Muscles

Research

8 pages, 487 KiB

Open AccessCommunication

The Correlation between Core Muscular Endurance, Body Composition, and Back Pain in Firefighters: An Observational Study

by Shelby Sanregret, Austin Alan Kohler, Andrew Ray Moore and Angelia Maleah Holland-Winkler

Muscles 2023, 2(4), 353-360; https://doi.org/10.3390/muscles2040027 - 24 Oct 2023

Cited by 2 | Viewed by 1770

Abstract

Firefighters are at a higher risk for experiencing back pain due to the nature of their job, but physical fitness may help to reduce this risk. Therefore, the primary purpose of this study was to determine if a correlation between subjective back pain [...] Read more.

Firefighters are at a higher risk for experiencing back pain due to the nature of their job, but physical fitness may help to reduce this risk. Therefore, the primary purpose of this study was to determine if a correlation between subjective back pain severity and core muscular endurance exists in firefighters. A secondary purpose was to determine if age or body composition were correlated with back pain severity. This cross-sectional study was performed at a fire department during their Physical Fitness Assessment Program and included 72 male firefighters. Measures included weight, body fat percentage, maximal plank hold times for core muscular endurance, and the Oswestry Low Back Pain Disability Questionnaire. A Pearson product correlation analysis was performed between back pain score and each of the following variables: body fat percentage, BMI, age, and plank hold times. A second set of correlation coefficient analyses was performed between the same variables exclusively in subjects who reported back pain. This study found that, within this population of firefighters, there was no significant correlation between back pain and plank times or body composition variables, although there was a trend toward significant correlations between BMI and body fat percentage when only subjects with back pain were considered. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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11 pages, 1359 KiB

Open AccessArticle

Discrepancy of Beta-Hydroxybutyrate Measurements between a Blood Meter and GC-MS Methods in Healthy Humans

by Angelia Maleah Holland-Winkler, Andrew R. Moore, Jenna K. Ansley, Noah A. Fritz and Ilya Bederman

Muscles 2023, 2(4), 327-337; https://doi.org/10.3390/muscles2040025 - 27 Sep 2023

Viewed by 1472

Abstract

Ketone salt (KS) supplementation induces temporary nutritional ketosis to achieve potential exercise performance and health benefits. Racemic KS includes both D/L isomers of β-hydroxybutyrate, yet commercially available measurement devices (i.e., blood meters) only measure the D variant. The aim of this study was [...] Read more.

Ketone salt (KS) supplementation induces temporary nutritional ketosis to achieve potential exercise performance and health benefits. Racemic KS includes both D/L isomers of β-hydroxybutyrate, yet commercially available measurement devices (i.e., blood meters) only measure the D variant. The aim of this study was to investigate the efficacy of a blood meter to measure serum β-hydroxybutyrate in comparison with gas chromatography–mass spectrometry (GC-MS) before and 30 min after consuming a placebo or racemic KS. In this triple-blinded cross-over study, 16 healthy adults were administered either a placebo or KS drink, and the circulating β-hydroxybutyrate concentration was measured at baseline (PRE) and 30 min following consumption (POST) using a blood ketone meter and by GC-MS. Compared to the placebo, both GC-MS and the blood meter obtained significantly greater β-hydroxybutyrate levels from PRE to POST time-points after consuming KS. Additionally, GC-MS results showed significantly higher levels of β-hydroxybutyrate with both the placebo and KS at PRE and POST time-points, as compared to the blood meter. These results indicate that (1) even in the absence of KS, the blood meter yields significantly lower β-hydroxybutyrate values than GC-MS, and (2) the inability of the blood meter to measure L-β-hydroxybutyrate values POST KS warrants the further development of publicly available ketone measurement apparatuses. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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24 pages, 8501 KiB

Open AccessEditor’s ChoiceArticle

Pathological Sequelae Associated with Skeletal Muscle Atrophy and Histopathology in G93A*SOD1 Mice

by Richa Aishwarya, Chowdhury S. Abdullah, Naznin Sultana Remex, Sadia Nitu, Brandon Hartman, Judy King, Mohammad Alfrad Nobel Bhuiyan, Oren Rom, Sumitra Miriyala, Manikandan Panchatcharam, A. Wayne Orr, Christopher G. Kevil and Md. Shenuarin Bhuiyan

Muscles 2023, 2(1), 51-74; https://doi.org/10.3390/muscles2010006 - 2 Feb 2023

Cited by 2 | Viewed by 4982

Abstract

Amyotrophic lateral sclerosis (ALS) is a complex systemic disease that primarily involves motor neuron dysfunction and skeletal muscle atrophy. One commonly used mouse model to study ALS was generated by transgenic expression of a mutant form of human superoxide dismutase 1 (SOD1) gene [...] Read more.

