The current manuscript sets out a series of guidelines for blood flow restriction exercise, focusing on the methodology, application and safety of this mode of training. With the emergence of this technique and the wide variety of applications within the literature, the aim of this review is to set out a current research informed guide to blood flow restriction training to practitioners. This covers the use of blood flow restriction to enhance muscular strength and hypertrophy via training with resistance and aerobic exercise and preventing muscle atrophy using the technique passively. The authorship team for this article was selected from the researchers focused in blood flow restriction training research with expertise in exercise science, strength and conditioning and sports medicine.

Many battlefield injuries involve penetrating soft tissue trauma often accompanied by skeletal muscle defects, known as volumetric muscle loss. This article presents the first known case of a surgical technique involving an innovative tissue engineering approach for the repair of a large volumetric muscle loss. A 19-year-old Marine presented with large volumentric muscle loss of the right thigh as a result of an explosion. The patient reported muscle weakness with right knee extension, secondary to volumentric muscle loss, primarily involving the vastus medialis muscle. This persisted 3 years postinjury, despite extensive physical therapy. With all existing management options exhausted, restoration of a portion of the lost vastus medialis muscle was attempted by surgical implantation of a multi-layered scaffold composed of extracellular matrix derived from porcine intestinal submucossa. The patient had no complications, was discharged home on postoperative day 5, and resumed physical therapy after 4 weeks. Four months postoperatively, the patient demonstrated marked gains in isokinetic performance. Computer tomography indicated new tissue at the implant site. This approach offers a treatment option to a heretofore untreatable injury and will allow us to improve future surgical treatments for volumetric muscle loss.

This study suggests that BFR is an effective intervention after knee arthroscopy. Further investigation is warranted to elucidate the benefits of this intervention in populations with greater initial impairment.

Open fracture is a common occurrence in civilian and military populations. Though great strides have been made in limb salvage efforts, persistent muscle strength deficits can contribute to a diminished limb function after the bone has healed. Over the past decade, a growing effort to establish therapies directed at de novo muscle regeneration has produced several therapeutic approaches. As this effort progresses and as therapies reach clinical testing, many questions remain regarding the pathophysiology of the volumetric loss of skeletal muscle. The current study demonstrates, in a rat "open fracture" model, that the volumetric loss of skeletal muscle results in persistent functional deficits that are dependent on muscle length and joint angle. Moreover, the injured muscle has an increased stiffness during passive stretch and a reduced functional excursion. A case study of a patient with an open type III tibia fracture resulting in volumetric muscle loss in the anterior and posterior compartment is also presented. Eighteen months after injury and tibia healing, persistent functional deficits are apparent with many of the same qualities demonstrated in the animal model. Muscle architectural adaptations likely underlie the altered intrinsic functional characteristics of the remaining musculature. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. J Orthop Res 33: 40-46, 2015.

Abstract-Extremity injuries comprise the majority of battlefield injuries and contribute the most to long-term disability of servicemembers. The purpose of this study was to better define the contribution of muscle deficits and volumetric muscle loss (VML) to the designation of long-term disability in order to better understand their effect on outcomes for limb-salvage patients. Medically retired servicemembers who sustained a combat-related type III open tibia fracture (Orthopedic cohort) were reviewed for results of their medical evaluation leading to discharge from military service. A cohort of battlefield-injured servicemembers (including those with nonorthopedic injuries) who were medically retired because of various injuries (General cohort) was also examined. Muscle conditions accounted for 65% of the disability of patients in the Orthopedic cohort. Among the General cohort, 92% of the muscle conditions were identified as VML. VML is a condition that contributes significantly to long-term disability, and the development of therapies addressing VML has the potential to fill a significant void in orthopedic care.

Background: High-energy extremity trauma is common in combat. Orthotic options for patients whose lower extremities have been salvaged are limited. A custom energy-storing ankle-foot orthosis, the Intrepid Dynamic Exoskeletal Orthosis (IDEO), was created and used with high-intensity rehabilitation as part of the Return to Run clinical pathway. We hypothesized that the IDEO would improve functional performance compared with a non-custom carbon fiber orthosis (BlueRocker), a posterior leaf spring orthosis, and no brace. Methods: Eighteen subjects with unilateral dorsiflexion and/or plantar flexion weakness were evaluated with six functional tests while they were wearing the IDEO, BlueRocker, posterior leaf spring, or no brace. The brace order was randomized, and five trials were completed for each of the functional measures, which included a four-square step test, a sit-to-stand five times test, tests of self-selected walking velocity over level and rocky terrain, and a timed stair ascent. They also completed one trial of a forty-yard (37-m) dash, filled out a satisfaction questionnaire, and indicated whether they had ever considered an amputation and, if so, whether they still intended to proceed with it. Results: Performance was significantly better with the IDEO with respect to all functional measures compared with all other bracing conditions (p < 0.004), with the exception of the sit-to-stand five times test, in which there was a significant improvement only as compared with the BlueRocker (p = 0.014). The forty-yard dash improved by approximately 35% over the values for the posterior leaf spring and no-brace conditions, and by 28% over the BlueRocker. The BlueRocker demonstrated a significant improvement in the forty-yard dash compared with no brace (p = 0.033), and a significant improvement in selfselected walking velocity on level terrain compared with no brace and the posterior leaf spring orthosis (p < 0.028). However, no significant difference was found among the posterior leaf spring, BlueRocker, and no-brace conditions with respect to any other functional measure. Thirteen patients initially considered amputation, but after completion of the clinical pathway, eight desired limb salvage, two were undecided, and three still desired amputation. Conclusions: Use of the IDEO significantly improves performance on validated tests of agility, power, and speed. The majority of subjects initially considering amputation favored limb salvage after this noninvasive intervention.

Blood flow restriction by itself or in combination with exercise has been shown to produce beneficial adaptations to skeletal muscle. These adaptations have been observed across a range of populations, and this technique has become an attractive possibility for use in rehabilitation. Although there are concerns that applying blood flow restriction during exercise makes exercise inherently more dangerous, these concerns appear largely unfounded. Nevertheless, we have advocated that practitioners could minimize many of the risks associated with blood flow-restricted exercise by accounting for methodological factors, such as cuff width, cuff type, and the individual to which blood flow restriction is being applied. The purpose of this article is to provide an overview of these methodological factors and provide evidence-based recommendations for how to apply blood flow restriction. We also provide some discussion on how blood flow restriction may serve as an effective treatment in a clinical setting.

Aggressive rehabilitation, an energy-storing ankle-foot orthosis, and running gait retraining can restore an active recreational lifestyle to patients who have undergone lower extremity limb salvage.