Journal Description
Muscles
Muscles
is an international, peer-reviewed, open access journal on muscle biology and physiology published quarterly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 36.2 days after submission; acceptance to publication is undertaken in 2.7 days (median values for papers published in this journal in the first half of 2024).
- Recognition of Reviewers: APC discount vouchers, optional signed peer review, and reviewer names published annually in the journal.
Latest Articles
PRKAG2 Variant, Motor Neuron Disease, and Parkinsonism: Fortuitous Association or a Potentially Underestimated Pathophysiological Mechanism?
Muscles 2024, 3(3), 235-241; https://doi.org/10.3390/muscles3030021 - 25 Jul 2024
Abstract
A 72-year-old Brazilian woman presented with a 4-year history of rest tremors of the hands, followed by slowness of movement, and a diagnosis of idiopathic Parkinson’s disease. She was started on dopamine agonists with significant improvement. After three years, she complained about slowly
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A 72-year-old Brazilian woman presented with a 4-year history of rest tremors of the hands, followed by slowness of movement, and a diagnosis of idiopathic Parkinson’s disease. She was started on dopamine agonists with significant improvement. After three years, she complained about slowly progressive dysphagia, dysphonia, quadriparesis, and cramps and fasciculations. A neurological examination disclosed distal-dominant quadriparesis, dysarthria, atrophy and fasciculation of the tongue, global brisk tendon reflexes, fasciculations, bilateral ankle clonus, and moderate spasticity of the lower limbs. She had also palpitations, dyspnea, and one episode of paroxysmal atrial fibrillation. Electrocardiography revealed a short PR interval, a widened QRS complex, and the delta wave, suggestive of Wolff–Parkinson–White syndrome. Brain and spine MR imaging, a cerebrospinal fluid analysis, and general serum lab exams were unremarkable. Needle electromyography disclosed chronic denervation involving cervical, thoracic, lumbosacral, and bulbar levels associated with acute denervation, including positive sharp waves, fasciculations, and fibrillation potentials. This patient fulfilled the diagnostic criteria for amyotrophic lateral sclerosis associated with parkinsonism. A broad next-generation sequencing-based panel disclosed the presence of the novel heterozygous variant c.1247C > T (p.Pro416Leu) in the PRKAG2 gene (NM_016203.4). Clinicians must be aware of the possibility of PRKAG2 variants in complex clinical scenarios associating cardiac arrhythmia, preexcitation syndromes, hypertrophic cardiomyopathy, motor neuron disease, and parkinsonism.
Full article
Open AccessArticle
Alternative Treatments to Exercise for the Attenuation of Disuse-Induced Skeletal Muscle Atrophy in Rats
by
Jinho Park, T. Brock Symons, Eun Hye Kwon, Eunhee Chung and Sukho Lee
Muscles 2024, 3(3), 224-234; https://doi.org/10.3390/muscles3030020 - 22 Jul 2024
Abstract
The prevalence of skeletal muscle atrophy, caused by disease and aging, is rising as life expectancy increases. Exercise is the most effective treatment option; however, it is often impractical for individuals suffering from disease or bedridden. The formulation of non-exercise-based interventions is necessary.
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The prevalence of skeletal muscle atrophy, caused by disease and aging, is rising as life expectancy increases. Exercise is the most effective treatment option; however, it is often impractical for individuals suffering from disease or bedridden. The formulation of non-exercise-based interventions is necessary. This study assessed the impact of acupuncture (AC), electro-acupuncture (EA), and electrical stimulation (ES) on muscle mass and contractile properties in a model of casting-induced muscle atrophy. Sprague-Dawley rats (n = 40) were assigned to five groups: control (CON), cast (CT), cast receiving AC (CT-AC), cast receiving EA (CT-EA), and cast receiving ES (CT-ES) (n = 8 each). Treatments were 15 min and three times/week for 14 days. Contractile properties and protein markers of atrophy and inflammation were measured. Casting decreased muscle mass and fiber cross-sectional area, but AC, EA, and ES attenuated cast-induced muscle atrophy. All treatments increased peak twitch tension compared to CT. CT increased the protein levels of MAFbx and MuRF1, while AC, EA, and ES mitigated the elevation of these proteins. Our results indicate that acupuncture, electro-acupuncture, and electrical stimulation show promise as therapeutic strategies to counteract skeletal muscle loss and dysfunction resulting from disuse atrophy caused by injury, disease, and aging.