Amyotrophic lateral sclerosis (ALS) is a complex systemic disease that primarily involves motor neuron dysfunction and skeletal muscle atrophy. One commonly used mouse model to study ALS was generated by transgenic expression of a mutant form of human superoxide dismutase 1 (SOD1) gene harboring a single amino acid substitution of glycine to alanine at codon 93 (G93A*SOD1). Although mutant-SOD1 is ubiquitously expressed in G93A*SOD1 mice, a detailed analysis of the skeletal muscle expression pattern of the mutant protein and the resultant muscle pathology were never performed. Using different skeletal muscles isolated from G93A*SOD1 mice, we extensively characterized the pathological sequelae of histological, molecular, ultrastructural, and biochemical alterations. Muscle atrophy in G93A*SOD1 mice was associated with increased and differential expression of mutant-SOD1 across myofibers and increased MuRF1 protein level. In addition, high collagen deposition and myopathic changes sections accompanied the reduced muscle strength in the G93A*SOD1 mice. Furthermore, all the muscles in G93A*SOD1 mice showed altered protein levels associated with different signaling pathways, including inflammation, mitochondrial membrane transport, mitochondrial lipid uptake, and antioxidant enzymes. In addition, the mutant-SOD1 protein was found in the mitochondrial fraction in the muscles from G93A*SOD1 mice, which was accompanied by vacuolized and abnormal mitochondria, altered OXPHOS and PDH complex protein levels, and defects in mitochondrial respiration. Overall, we reported the pathological sequelae observed in the skeletal muscles of G93A*SOD1 mice resulting from the whole-body mutant-SOD1 protein expression. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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13 pages, 2574 KiB

Open AccessArticle

Effects of ATP on Time Parameters of Contractility of Rats’ Slow and Fast Skeletal Muscles in Normal and Hypothermic Conditions

by Adel E. Khairullin, Sergey N. Grishin, Azat I. Gabdrahmanov and Ayrat U. Ziganshin

Muscles 2023, 2(1), 23-35; https://doi.org/10.3390/muscles2010003 - 12 Jan 2023

Cited by 2 | Viewed by 1949

Abstract

We have previously shown that hypothermia leads to an increase in the synaptic modulating effects of ATP but not of adenosine in several different animal skeletal muscles. In this paper, we studied the effect of ATP on the amplitude–time parameters of single and [...] Read more.

We have previously shown that hypothermia leads to an increase in the synaptic modulating effects of ATP but not of adenosine in several different animal skeletal muscles. In this paper, we studied the effect of ATP on the amplitude–time parameters of single and tetanic contractions of rats’ isolated fast (1) and slow (2) muscles at different temperatures. We found that when muscles were stimulated by the electrical field (0.1 Hz, 0.5 ms, 10 V), with a decrease in the bath temperature from 37 °C to 14 °C (3), there was an increase in the half-relaxation time of the slow muscle (m. soleus), but not of the fast muscle (m. EDL). Similar effects were observed using a carbachol-induced contraction technique, which suggests the postsynaptic (4) nature of the expansion of the contractile response of the slow muscle induced by ATP (5). To confirm the postsynaptic nature of the observed phenomenon, experiments were performed at a high calcium level (7.2 mM), in which the presynaptic effects of ATP were shown to be offset. We found that the hypercalcium condition did not significantly change the effects of ATP on the measured parameters in both muscles. To record muscle tetanic contractions, we gradually increased the frequency of electrical impulses with the increment of 2.5 Hz to achieve the fusion frequencies of 12.5 Hz for m. soleus and 17.5 Hz for m. EDL at normal temperatures. ATP (100 μM) did not change the fusion frequency for both muscles at a normal temperature but decreased this parameter for the slow muscle to 5 Hz at 14 °C without affecting that for the fast muscle. We conclude that ATP potentiates a hypothermia-induced increase in the half-relaxation time of the contraction of rats’ slow, but not fast, skeletal muscles by acting on postsynaptic P2 receptors (6). Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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11 pages, 1074 KiB

