characteristics of multiple cell types, and have revealed novel roles and functions for these cells in atherosclerosis. The potential for all vascular cells to cross-transdifferentiate, and detection of cells with mosaic characteristics in the atherosclerotic plaques reveal that the plaque environment is a complex and dynamic environment that could regulate the disease progression independent from the circulating lipid levels. We will also provide an overview on the interplay between sex and atherosclerosis, which has remained an underexplored area.

Cross-transfer Effects On Muscle Strength, Size, And Quality Following Unilateral Blood Flow Restriction Training

Cross-transfer Effects On Muscle Strength, Size, And Quality Following Unilateral Blood Flow Restriction Training

Fatigability And Blood Flow Restriction Training Of The Knee Extensors In Older Adults

Fatigability And Blood Flow Restriction Training Of The Knee Extensors In Older Adults

Effects Of Upper And Lower Body Blood Flow Restriction Training On Subjective Assessments

Effects Of Upper And Lower Body Blood Flow Restriction Training On Subjective Assessments

A Rare Case of Uvulitis Following Endotracheal Intubation Using C- Mac Videolaryngoscope and How To Avoid It

Uvular injuries are uncommon after general anesthesia and can result from direct trauma to the posterior part of the soft palate or compression and restriction of blood flow to the uvula caused by the inadvertent placement of the airway or suction devices in the oral cavity. There have been cases of inflammation and ulceration occurring in the midline oropharyngeal structures such as the uvula after general anesthesia with a tube or laryngeal mask airway, even in the absence of direct trauma or infection, presumably due to compression ischemia. While sore throat following general anesthesia is a common symptom, it is important to evaluate any severe or persistent pain to exclude uvulitis. Here we present a case of uvulitis that developed after the insertion of a flexometallic endotracheal tube using the midline technique during C-Mac video laryngoscopy. We also emphasize the measures that can be implemented to prevent such a complication. The entrapment of the uvula during intubation often goes unnoticed due to limited oral space after insertion of the video laryngoscope blade, with the intubating anesthetist staying focused on the monitor. This complication following the use of a C-Mac video laryngoscope has not been previously documented.

Effects Of Blood Flow Restriction On Motor Unit Behavior During A Single High-Load Contraction

Effects Of Blood Flow Restriction On Motor Unit Behavior During A Single High-Load Contraction

The Acute Effects and Clinical Application of Blood Flow Restriction on Extremities with exercise: A Systematic Review

The Acute Effects and Clinical Application of Blood Flow Restriction on Extremities with exercise: A Systematic Review

Usability Of A Web-based Application For The Clinical Implementation Of Blood Flow Restriction Exercise

Usability Of A Web-based Application For The Clinical Implementation Of Blood Flow Restriction Exercise