Full article
(This article belongs to the Collection Clinical Advances in Neuromuscular Diseases: Neurometabolic Disorders)
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Open AccessReview
Current Indications and Future Direction in Heat Therapy for Musculoskeletal Pain: A Narrative Review
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Gustavo Zanoli, Isabel Albarova-Corral, Michele Ancona, Ignazio Grattagliano, Thilo Hotfiel, Giovanni Iolascon, Karsten Krüger and Guillermo Rodríguez Maruri
Muscles 2024, 3(3), 212-223; https://doi.org/10.3390/muscles3030019 - 16 Jul 2024
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Background: Musculoskeletal pain is a non-negligible multifaceted condition affecting more than 30% of the global population. Superficial heat therapy (HT), through increasing tissue temperatures, plays a role in increasing local metabolism and function and relieving pain. Knee (KP) and sports pain represent two
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Background: Musculoskeletal pain is a non-negligible multifaceted condition affecting more than 30% of the global population. Superficial heat therapy (HT), through increasing tissue temperatures, plays a role in increasing local metabolism and function and relieving pain. Knee (KP) and sports pain represent two relevant fields of superficial HT application. Methods: In the present paper, a panel of experts performed a narrative review of the literature regarding the role of superficial HT in the management of knee and sports activity-related pain. Results: According to the reviewed literature, HT represents a therapeutic option in the management of musculoskeletal pain due to three main effects: pain relief, promotion of healing, and return to normal function and activity. Moreover, HT plays a role in sport activities both before and after exercise. Before performing sports, HT helps in preparing muscles for performance. After performing sports, it is capable to promote recovery and healing pathways. Combining and sequencing superficial heat and cold therapy represent an interesting topic of study. Overall, the application of heat wraps for superficial HT can be considered safe. Conclusions: HT has been shown to be a potentially beneficial and safe option in the management of several conditions including KP and sports. The key in the application of superficial HT is a multimodal and multidisciplinary approach.
Full article
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Open AccessArticle
Resting Systemic Irisin Concentrations Are Lower in Older versus Younger Males after 12 Weeks of Resistance-Exercise Training While Apelin and IL-15 Concentrations Were Increased in the Whole Cohort
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Dean M. Cordingley, Judy E. Anderson and Stephen M. Cornish
Muscles 2024, 3(3), 202-211; https://doi.org/10.3390/muscles3030018 - 1 Jul 2024
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Myokines released by exercise are identified as factors that can influence a person’s health and wellbeing. While myokine secretion in response to an acute bout of endurance and resistance-type exercise has been examined, the influence of resistance-exercise training on myokines at rest is
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Myokines released by exercise are identified as factors that can influence a person’s health and wellbeing. While myokine secretion in response to an acute bout of endurance and resistance-type exercise has been examined, the influence of resistance-exercise training on myokines at rest is less well established. Therefore, this study was designed to evaluate a panel of myokines at rest following a 12-week resistance-exercise training program in younger and older males. Participants (n = 15) completed a 12-week progressive resistance-exercise training program supervised by a certified fitness professional. The training protocol targeted all major muscle groups of the upper and lower body. Resting blood samples were collected before and after completion of the training program to determine concentrations of apelin, fibroblast growth factor-21 (FGF-21), interleukin (IL)-4, IL-6, IL-7, IL-15, leukemia inhibitory factor (LIF), and irisin. Two-way repeated ANOVAs were used to compare variables between time-points and age groups. There was a main effect of time found for apelin (p = 0.003) and IL-15 (p < 0.001), while no main effects for group or time were found for the other myokines (all p > 0.05). Age group × training status interactions were found for IL-6 (p = 0.04) and irisin (p = 0.014) without pairwise differences for IL-6 (p > 0.05), and younger males had higher concentrations of irisin compared to older males post-training (p = 0.036). Overall, the 12-week resistance-exercise training program significantly increased apelin and IL-15 over time but did not change the other resting myokine concentrations for the younger or older males. However, the higher concentration of irisin in younger versus older males post-training suggests a potential explanation for the anabolic resistance observed with aging.
Full article
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Open AccessReview
Sarcopenia and Pleural Effusions: Exploring a Potential Link
by
Georgios I. Barkas, Nikolaos D. Karakousis, Zoe Daniil, Konstantinos I. Gourgoulianis and Ourania S. Kotsiou
Muscles 2024, 3(3), 189-201; https://doi.org/10.3390/muscles3030017 - 22 Jun 2024
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Recent studies indicate a significant relationship between malnutrition, frailty, and pleural effusion (PE), highlighting the critical role of muscle mass in patient outcomes. This review investigates the association between sarcopenia—characterized by a decline in skeletal muscle mass and function—and PE, marked by fluid
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Recent studies indicate a significant relationship between malnutrition, frailty, and pleural effusion (PE), highlighting the critical role of muscle mass in patient outcomes. This review investigates the association between sarcopenia—characterized by a decline in skeletal muscle mass and function—and PE, marked by fluid accumulation in the pleural space. The findings reveal that sarcopenia is prevalent in patients with PE and is linked to increased postoperative complications and mortality rates. In liver transplantation, esophagectomy, and lung cancer surgeries, sarcopenia exacerbates the risk of adverse outcomes. Notably, preoperative muscle mass assessment serves as a predictive tool for identifying patients at higher risk of complications. This review underscores the importance of early diagnosis and intervention for sarcopenia to improve clinical outcomes in PE patients. The therapeutic approach should include comprehensive nutritional evaluations and targeted muscle-strengthening interventions. By addressing sarcopenia, healthcare providers can significantly reduce PE-related complications, enhance patient recovery, and improve survival rates. This review provides a foundation for future research to develop effective strategies for the management and treatment of sarcopenia in the context of PEs, aiming to optimize patient care and quality of life.
