Page 60 - Journal of Special Operations Medicine - Spring 2015
P. 60

Blood Flow Restriction Rehabilitation for Extremity Weakness:
                                                 A Case Series



                                      Christina Hylden, MD; Travis Burns, MD;
                                    Daniel Stinner, MD; Johnny Owens, BS, MPT







          ABSTRACT

          Background: Blood flow restricted (BFR) training, the   Keywords: strengthening, muscle mass, tourniquet, physi-
          brief and partial restriction of venous outflow of an ex­  cal therapy, blood flow restriction, vascular occlusion
          tremity  during  low  load resistance  exercises,  is a  safe
          and effective method of improving strength in healthy,
          active individuals. A relatively unexplored potential of   Introduction
          this adjunctive modality lies in treating patients with
          severe musculoskeletal trauma, persistent chronic quad­  BFR training has been studied in the preclinical setting
          riceps and hamstring weakness despite traditional ther­  through animal testing, primarily in an equine model.
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          apy, and low improvement during early postoperative   Preliminary clinical testing includes low­intensity walk­
          strengthening. Methods: This case series describes pa­  training in the elderly and more targeted studies looking
          tients with chronic quadriceps and hamstring weakness   at the muscle of younger, healthy subjects; the combi­
          who received an intervention of BFR at low loads, 20%   nation of these studies show BFR training being linked
          of 1 repetition max (1RM), to restore strength. A case   to changes in hormones, myogenic stem cell prolifera­
          series was conducted of seven patients, all located at one   tion, and protein synthesis.  It has also been proved
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          hospital and all with traumatic lower extremity injuries.   to be safe and effective in achieving muscular strength
          The seven patients were treated at the same medical   and hypertrophy in healthy adults or in elderly patients
          center and with the same BFR protocol. All seven pa­  with sarcopenia. 3,8,9  BFR training is not widely used in
          tients had isokinetic dynamometer testing that showed   rehabilitation for chronic muscle weakness secondary
          persistent thigh muscle weakness despite previous re­  to trauma. Based on a search of the literature through
          habilitation with traditional therapy and 35% to 75%   online databases (using “occlusion training” or “blood
          peak torque deficit in either knee extension or flexion   flow restriction” and “rehabilitation” or “physical ther­
          compared with the contralateral lower extremity. Pa­  apy”), this case series is the first to incorporate BFR use
          tients underwent 2 weeks of BFR training therapy using   as part of a physical therapy rehabilitation protocol in a
          a pneumatic tourniquet set at 110mmHg while perform­  patient population who has difficulty performing high­
          ing leg extensions, leg presses, and reverse leg presses.   resistance exercises due to their injuries.
          All affected extremities were retested after 2 weeks (six
          treatment sessions). Dynamometer measurements were   Discussion
          done with flexion and extension at two speeds: 90º and
          300º/sec. The data recorded included peak torque nor­  Rehabilitation programs primarily focus on regaining
          malized for body weight, average power, and total work.   muscular strength and endurance, but need to include
          Results: All seven patients demonstrated improvements   restoration  of  joint  range  of  motion  (ROM).  Muscles
          in peak torque, average power, and total work for both   must  be  strong  enough  to  withstand  long periods  of
          knee flexion and extension, with power being the most   physical activity to improve proprioception, indepen­
          improved overall. Peak torque improved an average of   dence in daily living activities, and (lost or weakened)
          13% to 37%, depending on contraction direction and   sports­specific or job­specific skills.
          speed. Average power improved an average of 42% to
          81%, and total work improved an average of 35% to   Because strength is such an important foundation, the
          55%. Conclusion: BFR therapy at low loads can affect   American College of Sports Medicine (ACSM) pub­
          improvement in muscle strength in patients who are un­  lished guidelines on the best resistance training practices
          able to perform high­resistance exercise or patients who   to achieve the goals of strength, power, and endurance.
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          have  persistent  extremity  weakness  despite  traditional   The recommended muscular load for a given resistance
          therapy.                                           exercise ranges from 60% to 100% of the one­ repetition



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