The effects of isokinetic exercise with acute blood flow restriction on isometric quadriceps strength, muscle fatigue, and muscle contraction displacement

Objectives: Blood flow restriction training (BFRT) involves obstruction of venous outflow of working muscles during exercise and may lead to more substantial recovery of quadriceps strength after anterior cruciate ligament (ACL) reconstruction. The purpose of this study is to examine the effects of BFRT in ACL reconstruction patients before and after exposure to BFRT. Methods: This study was a randomized controlled trial in which 36 patients who had torn their ACL and were scheduled to undergo ACL reconstructive surgery (ACLR) with an autograft were randomized to receive exercise with BFRT (N=18) or exercise without BFRT (N=18). Participants in both groups performed the same exercise, but either did or did not have blood flow restricted. The exercise component of the intervention consisted of all subjects performing a single-leg isokinetic leg press, at an intensity of 70% of the subjects’ one-repetition maximum, for four sets of ten repetitions two times per week for 8 weeks beginning at 8 weeks post-operatively. Patients randomized to the BFRT group performed the leg-press exercise with a blood flow restriction cuff applied to the thigh and set to a limb occlusion pressure of 80 percent. All participants were concurrently undergoing standard ACL rehabilitation at the same physical therapy clinic. Bilateral isometric (recorded at a knee angle of 90°) and isokinetic (60°/second) quadriceps strength were recorded using a Biodex dynamometer (System 4, Shirley, NY) prior to ACLR and after the conclusion of the 8-week intervention. Peak isometric and isokinetic quadriceps strength were utilized to generate isometric and isokinetic quadriceps symmetry indices ((ACLR limb strength/Healthy limb strength) x100). Change from baseline symmetry scores were then generated using the following equation: (post-intervention symmetry - pre-intervention symmetry)/pre-intervention symmetry in order to account for possible differences in strength between groups prior to intervention delivery. Change from baseline isometric and isokinetic quadriceps symmetry scores were then compared between groups (exercise with BFRT, exercise without BFRT) using one-way analysis of variance tests with an a priori α set to P≤ 0.05. Effect sizes (Cohen’s d) and 95% confidence intervals were also computed. Results: No significant differences were found for change from baseline isokinetic quadriceps symmetry index (P=0.39, BFRT mean=-0.05, Control mean=-0.19) or change from baseline isometric quadriceps symmetry index (P=0.62, BFRT mean=-0.04, control mean=-0.10). The effect sizes for isokinetic quadriceps symmetry index (d=0.28, 95% CI= -0.37, 0.93) and isometric quadriceps symmetry (d=0.16, 95% CI= -0.49, 0.80) were small with confidence intervals that crossed zero. Conclusion: An 8-week blood flow resistance training + exercise intervention did not increase quadriceps muscle strength in patients who had undergone ACL reconstruction. Based on our findings, application of blood flow restriction training in ACL reconstruction patients to improve quadriceps strength may not be warranted. Future studies may benefit from a longer follow-up and larger sample size.

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Impact of Blood Flow Restriction Exercise on Muscle Fatigue Development and Recovery

Medicine & Science in Sports & Exercise ◽

10.1249/mss.0000000000001475 ◽

2018 ◽

Vol 50 (3) ◽

pp. 436-446 ◽

Cited By ~ 17

Author(s):

FLORIAN HUSMANN ◽

THOMAS MITTLMEIER ◽

SVEN BRUHN ◽

VOLKER ZSCHORLICH ◽

MARTIN BEHRENS

Keyword(s):

Blood Flow ◽

Muscle Fatigue ◽

Blood Flow Restriction ◽

Flow Restriction ◽

Fatigue Development

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EMG-based detection of muscle fatigue during low-level isometric contraction: Effects of electrode configuration and blood flow restriction

2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society ◽

10.1109/iembs.2011.6090963 ◽

2011 ◽

Cited By ~ 4

Author(s):

Y. Hotta ◽

K. Ito

Keyword(s):

Blood Flow ◽

Muscle Fatigue ◽

Isometric Contraction ◽

Blood Flow Restriction ◽

Electrode Configuration ◽

Low Level ◽

Flow Restriction

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Surface electromyogram-based detection of muscle fatigue during cyclic dynamic contraction under blood flow restriction

2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society ◽

10.1109/embc.2014.6944056 ◽

2014 ◽

Cited By ~ 3

Author(s):

Kenichi Ito ◽

Yu Hotta

Keyword(s):

Blood Flow ◽

Muscle Fatigue ◽

Blood Flow Restriction ◽

Surface Electromyogram ◽

Flow Restriction ◽

Dynamic Contraction ◽

Cyclic Dynamic

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Perioperative and Postoperative Factors Influence Quadriceps Atrophy and Strength After ACL Reconstruction: A Systematic Review

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120930296 ◽

2020 ◽

Vol 8 (6) ◽

pp. 232596712093029

Author(s):

Jacqueline E. Baron ◽

Emily A. Parker ◽

Kyle R. Duchman ◽

Robert W. Westermann

Keyword(s):

Systematic Review ◽

Blood Flow ◽

Acl Reconstruction ◽

Nerve Block ◽

Quadriceps Strength ◽

Nutritional Supplementation ◽

Blood Flow Restriction ◽

Thigh Circumference ◽

Flow Restriction ◽

Level 1

Background: Quadriceps dysfunction after anterior cruciate ligament (ACL) reconstruction is common and may affect return to sport due to resulting muscle atrophy and muscle weakness. Purpose: To systematically review the available literature regarding the impact of perioperative and postoperative interventions on quadriceps atrophy and loss of strength after ACL reconstruction. Study Design: Systematic review; Level of evidence, 3. Methods: A systematic review was performed in accordance with the 2009 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using PubMed, CINAHL, Cochrane Central, and Embase. The quality of evidence was evaluated using the Modified Coleman Methodology Score to determine consensus scores. Eligible level 1 or level 2 studies included interventions of perioperative nerve block, intraoperative tourniquet use, postoperative nutritional supplementation, and postoperative blood flow restriction training. Additionally, the included studies quantified postoperative quadriceps measurements such as thigh circumference, quadriceps cross-sectional area (CSA), isokinetic quadriceps strength, and/or quadriceps electromyographic (EMG) testing. Results: In total, 15 studies met stated inclusion and exclusion criteria with the following intervention types: perioperative nerve block (n = 4), intraoperative tourniquet use (n = 5), postoperative nutritional supplementation (n = 3), and postoperative blood flow restriction (n = 3). Intraoperative tourniquet use resulted in decreased thigh circumference and detrimental EMG changes in quadriceps function in 3 of the 5 included studies. Perioperative femoral nerve blocks were associated with transient decreases in postoperative quadriceps strength, persisting up to 6 weeks after surgery, in 2 of the 4 studies. Postoperative blood flow restriction training augmented quadriceps size and function after ACL reconstruction in 2 of 3 studies. Postoperative nutritional supplementation was associated with increased quadriceps volume and strength in 1 of the 3 studies examined. Conclusion: The peri- and postoperative factors reviewed here may influence quadriceps atrophy and strength after ACL reconstruction. Our results tentatively indicated that blood flow restriction training may be beneficial to the quadriceps after ACL reconstruction and that intraoperative tourniquet use and nerve block administration may be detrimental; however, the strongest finding was that all of these interventions would benefit from further level 1 and 2 evidence studies, including multicenter, randomized controlled trials with extended follow-up, to definitively determine their impact on return to activity.

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