Biology and Life Sciences

Abstract: Osteoporosis arises from disrupted bone remodeling, and growing evidence shows that gut microbiota and their metabolites have a major influence on skeletal health through the gut-bone and gut-brain-bone axes. In this systematic review, we synthesize findings from 932 studies to identify key microbial taxa, metabolites, and signaling pathways that modulate osteoblast and osteoclast activities. Short‑chain fatty acids (SCFA), tryptophan‑derived metabolites, and β‑D‑glucuronidase-related estrogen regulation emerge as central microbial mechanisms affecting bone formation and resorption. By integrating these data with the Phylobone extracellular matrix proteins database, we highlight Osteopontin and Cathepsin K as important downstream mediators linking microbial signals to bone matrix turnover. Probiotic strains (particularly Lactobacillus rhamnosus GG and L. reuteri) show potential to improve bone health through metabolic, immune, and endocrine pathways. Together, these findings outline a mechanistic framework connecting gut function to skeletal biology and identify promising microbiome‑based targets for osteoporosis interventions.

Abstract: Background/Objectives: This study aimed to quantify the kinetic demands of multiple hops in series, movement tasks that are commonly used in strength and conditioning and physiotherapeutic practice. Focus was placed on comparing the demands of a quintuple-hop task to a triple-hop task, with particular focus on quantifying the eccentric braking stretch-load demands. Methods: Forty-four male university athletes (age 20.1 ± 1.4 years; body mass 71.2 ± 8.6 kg; stature 171.9 ± 5.1 cm) completed the hopping tasks across track-embedded force platforms, where braking and propulsion kinetics were measured across 54x track-embedded force platforms. Results: Significant (p < 0.001) averaged in-creases in maximal vertical (~32%) and horizontal braking impulses (~56%) for both TH and QH tasks were noted across hops. The last two hops of the QH task were found to have greater averaged vertical (~58%) and horizontal (~180%) stretch-load demands than the two initial hops (p < 0.001). Conclusions: This is the first study in which an extensive summary of kinetic measures for both triple and quintuple hops has been reported. The findings highlight the biomechanical, stretch-load aspects of these exercises, which can help practitioners better prescribe and program hops for injury prevention, rehabilitation, and performance enhancement.

Abstract: Background: Motor precision is a highly innate trait, while ambidexterity in high-precision tasks remains rare and biologically regulated. Few sports necessitate bilateral precision; however, the indigenous sport of picigin uniquely requires symmetrical palm-striking proficiency. Methods: This study investigated bilateral precision and ball velocity in 22 experienced players, divided into competitive (n=11) and recreational (n=11) groups. A specialized bilateral palm-precision test was developed to measure performance across both dominant and non-dominant hands. Key metrics included the asymmetry index for speed and accuracy, and the speed-accuracy trade-off (SAT). Results: Results indicate that competitors significantly outperform recreational players in both precision and velocity. Notably, the SAT analysis suggests that the dominant hand of recreational players performs at a level comparable to the non-dominant hand of competitors. While recreational players exhibited slightly lower asymmetry indices, the inter-manual gap remained stable despite years of experience. Conclusions: Findings suggest that bilateral training induces linear improvements on both sides, maintaining a constant asymmetry ratio rather than diminishing it through long-term practice.

Abstract: Dental pain due to dentine hypersensitivity or pulpitis is characterized by short or lasting episodes of pain triggered by normally innocuous stimuli originating from exposed dentine. Both represent the most frequent pain of the orofacial region. Transient receptor potential (TRP) superfamily of ion channels participates in the detection of different modalities of sensibility in the mammalian sensory teeth system, i.e., trigeminal neurons and odontoblasts. In particular, some members of the melastatin family (TRPM) serve as molecular thermal sensors, and temperature is one of the most potent stimuli in triggering dentine hypersensitivity. Here we review and update the information about the distribution of TRPM channels in the trigeminal ganglion and dental pulp cells, especially odontoblast, in humans and animal models. In addition to the well know sensory roles of TRPM, other functions such as in development and mineralization of teeth are considered.