Full article
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Graphical abstract
Open AccessArticle
Analyzing Respiratory Sinus Arrhythmia: A Markov Chain Approach with Hypertensive Patients and Arachnophobic Individuals
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Erika Elizabeth Rodriguez-Torres, María Fernanda Azpeitia-Cruz, Jaqueline Escamilla-Muñoz and Isaac Vázquez-Mendoza
Muscles 2024, 3(2), 177-188; https://doi.org/10.3390/muscles3020016 - 20 Jun 2024
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Respiratory Sinus Arrhythmia (RSA) manifests as cyclic fluctuations in heart rate in synchrony with breathing. Gaining insights into the dynamics of RSA within the cardiac muscle functioning is crucial for comprehending its physiological and clinical significance. This study presents an analytical framework employing
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Respiratory Sinus Arrhythmia (RSA) manifests as cyclic fluctuations in heart rate in synchrony with breathing. Gaining insights into the dynamics of RSA within the cardiac muscle functioning is crucial for comprehending its physiological and clinical significance. This study presents an analytical framework employing Markov chains to probe RSA patterns, with a specific emphasis on individuals with hypertension and arachnophobia. We delve into the concept of RSA and its potential cardiovascular implications, particularly among populations characterized by hypertension or normotension and fear of spiders. This study utilizes Markov chain modeling, an innovative method used to scrutinize RSA dynamics across diverse cohorts, with the aim of unveiling underlying patterns and mechanisms. This research contributes to the advancement of our understanding of RSA and its correlation with cardiac function across varied demographics, potentially guiding tailored diagnostic and therapeutic interventions. Our findings highlight significant disparities between hypertensive and normotensive participants, as well as spider-fearful individuals employing techniques to confront their fear compared with those without such strategies.
Full article
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Graphical abstract
Open AccessArticle
Massage It Out: Physiological Responses to a Percussive Therapy Device Used Intra-Resistance Exercise
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Daniel R. Greene, Jonathan J. Ruiz-Ramie and Andrew Craig-Jones
Muscles 2024, 3(2), 166-176; https://doi.org/10.3390/muscles3020015 - 19 Jun 2024
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Percussive therapy devices have been proven effective at reducing muscle inflammation, soreness, and tension and improving the range of motion before or after exercise. However, there is a notable lack of research on percussive therapy intra-exercise. Purpose: Examine the physiological responses (i.e., sets/reps)
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Percussive therapy devices have been proven effective at reducing muscle inflammation, soreness, and tension and improving the range of motion before or after exercise. However, there is a notable lack of research on percussive therapy intra-exercise. Purpose: Examine the physiological responses (i.e., sets/reps) to percussive therapy during single-arm biceps curls (BCs) and single-leg quadriceps extensions (LEs). Methods: Participants [N = 26, 10 females] completed an initial 10-repetition maximum (10 RM) for BCs and LEs. Following that, participants completed two testing sessions in which BCs and LEs were completed at their 10 RM until functional failure (i.e., <7 reps completed). Participants completed two testing sessions in which all body parts received percussive therapy at 25 Hz for 60 s between sets and no percussive therapy. Results: Participants completed more sets [p = 0.002; Cohen’s d = 0.54] and reps [p = 0.005; Cohen’s d = 0.51] during the control condition relative to the percussive therapy condition. There were no differences between body parts (i.e., BC vs. LE) or interaction effects. Conclusion: This study provides evidence that low-frequency long-duration percussive therapy used intra-resistance exercise decreases performance parameters.
Full article
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Open AccessArticle
Comparison between Short, Medium, and Long Fields of View in Estimating Bicep Femoris Fascicle Length
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Nicholas J. Ripley, Paul Comfort and John McMahon
Muscles 2024, 3(2), 153-165; https://doi.org/10.3390/muscles3020014 - 24 May 2024
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Measuring the bicep femoris long head fascicle length via the use of diagnostic ultrasound has become common practice within elite sport, using single images of between 4 and 6 cm. No study to date has compared single image estimations in terms of the
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Measuring the bicep femoris long head fascicle length via the use of diagnostic ultrasound has become common practice within elite sport, using single images of between 4 and 6 cm. No study to date has compared single image estimations in terms of the varying fields of view (i.e., 4, 6, and 10 cm). Therefore, the aim of this study was to determine whether differences occur when estimating the bicep femoris long head fascicle length using short (4 cm), medium (6 cm), and long (10 cm) fields of view across three estimation equations. A total of 36 male athletes (age: 23.8 ± 3.8 years, body mass: 83.7 ± 14.0 kg, height: 1.81 ± 0.06 m) had three ultrasound images of the bicep femoris long head collected on a single occasion with the fascicle length estimated. A significant main effect was observed (p < 0.001) with moderate–very large differences (p < 0.078, d = 0.91–4.01). The smallest fields of view resulted in the greatest fascicle length. There were significant moderate–large associations between the fields of view (p < 0.001, r = 0.542–0.892). Unacceptable limits of agreement were observed, and the developed correction equations remained unacceptable. The partial measure equation is the most accurate whilst using the 10 cm fields of view, while the basic trigonometry equation had the lowest variability between fields of view and the smallest differences between fields of view; hence, this equation may be more appropriate when a <6 cm field of view is the only field of view available.
