The virtual pivot point concept improves predictions of ground reaction forces.

Ground reaction forces (GRFs) are essential for the analysis of human movement. To measure GRFs, 3D force plates that are fixed to the floor are used with large measuring ranges, excellent accuracy and high sample frequency. For less dynamic movements, like walking or squatting, portable 3D force plates are used, while if just the vertical component of the GRFs is of interest, pressure plates or in-shoe pressure measurements are often preferred. In many cases, however, it is impossible to measure 3D GRFs, e.g., during athletic competitions, at work or everyday life. It is still challenging to predict the horizontal components of the GRFs from kinematics using biomechanical models. The virtual pivot point (VPP) concept states that measured GRFs during walking intercept in a point located above the center of mass, while during running, the GRFs cross each other at a point below the center of mass. In the present study, this concept is used to compare predicted GRFs from measured kinematics with measured 3D-GRFs, not only during walking but also during more static movements like squatting and inline lunge. To predict the GRFs a full-body biomechanical model was used while gradually changing the positions of the VPP. It is shown that an optimal VPP improves the prediction of GRFs not only for walking but also for inline lunge and squats.

Effectivenss of electroacupuncture for skeletal muscle pain in Parkinson's disease: a Clinical randomized controlled trial.

OBJECTIVE: To explore the effect of electroacupuncture on skeletal muscle pain in Parkinson's disease (PD). METHODS: A single-center randomized controlled trial was conducted with sixty patients with Parkinson's disease with skeletal muscle pain were randomly divided into electroacupuncture group and sham acupuncture control group with 30 patients each. The electric acupuncture group was treated with electric acupuncture, while the control group was treated with Park needle pseudoacupuncture. Both groups were treated 5 times a week for a total of 4 weeks, and both groups completed 20 treatments. King's Parkinson's Pain Scale (KPPS) and visual analog scale (VAS) were used before and after treatment to evaluate the pain degree of patients. Real-time shear wave elastography (SWE) and modified Ashworth score (MAS) were used to evaluate the changes of muscle tone. Parkinson's comprehensive Score Scale (MDS-UPDRS, including UPDRSⅡ and UPDRS Ⅲ) was used to evaluate exercise ability. Hamilton Depression Scale (HAMD) score was used to evaluate the emotional changes of patients. Spearman correlation analysis was used to explore the correlation between pain degree and muscle tone, exercise ability and emotion. RESULTS: During the study, one case fell off in the control group, and 30 cases were eventually included in the analysis and treatment group and 29 cases in the control group. After treatment, Young's modulus of biceps and quadriceps and shear wave velocity of biceps were decreased in electroacupuncture group compared with before treatment, while KPPS score, VAS score, UPDRSⅡ, UPDRS Ⅲ and modified Ashworth score were decreased, with statistical significance (P < 0.05). There was no statistical significance in control group (P > 0.05). After treatment, KPPS score, VAS score, UPDRSⅡ and UPDRS Ⅲ, MAS, HAMD score, Young's modulus of biceps and shear wave velocity in electroacupuncture group were significantly lower than those in control group (P < 0.05). Spearman correlation analysis showed that KPPS score was positively correlated with UPDRS Ⅲ (r = 0.414, P < 0.05). KPPS score was positively correlated with HAMD score (r = 0.576, P < 0.01). CONCLUSION: Electroacupuncture therapy can effectively improve skeletal muscle pain in patients with Parkinson's disease, reduce the muscle hardness of patients, improve patients' daily life ability, and improve patients' emotional disorders. The degree of skeletal muscle pain in PD patients is correlated with motor ability and emotional disorders, but there is no significant correlation between the degree of skeletal muscle pain and the muscle tone of PD patients.

Accelerated IVIM-corrected DTI in acute hamstring injury: towards a clinically feasible acquisition time.

BACKGROUND: Intravoxel incoherent motion (IVIM)-corrected diffusion tensor imaging (DTI) potentially enhances return-to-play (RTP) prediction after hamstring injuries. However, the long scan times hamper clinical implementation. We assessed accelerated IVIM-corrected DTI approaches in acute hamstring injuries and explore the sensitivity of the perfusion fraction (f) to acute muscle damage. METHODS: Athletes with acute hamstring injury received DTI scans of both thighs < 7 days after injury and at RTP. For a subset, DTI scans were repeated with multiband (MB) acceleration. Data from standard and MB-accelerated scans were fitted with standard and accelerated IVIM-corrected DTI approach using high b-values only. Segmentations of the injury and contralateral healthy muscles were contoured. The fitting methods as well as the standard and MB-accelerated scan were compared using linear regression analysis. For sensitivity to injury, Δ(injured minus healthy) DTI parameters between the methods and the differences between injured and healthy muscles were compared (Wilcoxon signed-rank test). RESULTS: The baseline dataset consisted of 109 athletes (16 with MB acceleration); 64 of them received an RTP scan (8 with MB acceleration). Linear regression of the standard and high-b DTI fitting showed excellent agreement. With both fitting methods, standard and MB-accelerated scans were comparable. Δ(injured minus healthy) was similar between standard and accelerated methods. For all methods, all IVIM-DTI parameters except f were significantly different between injured and healthy muscles. CONCLUSIONS: High-b DTI fitting with MB acceleration reduced the scan time from 11:08 to 3:40 min:s while maintaining sensitivity to hamstring injuries; f was not different between healthy and injured muscles. RELEVANCE STATEMENT: The accelerated IVIM-corrected DTI protocol, using fewer b-values and MB acceleration, reduced the scan time to under 4 min without affecting the sensitivity of the quantitative outcome parameters to hamstring injuries. This allows for routine clinical monitoring of hamstring injuries, which could directly benefit injury treatment and monitoring. KEY POINTS: • Combining high-b DTI-fitting and multiband-acceleration dramatically reduced by two thirds the scan time. • The accelerated IVIM-corrected DTI approaches maintained the sensitivity to hamstring injuries. • The IVIM-derived perfusion fraction was not sensitive to hamstring injuries.