Abstract: To maintain homeostatic conditions and optimal function during stressors, mitochondria initiate nuclear retrograde signaling. The mitochondrial Integrated Stress Response (ISR) and Unfolded Protein Response (UPR^mt) are critical quality control mechanisms activated during instances of mitochondrial perturbations. Restoration of mitochondrial homeostasis is orchestrated by three transcription factors, ATF4, CHOP, and ATF5, which upregulate protective genes to counteract stress. As the health and function of skeletal muscle is heavily dependent on a highly adaptive mitochondrial network, defining how mitochondrial health is maintained across various conditions is essential. Although several studies demonstrate the importance of these responses following instances of stress, the signaling mechanisms required to initiate such pathways remain poorly characterized in skeletal muscle. This review examines how the mitochondrial ISR/UPRmt and related transcription factors respond to organellar stress by emphasizing the molecular events that occur during exercise, aging and muscle disuse. Through consolidating the literature, this work aims to highlight the current understanding of mitochondrial stress response signaling within skeletal muscle and thus emphasize areas for future research and potential therapeutic strategies during divergent metabolic conditions.

Abstract: The teaching of human anatomy has historically relied on cadaveric dissection, atlases, and static imaging. While these approaches remain foundational, they insufficiently reflect the dynamic, bedside-oriented realities of modern clinical practice. Point-of-care ultrasound (POCUS) enables real-time visualization of living anatomy and physiology and is increasingly integral to clinical decision-making across specialties. I argue that sonographic anatomy should be incorporated longitudinally into all undergraduate medical curricula. Such integration enhances spatial understanding, reinforces clinical relevance, and accelerates the development of diagnostic reasoning. I propose a scalable, phased implementation model and address common barriers, including faculty training and resource constraints. The integration of ultrasound into anatomy education represents not an addition, but a necessary evolution.

Abstract: Elucidating the pathophysiological mechanisms of mental disorders remains a critical challenge in psychiatric research. Recent studies have highlighted the potential involvement of cytoskeletal and molecular motor abnormalities in the development of mental disorders such as schizophrenia and autism spectrum disorder (ASD). Although schizophrenia and ASD differ clinically, both disorders are increasingly regarded as neurodevelopmental conditions and share vulnerabilities in synapse formation and neural circuit maturation. This review synthesizes the latest findings on the relationship between cytoskeletal and molecular motor abnormalities and mental disorders. The cytoskeleton, composed of microtubules, actin filaments, and intermediate filaments, along with molecular motors such as kinesins, dyneins, and myosins, plays crucial roles in neurodevelopment, synapse formation, and neurotransmission. In schizophrenia, decreased expression of the microtubule-associated protein MAP2 and abnormalities in the DISC1 gene have been reported, potentially leading to dendritic morphological abnormalities and neurodevelopmental disorders. Additionally, abnormalities in molecular motors such as KIF17 and KIF1A have been implicated in schizophrenia pathophysiology. Myosin Id has been identified as a risk gene for ASD. Furthermore, abnormalities in actin-related proteins such as SHANK3 and CYFIP1 have been shown to cause synaptic dysfunction. These findings suggest that mental disorders arise from complex pathologies involving multiple cytoskeletal and molecular motor-related protein abnormalities. Future research should focus on elucidating the functions of individual proteins and adopting a comprehensive approach that includes glial cells. Advances in this field may deepen our understanding of the pathophysiological mechanisms of mental disorders and potentially lead to the development of novel therapeutic strategies.

Abstract: Post-COVID syndrome has been associated with potentially impaired exercise capacity. Here, we postulate that machine learning models trained on near-infrared spectroscopic (NIRS) signals collected during different physical activity states from four optodes over the quadriceps, using features selected by principal component analysis (PCA), can detect distinct patterns of oxygenation. These patterns differentiate post-COVID syndrome from healthy controls and are not evident from traditional analysis of NIRS signals. 228 time-series NIRS datasets from four optodes over different quadriceps regions were collected across multiple activity states in post-COVID syndrome and healthy participants. PCA was performed to reduce dimensionality and identify data patterns. K-Nearest Neighbour with Dynamic Time Warping, Canonical Interval Forests (CIF) and Convolutional Neural Network (CNN) models were trained on NIRS-derived features to classify post-COVID syndrome -related muscle abnormalities versus healthy responses. PCA revealed that tissue oxygenation index (StiO2) was the most effective parameter separating the populations, whereas the normalised total haemoglobin index (nTHI) was most sensitive to activity states. Learning models incorporating StiO2 and nTHI, exhibited excellent performance in distinguishing between populations, with CIF and CNN exhibiting best performance (Kappa>0.69, F1-score>0.85, Sensitivity>0.85, Precision>0.88, Accuracy>0.85, AUC>0.95). However, local muscle StiO2 heterogeneity and StiO2 on-transient mean response time did not show significant differences between populations. Our findings demonstrate the efficacy of learning models trained on time-series muscle oxygenation data for detecting distinct muscle oxygenation patterns in post-COVID syndrome participants. This provides a novel, non-invasive approach applicable at the individual level for identifying distinctive muscle oxygenation patterns, where traditional analytical methods lack sensitivity.