Open AccessArticle

Muscle Activation during the Squat Performed in Different Ranges of Motion by Women

by Lissiane Almeida Cabral, Leonardo Coelho Rabello Lima, Christian Emmanuel Torres Cabido, Rogério César Fermino, Saulo Fernandes Melo Oliveira, Alexandre Igor Araripe Medeiros, Luis Fabiano Barbosa, Thiago Mattos Frota de Souza, Túlio Banja and Cláudio de Oliveira Assumpção

Muscles 2023, 2(1), 12-22; https://doi.org/10.3390/muscles2010002 - 12 Jan 2023

Cited by 3 | Viewed by 10385

Abstract

Purpose: To analyze the muscle activation of the rectus femoris (RF), vastus lateralis (VL), gluteus maximus (GM), and biceps femoris (BF) in concentric and eccentric actions in the squat at 90° and 140° range of motion. Methods: Thirty-five women (32.9 ± 7.4 years; [...] Read more.

Purpose: To analyze the muscle activation of the rectus femoris (RF), vastus lateralis (VL), gluteus maximus (GM), and biceps femoris (BF) in concentric and eccentric actions in the squat at 90° and 140° range of motion. Methods: Thirty-five women (32.9 ± 7.4 years; 64.5 ± 11.5 kg; 1.63 ± 0.1 m; BMI: 24.2 ± 2.9 kg/m²; %fat: 24.9 ± 6.5%) experienced exercise for at least eight weeks. Electrodes were positioned in standardized locations. The signals were acquired by an A/D SAS1000 V8 converter and the electromyographic activity normalized in the percentage of the highest produced value (%RMS). The data were analyzed using repeated measures two-way ANOVA, with effect size (η²) and differences calculated in percentage points (∆ p.p.). Results: The RF (p = 0.001; ∆ = 5.1 p.p.) and BF activation (p = 0.020; ∆ = 4.0 p.p.) was higher at 90° in the eccentric action. The RF showed an interaction between the range of motion and %RMS, with a large effect size (F = 37.9; p = 0.001; η² = 0.485). The VL activation was higher at 140° (p = 0.005; ∆ = 3.9 p.p.) in the concentric action and higher at 90° (p = 0.006; ∆ = 3.7 p.p.) in the eccentric action, with a large effect size significant interaction (F = 21.3; p = 0.001; η² = 0.485). The GM activation was higher at 90° in the concentric (p = 0.020; ∆ = 5.4 p.p.) and eccentric action (p = 0.022; ∆ = 41 p.p.). Conclusions: The biarticular muscles were influenced by the squat range only in the eccentric action of the movement, while the monoarticular muscles were influenced by the squat in both concentric and eccentric muscle action. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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11 pages, 1140 KiB

Open AccessArticle

Effects of Caffeine Supplementation on the Recovery of Professional Soccer Players

by Thais Marques e Silva, Wilson Cesar Abreu, Eduardo Pimenta and Sandro F. da Silva

Muscles 2023, 2(1), 1-11; https://doi.org/10.3390/muscles2010001 - 30 Dec 2022

Viewed by 3395

Abstract

(1) Introduction: Soccer players face high demand for training and games. To facilitate their performance, many studies have investigated ergogenic supplements that can assist in the recovery and performance of players. The aim of this research was to assess whether caffeine supplementation can [...] Read more.