Associations of Ultra-Processed Food Intake with Body Fat and Skeletal Muscle Mass by Sociodemographic Factors.

Background: The effects of excessive ultra-processed food (UPF) consumption on body composition measures or sociodemographic disparities are understudied in Korea. We aimed to investigate the association of UPF intake with percent body fat (PBF) and percent appendicular skeletal muscle mass (PASM) by sociodemographic status in adults. Methods: This study used data from the Korea National Health and Nutrition Examination Survey 2008-2011 (n=11,123 aged ≥40 years). We used a NOVA system to classify all foods reported in a 24-hour dietary recall, and the percentage of energy intake (%kcal) from UPFs was estimated. PBF and PASM were measured by dual-energy X-ray absorptiometry. Tertile (T) 3 of PBF indicated adiposity and T1 of PASM indicated low skeletal muscle mass, respectively. Multinomial logistic regression models were used to estimate odds ratios (OR) with 95% confidence interval (CI) after adjusting covariates. Results: UPF intake was positively associated with PBF-defined adiposity (ORper 10% increase, 1.04; 95% CI, 1.002 to 1.08) and low PASM (ORper 10% increase, 1.05; 95% CI, 1.01 to 1.09). These associations were stronger in rural residents (PBF: ORper 10% increase, 1.14; 95% CI, 1.06 to 1.23; PASM: ORper 10% increase, 1.15; 95% CI, 1.07 to 1.23) and not college graduates (PBF: ORper 10% increase, 1.06; 95% CI, 1.02 to 1.11; PASM: ORper 10% increase, 1.07; 95% CI, 1.03 to 1.12) than their counterparts. Conclusion: A higher UPF intake was associated with higher adiposity and lower skeletal muscle mass among Korean adults aged 40 years and older, particularly in those from rural areas and with lower education levels.

Relationship of protein, calcium and vitamin D consumption with body composition and fractures in oldest-old independent people.

BACKGROUND & AIM: Some studies state that the protein intake has a protective effect against bone mass loss, while others show that the combination of low calcium intake and high protein consumption increases the risk of fractures. Perhaps this phenomenon is also altered by the consumption of vitamin D after the age 80 years. This study aimed to identify if there is an association of protein, calcium and vitamin D intake with body composition and fractures in community dwelling 80 years or older independent people. METHODS: This is a cross-sectional observational analytic study. We invited community dwelling 80 years or older independent people, with chronic diseases under control, according to the scientific guidelines. The food intake was obtained through a one-day food record (FR) and Avanutri software (4.1 version) was used to calculate the intake of total calories, calcium, protein, and other food nutrients. The body composition and bone densitometry were evaluated by whole-body Dual Energy X-ray Absorptiometry (DXA). The morphometric vertebral fractures were assessed through conventional X-ray of the vertebral, level T4 to L4, on side face position - semi quantitative technique. RESULTS: One hundred and fifty-nine 80 years or older independent people, mean age 87.0 ± 3.9 years old were studied. The mean calcium intake was 834.6 ± 374.7 mg/day and vitamin D was 6.1 ± 24.3 µg/day, in both cases they were complemented by supplements to reach the recommendations. The mean protein intake was 72.9 ± 26.8 g/day, we found that 48.4% had low muscle mass; there was a frequency of 45.3% of osteoporosis; and vertebral fractures in 24.7% of them. The estimates of the logistic regression model with the outcome variable obesity and low muscle mass with reference to "low muscle mass" showed that the 80 years or older independent people who have a fracture are more likely to be obese with low muscle mass compared to those with only low muscle mass. CONCLUSION: In the studied population of 80 years or older independent people, we observed that among all the nutrients studied, only dietary protein per g/kg/day was associated with body composition and bone mineral density, but not with fracture, although the elderly who have fracture are more likely to be obese with low muscle mass compared to those not obese with low muscle mass. More studies about nutrients intakes and its relationship with muscle and bone health in this population is necessary.

Association of Muscle Mass Loss with Diabetes Development in Liver Transplantation Recipients.

