INTRODUCTION: This study aimed to assess the impact of midline lumbar fusion with cortical bone trajectory screws (MIDLF/CBT) on the multifidus muscles, focusing on the evaluation of their postoperative atrophy. CLINICAL RATIONALE FOR THE STUDY: MIDLF/CBT is a relatively new technique increasingly used to treat spinal instability. Despite its reduced invasiveness compared to traditional posterior lumbar interbody fusion with traditional pedicle screws (PLIF/TP), concerns remain about potential damage to the multifidus muscles that are crucial for spinal stability. Understanding the extent of muscular atrophy post-MIDLF/CBT is vital for improving surgical outcomes, and potentially patient rehabilitation strategies. MATERIAL AND METHODS: This study retrospectively analysed preoperative and postoperative MRI scans of patients who underwent MIDLF/CBT for degenerative segmental spondylolisthesis. The bilateral width of the multifidus muscles at the operated segment and adjacent segments was measured using axial T2-weighted MRI scans. Statistical comparisons were made using a paired t test, with significance set at p < 0.05. RESULTS: The study included 16 patients with an average age of 57 ± 10 years, 10 of whom (62.5%) were women, and featured a mean follow-up period of 37 ± 25 months. Postoperative measurements showed a significant reduction in the width of the multifidus muscles at the operated segment (mean difference -3.3mm, p = 0.02) and the inferior adjacent segment (-7.4 mm, p < 0.01). A decrease in muscle width at the superior adjacent segment was also observed, although this was not statistically significant. CONCLUSIONS AND CLINICAL IMPLICATIONS: Our study concluded that MIDLF/CBT results in significant multifidus muscle atrophy at and below the operated segment, potentially impacting postoperative rehabilitation and recovery. These findings highlight the need for further research comparing MIDLF/CBT to other spinal stabilisation techniques. Additionally, incorporating functional electromyographic assessments of paraspinal muscles could provide deeper insights into the long-term consequences of spinal surgeries and helpdevelop new approaches and strategies to mitigate paravertebral muscles atrophy, thus enhancing patient outcomes.

• Klíčová slova
• cortical bone trajectory, midline lumbar fusion, multifidus muscles, spinal fusion, spinal instability, spinal stabilisation,
• MeSH
• bederní obratle * chirurgie   MeSH
• dospělí MeSH
• fúze páteře * škodlivé účinky   metody   MeSH
• hluboké zádové svaly * diagnostické zobrazování   patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• pedikulární šrouby škodlivé účinky   MeSH
• retrospektivní studie MeSH
• senioři MeSH
• spondylolistéza * chirurgie   MeSH
• svalová atrofie * etiologie   diagnostické zobrazování   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Fifty male 90-day-old Hyplus rabbits (PS19 × PS40) were slaughtered (carcass weight: 2126 ± 316.1 g) to determine the effect of post-mortem ageing methods (wet vs dry) and ageing period (7 or 14 days) on the physicochemical characteristics and sensory properties of the longissimus thoracis et lumborum (LTL) muscle. Of the 50 carcasses, 10 were used for physicochemical meat quality assessment on 24 h post-mortem (D1). The remaining carcasses were assigned to either wet ageing (deboned muscles in vacuum-packaging) or dry ageing (whole carcass), for 7 "D7" or 14 "D14" days (n = 10 per treatment combination). Physicochemical and sensory analyses were performed after each ageing period. Results revealed that wet-aged LTLs were lighter in colour (L*) than the dry-aged LTLs, regardless of the ageing period. The wet-aged samples also had the highest a* values (redness) on D14 than all other treatments. Cooking loss percentages were greater in wet- than dry-aged meat on D14, but did not differ on D1 and D7 of wet ageing. Shear force decreased from D1 to D7 of ageing, regardless of the method used, and then stabilised. The dry-aged meat on D14 exhibited the lowest moisture content and the highest ash content, whilst the greatest malondialdehyde concentration was reported on D7 for dry-aged meat corresponding with its higher scores for off-odour intensity by the sensory panel. Whilst no significant differences were noted for overall acceptance on D7, the positive flavour development during dry ageing after 14 days was favourably evaluated by the panellists.