Abstract: Background: Contextual interference (CI), defined as interleaved practice, improves motor skill learning in powerlifters. However, previous protocols lacked ecological validity. This study evaluated an alternative, highly specific CI exercise (the seal row) to provide a more practical approach for powerlifting routines. Methods: Fifteen powerlifters (10 males and 5 females, age: 23 ± 2 years, 1RM: 78 ± 32 kg) were randomized in high CI group (HCI) and low CI group (LCI) undergoing a 6-week training intervention. Powerlifters were tested on their bench press exercise strength and technical execution. Technical execution was assessed using a 13-item Likert scale. Results: Strength significantly increased in both groups (F (3.42, 46.5) = 9.553, p &lt; 0.05). Global technique analysis showed a group × time interaction (F (4,952) = 2.547, p = 0.038, pes = 0.01). A significant group × time interaction occurred for scapular adduction (F (2.98, 38.76) = 4.118, p = 0.013), with the HCI group showing greater improvement. Conclusions: Alternating a primary task (bench press) with antagonist overloads (seal row) improves technical execution over six weeks without hindering strength gains. These findings support practical CI strategies in resistance training to optimize skill acquisition.

Abstract: Contemporary models of resistance training often treat repetitions within a set as interchangeable, emphasize only those performed near failure, or prescribe controlled tempos that moderate effort across repetitions. These perspectives leave unclear how moment-to-moment intent and movement quality interact to determine where fatigue and adaptation are localized. We introduce the Targeted Intensity Cumulation (TIC) model, a minimal mechanistic framework in which high voluntary intent combined with high purity technique progressively concentrates mechanical and metabolic stress within target musculature across repetitions and sets. In this formulation, the rate of performance decay (e.g., as measurable by decline in concentric velocity) serves as an observable proxy for stimulus localization. The model provides a unifying account for (1) hypertrophy equivalence across repetition ranges, (2) the continuous accumulation of training stimuli, (3) exercise-specific 'performance cliffs,' and (4) cross-load performance transfer. By shifting the focus from external load to the internal state-space of intent and constraint, TIC generates testable predictions for optimizing training execution and monitoring.

Abstract: Heat stress (HS) has emerged as a major environmental stressor, inducing oxidative stress, hepatic steatosis and impairing production performance and health in laying hens, with limited evidence-based nutritional interventions available. This study investigated the hepatoprotective effects of dietary silymarin (SIL) against chronic HS. In a 10-week trial, 252 43-week-old Hy-Line Brown hens were exposed to daily HS (32 ± 1℃, temperature-humidity index [THI] > 73) and fed either a basal diet or one supplemented with 100 mg/kg SIL. SIL significantly increased laying rate (P < 0.05) and improved albumen height, Haugh units, and shell strength by week 8 (P < 0.05). Histological analysis showed a 48% reduction in non-alcoholic fatty liver disease (NAFLD) activity score, with significantly decreased hepatic triglyceride content (P < 0.05); Oil Red O staining confirmed reduced lipid droplet accumulation. SIL restored redox balance by increasing plasma and hepatic total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px) (P < 0.05), increasing hepatic catalase (CAT) and glutathione (GSH) levels while decreasing malondialdehyde (MDA) (P < 0.05). Untargeted plasma metabolomics identified 11 key metabolites related to 2-oxoglutarate and purine metabolism, while hepatic transcriptomics revealed 835 differentially expressed genes primarily in the PPAR signaling and fatty acid biosynthesis pathways. SIL suppressed de novo lipogenesis via downregulation of ACACA and FASN, and enhanced β-oxidation through upregulation of CPT1A and ACSL1 (P < 0.05). Molecular docking and Western blotting confirmed strong SIL binding to these targets and corresponding protein changes. Correlation networks associated ACSL1 and CPT1A with improved performance and antioxidant indices, while FASN, ACACA, and xanthosine showed inverse relationships. These findings emphasize the potential of SIL as a sustainable animal nutrition antioxidant additive, which can alleviate HS induced lipid disorders in the liver of laying hens and provide insights for livestock applications.