BACKGRUOUND: Post-transplant diabetes mellitus (PTDM) is one of the most significant complications after transplantation. Patients with end-stage liver diseases requiring transplantation are prone to sarcopenia, but the association between sarcopenia and PTDM remains to be elucidated. We aimed to investigate the effect of postoperative muscle mass loss on PTDM development. METHODS: A total of 500 patients who underwent liver transplantation at a tertiary care hospital between 2005 and 2020 were included. Skeletal muscle area at the level of the L3-L5 vertebrae was measured using computed tomography scans performed before and 1 year after the transplantation. The associations between the change in the muscle area after the transplantation and the incidence of PTDM was investigated using a Cox proportional hazard model. RESULTS: During the follow-up period (median, 4.9 years), PTDM occurred in 165 patients (33%). The muscle mass loss was greater in patients who developed PTDM than in those without PTDM. Muscle depletion significantly increased risk of developing PTDM after adjustment for other confounding factors (hazard ratio, 1.50; 95% confidence interval, 1.23 to 1.84; P=0.001). Of the 357 subjects who had muscle mass loss, 124 (34.7%) developed PTDM, whereas of the 143 patients in the muscle mass maintenance group, 41 (28.7%) developed PTDM. The cumulative incidence of PTDM was significantly higher in patients with muscle loss than in patients without muscle loss (P=0.034). CONCLUSION: Muscle depletion after liver transplantation is associated with increased risk of PTDM development.

Hepatic and skeletal muscle tissue immunometabolism in trained rats / Inmunometabolismo del tejido hepático y muscular esquelético de ratas entrenadas / Imunometabolismo tecidual hepático e muscular esquelético de ratos treinados

ABSTRACT Introduction: Physical exercise can be an alternative for preventing and treating the harmful effects of obesity, mainly inflammatory effects on skeletal muscle and liver tissues. However, no consensus exists regarding this purpose's best physical training model. Objective: Evaluate morphological, metabolic, and inflammatory alterations in rats' skeletal and hepatic muscle tissues caused by aerobic and resistance training. Methods: 24 Wistar rats were divided into sedentary (S), aerobic (AE), and resistance training (R) groups. Blood glucose, total cholesterol, and serum triglycerides were measured periodically. After euthanasia, body mass was measured to calculate the total mass gain during the experiment. High-density lipoprotein (HDL) was measured. Adipose tissue was extracted to calculate its percentage relative to body mass and the liver, soleus, and gastrocnemius muscles for morphological analyses and concentrations of glycogen, lipids, and Tumor Necrosis Factor α (TNF-α). The Kruskall-Wallis test and Dunn's post-test were performed for statistical analysis, adopting p<0.05. Results: Both training models reduced the percentage of adipose tissue, body mass gain, and hepatic TNF-α concentration (p<0.05). AE increased serum HDL, gastrocnemius fiber diameter and reduced the fractal dimension in the soleus (p<0.05). R reduced blood glucose and serum and liver lipids, increased liver and soleus glycogen concentrations, increased gastrocnemius fiber diameter, and decreased TNF-α (p<0.05). Conclusion: Both training models reduced body mass, relative visceral adipose tissue, serum total cholesterol concentration, and liver inflammation. However, resistance training was more effective in promoting metabolic effects in the liver and skeletal muscle and reducing muscle inflammation in rats. Level of Evidence V; Expert Opinion.

RESUMEN Introducción: El ejercicio físico puede ser una alternativa para prevenir y tratar los efectos nocivos de la obesidad, principalmente los efectos inflamatorios sobre los tejidos del músculo esquelético y del hígado. Sin embargo, no existe consenso sobre cuál es el mejor modelo de entrenamiento físico para este fin. Objetivo: Evaluar las alteraciones morfológicas, metabólicas e inflamatorias del entrenamiento aeróbico y de resistencia en sobre los tejidos músculo esqueléticos y hepáticos de ratas. Métodos: 24 ratas Wistar se dividieron en grupos sedentarios (S), aeróbicos (AE) y de entrenamiento de resistencia (R). Se midieron periódicamente glucosa en sangre, colesterol total y triglicéridos. Después de la eutanasia, se midió la masa corporal para calcular la ganancia de masa total durante el experimento. Se midió la lipoproteína de alta densidad (HDL). Se extrajo tejido adiposo para calcular su porcentaje relativo a la masa corporal, así como hígado, músculos sóleo y gastrocnemio para análisis morfológicos y concentraciones de glucógeno, lípidos y Factor de Necrosis Tumoral α (TNF-α). Para el análisis estadístico fueron utilizados Kruskall-Wallis y el post-test de Dunn, adoptando p<0,05. Resultados: Ambos entrenamientos redujeron el porcentaje de tejido adiposo, masa corporal y la concentración de TNF-α hepático (p<0,05). AE aumentó el HDL sérico, el diámetro de la fibra del gastrocnemio y redujo la dimensión fractal en el sóleo (p<0,05). R redujo la glucosa en sangre y los lípidos séricos y hepáticos, aumentó las concentraciones de glucógeno hepático y sóleo, aumentó el diámetro de la fibra del gastrocnemio y disminuyó el TNF-α (p<0,05). Conclusión: Ambos modelos de entrenamiento redujeron la masa corporal, el tejido adiposo visceral relativo, la concentración sérica de colesterol total y la inflamación hepática. El entrenamiento de resistencia demostró ser más eficaz para promover los efectos metabólicos en el hígado y el músculo esquelético, además de reducir la inflamación muscular en ratas. Nivel de Evidencia V; Opinión del Especialista.