(1) Introduction: Soccer players face high demand for training and games. To facilitate their performance, many studies have investigated ergogenic supplements that can assist in the recovery and performance of players. The aim of this research was to assess whether caffeine supplementation can help soccer players’ recovery and performance. (2) Methods: Professional players were given 210 mg of caffeine or placebo in seven games during the state championship, being offered placebo in three matches and caffeine in four matches, administered 30 min before the game, during the game, and after the game. Blood creatine kinase (CK) and heart rate variability (HRV) were measured. Participants rated their perceived recuperation (RPR) and exertion (RPE) on scales developed by Laurent and Borg, respectively. The time that the player spent on the field was also evaluated. t-tests and Levene’s test were used to analyze the results. In addition to mean differences, variations in the results were also analyzed. (3) Results: No significant differences were found in CK, HRV, RPR, RPE, or minutes on the field when comparing caffeine supplementation with the placebo. (4) Conclusion: Caffeine supplementation throughout the championship appears to have had no ergogenic effect on athlete performance and recovery. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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10 pages, 1634 KiB

Open AccessCommunication

Characterizing the Effects of Voluntary Wheel Running on Cardiac SERCA Function in Ovariectomized Mice

by Bianca M. Marcella, Mia S. Geromella, Ahmad Mohammad, Jacob Sweezey-Munroe, Rebecca E. K. MacPherson and Val A. Fajardo

Muscles 2022, 1(3), 152-161; https://doi.org/10.3390/muscles1030016 - 10 Dec 2022

Viewed by 1590

Abstract

The sarco(endo)plasmic reticulum Ca²⁺ ATPase (SERCA) actively transports Ca²⁺ into the sarcoplasmic reticulum to facilitate cardiac muscle relaxation. Phospholamban (PLN) allosterically inhibits SERCA, and an imbalance of SERCA2a, dominant cardiac isoform, and PLN content disrupts Ca²⁺ homeostasis and cardiac contractility. [...] Read more.

The sarco(endo)plasmic reticulum Ca²⁺ ATPase (SERCA) actively transports Ca²⁺ into the sarcoplasmic reticulum to facilitate cardiac muscle relaxation. Phospholamban (PLN) allosterically inhibits SERCA, and an imbalance of SERCA2a, dominant cardiac isoform, and PLN content disrupts Ca²⁺ homeostasis and cardiac contractility. A previous study has shown that ovariectomized (OVX) rats have reduced SERCA activity due to lowered SERCA2a and increased PLN content. Furthermore, it was found that forced treadmill running in OVX rats restored SERCA activity and protein content levels. Here, we investigated whether voluntary wheel running (VWR) would produce similar effects on cardiac SERCA function in OVX mice. Female mice were divided into the following groups for 8 weeks: SHAM; OVX; SHAM + VWR; and OVX + VWR (n = 10/group). SERCA activity and Ca²⁺ uptake assays were performed in cardiac muscle homogenates. Protein levels of SERCA2, PLN, and pPLN were determined via Western blot analysis. We found statistical interactions for Ca²⁺ uptake, maximal SERCA activity, and SERCA2a content where VWR increased these parameters in SHAM mice but not in OVX mice. We detected a main effect of OVX on PLN content, and main effects of OVX and VWR on pPLN content. The OVX mice ran significantly less than the SHAM mice, suggesting that estrogen deprivation and lack of regular exercise may blunt the effects of voluntary aerobic exercise on cardiac SERCA function. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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9 pages, 273 KiB

Open AccessArticle

Reduction in Skeletal Muscle Mass in Progressive Supranuclear Palsy in Comparison with Parkinson’s Disease: A Preliminary Retrospective Longitudinal Study

by Yasuyuki Takamatsu and Ikuko Aiba

Muscles 2022, 1(3), 143-151; https://doi.org/10.3390/muscles1030015 - 19 Nov 2022

Viewed by 2352

Abstract

Progressive supranuclear palsy (PSP) manifests with the loss of skeletal muscle mass, but the longitudinal changes have not been investigated. We studied changes in body composition, including in skeletal muscle mass, in patients with PSP twice, approximately 1 year or more apart, and [...] Read more.

