The Proximal and Distal Effects of Blood Flow Restriction Therapy on Upper and Lower Extremity Strengthening: A Randomized Controlled Trial. Issue 7 (29th July 2019)

• Record Type: Journal Article
• Authors: Bowman, Eric N.; El-shaar, Rami; Milligan, Heather; Jue, Greg; Mohr, Karen; Brown, Patty; Watanabe, Drew M.; Limpisvasti, Orr
• Is Part Of: Orthopaedic journal of sports medicine. Volume 7:Issue 7(2019)Supplement 5
• Publication Date: 2019-07-29
• Subjects: Sports medicine -- Periodicals; Orthopedics -- Periodicals; Arthroscopy -- Periodicals; Arthroplasty -- Periodicals; Knee -- Surgery -- Periodicals; 616.7
• DOI: 10.1177/2325967119S00337
• Languages: English
• ISSNs: 2325-9671

Abstract

Objectives: Blood flow restriction (BFR) therapy consists of low-intensity exercise performed under reduced venous return due to an inflatable tourniquet. This produces similar physiologic and clinical effects to high-intensity routines with less joint and tissue stress. Postoperative patients may benefit from more efficient rehabilitation. Proximal and distal effects of BFR have been evaluated, however, minimal literature exists on its use in orthopaedic conditions. The purpose of this study was to determine the effects of low-intensity BFR therapy both proximal and distal, in the upper and lower extremities. Methods: This was a prospective, randomized controlled trial of healthy subjects completing a standardized 6-week course of BFR therapy. Subjects were randomized to BFR therapy on one extremity or to a control group. Subjects were excluded for cardiac, pulmonary, or hematologic disease, pregnancy, or previous surgery in the extremity. Data collected at baseline and completion included: limb circumferences, isokinetic, and manual strength testing. Results: Forty subjects completed the protocol. Average age was 27.7 years; 54% were female. For both upper and lower extremity groups, a statistically significant increase was observed in manual and isokinetic strength both proximal and distal to the BFR tourniquet when compared to both the non-tourniquet extremity and the control group (p<0.05). Limb circumference significantly increased in the upper (p<0.01) and lower extremities (p=0.02). A significant increase in manual strength was noted in shoulder abduction and scaption, and hip extension and abduction even in the non-tourniquet BFR extremity compared to the control group (p<0.05). Conclusion: Low-intensity BFR therapy led to greater increases in muscle strength and hypertrophy. Similar strengthening effects were seen in proximal and distal muscle groups. Strength increases in the contralateral BFR extremity may corroborate a systemic effect. This study provides data to further evaluate the efficacy and safety of BFR therapy in operative and non-operative orthopaedic conditions. The mean percent increase and comparison between the BFR tourniquet limb and control group with p-values. LOWER EXTREMITY Control n=20 BFR limb n=16 p UPPER EXTREMITY Control n=20 BFR Limb n=14 p Circumference Circumference Thigh 0.8 3.5 <0.001 Arm 2.5 5.2 <0.001 Leg 0.4 2.8 0.001 Forearm 1.4 4.2 <0.001 Strength Strength Knee extension Shoulder IR Total work 6 15 0.046 Total work 0.1 12 0.043 Peak torque 3 11 0.018 Peak torque 7 16 0.018 Power 4 12 0.015 Avg Power 2 20 0.078 Knee flexion Shoulder ER Total work 14 27 0.044 Total work 12 15 0.389 Peak torque 5 11 0.173 Peak torque 2 10 0.041 Power 7 13 0.135 Avg Power 15 24 0.188 Hip abduction 27 46 0.021 Shoulder Scaption 18 48 0.021 Hip extension 42 60 0.046 Shoulder Flexion 16 39 0.001 Plantar flexion 18 33 0.018 Shoulder Abd 8 33 0.001 Heel raises 4 28 <0.001 Elbow Flexion 29 52 0.047 Elbow Extension 35 43 0.242 Grip Strength 0.4 9 0.002