Abstract: Model systems that mimic human cardiac structure and function are essential for the development of novel diagnostics and effective treatments for cardiovascular diseases. While non-human vertebrate models, from zebrafish to pig, remain vital to cardiovascular research, the translatability of findings to human patients is often limited. Therefore, animal experiments should be supplemented with human model systems, including human induced pluripotent stem cell-derived cells, 3D engineered constructs, and last but not least, native tissue preparations and isolated primary cardiomyocytes. However, while human myocardium remains the gold standard, human heart tissue – and particularly tissue from control hearts – remains scarce, and its use in research is generally restricted to settings where tissue has been excised from diseased or failing hearts. While it is in principle possible to use tissue from rejected non-failing donor hearts that cannot be transplanted, legal hurdles (for example in Germany) can restrict the use of non-transplanted donor organs in research. Given the challenges associated with accessing and using human tissue in biomedical research, an integrated strategy towards combining non-human vertebrate models, in silico models, and human tissue-derived models is recommended, enhancing the chances of successful research and development, and helping bridge the gap between preclinical and clinical research.

Abstract: Background: DanceSport involves intermittent high-intensity efforts that may differ between styles and partners within a dance couple. However, dance-specific relative oxygen uptake (%VO₂max) in elite Standard and Latin dancers remains insufficiently described. Objective: This study aimed to characterize relative oxygen uptake during simulated competition in elite Slovak national team dancers and to examine (i) differences between Latin and Standard styles, (ii) variability across individual dances, and (iii) sex-specific patterns. Methods: Twenty elite dancers (10 couples) were divided into Latin (n = 10) and Standard (n = 10) groups. VO₂max was determined via an incremental treadmill test. During a simulated final round, breath-by-breath gas exchange was recorded using portable spirometry. Relative oxygen uptake (%VO₂max) was calculated for each dance. Style-level differences were analyzed using a two-way ANOVA (Style × Sex), and dance-specific effects were examined using repeated-measures ANOVAs. Results: No significant differences in mean %VO₂max were observed between styles (p = .269), nor were there main effects of Sex or Style × Sex interaction (p > .05). In the Latin group, %VO₂max differed significantly between dances (p < .001), with Jive highest and Rumba lowest, without sex interaction. In the Standard group, a significant Dance × Sex interaction was observed (p < .001). Male dancers showed higher %VO₂max during Quickstep, whereas females exhibited a more uniform intensity profile. Conclu-sions: Oxygen demand in DanceSport is strongly dance-dependent. Latin dances demonstrate comparable relative intensities between sexes, whereas Standard dances show sex-specific metabolic patterns, likely reflecting distinct biomechanical roles within the partnership. These findings support dance-specific and partner-sensitive approaches to physiological monitoring and training design in elite DanceSport.

Abstract: (1) Background: As Para-Powerlifting (PP) athletes need the maximum bench press concentric strength performance during competitions, the velocity of the eccentric phase could be critical to the sport's success. (2) Methods: Through eccentric tempo modification, normative, faster, and slower bench press eccentric velocities were tested on 16 experienced PP athletes. Mean propulsive velocity (MPV), maximum velocity (Vmax), and power were measured during a single bench press set at different loads (90% and 100% of 1RM) and tempos. After the bench press set, Maximal isometric force (MIF), rate of force development (RFD), impulse, variability, and maximal average force (MAF) were obtained through an isometric bench press test. (3) Results: slower and faster tempos were not different in concentric performance than a normative tempo at the 90% 1RM load. A faster tempo generated higher MPV and Vmax than a normative one at the 100% 1RM load. A normative tempo produced higher MIF than a slower tempo, and higher impulse than a faster tempo after a 90% 1RM bench press set. (4) Conclusions: PP athletes seem to have an optimized technique in submaximal loads; however, they may need faster eccentric velocities in the 100% 1RM load to improve their concentric performance.