Full article
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Open AccessSystematic Review
The Use of Dixon Magnetic Resonance Imaging Methods for the Quantification of Rotator Cuff Fatty Infiltration: A Systematic Review
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Andrew J. Nasr, Joshua Harris, Jijia Wang, Michael Khazzam, Nitin B. Jain, Yi-Ting Tzen and Yen-Sheng Lin
Muscles 2024, 3(2), 133-152; https://doi.org/10.3390/muscles3020013 - 19 May 2024
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Fatty infiltration of the rotator cuff muscles is very common following rotator cuff tears and is one of the most important factors in determining treatment. Current clinical practice relies on subjective evaluation of fatty infiltration through categorical scoring based on the Goutallier classification
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Fatty infiltration of the rotator cuff muscles is very common following rotator cuff tears and is one of the most important factors in determining treatment. Current clinical practice relies on subjective evaluation of fatty infiltration through categorical scoring based on the Goutallier classification system. The Dixon magnetic resonance imaging (MRI) sequence provides flexibility in selecting echo times for water–fat separation. The Dixon method, therefore, has the potential to provide robust and high-quality fat quantification that allows for more accurate calculation of fat fraction (%Fat) of the rotator cuff muscles than the Goutallier classification system. However, significant variance exists in sequencing and post-processing methodology within the recent application of Dixon sequences to quantify rotator cuff fatty infiltration. In this paper, we conducted a systematic review to synthesize the relevant literature utilizing Dixon sequencing for the quantification of rotator cuff fatty infiltration. The literature search was extracted from 1094 articles, with 12 studies included in the final review. Regardless of the varying sequencing pattern and post-processing techniques among studies, the findings suggest the Dixon method is reliable for quantitatively calculating the fat fraction of the rotator cuff muscles, even at very low levels of fatty infiltration. In addition, a quantitative difference in fat fraction was observed between participants with different degrees of tear vs. those without any shoulder pathologies. Multi-point Dixon imaging has the potential to be utilized clinically to objectively quantify fatty infiltration and may lead to improved clinical decision making for patients with rotator cuff tears.
Full article
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Open AccessArticle
Sarcopenia Identification Using Alternative Vertebral Landmarks in Individuals with Lung Cancer
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Cecily A. Byrne, Giamila Fantuzzi, Jeremy T. Stephan, Sage Kim, Vanessa M. Oddo, Timothy J. Koh and Sandra L. Gomez
Muscles 2024, 3(2), 121-132; https://doi.org/10.3390/muscles3020012 - 16 Apr 2024
Abstract
(1) Background: Sarcopenia, or low skeletal mass index (SMI), contributes to higher lung cancer mortality. The SMI at third lumbar vertebrae (L3) is the reference standard for body composition analysis. However, there is a need to explore the validity of alternative landmarks in
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(1) Background: Sarcopenia, or low skeletal mass index (SMI), contributes to higher lung cancer mortality. The SMI at third lumbar vertebrae (L3) is the reference standard for body composition analysis. However, there is a need to explore the validity of alternative landmarks in this population. We compared the agreement of sarcopenia identification at the first lumbar (L1) and second lumbar (L2) to L3 in non-Hispanic Black (NHB) and White (NHW) individuals with lung cancer. (2) Methods: This retrospective, cross-sectional study included 214 NHB and NHW adults with lung cancer. CT scans were analyzed to calculate the SMI at L1, L2, and L3. T-tests, chi-square, Pearson’s correlation, Cohen’s kappa, sensitivity, and specificity analysis were used. (3) Results: Subjects presented with a mean age of 68.4 ± 9.9 years and BMI of 26.3 ± 6.0 kg/m2. Sarcopenia prevalence varied from 19.6% at L1 to 39.7% at L3. Cohen’s kappa coefficient was 0.46 for L1 and 0.64 for L2, indicating weak and moderate agreement for the identification of sarcopenia compared to L3. (4) Conclusions: Sarcopenia prevalence varied greatly depending on the vertebral landmark used for assessment. Using L2 or L1 alone resulted in a 16.8% and 23.8% misclassification of sarcopenia in this cohort of individuals with lung cancer.