RESUMO Introdução: O exercício físico pode se apresentar como uma alternativa para prevenção e tratamento de efeitos deletérios da obesidade, principalmente efeitos inflamatórios sobre os tecidos muscular esquelético e hepático. No entanto, não há consenso quanto ao melhor modelo de treinamento físico para tal finalidade. Objetivos: Avaliar alterações morfológicas, metabólicas e inflamatórias dos treinamentos aeróbico e resistido sobre os tecidos muscular esquelético e hepático de ratos. Métodos: 24 ratos Wistar foram divididos nos grupos sedentário (S), treinamento aeróbico (AE) e resistido (R). Glicemia, colesterol total e triglicerídeos séricos foram mensurados periodicamente. Após a eutanásia, a massa corporal foi mensurada para calcular o ganho total de massa durante o experimento. A lipoproteína de alta densidade (HDL) foi dosada. O tecido adiposo foi extraído para cálculo de sua porcentagem relativa à massa corporal assim como o fígado e os músculos sóleo e gastrocnêmio para as análises morfológicas e das concentrações de glicogênio, lipídios e Fator de Necrose Tumoral α (TNF-α). Para análise estatística, foram utilizados o teste de Kruskall-Wallis e o pós-teste de Dunn, adotando-se p<0,05. Resultados: Ambos os modelos de treinamento reduziram o percentual de tecido adiposo, ganho de massa corporal e concentração hepática de TNF-α (p<0,05). AE aumentou o HDL sérico, o diâmetro das fibras do gastrocnêmio e reduziu a dimensão fractal no sóleo (p<0,05). R reduziu a glicemia e os lipídios séricos e hepáticos, aumentou a concentração de glicogênio hepático e sóleo, aumentou o diâmetro das fibras gastrocnêmicas e diminuiu o TNF-α (p<0,05). Conclusão: Ambos os modelos de treinamento reduziram a massa corporal, o tecido adiposo visceral relativo, a concentração sérica de colesterol total e a inflamação hepática. No entanto, o treinamento resistido mostrou-se mais eficaz em promover efeitos metabólicos no fígado e no músculo esquelético, além de reduzir a inflamação muscular em ratos. Nível de Evidência V; Opinião do Especialista.

Changes related to muscle autophagy after exhaustive exercise and blunt trauma / Cambios relacionados con la autofagia muscular tras ejercicio exhaustivo y traumatismo contuso / Alterações relacionadas à autofagia muscular após exercício exaustivo e trauma contuso

ABSTRACT Objective: To study the temporal changes of autophagy related factors in skeletal muscle of rats after exhaustive exercise and blunt trauma. Methods: Forty-two male SD rats were divided into 7 groups with 6 rats in each group: Quiet control group (C), immediately after exhaustive exercise (E0), 24 hours after exhaustive exercise (E24), 48 hours after exhaustive exercise (E48), immediately after blunt trauma (D0), 24 hours after blunt trauma (D24), 48 hours after blunt trauma (D48). All groups of rats were killed and samped respectively at different time points specified above, and the right gastrocnemius muscle was taken, which was divided into two parts, one for mRNAs of, Lamp-2, BNIP3 and NIX by real-time fluorescent quantitative PCR, and the other for p62 protein by Western blotting. Results: (1) Compared with group C, mRNA levels of p62, Lamp-2 and NIX in group E48 were significantly increased after exhaustive exercise(P<0.05), suggesting that autophagy increased in 48h after exhaustive exercise. (2) Compared with group C, p62mRNA and Lamp-2 mRNA levels were significantly increased immediately after blunt trauma(P<0.05) and decreased significantly in 48h after blunt trauma(P<0.05), suggesting that autophagy activity was enhanced immediately after blunt trauma and decreased in 48h after injury. Conclusions: Generally, there were differences at each recovery phase between blunt trauma and exhausted exercise models, and the basal autophagy factors and mitochondrial autophagy factors were also inconsistent. Basal autophagy factors p62 and Lamp-2 increased significantly 48 hours after eccentric exhaustive exercise and immediately after blunt trauma. Mitochondrial autophagy factor BNIP3 did not increase after exhaustive exercise and blunt trauma, but NIX only increased after exhaustive exercise. Its molecular mechanism needs to be further studied. Level of Evidence III; Therapeutic Studies Investigating the Results of Treatment.

RESUMEN Objetivo: Estudiar los cambios temporales de los factores relacionados con la autofagia en el músculo esquelético de ratas tras el ejercicio exhaustivo y el traumatismo contuso. Métodos: Se dividieron 42 ratas SD macho en 7 grupos con 6 ratas en cada grupo: grupo de control silencioso (C), inmediatamente después del ejercicio exhaustivo (E0), 24 horas después del ejercicio exhaustivo (E24), 48 horas después del ejercicio exhaustivo (E48), inmediatamente después de un traumatismo contuso (D0), 24 horas después de un traumatismo contuso (D24), 48 horas después de un traumatismo contuso (D48). Todos los grupos de ratas fueron sacrificados y rotulados, respectivamente, en diferentes momentos especificados anteriormente, y se extrajo el músculo gastrocnemio derecho, dividido en dos partes, una para los ARNm Lamp-2, BNIP3 y NIX mediante PCR cuantitativa fluorescente en tiempo real, y la otra para la proteína p62 mediante Western blotting. Resultados: (1) En comparación con el grupo C, los niveles de ARNm de p62, Lamp-2 y NIX en el grupo E48 aumentaron significativamente tras el ejercicio exhaustivo (P<0,05), lo que sugiere que la autofagia aumentó en las 48 horas posteriores al ejercicio exhaustivo. (2) En comparación con el grupo C, los niveles de ARNm de p62 ARNm y Lamp-2 aumentaron significativamente inmediatamente después del traumatismo contuso (P<0,05) y disminuyeron significativamente a las 48 horas después del traumatismo contuso (P<0,05), lo que sugiere que la actividad de autofagia aumentó inmediatamente después del traumatismo contuso y disminuyó a las 48 horas después de la lesión. Conclusión: En general, hubo diferencias en cada fase de recuperación entre los modelos de traumatismo contuso y ejercicio exhaustivo, y los factores de autofagia basal y los factores de autofagia mitocondrial también fueron inconsistentes. Los factores de autofagia basal p62 y Lamp-2 aumentaron significativamente 48 horas después del ejercicio excéntrico exhaustivo e inmediatamente después del traumatismo contuso. El factor de autofagia mitocondrial BNIP3 no aumentó tras el ejercicio exhaustivo y el traumatismo contuso, pero NIX sólo aumentó tras el ejercicio exhaustivo. Su mecanismo molecular debe investigarse con más detalle. Nivel de Evidencia III; Estudios Terapéuticos que Investigan los Resultados del Tratamiento.