Progressive supranuclear palsy (PSP) manifests with the loss of skeletal muscle mass, but the longitudinal changes have not been investigated. We studied changes in body composition, including in skeletal muscle mass, in patients with PSP twice, approximately 1 year or more apart, and we compared these measurements with those of patients with Parkinson’s disease (PD). The total number of participants was 42: 10 men had PD, 13 men had PSP, 8 women had PD, and 11 women had PSP. Using a body composition analyzer, we measured such parameters as body mass index (BMI), skeletal muscle mass, basal metabolic rate (BMR), body fat percentage (BFP), and the ratio of extracellular water to total body water. We also calculated the skeletal muscle mass index (SMI). We measured the Barthel index to assess activities of daily living. The Barthel index was lower in patients with PSP than in those with PD at the first evaluation, and it worsened by the time of the second evaluation. In men with PSP, skeletal muscle mass was far more reduced than in those with PD, but no such changes were found among women with either disease. The SMI of men with PSP was correlated significantly with BMI, BMR, BFP, and the Barthel index. Skeletal muscle mass diminished faster in patients with PSP, especially in men, than in patients with PD, probably because of inactivity. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

10 pages, 1402 KiB

Open AccessArticle

Effects of Blood Flow Restricted Exercise on Electromechanical Delay and Time to Peak Force after Task Failure: A Randomized Crossover Trial

by Mikhail Santos Cerqueira, Maria Lira, Raiff Simplicio da Silva, Marco Machado and Rafael Pereira

Muscles 2022, 1(3), 133-142; https://doi.org/10.3390/muscles1030014 - 4 Nov 2022

Viewed by 1978

Abstract

Introduction: Electromechanical delay (ED) and time to peak force (TPF) could be used to investigate the central or peripheral sources of performance decline in fatiguing tasks. Exercise with partial blood flow restriction (BFR) has been shown to induce fatigue, but the repercussions of [...] Read more.

Introduction: Electromechanical delay (ED) and time to peak force (TPF) could be used to investigate the central or peripheral sources of performance decline in fatiguing tasks. Exercise with partial blood flow restriction (BFR) has been shown to induce fatigue, but the repercussions of exercise with partial BFR on ED and TPF are unclear. The present study aimed to compare the ED and TPF after an intermittent isometric task until failure with BFR and free blood flow (FBF). Methods: In this crossover randomized clinical trial, 15 healthy and physically active men volunteered in this study. Volunteers performed two intermittent isometric handgrip exercise (IIHE) to failure (72 h apart), combined with either BFR or FBF. Maximum voluntary isometric force (MVIF) concomitant with the electromyographic activity of the wrist and finger flexor muscles were assessed before (PRE) and one minute after (POST) the task failure. Within (PRE vs. POST) and between comparisons (eFBF vs. eBFR) of peak force, time to peak force, rate of force development (RFDpeak) and ED were carried out. Results: No significant between-intervention differences were identified pre- or post-exercise. Peak force and RFDpeak reduced significantly after both blood flow conditions (p < 0.05), but without between-condition difference. TPF was statistically higher after exercise only in the FBF intervention (p < 0.05). None of the interventions induced a significant change in the ED after IIHE. Conclusion: ED and TPF were similar after BFR and FBF, indicating both conditions induce similar acute performance impairments after IIHE, which seems not to be caused by local (i.e., muscular) factors, but probably by central (i.e., neural) factors. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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12 pages, 829 KiB

Open AccessArticle

Creatine Supplementation Improves Muscular Performance without Additional Impact on the Cardiovascular System in Trained Women

by Katia S. Azevedo, Steven B. Machek, Abby E. Lewis, Warleyson J. S. Azevedo, Jeffrey M. Willardson, Rafael Pereira and Marco Machado

Muscles 2022, 1(3), 121-132; https://doi.org/10.3390/muscles1030013 - 26 Oct 2022

Viewed by 3831

Abstract

Creatine monohydrate supplementation in females is largely under-represented in the literature, and their potentially differential hemodynamic responses are unknown. Methods: Twenty-eight resistance-trained women (25.5 ± 6.1 years, 59.7 ± 6.3 kg, 163 ± 5 cm) were randomly assigned to the supplement creatine monohydrate [...] Read more.

