A Case of Rhabdomyolysis Caused by Blood Flow-Restricted Resistance Training

Survey of Blood Flow Restriction Training Applications in Sports Medicine and Performance Practice Across North America

Colapietro, MA, Lee, JZ, and Vairo, GL. Survey of blood flow restriction training applications in sports medicine and performance practice across North America. J Strength Cond Res 38(5): 856–863, 2024—This study profiled current clinical applications of blood flow restriction (BFR) training and observed side effects by surveying active sports medicine and performance personnel across North America. An online survey consisting of questions derived from a related position statement was distributed through professional organizations, email listservs, and social media. Personnel with experience applying or prescribing BFR training with permanent residence within the United States or Canada were eligible to participate. Variables captured included demographics (profession, practice setting), BFR equipment, treatment parameters, observed side effects, and personal perceptions regarding BFR training. An alpha level of p < 0.05 determined significance. A convenience sample included 72 clinicians with 67 being from the United States. Athletic trainers (n = 35) and physical therapists (n = 30) primarily participated. Chi-square test of independence indicated that a higher proportion of physical therapists (90.3%) report receiving formal education in BFR training compared with athletic trainers (65.7%) ( = 4.1, p = 0.043). Parameters varied between respondents for exercise prescription and occlusion settings. Respondents primarily followed position statement recommendations with individualized pressure selections for resistance (80.9%) and aerobic (84.8%) BFR modes. Side effects reported included delayed onset muscle soreness (66.2%), inability to continue because of pain (28%), and numbness (22.5%). Personal perceptions between athletic trainers and physical therapists were compared using independent t-tests. Physical therapists indicated higher confidence in safety (difference = 0.37 ± 0.32, p = 0.026), understanding recommendations (difference = 0.47 ± 0.37, p = 0.011), and theoretical principles (difference = 0.80 ± 0.53, p = 0.004). Despite variation in BFR parameters used, sports medicine personnel demonstrate compliance with position statement recommendations and report mild side effects.

Overall Safety and Risks Associated with Blood Flow Restriction Therapy: A Literature Review

INTRODUCTION

Blood flow restriction therapy (BFRT) is used in scenarios ranging from muscle building in athletic performance to decreasing recovery time in postoperative orthopedic rehabilitation. The efficacy of BFRT for treating diseases has been increasingly researched; however, there has been less literature focused on establishing the safety of this therapy.

MATERIALS AND METHODS

An extensive literature review pertaining to BFRT and any deleterious events related to its usage was completed by searching multiple databases, including PubMed, EMBASE, and Cochrane Library using the terms "blood flow restriction therapy" or "KAATSU."

RESULTS

Ten case reports, five case series, two national surveys, two questionnaires, six randomized controlled studies, and one systematic review were included. A total of 1,672 individuals reported an adverse event following BFRT use out of 25,813 individuals. Commonly reported adverse events were numbness, dizziness, subcutaneous hemorrhage, and rhabdomyolysis. There were unique adverse effects of this therapy reported in individuals with comorbid conditions, such as hypertension and thoracic outlet syndrome, which included isolated cases of central retinal vein occlusion and Paget-Schroeder syndrome.

CONCLUSION

Blood flow restriction provides tremendous opportunity with a potential for accelerated exercise rehabilitation and injury prevention. This modality could be used in the military setting to help injured active duty personnel expeditiously return to deployable status. Further prospective randomized controlled trials are warranted to further support BFRT safety; however, from this literature review, it can be concluded that BFRT can be utilized safely in the proper patient population when administered by qualified professionals who have undergone the appropriate training.

Proximal, Distal, and Contralateral Effects of Blood Flow Restriction Training on the Lower Extremities: A Randomized Controlled Trial

Background:

Blood flow restriction (BFR) training involves low-weight exercises performed under vascular occlusion via an inflatable cuff. For patients who cannot tolerate high-load exercises, BFR training reportedly provides the benefits of high-load regimens, with the advantage of less tissue and joint stress.

Hypothesis:

Low-load BFR training is safe and efficacious for strengthening muscle groups proximal, distal, and contralateral to tourniquet placement in the lower extremities.

Study Design:

Randomized controlled trial.

Level of Evidence:

Level 1.

Methods:

This was a randomized controlled trial of healthy participants completing a standardized 6-week course of BFR training. Patients were randomized to BFR training on 1 extremity or to a control group. Patients were excluded for cardiac, pulmonary, or hematologic disease; pregnancy; or previous surgery in the extremity. Data collected at baseline and completion included limb circumferences and strength testing.

Results:

The protocol was completed by 26 patients, providing 16 BFR and 10 control patients (mean patient age, 27 years; 62% female). A statistically greater increase in strength was seen proximal and distal to the BFR tourniquet when compared with both the nontourniquet extremity and the control group (P < 0.05). Approximately twice the improvement was seen in the BFR group compared with controls. Isokinetic testing showed greater increases in knee extension peak torque (3% vs 11%), total work (6% vs 15%), and average power (4% vs 12%) for the BFR group (P < 0.04). Limb circumference significantly increased in both the thigh (0.8% vs 3.5%) and the leg (0.4% vs 2.8%) compared with the control group (P < 0.01). Additionally, a significant increase occurred in thigh girth (0.8% vs 2.3%) and knee extension strength (3% vs 8%) in the nontourniquet BFR extremity compared with the control group (P < 0.05). There were no reported adverse events.

Conclusion:

Low-load BFR training led to a greater increase in muscle strength and limb circumference. BFR training had similar strengthening effects on both proximal and distal muscle groups. Gains in the contralateral extremity may corroborate a systemic or crossover effect.

Clinical Relevance:

BFR training strengthens muscle groups proximal, distal, and contralateral to cuff placement. Patients undergoing therapy for various orthopaedic conditions may benefit from low-load BFR training with the advantage of less tissue stress.