Full article
(This article belongs to the Special Issue Sarcopenia: The Impact on Health and Disease)
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Open AccessArticle
Effects of Coping Strategies on Health-Related Quality of Life of People with Neuromuscular Diseases
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Irune García, Alicia Aurora Rodríguez, Corrado Angelini, Maddalen García-Sanchoyerto, Patricia Espinosa-Blanco and Oscar Martínez
Muscles 2024, 3(2), 110-120; https://doi.org/10.3390/muscles3020011 - 3 Apr 2024
Abstract
Neuromuscular diseases (NMD) cover a broad spectrum of different rare diagnoses in which the primary lesion is in the peripheral nervous system. The impairment caused by an NMD does not only interfere with physical status but also has a clear impact on health-related
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Neuromuscular diseases (NMD) cover a broad spectrum of different rare diagnoses in which the primary lesion is in the peripheral nervous system. The impairment caused by an NMD does not only interfere with physical status but also has a clear impact on health-related quality of life (HRQoL). It is therefore essential to know the coping style used by these patients. This study aims to analyze the coping strategies in a sample of people with NMD and how their coping style affects their HRQoL. This cross-sectional study included 61 adult patients diagnosed with a rare NMD. WHO-DAS II, SIP, SF-36, and COPE-60 instruments were administered. The results showed that people affected by NMDs tend to use more frequent coping strategies such as active planning, personal growth, and acceptance. In contrast, the least-used strategies were restraint, mental disengagement, venting, humor, and religion, which affected HRQoL negatively. Moreover, the degree of disability was a relevant variable, with an impact on HRQoL. Social support can be considered the main coping strategy that leads to an improvement in the psychosocial HRQoL (β = 503, p < 0.001). These findings are relevant to clinical practice, given the need to understand the coping variable to improve HRQoL.
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Open AccessEditor’s ChoiceCase Report
An Intronic Heterozygous SYNE2 Splice Site Mutation: A Rare Cause for Myalgia and hyperCKemia?
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Theresa Paulus, Natalie Young, Emily Jessop, Carolin Berwanger, Christoph Stephan Clemen, Rolf Schröder, Rafal Ploski, Christian Hagel, Yorck Hellenbroich, Andreas Moser and Iakowos Karakesisoglou
Muscles 2024, 3(1), 100-109; https://doi.org/10.3390/muscles3010010 (registering DOI) - 15 Mar 2024
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SYNE2 mutations have been associated with skeletal and cardiac muscle diseases, including Emery-Dreifuss muscular dystrophy (EDMD). Here, we present a 70-year-old male patient with muscle pain and elevated serum creatine kinase levels in whom whole-exome sequencing revealed a novel heterozygous SYNE2 splice site
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SYNE2 mutations have been associated with skeletal and cardiac muscle diseases, including Emery-Dreifuss muscular dystrophy (EDMD). Here, we present a 70-year-old male patient with muscle pain and elevated serum creatine kinase levels in whom whole-exome sequencing revealed a novel heterozygous SYNE2 splice site mutation (NM_182914.3:c.15306+2T>G). This mutation is likely to result in the loss of the donor splice site in intron 82. While a diagnostic muscle biopsy showed unspecific myopathological findings, immunofluorescence analyses of skeletal muscle and dermal cells derived from the patient showed nuclear shape alterations when compared to control cells. In addition, a significantly reduced nesprin-2 giant protein localisation to the nuclear envelope was observed in patient-derived dermal fibroblasts. Our findings imply that the novel heterozygous SYNE2 mutation results in a monoallelic splicing defect of nesprin-2, thereby leading to a rare cause of myalgia and hyperCKemia.
Full article
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Open AccessEditor’s ChoiceArticle
Age-Related Differences in Physical Fitness and Performance of an “Ability Test” among Firefighters
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Koulla Parpa and Marcos Michaelides
Muscles 2024, 3(1), 88-99; https://doi.org/10.3390/muscles3010009 - 7 Mar 2024
Cited by 1
Abstract
This study’s primary objective was to examine the differences in body composition, abdominal strength, absolute and relative power, handgrip strength, one repetition maximum for squat and bench press, and the maximum count of push-up and sit-up repetitions executed within a minute across different
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This study’s primary objective was to examine the differences in body composition, abdominal strength, absolute and relative power, handgrip strength, one repetition maximum for squat and bench press, and the maximum count of push-up and sit-up repetitions executed within a minute across different age cohorts of firefighters. Furthermore, this study aimed to evaluate the age-related differences in firefighters’ completion times of six firefighting tasks. Eighty-four male volunteer firefighters (age 33.79 ± 6.97 years) were grouped into three age categories, 20–30 years, 31–40 years, and 41–50 years, and underwent the aforementioned evaluations. One-way analysis of variance (MANOVA) revealed that age exerts a statistically significant influence (p < 0.001) on body fat percentage, waist circumference, and waist-to-hip ratio. Furthermore, age significantly affected the overall time of the ability test (p < 0.001) and the duration required to accomplish each individual task (p < 0.001). Additionally, age significantly affected abdominal strength, relative power (as measured by the step test), and the maximum count of push-up and sit-up repetitions performed within a minute. These outcomes support earlier research indicating an age-associated decrement in physical fitness parameters among firefighters. It is recommended that firefighters prioritize maintaining strength and endurance of the abdominal muscles, upper body muscular endurance, and a healthy body weight. The emphasis on specific muscular groups is essential for improving task performance within this profession.