Abstract: Many phenomena in resistance training are often attributed to intrinsic changes within the muscles targeted for hypertrophy. Examples include rapid “newbie gains” among novices, individual differences in training outcomes, and blunted anabolic responses to protein intake in experienced lifters. These are typically interpreted as reflecting diminishing responsiveness of muscles to repeated training stimuli. This article explores an alternative framework predicated on the fact that both performance and adaptation are seldom, if ever, limited only by the target muscle but also by supporting factors, including tendons, posture-specific musculature, neural coordination, skill, etc. Because these constraints often adapt at different rates than the target muscle, disparities in adaptation can create apparent stagnation even when muscle growth potential remains. This framework explains why alternating complementary exercises can sustain progress, why trainees respond differently to the same program, and why modality comparisons often yield null or mixed results. Practically, it underscores the importance of strategic variation, complementary exercise sequencing, individualized programming, and management of facilitating factors such as nutrition and recovery.

Abstract: Testicular metabolism can be noninvasively assessed using FDG-PET/CT, which provides insights into physiological and age-related changes. Understanding normal testicular FDG uptake is essential to distinguish between benign variation and pathological findings. In this retrospective study, 80 men (mean age 54.7 years, range 26–79) undergoing PET/CT for lung nodule evaluation were analyzed, excluding individuals with testicular disease, prior surgery, or elevated blood glucose (>180 mg/dL). FDG uptake (SUV_mean) and testicular volume were measured for each testis, and correlations with age, blood glucose, and volume were assessed using standard statistical methods. The mean testicular SUV_mean was 2.62 ± 0.50, showing a significant negative correlation with age and a weak positive correlation with testicular volume. After adjusting for volume, the negative association with age persisted, while no significant relationship with blood glucose was observed. These findings indicate that physiological testicular FDG uptake gradually declines with age, reflecting both metabolic and structural alterations. Recognizing these normal patterns is critical for accurate PET/CT interpretation and reducing the risk of false-positive findings.

Abstract: Background Sugaya type III rotator cuff re-tears are defined by a supraspinatus tendon thickness reduced to 50% or less of normal. These patients often experience prolonged pain and functional impairment. When considering reoperation, the burden of a long-term rehabilitation process and high risk of re-tear poses significant challenges for both patients and surgeons. Bioinductive collagen implants possess a mechanism that promotes the formation of new tendon tissue, holding potential to accelerate recovery and reduce re-tears. However, studies applying this technique in patients with Sugaya type III re-tear have not yet been reported. This study aimed to evaluate the clinical and radiologic outcomes of applying this procedure in patients with Sugaya type III re-tear. Method: This retrospective case series (Level IV) study included 15 patients (mean age 61.7 years) with Sugaya type III re-tears confirmed by MRI. All patients underwent arthroscopic rotator cuff repair combined with biologically induced collagen implant augmentation. Clinical outcomes were assessed at preoperative, 6-month, and 12-month postoperative time points using VAS, ASES, SANE, and WORC scores. Imaging findings were assessed via MRI, measuring supraspinatus thickness, and evaluating joint range of motion (ROM) and implant failure. Thickness measurements were performed twice each by an orthopedic surgeon (15 years' experience) and a radiologist (9 years' experience), with mean values used and intra- and inter-observer reliability (ICC) calculated. Results: The average VAS score decreased significantly from 6.5 ± 1.0 to 2.1 ± 0.8 (p < 0.001), and the ASES score improved from 45.2 ± 8.5 to 78.5 ± 8.9 (p < 0.001). SANE and WORC scores also showed significant improvement from 41.0 ± 12.1 to 81.4 ± 9.8 and from 39.6 ± 10.7 to 83.3 ± 10.1 respectively (p < 0.001). Supraspinatus thickness on MRI recovered from 4.5 ± 2.2 mm to 6.9 ± 2.5 mm (p < 0.001). At the final follow-up, all patients’ recovery of full or near-full range of motion was observed, and no implant failure were observed at either 6-month or 12-month follow-ups (0%). For MRI measurements, the inter-observer ICC was 0.93 (95% CI 0.85–0.97), and the intra-observer ICC ranged from 0.94 to 0.95. This indicates a high level of reliability. Conclusion: This study represents the first application of arthroscopic reattachment combined with bioengineered collagen implant augmentation in patients with Sugaya type III rotator cuff re-tears. Short-term follow-up confirmed significant improvement in pain and function, restoration of tendon thickness, and a 0% graft failure rate. This procedure is considered a useful method for treating patients with Sugaya type III re-tear, minimizing rehabilitation periods and avoiding the risk of re-tear.

