Journal of science and medicine in sport最新文献

Objectives: Although exercise-induced vascular adaptations have been extensively reported in racket sports athletes, the applicability of these findings to athletes in other overhead sports is unclear. This study aimed to investigate exercise-induced vascular adaptations in college male baseball players. Furthermore, since the training frequency of the upper arm may differ by baseball playing position, this study also focused on playing position-specific differences in brachial arterial adaptations.

Design: Cross-sectional study.

Methods: Seventy-five baseball players and 23 sedentary young men aged 18-23 years participated in this study. The participants' brachial artery diameter, blood flow velocity, and blood flow volume were measured using an ultrasonic diagnostic imaging system. Brachial hemodynamic measurements of both hands were obtained randomly in a seated resting position.

Results: Baseball players demonstrated significantly greater brachial lean mass, circumference, arterial diameter, and blood flow volume than sedentary control participants. Statistically significant differences in brachial artery diameters between the non-dominant and dominant arms were observed only in the baseball pitcher group. Furthermore, body surface area- and brachial lean mass-corrected artery diameters in the dominant arm were also significantly larger than those in the non-dominant arm in the baseball pitcher group. A simple correlation analysis revealed a positive association between brachial lean mass/circumference and arterial diameter in all participants.

Conclusions: These findings suggest asymmetrical exercise-induced vascular adaptations in the brachial artery of baseball players, particularly pitchers, indicating the potential role of playing position-specific demands in vascular remodeling. Understanding these adaptations may inform training strategies and help prevent injuries in baseball players.

Objectives: To examine the within- and cross-season neuromuscular fatigue responses in English Premier League U-18 academy football players.

Design: Twenty-five players from the same team completed weekly countermovement jump and isometric adductor and posterior chain strength tests for a full competitive season.

Methods: Global positioning system measures of training and match total, high-metabolic load and sprint distance were recorded daily and converted into exponentially weighted moving average seven- and twenty-eight-day values.

Results: TD₂₈ (p < .001), HML₂₈ (p < .001), and SD₂₈ (p = .002) shared negative relationships with countermovement jump height, but there was no main cross-season effect (p = .137). TD₂₈ (p = .016) and HML₂₈ (p = .012) positively related to isometric posterior chain strength but there was no effect of SD₂₈ (p = .653), SD₇ (p = .549), TD₇ (p = .080) or HML₇ (p = .104). Cross season, isometric posterior chain strength followed a curvilinear response whereby performance increased across the beginning of the season and decreased towards the end of the season (p = .003). There was no effect of training load or time on isometric adductor strength performance (p > .094).

Conclusions: Neuromuscular status, signalled by countermovement jump height changes fluctuates across the season in response to sustained changes in training and match load, but there is no evidence of a main cross-season linear effect. Total training and match volume exert moderating effects on the internal training load dose, and in-turn, important moderating effects on neuromuscular fatigue, particularly when composed of high volumes of high-intensity and sprint distances. The posterior chain might be particularly susceptible to fatigue towards the end of the season.

Prehospital management of exertional heat stroke (EHS) consists of monitoring rectal temperature (T_re) while aggressively cooling via cold water immersion. Recent recommendations suggest using central nervous system (CNS) dysfunction to determine cessation of cooling when T_re is not available. We examined cognitive responses of two runners with EHS after a road race. This comparison illustrates the need to use caution with this recommendation, as the manifestation of CNS responses in EHS patients can be unpredictable. The variables in both cases highlight the importance of avoiding using mental status alone when cooling EHS patients and support T_re serving as the main clinical indicator during treatment.

Objectives: To investigate whether the effectiveness of progressive tendon loading exercises (PTLE) on patellar tendinopathy is mediated through changes in physical or imaging properties.

Design: Mediation analyses based on a randomized clinical trial (n = 76) in patellar tendinopathy comparing PTLE with eccentric exercise therapy (EET).