Full article
Open AccessEditor’s ChoiceReview
Clinical and Therapeutic Implications of BCAAs Metabolism during Chronic Liver Disease in Humans: Crosstalk between Skeletal Muscle and Liver
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Maria Camila Trillos-Almanza, Magnolia Martinez-Aguilar, Johanna C. Arroyave-Ospina, Frederike van Vilsteren, Hans Blokzijl and Han Moshage
Muscles 2024, 3(1), 71-87; https://doi.org/10.3390/muscles3010008 - 4 Mar 2024
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This comprehensive review focuses on the dynamics of branched-chain amino acids (BCAAs) metabolism and its clinical implications in chronic liver disease, with emphasis on the emerging concept of muscle–liver crosstalk. BCAAs, indispensable for protein synthesis and metabolic pathways, undergo unique tissue-specific processing in
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This comprehensive review focuses on the dynamics of branched-chain amino acids (BCAAs) metabolism and its clinical implications in chronic liver disease, with emphasis on the emerging concept of muscle–liver crosstalk. BCAAs, indispensable for protein synthesis and metabolic pathways, undergo unique tissue-specific processing in skeletal muscle and liver. The liver, responsible for amino acid metabolism, plays a distinctive role in sensing BCAAs catabolism, influencing glucose regulation and contributing to the systemic metabolism of BCAAs. Within the context of chronic liver disease, compromised liver metabolism becomes evident through amino acid abnormalities, particularly in the decrease of the Fischer ratio (BCAAs/aromatic amino acids concentrations in plasma). This reduction becomes important in assessing the severity of liver dysfunction due to its associations with adverse outcomes, including increased mortality and complications related to the liver disease. BCAAs supplementation, as explored in this review, emerges as a promising avenue, displaying positive effects on skeletal muscle mass, strength, and overall nutritional status in cirrhosis management. Understanding this interplay offers insights into therapeutic strategies for chronic liver diseases, exploring the way for precision interventions in clinical practice.
Full article
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Open AccessEditor’s ChoiceArticle
The Effects of Regional Muscle Strength and Mass on Standing Long Jump Performance
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Yuki Nakai, Yujiro Usumoto and Yasufumi Takeshita
Muscles 2024, 3(1), 60-70; https://doi.org/10.3390/muscles3010007 - 4 Mar 2024
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Muscle strength and mass strongly influence performance. The role of the trunk, upper limbs, and lower limbs in a specific performance is important but unclear in terms of muscle strength, muscle mass, and the degree of influence of each part. Standing long jump
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Muscle strength and mass strongly influence performance. The role of the trunk, upper limbs, and lower limbs in a specific performance is important but unclear in terms of muscle strength, muscle mass, and the degree of influence of each part. Standing long jump is a performance that produces results by not only the muscles of the lower limbs working together but also the entire body, including the trunk and upper limbs. To determine the influence of muscle strength and the mass of each body part on standing long jump, 31 healthy young adults (18 males and 13 females) participated in this study. Abdominal trunk muscle strength, grip strength, and knee extension muscle strength were measured, each of which was defined as trunk, upper limb, and lower limb muscle strength. The trunk, upper limb, and lower limb muscle masses were measured using a body composition analyzer. Performance was measured using the standing long jump test (jumping power). Factors influencing standing long jump were examined. A multiple regression analysis revealed that trunk (β = 0.367, p = 0.006) and upper limb (β = 0.608, p < 0.001) muscle strength values were extracted for standing long jump (adjusted R2 = 0.574, p < 0.01). Trunk and upper limb muscle strength influence standing long jumps.
Full article
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Open AccessEditor’s ChoiceReview
Sarcopenia and Pleural Mesothelioma: The Current Knowledge
by
Nikolaos D. Karakousis, Konstantinos I. Gourgoulianis, Nikolaos Papanas and Ourania S. Kotsiou
Muscles 2024, 3(1), 48-59; https://doi.org/10.3390/muscles3010006 - 8 Feb 2024
Abstract
Pleural mesothelioma (PM) is a tumor related to adverse prognosis. The PM WHO classification has mainly identified three major subtypes of PM which are epithelioid, biphasic, and sarcomatoid. Sarcopenia is a medical issue related to a reduction in muscle mass and strength. It
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Pleural mesothelioma (PM) is a tumor related to adverse prognosis. The PM WHO classification has mainly identified three major subtypes of PM which are epithelioid, biphasic, and sarcomatoid. Sarcopenia is a medical issue related to a reduction in muscle mass and strength. It represents a major health issue globally because it is related to adverse effects such as hospitalization, increased length of stay, disability, increased morbidity and mortality and augmented health care expenditures. In this literature review, we attempted to examine the upcoming association between sarcopenia and PM. As recorded by the current literature, muscle loss in PM subjects was related to poorer survival and lower levels of activity. Subjects with PM had increased rates of pre-sarcopenia and malnutrition, while pre-sarcopenia was related to worse activity levels, and malnutrition was related to worse quality of life (QoL). Both tumor volume and sarcopenia were related to long-term mortality in surgically treated PM subjects, while sarcopenia was present both pre-operatively and post-operatively in these subjects. In addition, post-operative sarcopenic subjects showed a decreased 3-year overall survival (OS) in comparison with those who did not have sarcopenia, while pre-operative sarcopenia was importantly related to an increased rate of post-operative adverse outcomes. More studies are needed to validate these claims.