Abstract:

Background and Objectives: The thoracolumbar fascia (TLF) has been implicated in low back pain, but imaging-based characterization in specific degenerative lumbar pathologies—particularly in surgical cohorts—remains limited. To evaluate TLF thickness on Magnetic resonance imaging (MRI) and Ultrasound (US) across common lumbar pathologies, examine associations with age, body mass index, disability, and assess MRI–US agreement for TLF thickness. Materials and Methods: In this prospective single-centre cohort, adults scheduled for elective lumbar surgery underwent preoperative US (short- and long-axis at L3) and review of routine lumbar MRI (axial and sagittal T1-weighted measurements at L3) using standardized protocols. Disability was assessed using the Oswestry Disability Index (ODI). Group comparisons, correlation analyses, and intraclass correlation coefficients were used to evaluate between-diagnosis differences, patient-factor associations, and MRI–US agreement. Results: Thirty-seven patients were eligible (15 lumbar spinal stenosis, 5 discs herniations, 4 spondylolisthesis, 2 scoliosis, 9 revision surgeries, 2 trauma comparators). Median TLF thickness was 0.86 mm (0.16–1.40) on axial MRI, 1.12 mm (0.47–2.33) on sagittal MRI, 2.38 mm (1.01–5.91) on US short-axis, and 2.87 mm (1.12–5.74) on US long-axis. Axial MRI thickness differed across groups (p=0.010), driven by thinner measurements in trauma versus disc herniation (p=0.031); no significant group effects were observed on sagittal MRI or US. Age correlated positively with axial MRI thickness (p=0.021). No significant correlations were detected between ODI and TLF thickness on MRI or US. MRI–US agreement was poor, indicating the modalities are not interchangeable for TLF thickness measurement. Conclusions: TLF thickness measured on MRI and US did not consistently differentiate diagnostic groups and was not associated with disability. Thickness estimates differed substantially by modality, with poor MRI–US agreement. Larger studies with standardized acquisition and reliability testing are needed to clarify the clinical and mechanistic relevance of TLF imaging in degenerative lumbar disease and to determine whether it can support phenotype-based stratification within degenerative spine disease.

Abstract: Two leading paradigms dominate perspectives on obesity: (1) the Energy Balance Model (EBM), which views obesity as a phenomenon of essentially excess calories consumed over calories expended; and (2) the Carbohydrate-Insulin Model (CIM), which emphasizes carbohydrate-driven metabolic changes that promote fat storage. We introduce the Protein Partitioning Model (PPM) as a muscle-centric perspective on body composition. On this view, dietary protein and muscle activity can critically influence fat gain and loss – even under constant caloric intake – in ways that subsume the CIM-based mechanisms of fat-insulin dynamics. Building on comparisons with CIM, we extend PPM to a Rational Addiction framework to explore how protein and sugar consumption change over time in interaction with their biological stocks, muscle and fat, respectively, allowing total caloric intake to vary. When combined with regular resistance exercise, protein intake builds muscle, which, in turn, increases the marginal utility of protein consumption, contributing to a virtuous feedback loop of “protein addiction”, where consumption is bounded and converges on stable steady states characterised by modest changes in body composition. By contrast, sugar addiction is volatile and binge-prone, driven by insulin-mediated energy partitioning. These differences suggest that PPM offers an important angle in addition to simple EBM-based views because of the differing implications of whether caloric surpluses occur through protein or non-protein sources of energy and the motivations driving consumption behaviour. Put simply, factors promoting addiction to protein may protect against obesity arising from excessive eating in general and from high levels of carbohydrate consumption in particular.

Abstract: The axillary arch (AA), also known as Langer’s axillary arch, is the most common muscular variation encountered in the axilla. It typically arises from the latissimus dorsi and traverses the axillary fossa, often crossing anterior to the neurovascular structures before inserting into the pectoralis major or surrounding fascia. Although frequently asymptomatic, this variant may cause neurovascular compression or complicate surgical procedures involving the axilla. During routine cadaveric dissection, an axillary arch muscle was identified in a 97-year-old male donor. The muscular slip originated from the medial border of the latissimus dorsi and inserted into the trilaminar tendon of the pectoralis major, passing anterior to the axillary artery and median nerve. No additional muscular variations were observed. This report highlights the anatomical features and clinical relevance of the axillary arch and emphasizes the importance of recognizing this variation to avoid diagnostic confusion and surgical complications.