Utility of Neuromuscular Electrical Stimulation to Preserve Quadriceps Muscle Fiber Size and Contractility After Anterior Cruciate Ligament Injuries and Reconstruction: A Randomized, Sham-Controlled, Blinded Trial

Background: Anterior cruciate ligament (ACL) injuries and reconstruction (ACLR) promote quadriceps muscle atrophy and weakness that can persist for years, suggesting the need for more effective rehabilitation programs. Whether neuromuscular electrical stimulation (NMES) can be used to prevent maladaptations in skeletal muscle size and function is unclear. Purpose: To examine whether early NMES use, started soon after an injury and maintained through 3 weeks after surgery, can preserve quadriceps muscle size and contractile function at the cellular (ie, fiber) level in the injured versus noninjured leg of patients undergoing ACLR. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Patients (n = 25; 12 men/13 women) with an acute, first-time ACL rupture were randomized to NMES (5 d/wk) or sham (simulated microcurrent electrical nerve stimulation; 5 d/wk) treatment to the quadriceps muscles of their injured leg. Bilateral biopsies of the vastus lateralis were performed 3 weeks after surgery to measure skeletal muscle fiber size and contractility. Quadriceps muscle size and strength were assessed 6 months after surgery. Results: A total of 21 patients (9 men/12 women) completed the trial. ACLR reduced single muscle fiber size and contractility across all fiber types ( P < .01 to P < .001) in the injured compared with noninjured leg 3 weeks after surgery. NMES reduced muscle fiber atrophy ( P < .01) through effects on fast-twitch myosin heavy chain (MHC) II fibers ( P < .01 to P < .001). NMES preserved contractility in slow-twitch MHC I fibers ( P < .01 to P < .001), increasing maximal contractile velocity ( P < .01) and preserving power output ( P < .01), but not in MHC II fibers. Differences in whole muscle strength between groups were not discerned 6 months after surgery. Conclusion: Early NMES use reduced skeletal muscle fiber atrophy in MHC II fibers and preserved contractility in MHC I fibers. These results provide seminal, cellular-level data demonstrating the utility of the early use of NMES to beneficially modify skeletal muscle maladaptations to ACLR. Clinical Relevance: Our results provide the first comprehensive, cellular-level evidence to show that the early use of NMES mitigates early skeletal muscle maladaptations to ACLR. Registration: NCT02945553 (ClinicalTrials.gov identifier)

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Effect of neuromuscular electrical stimulation on skeletal muscle size and function in patients with breast cancer receiving chemotherapy

Journal of Applied Physiology ◽

10.1152/japplphysiol.00203.2020 ◽

2020 ◽

Vol 128 (6) ◽

pp. 1654-1665 ◽

Cited By ~ 2

Author(s):

Michael J. Toth ◽

Thomas B. Voigt ◽

Timothy W. Tourville ◽

Shannon M. Prior ◽

Blas A. Guigni ◽

...

Keyword(s):

Skeletal Muscle ◽

Electrical Stimulation ◽

Muscle Fiber ◽

Neuromuscular Electrical Stimulation ◽

Skeletal Muscle Fiber ◽

Muscle Size ◽

Fiber Types ◽

Fiber Size ◽

Subsarcolemmal Mitochondria ◽

And Function

This is the first study to evaluate whether neuromuscular electrical stimulation (NMES) can be used as an exercise surrogate to improve skeletal muscle fiber size or function in cancer patients receiving treatment. We show that NMES promoted muscle fiber hypertrophy and fiber types shift but had minimal effects on single-fiber contractility and reduced subsarcolemmal mitochondria.

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Improvements in skeletal muscle fiber size with resistance training are age-dependent in older adults: a systematic review and meta-analysis

Journal of Applied Physiology ◽

10.1152/japplphysiol.00170.2020 ◽

2020 ◽

Vol 129 (2) ◽

pp. 392-403

Author(s):

Chad R. Straight ◽

Michael V. Fedewa ◽

Michael J. Toth ◽

Mark S. Miller

Keyword(s):

