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Povzetek: Evidence suggests athletes with lower baseline cognitive performance are at higher risk of musculoskeletal injuries. This prospective cohort study investigates basic and executive cognitive functions in predicting injuries in 78 professional male football (soccer) players from four Slovenian f irst league teams. Data were collected during the 2018/2019 winter break, and injuries recorded in the second half of that and the 2019/2020 season. Cognitive functions assessed by computerized tests (PsyToolkit) included psychomotor vigilance (simple, choice reaction time) and visuospatial memory (Corsi-block-tapping-test), while pen-and-paper tests assessed motor speed, visual scanning, and executive functions (TMT; Delis-Kaplan-Executive-Function-System). Forty-two players sustained at least one musculoskeletal injury (9 contact injuries), 36 remained injury-free. Logistic regression analyses indicated that none of the cognitive measures significantly influenced injury occurrence (p > 0.05). However, non-significant trends were observed for the TMT ratio score (p = 0.065, OR = 1.64), reflecting cognitive flexibility, and for TMT-A (p = 0.05, OR = 0.60), reflecting visual scanning. Specifically, players with lower cognitive flexibility showed a 64% increase in the odds of sustaining an injury, while better visual scanning performance was associated with a 40% reduction in injury odds. No significant association was found between basic or executive cognitive functions and musculoskeletal injuries in professional male football players. However, a non-significant trend suggested that lower cognitive flexibility may be associated with increased injury risk. These findings underscore the need for larger studies to better clarify the role of executive functions in assessing injury risk in football.
Ključne besede: neurocognitive testing, cognitive-motor tests, sports injury, risk screening
Objavljeno v DiRROS: 08.09.2025; Ogledov: 264; Prenosov: 126
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Povzetek: We aimed to identify early tensiomyography alterations in six muscles during a 10-day bed rest (BR10), followed by a 30-day recovery period (R+30), and to compare these changes with those observed after the 54-day COVID-19 lockdown in ten healthy males (22.9 ± 5.0 years). Tensiomyography and muscle thickness (sonography) were assessed at baseline, during bed rest, at BR10, R+30, and after the COVID-19 lockdown. Additional assessments included vertical jump performance (force plate), body composition (bioimpedance), physical activity (GPAQ), and lower back pain (VAS). By BR10, participants experienced a 1.9% body mass loss, a 3.8% increase in fat mass, and a 2.4% reduction in muscle mass. While anthropometric parameters returned to baseline by R+30, fat mass increased again by 3.9% post-lockdown. Jump height declined by 10.1% at BR10, returned to baseline at R+30, and remained stable thereafter. Muscle thickness decreased by 7.0% in the vastus lateralis at BR10 and by 10.1% post-lockdown. Tensiomyographic amplitude increased in all five leg muscles prior to BR10, recovered at R+30 and increased again after the COVID-19 lockdown, while a reduction was observed in the erector spinae within the first 48 hours, coinciding with reported lower back pain. In the erector spinae, both delay and contraction time decreased during BR10 and post-lockdown. In contrast, contraction time of the biceps femoris increased before BR10 and remained elevated post-lockdown. Overall, tensiomyographic parameters after the COVID-19 lockdown changed in the same direction as during bed rest, though to a lesser degree, make it a sensitive tool for detecting changes in muscle structural and functional quality after bed rest and reduced activity paradigms.
Ključne besede: Atrophy, Bed rest, Physical inactivity, Skeletal muscle, Tensiomyography
Objavljeno v DiRROS: 25.06.2025; Ogledov: 434; Prenosov: 0
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Povzetek: Previous studies showed that properties of higher‐threshold motor units (MUs) and neuromuscular junction (NMJ) function are preserved during short‐term disuse. This study aimed to test how a longer disuse period affects MU properties, NMJ transmission, and NMJ morphology remodeling. Nine young healthy males (age: 18‐29 years) underwent 21 days of horizontal bed rest. Pre‐ (BR0) and post‐bed rest (BR21), quadriceps maximal voluntary contraction (MVC), and size were assessed. We combined intramuscular electromyography (iEMG) and high‐density surface electromyography (HDsEMG) recordings on the vastus lateralis to assess MU properties at 25% and 50% of MVC. Muscle biopsies and blood samples were also collected. Quadriceps MVC and size decreased at BR21. We found alterations in MU properties at both contraction intensities, including reduced discharge rate, MU potential area changes, and increased complexity. NMJ transmission was found to be reduced at BR21 at 25% MVC. This functional NMJ impairment was biochemically corroborated by an increase in serum C‐terminal agrin fragment concentration, a biomarker of NMJ instability. In addition, a direct assessment of NMJ morphology revealed the presence of some denervated NMJs exclusively at BR21. In conclusion, 21‐day bed rest altered MU properties across different contraction intensities and impaired NMJ transmission with initial signs of remodeling/denervation. Disuse duration appears to be a critical factor, as previous shorter studies failed to detect some of these changes. We believe these findings are clinically relevant for disuse after trauma, surgery, or illness, and may support the development of effective countermeasures.
