The aim of this study was to establish the role of maturation on the development of physical performance in adolescent athletes and nonathletes. The total studied sample consisted of 231 participants (131 athletes: 72 boys with an average chronological age of 13.53 ± 0.7 and 59 girls with an average chronological age of 11.97 ± 0.8; 100 nonathletes: 47 boys with an average chronological age of 13.73 ± 0.47 and 53 girls with an average chronological age of 11.93 ± 0.33), distributed according to their biological maturity stage (Pre-, Mid-, and Post-Peak Height Velocity [PHV]) and to their gender. The assessment of physical performance was performed using the following tests: Countermovement jump (CMJ), countermovement jump with arm swing (CMJA), squat jump (SJ), five-jump test (5JT), 5 m sprint (5 m), 10 m sprint (10 m), 20 m sprint (20 m), T-test, Zig Zag, and Slalom. The differences in athletes according to biological maturity were identified in all variables except for 5 m (p = 0.33) and Slalom (p = 0.07), while in nonathletes the differences were found in 5JT (p = 0.01), 5 m (p = 0.02), 10 m (p = 0.01), and 20 m (p = 0.01) tests. Additionally, a significant interaction of gender and biological maturity was detected for CMJ (p = 0.03), CMJA (p = 0.01), and Zig Zag (p = 0.05) in athletes. The findings of the current study confirm the importance of maturity status in the assessment of physical performance. As a consequence, a more rational selection of talented athletes could be provided, also enabling the timely development of physical performance in nonathletes as a “window of opportunity”.

Keeping the head in a forward position can, in the long run, cause a postural disorder termed upper crossed syndrome - UCS. Upper crossed syndrome is defined as overactivity, or tightening, of the upper trapezius, major pectoralis and levator scapulae, combined with a weakened rhomboid, serratus anterior, middle and lower trapezius, as well as deep cervical flexors. This posture can result in neck pain, as well as upper back pain. The syndrome has been exacerbated with technological advancement, and the ever-increasing use of computers and smartphones. It affects school-age children, university students, as well as employees who work in an incorrect position or repeat the same actions throughout their working day. Physical exercise, namely, strength and stretching exercises, is one of the possible methods of correcting this postural disorder. Therefore, the objective of this study is to conduct a systematic review of studies to date in order to determine the effects of implementing different exercise programs on the treatment of upper crossed syndrome. The analyzed scientific papers were collected by searching online databases of electronic academic journals: Google Scholar, PubMed, Wolters Kluwer. The review focused on papers published between 2000 and 2019. Key words used for searching the databases included: upper crossed syndrome, effects, exercise program. Studies were included based on meeting the following criteria: examining the effects of different exercise programs on upper crossed syndrome, as well as on reducing neck and upper back pain, and improving functional ability. Based on the criteria set, a total of 15 studies were included in the final analysis. The final analysis established that upper crossed syndrome was affected most favorably by programs containing strength and stretching exercises, when these were administered over a 4-week period, with a minimum weekly frequency of 3 practice sessions

Carbon tetrachloride (CCl₄) is a toxic compound that causes severe oxidative stress and inflammation in skeletal muscles, resulting in structural damage, mitochondrial dysfunction, and impaired contractile function. While CD45 and melatonin (MLT) are implicated in immune modulation and antioxidative defense, their precise roles in mitigating CCl₄-induced muscle damage remain incompletely understood, warranting further investigation. This study used 24 Wistar rats divided into four groups to evaluate the effects of MLT on CCl₄-induced muscle inflammation. The first group was used as a control group, the second received only MLT (50 mg/kg), and the third group received CCl₄, while the fourth group received MLT (50 mg/kg) and CCl₄. Muscle tissues, obtained 24 h after the commencement of the experiment, were analyzed using biochemical assays for inflammatory markers, histological staining, and immunohistochemistry to assess structural and cellular changes. CCl₄ exposure significantly increased NF-κB activity, nitric oxide levels, iNOS expression, and CD45-positive immune cell infiltration in skeletal muscles, indicating heightened inflammation and oxidative stress. Pretreatment with MLT markedly reduced these inflammatory markers, restoring damaged tissue and diminishing immune cell infiltration. Histological analyses confirmed reduced inflammatory cell presence and tissue damage in MLT-treated animals, highlighting its protective effects. Melatonin demonstrates significant protective effects against CCl₄-induced skeletal muscle damage by reducing inflammation, oxidative stress, and immune cell infiltration, highlighting its potential as a therapeutic agent.

Background/Aim. There is a reduction of the psoas muscle with aging, and histopathological analysis (HPA) on postmortem material also shows its significant changes with advancing age. The aim of this study was to determine the presence and distribution of types I and II muscle fibers in the human psoas muscle in individuals of different ages and genders. Methods. The material consisted of tissue samples of the right iliopsoas muscle taken from 30 adult cadavers (18 males and 12 females), aged from 30 to 90 years, divided into three age groups. The material was obtained from the Institute of Forensic Medicine, Faculty of Medicine, University of Nis, Serbia. Hematoxylin and eosin (H&E) staining was used in the H PA of muscle cells. Results. The values of astereological parameters (area, perimeter, and Feret's diameter) of type I and type II muscle fibers were greater in male cases in comparison with female ones, although with no statistically significant difference. Based on the histochemical and morphometric analysis, it was concluded that, after 70 years of life, a loss of type II muscle fibers occurred, which was more conspicuous in female cases. Conclusion. During aging, the loss of type II muscle fibers, as well as the atrophy of type I and type II muscle fibers, demonstrate similar dynamics in both genders.

Sarcopenia is an epidemic that has been recognized only recently, presenting a threat to the functional independence and quality of life of the elderly. Sarcopenia is defined as a loss of muscle mass in combination with changes in muscle quality and physical function. Common causes of sarcopenia are the aging process, an imbalance of sex hormones, lack of physical activity or chronic diseases, which is why sarcopenia, apart from the elderly, can also occur in the younger population. Both dimensions of sarcopenia, quantitative, skeletal muscle loss, and qualitative, loss of quality of life and disability, should be considered when creating and designing preventive and therapeutic measures. There are quick and simple tests for the diagnosis of sarcopenia, but they are still not sufficiently recognized and regularly used as part of physiotherapy assessment.