Systematic Review ◽

Older Adults ◽

Resistance Training ◽

Muscle Fiber ◽

Meta Analysis ◽

Similar Response ◽

Training Intensity ◽

Mhc I ◽

Mhc Ii ◽

Fiber Size

As studies examining the hypertrophic effects of resistance training (RT) at the cellular level have produced inconsistent results, we performed a systematic review and meta-analysis to investigate muscle fiber size before and after a structured RT intervention in older adults. A random-effects model was used to calculate mean effect size (ES) and 95% confidence intervals (CI). Thirty-five studies were included (age range: 59.0–88.5 yr), and 44 and 30 effects were used to estimate RT impact on myosin heavy chain (MHC) I and II fiber size. RT produced moderate-to-large increases in MHC I (ES = +0.51, 95%CI +0.31 to +0.71; P < 0.001) and II (ES = +0.81, 95%CI +0.56 to +1.05; P < 0.001) fiber size, with men and women having a similar response. Age was negatively associated with change in muscle fiber size for both fiber types (MHC I: R2 = 0.11, β = −0.33, P = 0.002; MHC II: R2 = 0.10, β = −0.32, P = 0.04), indicating a less robust hypertrophic response as age increases in older adults. Unexpectedly, a higher training intensity (defined as percentage of one-repetition maximum) was associated with a smaller increase in MHC II fiber size ( R2 = 15.09%, β = −0.39, P = 0.01). Notably, MHC II fiber subtypes (IIA, IIX, IIAX) were examined less frequently, but RT improved their size. Overall, our findings indicate that RT induces cellular hypertrophy in older adults, although the effect is attenuated with increasing age. In addition, hypertrophy of MHC II fibers was reduced with higher training intensity, which may suggest a failure of muscle fibers to hypertrophy in response to high loads in older adults.

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Faculty Opinions recommendation of The decline in skeletal muscle mass with aging is mainly attributed to a reduction in type II muscle fiber size.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.721692484.793516987 ◽

2016 ◽

Author(s):

Simon Melov

Keyword(s):

Skeletal Muscle ◽

Muscle Mass ◽

Muscle Fiber ◽

Skeletal Muscle Mass ◽

Type Ii ◽

Fiber Size

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Pre-training Skeletal Muscle Fiber Size and Predominant Fiber Type Best Predict Hypertrophic Responses to 6 Weeks of Resistance Training in Previously Trained Young Men

Frontiers in Physiology ◽

10.3389/fphys.2019.00297 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 17

Author(s):

Cody T. Haun ◽

Christopher G. Vann ◽

C. Brooks Mobley ◽

Shelby C. Osburn ◽

Petey W. Mumford ◽

...

Keyword(s):

Skeletal Muscle ◽

Resistance Training ◽

Muscle Fiber ◽

Fiber Type ◽

Young Men ◽

Skeletal Muscle Fiber ◽

Fiber Size

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Skeletal muscle fiber size and fiber type distribution in human cancer: Effects of weight loss and relationship to physical function

Clinical Nutrition ◽

10.1016/j.clnu.2016.02.016 ◽

2016 ◽

Vol 35 (6) ◽

pp. 1359-1365 ◽

Cited By ~ 16

Author(s):

Michael J. Toth ◽

Damien M. Callahan ◽

Mark S. Miller ◽

Timothy W. Tourville ◽

Sarah B. Hackett ◽

...

Keyword(s):

Skeletal Muscle ◽

Weight Loss ◽

Physical Function ◽

Muscle Fiber ◽

Human Cancer ◽

Fiber Type ◽

Skeletal Muscle Fiber ◽

Type Distribution ◽

Fiber Size ◽

Fiber Type Distribution

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Neuromuscular electrical stimulation is effective in strengthening the quadriceps muscle after anterior cruciate ligament surgery

Knee Surgery Sports Traumatology Arthroscopy ◽

10.1007/s00167-017-4669-5 ◽

2017 ◽

Vol 26 (2) ◽

pp. 399-410 ◽

Cited By ~ 14

Author(s):

Annette V. Hauger ◽

M. P. Reiman ◽

J. M. Bjordal ◽

C. Sheets ◽

L. Ledbetter ◽

...

Keyword(s):

Anterior Cruciate Ligament ◽

Electrical Stimulation ◽

Cruciate Ligament ◽

Neuromuscular Electrical Stimulation ◽

Quadriceps Muscle ◽

Anterior Cruciate ◽

Anterior Cruciate Ligament Surgery

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Identification and Characterization of Circular RNAs in Longissimus Dorsi Muscle Tissue from Two Goat Breeds using RNA-Seq

10.21203/rs.3.rs-944970/v1 ◽

2021 ◽

Author(s):