RESUMO Objetivo: Estudar as alterações temporais dos fatores relacionados à autofagia no músculo esquelético de ratos após exercício exaustivo e trauma contuso. Métodos: Quarenta e dois ratos machos SD foram divididos em 7 grupos com 6 ratos em cada grupo: Grupo de controle silencioso (C), imediatamente após o exercício exaustivo (E0), 24 horas após o exercício exaustivo (E24), 48 horas após o exercício exaustivo (E48), imediatamente após o trauma contuso (D0), 24 horas após o trauma contuso (D24), 48 horas após o trauma contuso (D48). Todos os grupos de ratos foram mortos e rotulados, respectivamente, em diferentes momentos especificados acima, e o músculo gastrocnêmio direito foi retirado, dividido em duas partes, uma para mRNAs de Lamp-2, BNIP3 e NIX por PCR quantitativo fluorescente em tempo real, e a outra para a proteína p62 por imunotransferência. Resultados: (1) Em comparação com o grupo C, os níveis de mRNA de p62, Lamp-2 e NIX no grupo E48 aumentaram significativamente após o exercício exaustivo (P<0,05), sugerindo que a autofagia aumentou em 48 horas após o exercício exaustivo. (2) Em comparação com o grupo C, os níveis de mRNA de p62mRNA e Lamp-2 foram significativamente aumentados imediatamente após o trauma contuso (P<0,05) e diminuíram significativamente em 48 horas após o trauma contuso (P<0,05), sugerindo que a atividade de autofagia foi aumentada imediatamente após o trauma contuso e diminuiu em 48 horas após a lesão. Conclusão: Houve, via de regra, diferenças em cada fase de recuperação entre os modelos de trauma contuso e de exercício exaustivo, sendo que os fatores de autofagia basal e os fatores de autofagia mitocondrial também foram inconsistentes. Os fatores de autofagia basal p62 e Lamp-2 aumentaram significativamente 48 horas após o exercício excêntrico exaustivo e imediatamente após o trauma contuso. O fator de autofagia mitocondrial BNIP3 não aumentou após o exercício exaustivo e o trauma contuso, mas o NIX aumentou somente após o exercício exaustivo. Seu mecanismo molecular precisa ser investigado com mais detalhes. Nível de Evidência III; Estudos Terapêuticos que Investigam os Resultados do Tratamento.

The relationship between skeletal muscle mass and the KOSHA cardiovascular risk in obese male workers.

Background: Efforts for the prevention and management of cardiovascular diseases (CVDs) in workers have been actively pursued. Obesity is one of the important risk factors related to CVDs. Obesity has various metabolic characteristics, and some individuals can be metabolically healthy. Body composition including skeletal muscle mass is known to have protective effect in obesity. The study aims to investigate the association between skeletal muscle mass and Korea Occupational Safety and Health Agency (KOSHA) CVD risk among obese male manufacturing workers in Korea and to identify appropriate indicators of skeletal muscle mass for predicting risk of CVDs. Methods: The study was conducted on 2,007 obese male workers at a manufacturing industry aged more than 19 years. Skeletal muscle mass, skeletal muscle index (SMI), skeletal muscle mass percent (SMM%) and skeletal muscle to body fat ratio (MFR) were used to evaluate body composition and these indicators were divided into quartiles. The odds ratios (ORs) and 95% confidence intervals (CIs) for the KOSHA CVD risk groups according to quartiles of skeletal muscle mass indicators were estimated using ordinal logistic regression analysis. Results: The OR for the KOSHA CVD risk groups in the highest quartile of SMI was 1.67 (95% CI: 1.42-1.92), while the ORs for the KOSHA CVD risk groups in the highest quartiles of SMM%, SMM/body mass index (BMI), and MFR were 0.47 (95% CI: 0.22-0.72), 0.51 (95% CI: 0.05-0.76), and 0.48 (95% CI: 0.23-0.74), respectively. Conclusions: We found that high SMI increase the likelihood of high risk of CVDs, while high SMM%, SMM/BMI, and MFR lower the likelihood of high risk of CVDs. Accurate evaluation of skeletal muscle mass can help assess the cardiovascular risk in obese male workers.

Resistance training prescription for muscle strength and hypertrophy in healthy adults: a systematic review and Bayesian network meta-analysis.

