Vitamin D deficiency is a worldwide epidemic, with well known impacts on calcium metabolism and bone health, but increasingly recognized associations with chronic health problems such as bowel and colonic cancer, arthritis, diabetes and cardiovascular disease. In recent years in the Sports Medicine literature, there has been an increased focus on the potential impact that inadequate Vitamin D levels may have on athletic performance. In the early 20th Century, athletes and coaches felt that ultraviolet rays had a positive impact on athletic performance, and while remaining limited, evidence is accumulating to support this view. Muscle structure and function is recognised to play a key role in athletic performance, and both cross-sectional and longitudinal studies allude to a functional role for Vitamin D in muscle. The identification of the Vitamin D receptor in muscle tissue provides a direct pathway for Vitamin D to impact upon Skeletal Muscle structure and function. This review focuses on the current understanding of the action of Vitamin D within skeletal muscle tissue, and the potential impact on performance.

Core stability is the ability to control the position and motion of the trunk over the pelvis and legs to allow optimum production and transfer of force to the terminal segment in sporting activities. The role of core stability in lower extremity performance has been evaluated in some studies. However، results of such studies contradict each other. In this respect، it has been shown that studying the effect of core muscle fatigue on lower extremity performance can provide useful information about the role of core stability in lower extremity performance. Therefore، the purpose of this study was to investigate the effect of core muscle fatigue on measurements of lower extremity functional performance in male athletes. Thirty-four healthy male Physical Education and Sport Sciences students did the lower extremity functional performance tests including Y balance، side-to-side hop، figure-eight hop and triple hop in non-fatigued condition during one session. In the second session، at first، athletes participated in the core fatigue protocol consisting of seven exercises and immediately did the lower extremity functional performance tests. Paired t-test was used to compare the results of the lower extremity functional performance tests before and after core fatigue. Core fatigue protocol caused significant reduction in the scores of all lower extremity functional performance tests including Y balance، side-to-side hop، figure-eight hop and triple hop (p = 0. 001 for all tests). From this study’s result، it can be concluded that core muscle function affects lower extremity performance، as core muscle fatigue resulted in decreased scores in all lower extremity functional performance tests in this study. Given the possibility that core muscles may become fatigued during long sporting events، training programs which increase core muscle endurance and improve their ability to resist fatigue، could probably be suggested as a way to prevent reduction of lower extremity performance during prolonged sporting activities.

Youth swimming performance may be influenced by anthropometric, physiology, and biomechanical factors. The purpose of this study was to analyze the relationships between 50-m front-crawl swimming performance and relevant anthropometrical (body height, body mass, body mass index, arm span, shoulders width, thigh, leg and upper arm lengths), muscle architectural (muscle thickness, pennation angle, and fascicle length) and biomechanical (stroke rate, stroke length, and stroke index) parameters in male young swimmers, with 13.86±0.86 years of age (n = 23). Multiple regression analysis was used to examine the variance of the 50 meters front-crawl. Results indicate that stroke index, muscle thickness of Vastus Lateralis, and stroke length explained %89 (p <. 01) of 50-m front-crawl swimming performance variability in these young male swimmers, and stroke index was the best single predictor of swimming performance (R2=0.519, p<0.001). To conclude, performance of young male swimmers in the 50 meters front-crawl is determined predominantly by biomechanical and muscle architectural factors, and must be considered when predicting success in young swimmers.

The aim of this study was to evaluate the effects of physical exercise during Inra- Dialysis on muscular function (muscle strength, muscle atrophyIndex, muscle cramps) and physical performance (2-minute walk test) in hemodialysis patients.In this study, 30 hemodialysis patients (Age: 45± 3.4 years, weight: 72± 6.7 kg and disease history: 6±1/2 years) who had to do dialysis three times a week were selected and divided randomly into two groups one as experimental and a control.Data by 2-minute walk testto measure physical performance, anthropometry and skinfold method calf muscle area to measure muscular atrophy, takeoff and landing tests on a chair to measure muscle strength and cramps were collected through a questionnaire. Exercise using a bicycle Motomed Viva1 during dialysis, 5 months, three 60-minute sessions per week, for the experimental group was designed.After data collection, data was analyzed with ANCOVA by using SPSS18 at a significance level ofα= 0/05.The results showed ignificant difference After the exercise, there was a significant increase in physical performance and muscle strenght and significant decrease in progress of the muscle atrophy and cramp in case group)P>0/05(. But In the control group, a significant decrease in physical performance)P>0/05(and muscle strength, muscle atrophy, muscle cramps (severe) showed no significant difference)P<0/05(.According to the results, exercise in hemodialysis centers can be considered as a therapeutic intervention and helping patients back to life before the disease.