Methods: Pain-related disability on Victorian Institute of Sports Assessment-Patella (VISA-P, 0 to 100) and pain (Visual Analogue Score) after single-leg decline squat (VAS-SLDS, 0 to 10) at 24 weeks were outcome measures. Selected mediators, including the physical (quadriceps muscle strength, ankle dorsiflexion range, jumping performance) and imaging domains (ultrasonographic tendon thickness and degree of neovascularization), were measured at 12 weeks. Directed acyclic graphs were performed to identify critical confounders. Causal mediation analysis was used to estimate natural indirect, natural direct and total effects by a simulation approach under the counterfactual framework.

Results: Complete data from 61 of 76 participants were included. There was no evidence showing that the beneficial effect of PTLE on VISA-P or VAS-SLDS outcomes was mediated by changes in any of the selected physical or imaging variables. The indirect effects for all mediators were unsubstantial (estimates ranging from -1.63 to 1.53 on VISA-P and -0.20 to 0.19 on VAS-SLDS), with all 95 % confidence intervals containing zero.

Conclusions: The beneficial effect of PTLE on patellar tendinopathy was not mediated by changes in physical properties, tendon thickness or degree of neovascularization. Healthcare professionals may consider exploring other potential factors when managing patients with patellar tendinopathy, but further large-scale research is needed to confirm these results and to identify alternative treatment targets.

Sports physicians need to be aware of potential complications related to breast implants in athletes. Problems with breast implants can affect an athlete's physical health, overall mental well-being and performance. This case report explores the challenges sports physicians face in diagnosing and managing breast implant ruptures in athletes. It outlines the complexities of identifying ruptures, conducting appropriate screenings, and determining fitness to play following chest injuries sustained during sports. This publication also offers practical guidance on addressing these challenges and emphasises the importance of comprehensive evaluation, proactive screening, and a multidisciplinary approach to management.

Objectives: The EyeGuide Focus system is a simple, portable, test of visual tracking with potential use for concussion screening. This study investigated the repeatability, reproducibility, distribution, and modifiers of EyeGuide Focus measurements in healthy elite Rugby players.

Design: Cross sectional repeated measures study and controlled pre-test post-test sub-study.

Methods: EyeGuide Focus testing was performed in a medical room at rest. Test-retest repeatability (within-subject standard deviation (Sw), coefficient of variation (CV), repeatability coefficient (RC)) and reliability intra-class correlation coefficient (ICC A,1) of 3 test results were evaluated. The distribution of best score across replicates was then examined using summary statistics, and the influence of subject characteristics investigated. A controlled pre-test post-test sub-study examined the effect of exercise on best EyeGuide Focus score using an analysis of covariance (ANCOVA).

Results: A total of 769 elite male Rugby players underwent EyeGuide Focus testing. Repeated test scores demonstrated positively skewed distributions. Test-retest repeatability (Sw 1.46, CV 46.0 %, RC 2.85, natural log transformed data) and reliability (ICC 0.41, natural log transformed data) were low. The distribution of best EyeGuide Focus score was unaffected by previous concussion, eye conditions, or age. No learning or exercise effects were apparent in the controlled pre-test post-test sub-study (ANCOVA, n = 89, p = 0.69).

Conclusions: EyeGuide Focus test-retest repeatability and reliability were low and could limit diagnostic accuracy. Best test score achieved across repeated measurements is a possible metric for operationalisation and future research is required to determine if this differs in patients with concussion compared to normal subjects.

Objectives: Insomnia affects at least one-third of the global population and is more common in women. Exercise has been reported to improve sleep quality and subsequent use of hypnotics. Therefore, we performed a meta-analysis to assess the effect of exercise on sleep quality in adult women.

Design: This meta-analysis systematically assessed the effects of exercise on women's sleep quality using a random-effects model.

