Effects Of Blood Flow Restriction Exercise Training And Protein Supplementation On Muscle Strength And Volume.

PURPOSE: To evaluate the effects of a combination of blood flow restriction exercise training (BFRT) plus essential amino acid oral supplementation (EAAs) among severe Knee Osteoarthritis (OA) patients prior to total knee arthroplasty (TKA) on muscle strength and muscle volume. METHODS: Five severe knee OA patients were recruited to participate in a BFRT exercise training program with a protein supplement prior to TKA surgery. After IRB approval and patient informed consent. 5 subjects were enrolled in a one month BFRT plus EAA oral supplement prior to TKA. At baseline, subjects completed a physical exam, MRI of both legs for muscle volume, and strength testing (both 1 RM and 5 RM) on both legs for leg extension and leg press. Subjects then performed BFRT on the severe knee OA limb at OHSU Physical Therapy department 3 times per week for 4 weeks with ingestion of a 25 gram protein supplement beverage within 30 minutes of training session. Post testing included the MRI and strength testing. RESULTS: Muscle strength testing included both the 1 RM and 5 RM on both legs. Muscle strength increased 19% +/- 2 (mean and SEM) and 16% +/- 1.5 (mean and SEM) on the 1 RM and 5 RM for the pre-TKA leg after BFRT + EAA. Muscle strength increased 13% +/- 2 (mean and SEM) and 11% +/-2 (mean and SEM) for untrained leg (P < 0.05 for both 1 RM and 5 RM) MRI scans were obtained for muscle volume in both limbs before and after the unilateral BFRT pre-TKA exercise 4 weeks. Each MRI was obtained a minimum of 48 hours after the last bout of BFRT to avoid muscle edema influencing outcomes. Compared to baseline mid-thigh quadriceps volume, the BFRT limb increased 9% higher in muscle volume as compared to the nontrained BFRT limb. CONCLUSIONS: There are close to 1 million TKA procedures performed annually in the U.S. with an expected 3.5 million TKA surgeries by 2030. The morbidity and mortality due to disuse atrophy and weakness associated with this is profound. BFRT with EAA supplementation appears to be safe, feasible, and efficacious in prehabilitation prior to TKA. A future large randomized clinical trial will assess this treatment modality. Study was supported by a Medical Research Foundation of Oregon grant.