Freestyle wrestling requires precise and coordinated movement execution, with the Double-Leg Attack technique playing a crucial role in gaining an advantage. Understanding the underlying mechanisms and effects of specialized wrestling training is essential for optimizing performance. Muscle synergy or modular movement control involves coordinated patterns of muscle activation and the organization of muscles into functional units or modules. Exploring these concepts in freestyle wrestling can provide insights into optimizing movement coordination and performance outcomes by studying the synergistic interaction of different muscles. This study  investigates the effect of consistent and specialized Freestyle wrestling training on upper limb muscle synergy during the Double-Leg Attack maneuver, specifically comparing elite and sub-elite wrestlers. Thirty-eight junior Iranian male freestyle wrestlers were categorized based on their skill level. Elite group (n = 19) who participated in national or international-level competitions and achieved notable success and sub-elite group (n = 19) actively engaged in training but have not yet reached the same competitive level. We recorded EMG activity from five unilateral upper limb muscles and employed a non-negative matrix factorization (NMF) algorithm to extract the muscle synergy composition and temporal activation patterns during the Double-Leg Attack maneuver. In both the elite and sub-elite groups, three distinct muscle synergies (Syn1, Syn2, and Syn3) were identified and extracted. Notably, both groups showed impressive coherence within their respective groups in terms of spatial structures and temporal activation patterns of muscle synergies during the Double-Leg Attack technique. However, it was observed that elite wrestlers exhibited significantly higher values in temporal activation patterns compared to their sub-elite counterparts (P=0.000). The findings of this study highlight the importance of consistent and specialized Freestyle wrestling training in optimizing muscle synergy during the Double-Leg Attack technique. Significant differences observed in the temporal activation patterns suggest that elite wrestlers possess a higher level of temporal precision and coordination, which may contribute to their competitive advantage. These findings provide valuable insights for wrestlers and coaches to guide training strategies focused on enhancing muscle synergy and temporal coordination for improved performance in Freestyle wrestling.

To investigate the effects of sodium bicarbonate (NaHCO3) on exhaustive activity and physiological parameters of fatigue in conscripts. Thirty conscripts did Wingate test in two groups: sodium bicarbonate group (treatment) and placebo (control) group. In both groups, sodium bicarbonate (0.3 g/kg of body mass) or placebo was ingested 60 minutes before the training in 250 mL solution. Blood sample was collected before and after doing Wingate test. All parameters were compared using two-way analysis of variance (ANOVA), followed by Tuke y’s post-hoc test. Significance level was set at. 05. After sodium bicarbonate supplementation, the La Anion in Wingate test was significantly higher in the treatment group than the control group (17.93 ± 3.8 mmol/L vs 15.67 ± 3.29 mmol/L P <. 01). Sodium bicarbonate supplementation had no significant effect on heart rate in both groups. Sodium bicarbonate improves conscripts’ performance by increasing glycolytic capacity but does not improve fatigue indicators.

This study aimed to investigate the extent to which an 8-week scapular stabilizer strengthening and stretching exercise can reduce shoulder pain and improve wheelchair basketball sport skills. This is a parallel-group randomized controlled trial involving twenty-five elite wheelchair basketball players aged 25 to 54 who experienced shoulder pain. They were randomly assigned to either the exercise group (n=13) or the control group (n=12). The 8-week exercise program consisted of strengthening exercises targeting the serratus anterior, scapular retractor, and shoulder external rotator muscles, as well as stretching exercises for the upper trapezius, pectoralis major and minor muscles, and the posterior glenohumeral capsule and underlying soft tissues. Shoulder pain intensity was assessed using the wheelchair user's shoulder pain index, and basketball performance was evaluated using wheelchairs’ basketball skill tests. In addition, measurements of shoulder internal and external rotation range of motion, scapular upward rotation, maximal isometric muscle strength of middle and lower trapezius muscles, and pectoralis minor muscle length were taken at baseline and after the 8-week exercise intervention.Top of Form Participants in the exercise group experienced a significantly lower level of shoulder pain (p=0.001) and demonstrated a higher level of sports performance in all tests (p<0.05) compared to the control group. Moreover, the exercise group showed significant improvements in shoulder internal and external rotation range of motion (ROM) (p>0.001), external rotators muscle strength (p<0.001), and middle and lower trapezius muscle strength (p=0.003 and p=0.004, respectively) in comparison to the control group. Additionally, scapular upward rotation (p<0.001) and pectoralis minor length (p<0.001) were significantly increased in the exercise group compared to the control group (p<0.05). Indeed, the results suggest that an eight-week exercise program focused on scapular stabilizers and rotator cuff muscles can improve glenohumeral internal rotation, pectoralis minor length, and lower trapezius muscle strength. As a result, this exercise program could be considered a viable option for alleviating shoulder pain and enhancing sports performance in wheelchair basketball players.

first step in determination of the Islamic and Iranian scientists’ contribution to medicalscience advancements and also achieving their knowledge is critical and comparativeanalysis of their knowledge versus modern sciences. In this study, we have compared some points of “muscles” treaties of the Persian book “Tashrih-e badan-e ensan” (human body anatomy), also known as Tashrih-e Mansuri, by Mansur Ibn Mohammad Ibn Ahmad Shirazi with modern science. In this paper, nine points were compared and criticized, including: 1- describing the brain function and that brain is the origin of sense and movement,2- accompanying of nerves, connective tissue, tendons, and ligament with muscular fibers,3- the function of muscles, mechanism of muscle traction, five criteria for classification ofbody muscles including the size of a muscle, its shape, its status, its combination with other muscles, and having or lacking tendons, the performance of antagonist muscles, considering extensor digitorum longus, which ends in four tendons, and describing dorsal interossei muscles. Moreover, 31 short points were extracted from the most detailed image in the “muscles” treatise. Five noteworthy points of this section are the number of abdominal wall muscles, bladder sphincter, the muscular part of male genital organ, muscular part of pharynx, and the muscles whose origin or insertion are hyoid bone.

Age–related decline in muscle power may be an early sign of stability deficit and fall risk, even in nonfrail adults. This study examined the dose–depended effect of power training on stability performance in healthy elderly men. Eighty community– dwelling healthy elderly men (≥ 60 years) were randomized into 12 weeks of power training at 20% (LOW), 50% (MED), 80% (HIGH) of maximal strength, and a nontraining control (CON) group. Participants trained twice weekly using pneumatic resistance machines. Balance, muscle performance (power, strength, endurance, and contraction velocity) were measured. Power training significantly improved stability performance in participants who underwent power training compared to controls. Low intensity power training produced the greatest improvement in stability performance (Eta coefficient = 0.38). Power training improves stability, particularly using a low load, high velocity regimen, in elderlymen with an initial low muscle power and slower contraction. Further studies are warranted to define the mechanisms underlying this adaptation, as well as the optimum power training intensity for a range of physiological and clinical outcomes in elderly men with different levels of health status and functional independence.

The purpose of this study was to investigate the relationship between sprint performance of front-crawl swimming and muscle fascicle length in 23 male young swimmers. The sample was divided into two groups by 25-m sprint front-crawl swimming performance: 14.6-15.7 s (S1, n=11) and 15.8-17 s (S2, n=12). Muscle thickness and pennation angle and fascicle length of the Biceps Brachii (only muscle thickness) and Triceps Brachii and Vastus Lateralis and Gastrocnemius Medialis and Lateralis muscles were measured by B-mode ultrasonography. S1 had a significantly greater Vastus Lateralis, Gastrocnemius Lateralis, and Triceps Brachii muscle thickness. Pennation angle only in Triceps Brachii was significantly smaller in S1. S1 in Vastus Lateralis, Gastrocnemius Lateralis, and Triceps Brachii muscles had significantly absolute longer fascicle length and in Vastus Lateralis and Triceps Brachii muscles, had relatively (relative to limb length) longer fascicle length. There was a significant relationship between sprint performance of front-crawl and absolute and relative fascicle length in Vastus Lateralis (absolute: r = - 0.49, relative: r = -0.43) and Gastrocnemius Lateralis (absolute: r = -0.47, relative: r = -0.42). It is concluded that muscle fascicle length is one of the effective factors on the sprint front-crawl swimming in young swimmers.