Methods: We searched seven databases for randomised controlled trials examining the effect of exercise on sleep quality in women. Inclusion criteria were women aged 18 or older with insomnia symptoms, exercise used as an intervention, and the Pittsburgh Sleep Quality Index or Insomnia Severity Index as outcome measures. We excluded studies using other treatments, those involving cancer patients or pregnant women, and those with unclear, unanalysable data. A random-effects model was used for meta-analysis, with outcomes expressed as the weighted mean difference and 95 % confidence interval. Risk of bias was assessed using Cochrane Handbook criteria.

Results: The meta-analysis included 16 studies. The results indicated that exercise significantly reduced the Pittsburgh Sleep Quality Index total score. Exercise implemented for <12 weeks was more effective in improving sleep quality and daytime dysfunction, whilst interventions ≥12 weeks reduced the use of sleep medication.

Conclusions: Exercise training can significantly improve sleep quality in adult women, as measured by the Pittsburgh Sleep Quality Index. Therefore, exercise can be crucial in promoting health, especially as a non-pharmacological treatment. When more studies will be available in the future, it will be possible to further explore the impact of age, type of exercise, and time of exercise.

Objectives: Primary prevention of concussions is a priority in contact sports, with growing interest in the role of neck strength in mitigating the risks of concussion. The aim of this study was to determine if neck function was associated with in-season concussions in adolescent rugby union and league athletes, and to establish clinical values to identify players with increased risk of sustaining a concussion.

Design: Prospective cohort study.

Methods: Assessment of neck function included isometric strength, endurance and proprioception. In-season concussion injuries were recorded. Preliminary multivariate analysis-of-covariance models were conducted to investigate differences in neck function between players who did and did not sustain an in-season concussion. If significant, receiver operated characteristic curves were used to determine optimal cut-points for each variable to distinguish between concussion groups. Unadjusted odds ratios were estimated from the cross tabulation chi-squared test. Significance was set at p < 0.1.

Results: A total of 43 players (aged 15-18 years) were assessed during preseason. Eleven players sustained a concussion during the season. Players who sustained a concussion during the season had weaker neck extension strength in kilogrammes (p = 0.043, effect size = 0.74) and when normalised to body weight (p = 0.041, effect size = 0.74). The optimal cut-point for extension strength was 32.1 kg (sensitivity 0.64, specificity 0.75) and 3.71 N/kg (sensitivity 0.64, specificity 0.66). Players with a flexor to extensor strength ratio above 0.74 were 3-times more likely to sustain a concussion (p = 0.09). There were no differences for other neck function variables.

Conclusions: Interventions targeting neck strength could reduce the risk of concussion.

Objectives: To compare the prevalence of training-related ECG findings in white, mixed-race, and black male Brazilian soccer players.

Design: Multicenter observational study.

Methods: This study involved athletes aged 15 to 35 years from 82 professional clubs across Brazil's five regions. It included athletes who underwent preparticipation cardiovascular screening between February 2002 and September 2023.

Results: A total of 6125 players (median age: 18) were included (2496 white, 2004 mixed-race, and 1625 black). Ninety-seven percent of the ECGs were normal. Sinus bradycardia was observed in 50.1 %, while left ventricular hypertrophy in 35.1 %, with a higher prevalence in black players (41.7 %) compared to white (31.7 %) or mixed-race (34.1 %) players. Early repolarization was most prevalent among black athletes (48.2 %) compared to white (34.3 %) and mixed-race (40.5 %) athletes. The mean PR interval was 153.0 ms, higher in black players (156.8 ms) than in white (150.6 ms) or mixed-race (152.8 ms) players. Black athletes had more first-degree AV block (4.1 %) compared to mixed-race athletes (2.7 %). Conversely, white athletes (15.4 %) had more incomplete right bundle branch block than mixed-race (11.4 %) or black (9.8 %) athletes. The 'African/Afro-Caribbean pattern' was found in 1.8 % of black players.

Conclusions: Ninety-seven percent of male Brazilian soccer players had normal ECG patterns. Training-related ECG findings were more common in black players compared to white or mixed-race players. The 'African/Afro-Caribbean pattern' was rare in black players.