Creatine monohydrate supplementation in females is largely under-represented in the literature, and their potentially differential hemodynamic responses are unknown. Methods: Twenty-eight resistance-trained women (25.5 ± 6.1 years, 59.7 ± 6.3 kg, 163 ± 5 cm) were randomly assigned to the supplement creatine monohydrate (CRE; 5 g creatine monohydrate + 5 g dextrose) or placebo (PLA; 10 g dextrose) four times per day for 7 days in a double-blind fashion. Each subject subsequently completed resistance training sessions (3 × week) for four weeks with four sets to muscular failure of both half-squat and leg press exercises. The change in body mass (BM), exercise repetition number (REP), rated perceived exertion (RPE), and cardiovascular variables were assessed (sessions 1, 6, and 12). Statistical analyses were performed at a significance level of p ≤ 0.05. Results: Analyses revealed a significant CRE-specific BM increase (p = 0.013), as well as significantly greater half-squat (p = 0.006) and leg press (p = 0.017) REP per set versus PLA. Additionally, CRE demonstrated significantly lower relative RPE values at session 12 compared with previous sessions. Any significant main or interaction effects were observed for the studied cardiovascular variable. Conclusions: The present data substantiate the creatine’s efficacy to improve muscular performance in females while demonstrating the safety of combined creatine monohydrate supplementation and resistance training on cardiovascular parameters. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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Review

Jump to: Research, Other

13 pages, 1198 KiB

Open AccessReview

An Update of Clinical, Epidemiological, and Psychosocial Features in Gamma-Sarcoglycanopathy

by Naoufel Chabbi, Corrado Angelini and Alicia Aurora Rodriguez

Muscles 2023, 2(2), 164-176; https://doi.org/10.3390/muscles2020012 - 3 Apr 2023

Cited by 3 | Viewed by 2661

Abstract

Limb-girdle muscular dystrophies (LGMDs) represent a group of muscle diseases due to monogenic mutations encoding muscle proteins that are defective for heterozygous and homozygous mutations prevalent in certain regions. Advances in knowledge of their pathophysiology have shed light on these rare diseases, which [...] Read more.

Limb-girdle muscular dystrophies (LGMDs) represent a group of muscle diseases due to monogenic mutations encoding muscle proteins that are defective for heterozygous and homozygous mutations prevalent in certain regions. Advances in knowledge of their pathophysiology have shed light on these rare diseases, which were, until recently, difficult to diagnose. This paper has described the process of diagnosis in autosomal recessive limb-girdle dystrophy that in Tunisia are due to the c.521del mutation in gamma-sarcoglycanopathy and to ethnically specific mutations in other countries such as Italy. The epidemiology, pathophysiology clinical features, and the main socioeconomic needs as well as research progress are discussed. We discuss an Italian case for its psychosocial impact and socioeconomic consideration and compare this case with Tunisian patients. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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Other

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10 pages, 727 KiB

Open AccessCase Report

Two Cases of Myofibrillar Myopathies: Genetic and Quality of Life Study

by Corrado Angelini, Chiara Ceolin, Alicia Aurora Rodriguez and Vincenzo Nigro

Muscles 2023, 2(2), 177-186; https://doi.org/10.3390/muscles2020013 - 6 Apr 2023

Viewed by 2816

Abstract

We describe two cases of myofibrillar myopathies, due to different gene mutations. The first was a girl with cardiomyopathy and sensory axonal neuropathy that underwent cardiac transplantation at 15 years and suffers from rotatory scoliosis due to BAG3 mutation. The second is a [...] Read more.

We describe two cases of myofibrillar myopathies, due to different gene mutations. The first was a girl with cardiomyopathy and sensory axonal neuropathy that underwent cardiac transplantation at 15 years and suffers from rotatory scoliosis due to BAG3 mutation. The second is a male patient, with evident limb-girdle weakness since age 3. Two muscle biopsies were performed at ages 3 and 15, with muscle MRI, and LDB3 gene sequence analysis also carried out. Muscle biopsies revealed the presence of dystrophic changes in the first biopsy and myopathic abnormalities in the second, and the MRI images of the lower limbs showed an asymmetrical involvement in the thigh of quadriceps muscles and in the calf of gastrocnemius muscles. The patient was responsive to treatment with an intermittent steroid regimen and muscle-strengthening exercises. Considerations on both muscle–bone interaction and psychological and socioeconomic conditions are carried out for both cases. Full article

(This article belongs to the Special Issue Feature Papers in Muscles)

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