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(This article belongs to the Special Issue Sarcopenia: The Impact on Health and Disease)
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Open AccessEditor’s ChoiceCase Report
Eculizumab as Additional Rescue Therapy in Myasthenic Crisis
by
Francesco Crescenzo, Mattia Zanoni, Laura Ferigo, Francesca Rossi, Matteo Grecò, Angelica Lupato, Alessandra Danese, Domenico Ajena and Michelangelo Turazzini
Muscles 2024, 3(1), 40-47; https://doi.org/10.3390/muscles3010005 - 7 Feb 2024
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Eculizumab is a monoclonal antibody blocking the terminal complement protein C5. As demonstrated in the phase III randomized, placebo-controlled, REGAIN clinical trial, eculizumab is efficacious in acetylcholine receptor antibody (AChR-Ab)-positive refractory generalized myasthenia gravis (gMG) (Myasthenia Gravis Foundation of America—MGFA class II–IV). It
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Eculizumab is a monoclonal antibody blocking the terminal complement protein C5. As demonstrated in the phase III randomized, placebo-controlled, REGAIN clinical trial, eculizumab is efficacious in acetylcholine receptor antibody (AChR-Ab)-positive refractory generalized myasthenia gravis (gMG) (Myasthenia Gravis Foundation of America—MGFA class II–IV). It has not been studied in severe myasthenic exacerbation or myasthenic crisis (MGFA V). A 73-year-old man diagnosed with myasthenia gravis AChR-Ab positivity came to our observation for symptoms of bulbar and ocular weakness and unresponsiveness or intolerability to conventional immunosuppressive therapies (prednisone and azathioprine). Due to the recurrent clinical worsening with intubation over a short-term period, the patient was treated with eculizumab. After 15 days of eculizumab treatment, we observed a significant recovery of clinical condition. We discharged the patient to an outpatient regimen, where he is continuing with maintenance doses of eculizumab and slowly tapering steroid intake. The use of eculizumab in myasthenic crises is still anecdotal. Our case aims to provide eculizumab benefit for refractory severe gMG in a practical, real-world setting beyond the criteria of the REGAIN study. Further studies are needed to evaluate the efficacy and safety of eculizumab in myasthenic crises.
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Open AccessArticle
Incobotulinumtoxin A and Yoga-like Isometric Exercise in Adolescent Idiopathic Lumbar Scoliosis—A Randomized Pilot Study
by
Loren Fishman
Muscles 2024, 3(1), 28-39; https://doi.org/10.3390/muscles3010004 - 1 Feb 2024
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Background: Approximately 90% of scoliosis cases are adolescent-idiopathic (AIS). From the first appearance of scoliosis at 10–14 years of age until the age of 18, the spine is most vulnerable to deterioration; young, growing people are most susceptible to the worsening of one
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Background: Approximately 90% of scoliosis cases are adolescent-idiopathic (AIS). From the first appearance of scoliosis at 10–14 years of age until the age of 18, the spine is most vulnerable to deterioration; young, growing people are most susceptible to the worsening of one or more scoliotic curves. An effective non-surgical means of remediation would be welcome. Design: This was a randomized, controlled, two-arm study assessing the safety and efficacy of combining incobotulinum injections with yoga to reverse lumbar and thoracolumbar AIS. Methods: In a private clinic setting, non-pregnant, healthy 12–18 year-olds were either taught a symmetrical “placebo” yoga pose (control sub-group 1), performed the side plank (Vasisthasana) three times daily with a placebo injection (control sub-group 2) or performed the three-times-daily side plank with a botulinum injection (intervention group 3). Injection: For the injection, 33 IU of incobotulinumtoxin type A (Xeomin) was injected into the concave-side lumbar paraspinals and quadratus lumborum at L2–3 and the psoas muscle at L3–4, or participants were injected similarly with a placebo. Randomization was achieved using random.org. Objective: The objective was to determine whether the treatment of muscular asymmetry with botulinum toxin injections and side planks is safe and effective in AIS. Results/Outcome: Eleven intervention and thirteen placebo patients (Groups 1 + 2), who were 12–18 years old, completed the three-month study. Mean daily side plank time = 165 s. The mean initial lumbar curvature was 36.9 degrees (SD 14.36), (p < 0.0001); the mean Group 3 curvature at 3 weeks was 29.5 degrees (SD 14.23) (p < 0.0001); and the mean Group 3 curvature at 3 months was 26.0 degrees (SD 12.81). Onset vs. 3-month value: p < 0.0001. Harms were limited to one patient in Group 2 and one in Group 3, who complained of transient shoulder pain and supported themselves temporarily on their forearm instead of the palm of the extended hand. Conclusion: Muscle strength asymmetry appears to be relevant to AIS treatment. Incobotulinum injections combined with side planks performed with the convex side downward may be more effective in reversing lumbar AIS than placebo exercises or side planks and placebo injections.