• Klíčová slova
• Cooking loss, Flavour, Malondialdehyde, Off-odour, Vacuum packaging,
• MeSH
• barva MeSH
• chuť MeSH
• kosterní svaly chemie   MeSH
• králíci MeSH
• lidé MeSH
• manipulace s potravinami * metody   MeSH
• maso * analýza   MeSH
• posmrtné změny MeSH
• vaření MeSH
• voda analýza   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• voda MeSH

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have transformed the management of obesity, demonstrating significant efficacy in inducing weight loss and improving metabolic parameters. However, emerging clinical and paraclinical evidence suggests that these agents may also contribute to an unintended reduction in skeletal muscle mass, potentially exacerbating or precipitating sarcopenic obesity, particularly in older or frail individuals with limited muscular reserves. This review critically examines current data on the effects of GLP-1 RAs on body composition, explores the underlying pathophysiological mechanisms of skeletal muscle wasting, and offers evidence-based strategies for attenuating these potential adverse outcomes. While GLP-1 RAs therapy remains central to obesity management, optimizing its use through early recognition and management of associated risks is essential to preserve muscular health, patient functional status and quality of life.

• Klíčová slova
• GLP-1 receptor agonists, Muscle mass, Obesity, Sarcopenia, Skeletal muscle loss, Weight loss,
• MeSH
• agonisté receptoru pro glukagonu podobný peptid 1 * škodlivé účinky   farmakologie   MeSH
• hmotnostní úbytek MeSH
• hypoglykemika škodlivé účinky   farmakologie   MeSH
• kosterní svaly * účinky léků   MeSH
• látky proti obezitě škodlivé účinky   farmakologie   MeSH
• lidé MeSH
• obezita farmakoterapie   MeSH
• sarkopenie * chemicky indukované   MeSH
• složení těla MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• agonisté receptoru pro glukagonu podobný peptid 1 * MeSH
• hypoglykemika MeSH
• látky proti obezitě MeSH

BACKGROUND: This case-control study aimed to quantitatively assess the orbicularis oris muscle (OOM) in children with unilateral cleft lip and palate (UCLP) after primary lip repair using high-resolution ultrasonography, and to compare these measurements with children presenting isolated cleft palate (CP) without lip involvement. METHODS: For this, 12 infants with UCLP who had undergone primary lip repair at 4-5 months of age were examined during subsequent palatoplasty at 9-12 months. They were compared to eight age-matched controls with isolated CP. Using a 22 MHz "hockey stick" transducer under general anaesthesia, muscle thickness (MT), height (MH), and cross-sectional area (CSA) of the OOM were measured on both sides of the upper lip. RESULTS: The cleft side of the study group showed a significantly reduced CSA compared to the non-cleft side (p = 0.05), while MT was lower but not statistically significant. When compared with the control group, the cleft side showed significantly smaller CSA (p = 0.02) and MT (p = 0.05). No significant differences were observed between the non-cleft side and the control group, indicating normal muscle development on the unaffected side. CONCLUSIONS: Ultrasound proved to be a safe, reliable, and accessible tool for evaluating perioral muscle morphology in infants. The findings indicate persistent hypoplasia of the OOM on the cleft side post-repair, while the non-cleft side exhibits regular growth. These results may inform surgical technique selection and underline the potential of ultrasound for longitudinal studies. Future research could further enhance our understanding of muscle development and surgical outcomes in cleft patients.

• Klíčová slova
• Case-control study, Cleft lip, Cleft palate, Facial growth, Muscle morphology, Orbicularis oris muscle, Ultrasonography,
• MeSH
• kojenec MeSH
• lidé MeSH
• obličejové svaly * diagnostické zobrazování   MeSH
• rozštěp patra * chirurgie   diagnostické zobrazování   MeSH
• rozštěp rtu * chirurgie   diagnostické zobrazování   MeSH
• studie případů a kontrol MeSH
• ultrasonografie MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