OBJECTIVE: To determine how distinct combinations of resistance training prescription (RTx) variables (load, sets and frequency) affect muscle strength and hypertrophy. DATA SOURCES: MEDLINE, Embase, Emcare, SPORTDiscus, CINAHL, and Web of Science were searched until February 2022. ELIGIBILITY CRITERIA: Randomised trials that included healthy adults, compared at least 2 predefined conditions (non-exercise control (CTRL) and 12 RTx, differentiated by load, sets and/or weekly frequency), and reported muscle strength and/or hypertrophy were included. ANALYSES: Systematic review and Bayesian network meta-analysis methodology was used to compare RTxs and CTRL. Surface under the cumulative ranking curve values were used to rank conditions. Confidence was assessed with threshold analysis. RESULTS: The strength network included 178 studies (n=5097; women=45%). The hypertrophy network included 119 studies (n=3364; women=47%). All RTxs were superior to CTRL for muscle strength and hypertrophy. Higher-load (>80% of single repetition maximum) prescriptions maximised strength gains, and all prescriptions comparably promoted muscle hypertrophy. While the calculated effects of many prescriptions were similar, higher-load, multiset, thrice-weekly training (standardised mean difference (95% credible interval); 1.60 (1.38 to 1.82) vs CTRL) was the highest-ranked RTx for strength, and higher-load, multiset, twice-weekly training (0.66 (0.47 to 0.85) vs CTRL) was the highest-ranked RTx for hypertrophy. Threshold analysis demonstrated these results were extremely robust. CONCLUSION: All RTx promoted strength and hypertrophy compared with no exercise. The highest-ranked prescriptions for strength involved higher loads, whereas the highest-ranked prescriptions for hypertrophy included multiple sets. PROSPERO REGISTRATION NUMBER: CRD42021259663 and CRD42021258902.

The dorsal portion of the bovine diaphragm as a useful tissue for producing a 3D muscle scaffold.

Three-dimensional (3D) organoids are an innovative approach to obtain an in vitro model for ex vivo studies to overcome the limitations of monolayer cell culture and reduce the use of animal models. An organoid of skeletal muscle requires the presence of the extracellular matrix to represent a functional muscle in vitro, which is why decellularized tissue is an optimal choice. Various muscles have been considered to produce a muscle organoid, most from rodents or small animals, and only recently some studies have been reported on the muscles of large animals. This work presents a muscular organoid produced from the bovine diaphragm, which has a peculiar multilayered structure with different fibre orientations depending on the considered area. This paper analyses the anatomical structure of the bovine diaphragm, selects the most appropriate portion, and presents a decellularization protocol for a multilayered muscle. In addition, a preliminary test of recellularization with primary bovine myocytes was presented with the future aim of obtaining a 3D muscle allogenic organoid, completely bovine-derived. The results demonstrate that the dorsal portion of bovine diaphragm presents a regular alternation of muscular and fibrous layers and that the complete decellularization does not affect the biocompatibility. These results provide a strong foundation for the potential application of this portion of tissue as a scaffold for in vitro studies of muscle organoids.

Hematologic toxicities, sarcopenia, and body composition change in breast cancer patients undergoing neoadjuvant chemotherapy.

PURPOSE: Evaluation of body composition and sarcopenia status could provide evidence for more sensitive prediction of chemotherapy toxicities and support mitigation of the negative impacts of chemotherapy. This study evaluated associations among hematologic toxicities, sarcopenia, and body composition change in breast cancer patients undergoing neoadjuvant chemotherapy. METHODS: This retrospective cohort study employed data from 298 breast cancer patients undergoing neoadjuvant chemotherapy. We evaluated two abdominal computed tomography scans before and after neoadjuvant chemotherapy to identify body composition change. As hematologic toxicities, severe (grade 3 or 4) anemia, neutropenia, and thrombocytopenia were assessed throughout the treatment period using Common Terminology Criteria for Adverse Events (version 5.0). RESULTS: Participants experienced severe neutropenia (23.5%), anemia (7.1%), and thrombocytopenia (0.7%) during chemotherapy. After chemotherapy, the group with sarcopenia had double the anemia prevalence of the group without sarcopenia (p < 0.001). The group with anemia had significantly decreased skeletal muscle index (SMI, p = .0013) and subcutaneous fat index (SFI, p = .0008). Almost 50% of the sarcopenia group treated with an AC-T (weekly) regimen (combined anthracycline and cyclophosphamide followed by a weekly taxane) had neutropenia. Multiple logistic regression showed that the AC-T (weekly) group had higher neutropenia prevalence than other regimen groups. CONCLUSION: Our findings of higher anemia prevalence in breast cancer patients with sarcopenia and decreased SMI and SFI after neoadjuvant chemotherapy provide evidence of a relationship between anemia and body composition change. Early screening and combined consideration of body composition change, sarcopenia status, and chemotherapy regimen could improve clinical outcomes.

[Intensive care unit-acquired weakness-Diagnostic value of neuromuscular ultrasound]. / Intensive Care Unit-Acquired Weakness ­ diagnostischer Stellenwert des neuromuskulären Ultraschalls.