Ključne besede: disuse, unloading, physical inactivity, electrophysiology, electromyography
Objavljeno v DiRROS: 13.05.2025; Ogledov: 629; Prenosov: 270
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Povzetek: The neuromuscular junction (NMJ) plays a key role in modulating muscle contraction,but the impact of short-term disuse on NMJ structure and function, particularly in older humans,remains unclear. This study aimed to investigate NMJ alterations following 10 days of horizontalbed rest in 10 older males (68.5 ± 2.6 years). Before and after bed rest, vastus lateralis musclebiopsies were obtained to evaluate NMJ morphology, intramuscular EMG (iEMG) was recordedto assess NMJ function and blood samples were collected to determine circulating C-terminal agrinfragment (CAF) concentration, a biomarker of NMJ remodelling. In a sub-cohort of six participantswho had NMJs in both pre- and post-bed rest biopsies, we observed altered NMJ morphology,including reduced overlap between NMJ terminals, as well as increased endplate area and peri-meter. CAF concentration was elevated after bed rest, suggesting ongoing NMJ remodelling. iEMGanalysis showed increased motor unit potential complexity and reduced firing rate. In addition,we observed impaired NMJ transmission, inferred from increased near-fibre jiggle and segmentjitter. These findings suggest that older male individuals are susceptible to NMJ remodelling andimpaired transmission with short-term disuse, providing valuable insights into the morphologicaland functional consequences of inactivity in an ageing population. Our study highlights theimportance of developing interventions for mitigating the detrimental consequences of inactivityon neuromuscular health in older adults, which they frequently experience following injury, trauma,illness or surgery.
Ključne besede: ageing, C-terminal agrin, fragment disuse, electromyography, motor unit, NMJ unloading
Objavljeno v DiRROS: 19.03.2025; Ogledov: 740; Prenosov: 450
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Povzetek: Introduction: Sarcopenia is a multifaceted condition affecting between 10 and 16% of the global population, and although multiple classification algorithms exist, no prevalence has been reported for a representative sample of the Slovenian population. Furthermore, multiple behavioural factors, such as malnutrition, physical inactivity, sedentary lifestyle and lower cognitive function, can contribute to the risk of sarcopenia. This study aims to: a) determine sarcopenia prevalence among Slovenian older adults according to different classification algorithms, b) compare the agreement among the algorithms and c) evaluate the relationship between proposed risk factors and sarcopenia. Methods: 654 participants (≥60 years, 30.4% males) have been classified into sarcopenia groups according to eight algorithms, and agreement (Fleiss K) between them was calculated. Additionally, age, sex, nutritional status, physical activity, sedentary levels and cognitive function were assessed as sarcopenia risk/protective factors. Results: The prevalence of sarcopenia according to EWGSOP2 was 4.1%, ranging from 2.1% to 15.3%, when classified by all eight algorithms. Overall agreement between algorithms was weak (K=.429; 95% CI .414 to .444) with 0.6% of participants classified as sarcopenic by all eight algorithms. Adequate nutrition and physical activity were identified as protective factors, while age, lower cognitive function and sedentary lifestyle were considered risk factors. Conclusion: Sarcopenia prevalence among the Slovenian general population was lower than in the global population. We can conclude that different sarcopenia algorithms lead to a different prevalence of sarcopenia. It is of great importance to be cautious when comparing prevalences among studies and to further validate the classification algorithms.
Ključne besede: sarcopenia, prevalence, epidemiology, classification algorithms, risk factors
Objavljeno v DiRROS: 03.03.2025; Ogledov: 588; Prenosov: 318
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