This study investigates the passive viscoelastic properties of cardiac muscle by introducing a theoretical model that explains the observed power-law kinetics of murine cardiac trabeculae passive stress decay. The model accounts for two parallel processes contributing to passive mechanics: an elastic component and a viscoelastic component designed to simulate stress/strain-mediated unfolding of serial domains in the titin molecule. Under stress, serial globular domains within the elastic region of the titin molecule reversibly unfold. This unfolding phenomenon contributes to both hysteresis (a lag in stress between loading and unloading) and preconditioning effects in simulated mechanics. Experimental evidence indicates that stress relaxation in cardiac muscle follows a power law and that the muscle's non-linear stress-strain relationship and hysteresis behaviour are calcium-dependent. To analyse these phenomena, we simulate the apparent viscous element as a mesoscopic-scale ensemble of chains, each composed of serial globular domains that unfold in a stress-dependent manner. The observed increase in passive tension with increased Ca2+ concentration is attributed to Ca2+-mediated: (1) PEVK attachment to actin; (2) stiffening of the proximal element; and (3) stabilization of folded conformations of serial domains in the titin chain. Although the model was developed to represent the behaviour of titin, it equivalently represents any contributing process involving a linked series of domains that undergo stress-mediated unfolding. By providing a unified basis for the observed viscoelastic and preconditioning effects, calcium dependency, and power-law stress relaxation phenomena, this study offers a novel theoretical basis for understanding and simulating the role of titin in striated muscle mechanics. KEY POINTS: Passive stress relaxation of cardiac muscle follows a power-law decay, a phenomenon that is explained using a theoretical model of dynamic unfolding of globular domains along polymer chain. The theoretical model simulates the behaviour of titin, a giant sarcomere protein linking myosin thick filaments to the Z disk and providing passive restoring force during muscle stretch. The theoretical model is able to account the observed effects of Ca2+ on the effective viscoelastic passive mechanics of cardiac muscle. This model provides a theoretical basis for understanding passive viscocelastic properties and titin's role in striated muscle mechanics.

• Klíčová slova
• calcium, cardiomyocyte, model, power law, titin, viscoelasticity,
• MeSH
• biomechanika MeSH
• konektin metabolismus   fyziologie   MeSH
• mechanický stres MeSH
• myokard * metabolismus   MeSH
• myši MeSH
• pružnost MeSH
• vápník * metabolismus   fyziologie   MeSH
• viskozita MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• konektin MeSH
• vápník * MeSH

Euler and Cardan angles representation in biomechanical analysis allows straightforward description of joint rotations. However, application of Euler or Cardan angles can be problematic due to a singularity called gimbal lock. Quaternions offer an alternative way to describe rotation that avoids this problem, but they are not commonly used in biomechanics as they are complex and not inherently intuitive, specifically in dynamic models actuated by muscles. This study introduces a mathematical framework for describing muscle actions in dynamic quaternion-based musculoskeletal simulations. The proposed method estimates muscle torques in a quaternion-based musculoskeletal model. Its application is shown in a three-dimensional double-pendulum system actuated by muscle elements. Furthermore, the transformation of muscle moment arms obtained from muscle paths based on Euler or Cardan angles into a quaternion-based description is presented. The proposed method is advantageous for dynamic modeling of musculoskeletal models with complex kinematics and joints with large ranges of motion like the shoulder joint.

• Klíčová slova
• Biomechanics, Moment arm, Musculoskeletal modeling, Quaternion,
• MeSH
• biologické modely * MeSH
• biomechanika MeSH
• kosterní svaly * fyziologie   MeSH
• lidé MeSH
• počítačová simulace MeSH
• ramenní kloub * fyziologie   MeSH
• rozsah kloubních pohybů fyziologie   MeSH
• svalová kontrakce * fyziologie   MeSH
• točivý moment MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND&AIMS: Obesity and sarcopenia are major health concerns, particularly among older populations. Dietary protein may help preserve muscle mass and function, but high-protein diets, especially from animal sources, may also increase adipose mass. We investigated associations of total, animal, and plant protein intake with body composition trajectories, sarcopenia, and sarcopenic obesity. METHODS: We included 4576 participants (mean age 65.1 years, 56 % women) from the population-based Rotterdam Study. Dietary protein was measured using food-frequency questionnaires at baseline (2004-2009). Body composition was measured every 4-5 years using dual X-ray-absorptiometry. Handgrip strength (HGS) was assessed starting 2006 using a hydraulic dynamometer. Sarcopenia was determined based on low appendicular skeletal muscle and HGS; and sarcopenic obesity risk based on measures of lean mass, HGS and body fat. Analyses used linear mixed models and generalized estimate equation models. RESULTS: Higher total protein intake was associated with increased BMI over time (mean difference [95 %-confidence interval (CI)]: 0.86 kg/m2 [0.01,1.71] per 5E% increase), and increased fat-mass index (1.33 [0.67,1.99]), body-fat-percentage (4.54[2.76,6.31]), and both gynoid and android fat percentage. Higher protein intake was also associated with a higher sarcopenic obesity risk (-0.85[-1.5,-0.2]), but with a lower sarcopenia risk (odds ratio: 0.62 [0.43,0.90]). These associations were mainly driven by animal protein. CONCLUSION: Higher protein intake, particularly from animal food sources, is protective against sarcopenia but also linked to a higher obesity risk. A balanced protein intake advice for older persons should be formulated based on individual needs and health status to prevent sarcopenia, obesity, and sarcopenic obesity.