Intensive care unit-acquired weakness (ICUAW) is one of the most common neuromuscular complications in intensive care medicine. The clinical diagnosis and assessment of the severity using established diagnostic methods (e.g., clinical examination using the Medical Research Council Sum Score or electrophysiological examination) can be difficult or even impossible, especially in sedated, ventilated and delirious patients. Neuromuscular ultrasound (NMUS) has increasingly been investigated in ICUAW as an easy to use noninvasive and mostly patient compliance-independent diagnostic alternative. It has been shown that NMUS appears to be a promising tool to detect ICUAW, to assess the severity of muscular weakness and to monitor the clinical progression. Further studies are needed to standardize the methodology, to evaluate the training effort and to optimize outcome predication. The formulation of an interdisciplinary neurological and anesthesiological training curriculum is warranted to establish NMUS as a complementary diagnostic method of ICUAW in daily clinical practice.

Application of tenotomy on Korean native cattle (Hanwoo) with spastic paresis symptoms in the field.

Bovine spastic paresis (BSP) is a neuromuscular disorder characterized by hypertension and stiffness of hindlimb. Two Korean native cattle (Hanwoo) calves developed BSP or BSP-like symptoms, and a tenotomy of superficial tendon of medial head and deep tendon of lateral head of gastrocnemius muscle was performed for treatment. A cast was applied postoperatively to prevent muscle rupture and was removed three weeks later. The prognosis was evaluated at 3 weeks, 6 and 18 months postoperatively. Neither calf showed any other postoperative sequelae. This is the first case study to report the diagnosis, treatment, and prognosis of BSP in Hanwoo.

Association between thoracic and third lumbar CT-derived muscle mass and density in Caucasian patients without chronic disease: a proof-of-concept study.

BACKGROUND: Computed tomography (CT) is increasingly used in the clinical workup, and existing scan contains unused body composition data, potentially useful in a clinical setting. However, there is no healthy reference for contrast-enhanced thoracic CT-derived muscle measures. Therefore, we aimed at investigating whether there is a correlation between each of the thoracic and third lumbar vertebra level (L3) skeletal muscle area (SMA), skeletal muscle index (SMI), and skeletal muscle density (SMD) at contrast-enhanced CT in patients without chronic disease. METHODS: A proof-of-concept retrospective observational study was based on Caucasian patients without chronic disease, who received CT for trauma between 2012 and 2014. Muscle measures were assessed using a semiautomated threshold-based software by two raters independently. Pearson's correlation between each thoracic level and third lumbar and intraclass correlation between two raters and test-retest with SMA as proxy parameters were used. RESULTS: Twenty-one patients (11 males, 10 females; median age 29 years) were included. The second thoracic vertebra (T2) had the highest median of cumulated SMA (males 314.7 cm2, females 118.5 cm2) and SMI (97.8 cm2/m2 and 70.4 cm2/m2, respectively). The strongest SMA correlation was observed between T5 and L3 (r = 0.970), the SMI between T11 and L3 (r = 0.938), and the SMD between the T10 and L3 (r = 0.890). CONCLUSIONS: This study suggests that any of the thoracic levels can be valid to assess skeletal muscle mass. However, the T5 may be most favourable for measuring SMA, the T11 for SMI, and T10 for SMD when using contrast-enhanced thoracic CT. RELEVANCE STATEMENT: In COPD patients, a CT-derived thoracic muscle mass assessment may help identify who would benefit from focused pulmonary rehabilitation: thoracic contrast-enhanced CT conducted as part of the standard clinical workup can be used for this evaluation. KEY POINTS: • Any thoracic level can be used to assess thoracic muscle mass. • Thoracic level 5 is strongly associated with the 3rd lumbar muscle area. • A strong correlation between the thoracic level 11 and the 3rd lumbar muscle index. • Thoracic level 10 is strongly associated with the 3rd lumbar muscle density.

Association of Myosteatosis with Nonalcoholic Fatty Liver Disease, Severity, and Liver Fibrosis Using Visual Muscular Quality Map in Computed Tomography.

BACKGROUND: The association of myosteatosis measured using visual muscular quality map in computed tomography (CT) with nonalcoholic fatty liver disease (NAFLD), its severity, and fibrosis was analyzed in a large population. METHODS: Subjects (n=13,452) with abdominal CT between 2012 and 2013 were measured total abdominal muscle area (TAMA) at L3 level. TAMA was segmented into intramuscular adipose tissue and skeletal muscle area (SMA), which was further classified into normal attenuation muscle area (NAMA) and low attenuation muscle area (LAMA). The following variables were adopted as indicators of myosteatosis: SMA/body mass index (BMI), NAMA/BMI, NAMA/TAMA, and LAMA/BMI. NAFLD and its severity were assessed by ultrasonography, and liver fibrosis was measured by calculating the NAFLD fibrosis score (NFS) and fibrosis-4 index (FIB-4) scores. RESULTS: According to multiple logistic regression analyses, as quartiles of SMA/BMI, NAMA/BMI, and NAMA/TAMA increased, the odds ratios (ORs) for NAFLD decreased in each sex (P for trend <0.001 for all). The ORs of moderate/severe NAFLD were significantly higher in the Q1 group than in the Q4 group for SMA/BMI, NAMA/BMI, and NAMA/TAMA in men. The ORs of intermediate/high liver fibrosis scores assessed by NFS and FIB-4 scores increased linearly with decreasing quartiles for SMA/BMI, NAMA/BMI, and NAMA/TAMA in each sex (P for trend <0.001 for all). Conversely, the risk for NAFLD and fibrosis were positively associated with LAMA/BMI quartiles in each sex (P for trend <0.001 for all). CONCLUSION: A higher proportion of good quality muscle was associated with lower risks of NAFLD and fibrosis.