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Open AccessEditor’s ChoiceArticle
Neuromuscular Rehabilitation of the Brachioradialis Muscle after Distal Radius Fracture in Two Professional Soccer Players Using Electromyographic Biofeedback
by
Verónica Morales-Sánchez, Rafael E. Reigal, Verónica García-Morales, Antonio Hernández-Mendo and Coral Falcó
Muscles 2024, 3(1), 16-27; https://doi.org/10.3390/muscles3010003 - 23 Jan 2024
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The use of electromyographic biofeedback (EMG-BF) in the rehabilitation of injuries has been widely referenced in the psychological literature. However, despite some pioneering work in the field of sports, its use in the rehabilitation of sports injuries has hardly been explored. A case
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The use of electromyographic biofeedback (EMG-BF) in the rehabilitation of injuries has been widely referenced in the psychological literature. However, despite some pioneering work in the field of sports, its use in the rehabilitation of sports injuries has hardly been explored. A case of two professional soccer players who each suffered a distal radius fracture is presented here. Parallel to the rehabilitation plan established by medical services, an intervention strategy using EMG-BF was established. An EMG-BF intervention was performed on the brachioradialis muscle with the aim of improving the voluntary control of its electromyographic activity. The study protocol was registered with the identifier NCT05376072. An ABA design was used. In each session, a pre- and postline was recorded to determine the EMG gain acquired at each point of the session. After six sessions, the intervention was terminated. One more follow-up session was performed. The results obtained indicated the efficacy of the intervention; a statistically significant increase in muscle activity in the brachioradialis muscle was observed.
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Open AccessCase Report
PNPT1 Spectrum Disorders: An Underrecognized and Complex Group of Neurometabolic Disorders
by
Paulo Sgobbi, Igor Braga Farias, Paulo de Lima Serrano, Bruno de Mattos Lombardi Badia, Hélvia Bertoldo de Oliveira, Alana Strucker Barbosa, Camila Alves Pereira, Vanessa de Freitas Moreira, Marco Antônio Troccoli Chieia, Adriel Rêgo Barbosa, Pedro Henrique Almeida Fraiman, Vinícius Lopes Braga, Roberta Ismael Lacerda Machado, Sophia Luiz Calegaretti, Isabela Danziato Fernandes, Roberta Correa Ribeiro, Marco Antonio Orsini Neves, Wladimir Bocca Vieira de Rezende Pinto and Acary Souza Bulle Oliveira
Muscles 2024, 3(1), 4-15; https://doi.org/10.3390/muscles3010002 - 19 Jan 2024
Abstract
An 18-year-old man presented with slowly progressive infancy-onset spasticity of the lower limbs and cerebellar ataxia, associated with painless strabismus, intellectual disability, urinary incontinence, bilateral progressive visual loss, and cognitive decline since early adolescence. A neurological examination disclosed spastic dysarthria, left eye divergent
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An 18-year-old man presented with slowly progressive infancy-onset spasticity of the lower limbs and cerebellar ataxia, associated with painless strabismus, intellectual disability, urinary incontinence, bilateral progressive visual loss, and cognitive decline since early adolescence. A neurological examination disclosed spastic dysarthria, left eye divergent strabismus, bilateral ophthalmoparesis, impaired smooth pursuit, severe spastic paraparesis of the lower limbs with global brisk tendon reflexes, bilateral extensor plantar responses, and bilateral ankle clonus reflex. Bilateral dysdiadochokinesia of the upper limbs, Stewart-Holmes rebound phenomenon, bilateral dysmetria, and a bilateral abnormal finger-to-nose test were observed. Markedly reduced bilateral visual acuity (right side 20/150, left side 20/400) and moderate to severe optic atrophy were detected. Neuroimaging studies showed cerebellar atrophy and bilateral optic nerves and optic tract atrophy as the main findings. As a complicated Hereditary Spastic Paraplegia, autosomal dominant Spinocerebellar Ataxia, or inherited neurometabolic disorders were suspected, a large next-generation sequencing-based gene panel testing disclosed the heterozygous pathogenic variant c.162-1G>A in intron 1 of the PNPT1 gene. A diagnosis of PNPT1-related spastic ataxia was established. Clinicians must be aware of the possibility of PNPT1 pathogenic variants in cases of spastic ataxia and spastic paraplegias that are associated with optic atrophy and marked cognitive decline, regardless of the established family history of neurological compromise.
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(This article belongs to the Collection Clinical Advances in Neuromuscular Diseases: Neurometabolic Disorders)
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