• Klíčová slova
• Body compositions, Dietary protein intake, Longitudinal cohort study, Sarcopenia, Sarcopenic obesity,
• MeSH
• dieta * MeSH
• dietní proteiny * aplikace a dávkování   MeSH
• index tělesné hmotnosti MeSH
• kosterní svaly MeSH
• lidé středního věku MeSH
• lidé MeSH
• obezita * epidemiologie   MeSH
• prospektivní studie MeSH
• sarkopenie * epidemiologie   MeSH
• senioři MeSH
• síla ruky MeSH
• složení těla * MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Nizozemsko epidemiologie   MeSH
• Názvy látek
• dietní proteiny * MeSH

INTRODUCTION: Ultrasonography is a non-invasive and safe method for assessing muscle morphology. Among its parameters, echo intensity (EI), derived from grayscale image analysis, has emerged as a promising indicator of muscle quality and intramuscular fat infiltration. This study aims to validate EI as a marker for evaluating muscle quality in a population of Czech children, through integration with gold-standard assessments of muscle strength and body composition. The primary aim of this study is to assess the reliability and construct validity of quadriceps muscle EI using ultrasound as a proxy measure of morphological muscle quality in children aged 10-14 years. METHODS AND ANALYSIS: Children aged 10-14 years will undergo ultrasound assessment of the quadriceps femoris (QF). EI will be derived from longitudinal scans of each QF head and the cross-sectional area (CSAQF) from panoramic mid-thigh images. Muscle function will be assessed as maximal voluntary contraction (MVC) of isometric knee extension with muscle quality expressed as MVC/CSAQF. A 30 s sit-to-stand test (30STS) will be used as an additional functional measure. EI reliability (intra-rater, inter-rater and test-retest) will be evaluated with intraclass correlation coefficients (ICC), Bland-Altman plots and complementary indices. Exploratory known-groups validity will be tested by comparing EI between weight-status groups. Control variables include dual-energy X-ray absorptiometry (DXA)-derived body composition, skeletal age (as determined by DXA hand scans) and physical activity (assessed using 7-day accelerometry).This study will include 200 children (100 girls and 100 boys) aged 10-14 years using an a priori power analysis based on the primary objective of assessing construct validity through multiple linear regression, assuming an alpha level of 0.05 and 80% power. Participants will be recruited from paediatric outpatients of the Paediatric Obesity Clinic and individuals reached through a recruitment campaign. Inclusion criteria require general good health, while exclusion criteria include a history or symptoms of cardiovascular, pulmonary, metabolic or neurological disease, as well as the use of over-the-counter or prescribed medications. Informed consent and assent will be obtained from all participants.Reliability of ultrasound-derived EI will be assessed for intra-rater, inter-rater and test-retest agreement using ICC coefficients, Bland-Altman plots and complementary indices such as SE of measurement, coefficient of variation and minimal detectable change at 95% CI, following Consensus-based Standards for the selection of health Measurement Instruments guidelines. Construct validity will be examined by modelling associations between EI and functional muscle quality (MVC/CSAQF), with 30STS as an additional functional measure. Known-groups validity will be tested by comparing EI across weight groups, using generalised linear regression models adjusted for skeletal age, body composition and physical activity. All validity analyses will be conducted separately for girls and boys. Ultrasound-derived EI of the QF is expected to show high reliability (ICC≥0.80) and acceptable test-retest reproducibility. Construct validity should be supported by moderate associations with functional muscle quality (MVC/CSAQF), while known-groups validity is expected to reveal higher EI values in children with obesity and/or insufficient physical activity. ETHICS AND DISSEMINATION: The study will be conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of the Faculty of Physical Education and Sport, Charles University (EK 101/2024). Written parental consent and verbal assent from children will be obtained, with all data handled confidentially and anonymised. Results will be disseminated transparently to participants and their families in line with ethical principles of respect, beneficence and justice. TRIAL REGISTRATION NUMBER: NCT06792279.