Treatment outcome of local injection of botulinum toxin for claw toe: Differences between cerebral hemorrhage and infarction.

BACKGROUND: Some patients with post-stroke claw toe respond well to botulinum toxin (BoNT) treatment while others do not. This study was designed to assess the impact of stroke type (cerebral hemorrhage and cerebral infarction) on the outcome of BoNT treatment for claw toe. METHODS: We retrospectively examined the medical records of patients who received local BoNT (onabotulinumtoxin A) injections into the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) muscles. All patients suffered stroke-related leg paralysis and spasticity. RESULTS: The study participants were 58 patients (mean age, 61.4 ± 10.3 years, ± SD) with time since stroke of 6.7 ± 4.4 years. The stroke type was cerebral hemorrhage (n = 38) and cerebral infarction (n = 20). After a total of 124 BoNT administrations with medical records entries on the subjective symptoms, the odds for symptomatic improvement was approximately 5.8 times higher in patients of the infarction group compared with the hemorrhage group (OR = 5.787, 95% CI = 2.369-14.134, p = 0. 000). Fifty-one patients (32 with cerebral hemorrhage, 19 with cerebral infarction) received the first local BoNT injection and had available medical records, analysis of which showed a significantly higher rate of symptomatic improvement in patients of the infarction group than those of the hemorrhage group (p = 0.006). After adjustment by factors known to influence treatment outcome (degree of spasticity and paralysis, BoNT dosage, and extent of FDL muscle control of toe movements), the treatment effect was predominantly higher in patients with cerebral infarction. CONCLUSION: The BoNT treatment response was better for claw toes in cerebral infarction patients than in hemorrhage patients, possibly suggesting that claw toe is associated with more severe spasticity in this group of patients.

The validation of low-dose CT scans from the [18F]-FDG PET-CT scan to assess skeletal muscle mass in comparison with diagnostic neck CT scans.

PURPOSE: Radiologically defined sarcopenia, or a low skeletal muscle index (SMI), is an emerging biomarker for adverse clinical outcomes in head and neck cancer (HNC) patients. Recently, SMI measurements have been validated at the level of the third cervical vertebra (C3) on diagnostic neck CT scans but are not yet validated on low-dose (LD) neck CT scans from the [18F]-FDG PET-CT. This hampers SMI analysis in HNC patients without a diagnostic neck CT but with a [18F]-FDG PET-CT scan. Therefore, the aim was to study whether (low) SMI based on LD CT scan from [18F]-FDG PET-CT is comparable to those derived from diagnostic neck CT scans. METHODS: HNC patients with both diagnostic CT and [18F]-FDG PET-CT of the neck were prospectively included into the OncoLifeS data-biobank. Skeletal muscle was retrospectively delineated at the level of the third cervical vertebra (C3), and (low) SMI (cm2/m2) was calculated for diagnostic and LD neck CTs. (Low) SMI from the diagnostic neck CT was considered the reference standard. Intra-class correlation coefficient (ICC), Bland-Altman plots, and Cohen's Kappa analysis were performed. RESULTS: The cohort (n = 233) mean age was 66.2 ± 12.8 years, and 74.2% of patients were male. Inter-rater reliability was excellent (ICC > 0.990, 95% confidence interval 0.975-0.996, p < 0.001). The agreement of SMI between both modalities was high according to the Bland-Altman plot (mean ΔSMI = - 0.19 cm2/m2), and there was no substantial bias. Cohen's Kappa analysis showed an almost perfect agreement of low SMI between the two modalities (κ = 0.911, p < 0.001). The position of arms didn't affect the high agreement of (low) SMI. CONCLUSION: Skeletal muscle mass, as measured with (low) SMI, remains constant irrespective of CT acquisition parameters (diagnostic neck CT scans versus LD neck scans of the [18F]-FDG PET-CT scan), positioning of arms, and observers. These findings contribute to the construction of a clinically useful radiological biomarker for SMI and therefore identify patients at risk for adverse clinical outcomes.

Effect of dexmedetomidine on tourniquet-induced skeletal muscle injury

SUMMARY OBJECTIVE: The aim of this study was to investigate whether dexmedetomidine could reduce tourniquet-induced skeletal muscle injury. METHODS: C57BL6 male mice were randomly assigned to sham, ischemia/reperfusion, and dexmedetomidine groups. Mice in the ischemia/reperfusion and dexmedetomidine groups received normal saline solution and dexmedetomidine intraperitoneally, respectively. The sham group underwent the same procedure as the ischemia/reperfusion group, with the exception of tourniquet application. Subsequently, the ultrastructure of the gastrocnemius muscle was observed, and its contractile force was examined. In addition, Toll-like receptor 4 and nuclear factor-κB expression within muscles was detected by Western blot. RESULTS: Dexmedetomidine alleviated myocyte damage and increased the contractility of skeletal muscles. Moreover, dexmedetomidine significantly inhibited the expression of Toll-like receptor 4/nuclear factor-κB in the gastrocnemius muscle. CONCLUSION: Taken together, these results demonstrate that dexmedetomidine administration attenuated tourniquet-induced structural and functional impairment of the skeletal muscle, partly through inactivation of the Toll-like receptor 4/nuclear factor-κB pathway.