Jiyuan Shen ◽

Huimin Zhen ◽

Lu Li ◽

Yuting Zhang ◽

Jiqing Wang ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Fiber ◽

Muscle Development ◽

Production Performance ◽

Differentially Expressed ◽

Circular Rnas ◽

Longissimus Dorsi ◽

Rna Seq ◽

Skeletal Muscle Development ◽

Fiber Size

Abstract Background: Circular RNAs (circRNAs) are a class of non-coding RNA that play crucial roles in the development of skeletal muscle. However, little is known about the role of circRNAs in caprine skeletal muscle. In this study, the muscle fiber size and expression profiles of circRNAs were compared in Longissimus dorsi muscle of Liaoning cashmere (LC) goats and Ziwuling black (ZB) goats with significant phenotypic differences in meat production performance, using hematoxylin and eosin staining and RNA-Seq, respectively.Results: The muscle fiber size in LC goats were larger than those in ZB goats (P < 0.05). A total of 10,875 circRNAs were identified and 214 of these were differentially expressed between the two caprine breeds. The authentication and expression levels of 20 circRNAs were confirmed using reverse transcriptase-polymerase chain reaction (RT-PCR) and DNA sequencing. The parent genes of differentially expressed circRNAs were mainly enriched in connective tissue development, Rap1, cGMP-PKG, cAMP and Ras signaling pathway. Some miRNAs reportedly associated with skeletal muscle development and intramuscular fat deposition would be targeted by several differentially expressed circRNAs and the most highly expressed circRNA (circ_001086).Conclusion: These results provide an improved understanding of the functions of circRNAs in skeletal muscle development of goats.

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Skeletal Muscle Fiber Size and Gene Expression in the Oldest-Old With Differing Degrees of Mobility

Frontiers in Physiology ◽

10.3389/fphys.2019.00313 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 9

Author(s):

Fabio Naro ◽

Massimo Venturelli ◽

Lucia Monaco ◽

Luana Toniolo ◽

Ettore Muti ◽

...

Keyword(s):

Gene Expression ◽

Skeletal Muscle ◽

Muscle Fiber ◽

Oldest Old ◽

Skeletal Muscle Fiber ◽

Fiber Size

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Longitudinal Assessment of Quadriceps Muscle Morphology Before and After Anterior Cruciate Ligament Reconstruction and Its Associations With Patient-Reported Outcomes

Sports Health A Multidisciplinary Approach ◽

10.1177/1941738119898210 ◽

2020 ◽

Vol 12 (3) ◽

pp. 271-278

Author(s):

Steven A. Garcia ◽

Michael T. Curran ◽

Riann M. Palmieri-Smith

Keyword(s):

Ligament Reconstruction ◽

Cruciate Ligament ◽

Rectus Femoris ◽

Quadriceps Muscle ◽

Muscle Quality ◽

Muscle Size ◽

Muscle Morphology ◽

Patient Reported ◽

Ikdc Score ◽

Anterior Cruciate

Background: Reductions in muscle size are common after anterior cruciate ligament reconstruction (ACLR) and may contribute to suboptimal patient outcomes. However, few studies have quantified postoperative alterations in muscle quality and evaluated its associations with patient-reported function. Hypotheses: Rectus femoris cross-sectional area (CSA) will decrease postoperatively but improve at return to activity (RTA), rectus femoris muscle quality (percentage fat [PF]) will increase postoperatively and be greater at RTA compared with preoperative values, and rectus femoris CSA and PF will be associated with International Knee Documentation Committee (IKDC) scores at both postoperative time points. Study Design: Case series. Level of Evidence: Level 4. Methods: A total of 26 individuals who sustained an ACL injury and underwent reconstructive surgery were evaluated preoperatively (T0), 9 weeks post-ACLR (T1), and at RTA. Rectus femoris CSA and PF were evaluated bilaterally via ultrasound imaging, and patient-reported function was assessed using the IKDC score. Results: Bilateral reductions in rectus femoris CSA were noted from T0 to T1 ( P < 0.01). Only the uninvolved limb returned to preoperative CSA ( P = 0.80), as the involved limb failed to return to preoperative levels at RTA ( P = 0.04). No significant changes in rectus femoris PF were observed across time points ( P > 0.05). Lesser PF ( P < 0.01) but not CSA ( P = 0.75) was associated with higher IKDC score at T1. Lesser PF ( P = 0.04) and greater CSA ( P = 0.05) was associated with higher IKDC score at RTA. Conclusion: Substantial atrophy occurs bilaterally after ACLR, and the involved limb does not return to preoperative muscle size despite the patient completing rehabilitation. Quadriceps muscle morphology is associated with patient-reported function and may be an important rehabilitation target after ACLR. Clinical Relevance: Quadriceps atrophy and poor muscle quality may contribute to suboptimal patient functioning and quadriceps dysfunction and may be important in RTA decision making. Assessing muscle morphology using ultrasound may be a feasible and clinically beneficial tool in patients after ACLR.

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