• Klíčová slova
• Child, Obesity, Ultrasound,
• MeSH
• čtyřhlavý sval stehenní * diagnostické zobrazování   fyziologie   MeSH
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• pozorovací studie jako téma MeSH
• průřezové studie MeSH
• reprodukovatelnost výsledků MeSH
• složení těla MeSH
• svalová síla * fyziologie   MeSH
• ultrasonografie metody   MeSH
• validační studie jako téma MeSH
• výzkumný projekt MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• protokol klinické studie MeSH
• Geografické názvy
• Česká republika MeSH

Clinically relevant variations in the area of the groove for the ulnar nerve include accessory muscles, accessory bones, and fibrous structures. Accessory muscles involve the epitrochleoanconeus muscle, chondroepitrochlearis muscle, and high origin of the pronator teres muscle. The nerve can also be compressed by the medial head of the triceps brachii muscle. Fibrous structures are found proximally, distally to the cubital tunnel, or directly at the location of the cubital tunnel and can cause compression of the ulnar nerve. Structures located proximally to the cubital tunnel include the medial intermuscular septum of the arm and Struthers' arcade. The roof of the cubital tunnel is formed by Osborne's ligament, which can cause compression of the ulnar nerve. Its absence is a predisposing factor for nerve dislocation. Among the bony structures, the clinical significance lies in the variability of the depth of the groove for the ulnar nerve. A shallow groove is a predisposing factor for compression of the ulnar nerve, especially during elbow flexion, which can lead to its subluxation or dislocation. The ulnar nerve itself also shows considerable variability. The ulnar nerve gives off branches inner-vating the joint capsule and motor branches for the both heads of the flexor carpi ulnaris muscle and a part of the flexor digitorum profundus muscle. Articular branches can hinder sufficient mobilization of the nerve during transposition, which can be over-come by intraneural dissection. During transposition, it is important to protect the motor branches to prevent paresis of the innervated muscles. The variability of anatomical structures in the groove for the ulnar nerve is cru-cial for clinical practice, as it can complicate surgical approaches to the elbow, limit ulnar nerve transposition, or contribute to the development of cubital tunnel syndrome.

• Klíčová slova
• accessory bones, accessory muscles, cubital tunnel syndrome, ulnar nerve,
• MeSH
• kosterní svaly MeSH
• lidé MeSH
• loket * chirurgie   inervace   MeSH
• loketní kloub * chirurgie   inervace   MeSH
• nervus ulnaris * anatomie a histologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Ruptures of the distal tendon of the biceps brachii muscle usually require surgical treat-ment to restore strong elbow flexion and forearm supination. However, the surgical procedure carries a risk of injury to neurovascular structures adjacent to the insertional tendon, and its success relies on respecting the original anatomical relations during reconstruction of the tendon. The aim of this article is to present a compendious review of relevant anatomy and practical notes which may enhance the optimal functional outcomes. Structured discussion on morphological aspects of the insertional tendon and its topography in relation to osseous and soft-tissue structures is presented. Moreover, attention is paid to technical aspects of implantation of fixation devices, so that physiological and anatomical reconstruction can be assured. This paper contains numerous schematic drawings to demonstrate the surgically relevant anatomy.

• Klíčová slova
• biceps brachii muscle, complication, complications, distal biceps tendon rupture, surgical anatomy,
• MeSH
• kosterní svaly * anatomie a histologie   chirurgie   MeSH
• lidé MeSH
• poranění šlachy * chirurgie   MeSH
• šlachy * anatomie a histologie   chirurgie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH