Journal of Sports Medicine and Physical Fitness最新文献

Background: The batting motion has been reported to have a possible association with the development of low back pain (LBP) in baseball players. This study aimed to identify the kinematics of the batting motion in baseball players with a history of LBP, focusing on rotational and extension movements of the pelvis and trunk.

Methods: This study employed a cross-sectional design. Twenty-five experienced baseball players (age: 20.8±1.6 years; height: 173.4±6.3 cm; weight: 68.4±9.4 kg) were randomly recruited at the International University of Health and Welfare university, and all participants were classified into either the LBP (N.=13) or non-LBP (N.=12) group. The joint angles of the trunk and pelvis were measured during batting motion with a three-dimensional motion analysis system.

Results: The LBP group showed a significantly smaller trunk rotation and pelvis posterior tilt angle and earlier timing of trunk rotation to the batting side as compared to the non-LBP group (P<0.05).

Conclusions: This study revealed that experienced players with no history of LBP showed a delay in the timing of trunk rotation to the batting side while increasing the trunk rotation angle to the non-batting side to efficiently transfer the rotational energy generated from the lower limbs to the trunk and the upper limbs. Conversely, players with a history of LBP might have repeated inefficient motion in the process of transferring rotational energy generated by the lower extremities, pelvis, and trunk to the upper extremities.

Sports dance, an evolution of traditional couple dances into a competitive sporting discipline, encompasses a diverse range of genres. This study explores Caribbean and Latin American dances (CLADs), which highlight rich cultural heritages and offer significant health benefits. Through a scoping review, we synthesized findings from multiple studies on the physiological and psychological impacts of CLADs, both in competitive and recreational contexts. Our literature search, conducted across Google Scholar, PubMed, and Web of Science, identified 476 potential articles, of which 27 were selected for detailed analysis. These studies revealed that CLADs enhance motor coordination, self-awareness, body control, balance, and memory. The physical demands of these dances improve posture, flexibility, and cardiovascular health, comparable or superior to other forms of exercise. Specifically, studies demonstrated significant improvements in postural control, leg strength, and energy expenditure. Psychologically, dance interventions reduce symptoms of depression, anxiety, and stress, while boosting self-efficacy, motivation, and social cognition. The social and enjoyable nature of dance fosters mental well-being and cognitive function, especially in group settings. Despite challenges in adherence to physical activity, the intrinsic enjoyment of dance enhances participation rates and amplifies health benefits. The implications of these findings suggest that integrating dance into regular physical activity routines offers a holistic approach to health, addressing both physical and mental aspects. For older adults, dance maintains fitness and cognitive function, potentially reducing the healthcare burden associated with aging. The adaptability and minimal equipment requirements of dance make it accessible and practical for diverse populations.

Background: Athletic movements in American football render the shoulder vulnerable to injury. The aim of this study was to explore the epidemiology of shoulder injuries in the National Football League (NFL).

Methods: Injury data from the 2019-2022 seasons were extracted from official NFL website and secondary resources. Injury parameters included type, severity, week, position and other demographic characteristics. Injury rates were calculated per 1000 athletic exposures (AE) and statistical analyses were used to determine whether any significant differences exist in injury patterns across different positions and types.

Results: A total of 6732 injuries were reported during our study period, of which 452(6.7%) were attributed to the shoulder, leading to an injury rate of 4.5 per1000 AE. Linebackers, cornerbacks, wide receivers, and safety positions had significantly higher numbers of shoulder injuries than other defensive and offensive positions. Most injuries were mild (66%, P<0.001). Muscular (40.9%) and ligamentous (37.4%) injuries were the most common injury types. Fractures and ligamentous injuries were significantly more severe than muscular and other injuries (P<0.05). Even though week 17 had the highest mean number of shoulder injuries at 10.75/season, there was no apparent shoulder injury distribution trend across the football season.

Conclusions: Shoulder injuries are common in American football. Introducing a deidentified injury registry that provides detailed injury information in the NFL may help develop better prevention strategies and protocols.

Background: The flexibility development issue has not been studied well enough. Still, the problem can be partially solved in physical education lessons in a secondary school if a set of simple exercises for flexibility development is permanently added to the standard physical education (PE) program. The study aimed to increase flexibility in children aged 9-10 years in PE lessons.

Methods: The research was conducted in secondary school number 40 (Kirov, Russia). The study involved 56 children from 3^rd grade. Students were split into 2 groups of 28 children each. School children in each group were engaged in PE according to the school schedule 3 times a week for 40 minutes. The control group (CG) was engaged in the usual program and the children from the experimental group (EG) in the preparatory and final part of the lesson performed special sets of physical exercises to develop flexibility. To match the training volume, CG prolonged the usual program accordingly. The research used tests that determined mobility in the hip joint (forward tilt), the flexibility of the spine (exercise "bridge") and mobility in the shoulder joint (exercise "boat").

Results: For forward tilt performance, there was a significant difference in poststudy with EG resulting in higher performance than CG. Regarding post-to-pre research, EG and CG showed a significant difference with better values post compared with preintervention. Regarding the bridge test, a significant difference between groups was found regarding delta change with better performance for EG than CG. For post-to-preintervention comparisons, both EG and CG showed a significant difference with better values at post compared with prestudy. Concerning the boat test, EG resulted in higher performance than CG postintervention.

Conclusions: If a set of physical exercises is introduced in PE classes to develop flexibility in schoolchildren aged 9-10, then their indicators will significantly improve.

Background: This study aimed to examine the effects of sex differences on each energy supply (phosphagen, glycolytic, and oxidative systems) when athletes performing short-duration high-intensity exercises for different durations.

Methods: Eight male and seven female college students specializing in tracks and fields participated in this experiment. They performed full-strength pedaling for the experimental exercise. The participants were asked to pedal at a load of 6.5% of their body weight (kp) for three conditions: 10, 30, and 50 s. The phosphagen system was calculated by considering the fast component of the excess post-exercise oxygen consumption after all tests. The glycolytic system was expressed as the delta value of the difference between the peak and baseline blood lactate concentrations measured during the test. The oxidative system was estimated by subtracting the baseline oxygen uptake from the area of sprint oxygen uptake.

Results: At 10 s, a significant correlation was found between the relative mean power and the phosphagen and glycolytic systems in males. At 30 s, a significant correlation was found between relative mean power and phosphagen and oxidative systems in males, and between glycolytic and oxidative systems in females. At 50 s, a significant correlation was found between relative mean power and oxidative systems in males.

Conclusions: The results of this study indicate that the energy delivery systems supporting high performance in short-duration high-intensity exercise differ between males and females, a finding that is valuable for developing training plans.

Background: Photobiomodulation (PBM), has been shown to improve muscular performance during single-joint resistance exercises. It is unclear whether this benefit extends to multiple-joint exercises, such as the barbell bench press.

Methods: In a within-group design, 15 collegiate athletes (mean±SD; age 20.2±1.6 yrs; BMI 26.0±4.5 kg^.m^-2) received PBM or sham treatment six hours prior and then immediately preceding a bench press protocol. Two treatment sites each on the pectoralis major, triceps, and deltoids were irradiated. Bench press one repetition maximum (1RM), volume load (VL) lifted during five sets to failure at 60% 1RM, and muscular soreness were compared between PBM and sham conditions. Testing was conducted over three sessions separated by a week each, with a baseline testing day occurring first, and the PBM and sham condition testing days following in a counterbalanced fashion. A repeated measures ANOVA was applied for analysis (alpha level=0.05).

Results: No significant differences were observed between PBM and sham conditions for bench press 1RM or soreness (P≥0.05). VL was greater in both PBM and sham conditions compared to baseline (P≤0.05). VL was not significantly different between PBM and sham.

Conclusions: These findings suggest that muscular performance during multi-joint resistance exercises such as the bench press may not benefit from PBM in the same fashion as single-joint resistance exercises.

Background: Hepatitis B is a viral infection spread by contact with infected blood, semen, or other bodily fluids. The availability of a safe and effective vaccine has played a tremendous role in decreasing the prevalence of the disease since 1981. However, according to the Center for Disease Control, when adjusting for under-ascertainment and under-reporting, there were approximately 14,000 acute hepatitis B cases in the USA in 2020. There have been multiple outbreaks of vaccine-preventable disease in sports leagues including mumps and measles. However, there is limited literature available assessing hepatitis B prevalence of immunity in NCAA athletes.

Methods: Hepatitis B immunization data from local NCAA Division I and III athletes were analyzed from the years 2016-2023 through Epic chart review. The age range of the cohort was set at 18-24, upon time of evaluation. An Epic Reportwriter ran a SlicerDicer query searching for athletes who presented to our healthcare system clinic and/or training room facilities meeting the appropriate criteria outlined above. All NCAA sports were included. Data obtained included gender, race, country of birth, hepatitis B vaccination records, and hepatitis B surface antibodies if available.

Results: We had a total of 379 athletes. The median age for the cohort was 20 years. Overall, 64.6% of the athletes had received the hepatitis B vaccine. Only 4 athletes (1.06%) had hepatitis B surface antibody results available in their chart. All 4 of those athletes had a negative titer.

Conclusions: A majority of the athletes in this study had completed their hepatitis B vaccination. While 64.6% of athletes were vaccinated, the healthcare system needs to do a better job addressing vaccine adherence and hesitancy to prevent future outbreaks.

Background: Persistent physical fatigue (PPhF) accompanying daily intensive training often results in underperformance. While salivary secretory immunoglobulin A (SIgA) has been traditionally used as an immunological marker, salivary human herpesvirus 6 and/or 7 (HHV-6/7) have recently been presented as "microbiological" markers of PPhF. This study aimed to examine the monthly variabilities of salivary HHV-6/7 levels and the difference with SIgA along the training periodization.

Methods: A total of 27 healthy male university baseball players (N.=17) and non-players (student staff, N.=10) were followed up for 4 months (August, pre-competition period; September and October, competition period; November, post-competition period). The main measures were subjective and objective fatigue parameters (questionnaires and performance tests), and salivary HHV-6/7 and SIgA levels.

Results: The fatigue parameters indicated a decrease in athletic performance from August to September due to PPhF during high intensity training in August. Two-way repeated analysis of variance showed that salivary HHV-6 and -7 levels were higher in players compared to non-players (P<0.05). Salivary HHV-6 levels gradually decreased (P<0.05), whereas HHV-7 levels remained unchanged (P>0.05). Salivary SIgA levels were higher in players rather than in non-players (P>0.05), and the levels did not change (P>0.05).

Conclusions: Our findings suggest that salivary HHV-6/7 levels, specifically in HHV-6, reflect the degree of PPhF independently of SIgA levels. As saliva can be collected anywhere, periodic monitoring of salivary HHV-6/7 levels may be easily applicable for assessing PPhF beside sports field and allow appropriate conditioning.

Background: Breath-hold (BH) training over several years may result in mild but persistent neurocognitive impairment. Paradoxically, the acute effects of repeated BH generating intermittent hypoxia on neurocognitive functions are still poorly understood. Therefore, we decided to examine the impact of five-repeated maximal BH on attention, processing speed, and reasoning abilities.

Methods: Thirty six men separated in 3 groups (12 elite BH divers: EBHD; 12 novice BH divers: NBHD; and 12 non BH divers: CTL) performed before and after 5 maximal BHs, neuropsychological computerized tasks sensitive to hypoxia. Heart rate (HR) and peripheral oxygen saturation were recorded continuously during all tests.

Results: Immediately after the five BHs, all the participants presented lower response time on the visual reaction task. EBHD did not exhibit difference in neuropsychological performance compared to NBHD and CTL, despite enduring longer BH durations.

Conclusions: Regardless of BHD training level, repeated maximal BH may affect certain aspects of neuropsychological performance, in particularly visual reaction times. However, elite BHDs may have developed adaptive mechanisms that allow them to maintain their neurocognitive function at levels comparable to those of less trained BHDs and CTL, even with a higher dose of hypoxia.

Background: We analyzed how stress and heart rate variability affect the performance of male fencing athletes expected to compete in various international events representing Korea.

Methods: This study included 72 fencing athletes who participated in training and competition from January 2020 to December 2023. The stress was analyzed using the Sports Competition Anxiety Test (SCAT). Heart rate variability (HRV) was measured using an autonomous neurodiagnostic device (SA-6000). Heart rate variability measurement items were time domain analysis (heart rate, standard deviation of NN interval, and root mean square of the successful differences) and frequency domain analysis (total power, low frequency, and low frequency/high-frequency ratio). All athletes were classified into two categories: victory (high performance) and defeat (low performance) groups in the recent national championships.

Results: In SCAT, there was no significant difference between high and low performance. After comparing HRV, it was found that there is a significant difference in heart rates (P=0.030) and low frequency/high-frequency ratio (P=0.006) between high and low performance. heart rates and low-frequency/high-frequency ratio during the high performance were observed to be higher than during low performance.

Conclusions: In our study, we found that SCAT does not affect performance, while HRV has been shown to have an impact on performance. These findings can be valuable for coaches and athletes in developing strategies to improve performance results, particularly for elite male fencing athletes.