International journal of sports medicine最新文献

This study aims to explore the relationship between blood biochemical indexes and injury risk of elite male athletes in racing ice sports. The male athletes compared the demographic indexes, monthly injuries, and longitudinal tracking data. The non-linear relationship was analyzed using an unrestricted cubic spline. Generalized estimating equations estimated the relative risk (OR) of injury occurrence. Receiver operating characteristics and the area under the curve determined diagnostic accuracy. In the snow sledding group, when creatine kinase rises to 489.46 u/L or Testosterone decreases to 41.32 ng/ml, the risk increases by 1.70 times (OR=1.70, p<0.001) and 1.69 times(OR=1.69, p<0.001) with statistical significance. the Creatine kinase (OR=1.01, P=0.007) and Testosterone (OR=1.00, P＜0.001) were included in the injury prediction model. The model exhibits excellent discrimination, with sensitivity and specificity of 82.8% and 86.5%, respectively. In the ice skating group, when Creatine kinase rise to 467.00 u/L, the risk increases by 2.56 times with statistical significance (OR=2.56, p<0.001). Creatine kinase (OR=1.01, P＜0.001) was included in the predictive model. The model demonstrates good discrimination, with sensitivity and specificity of 90.5% and 66.7%, respectively. Creatine kinase and Testosterone are the risk predictors of injury in elite snowmobile male athletes. Creatine kinase is an independent risk factor for injury in elite speed skaters.

This study aimed to determine the influence of sport type and training volume during adolescence on low bone mineral density (BMD) in long-distance runners. In total, 125 competitive long-distance runners (64 males; 21.3 ± 4.2 years, 61 females; 21.4 ± 3.1 years) participated in this retrospective cohort study. We collected training history data during adolescence using a questionnaire and measured BMD of the lumbar spine and whole body using dual-energy X-ray absorptiometry (DXA). Male runners with low BMD ran for more hours (p = 0.02) and had a smaller proportion of multidirectional loading activity (p = 0.03) in elementary school than those with normal BMD. Although female runners with low BMD performed multidirectional activity for more hours in middle school than those with normal BMD (p = 0.01), running volume was similar between groups. There was an increasing trend in the total number of hours of physical activity in middle school in female runners with low BMD (p = 0.05). These results suggest that avoiding specialization in long-distance running, increasing the proportion of multidirectional sports, and preventing overload during the bone growth phase may reduce the risk of low BMD among runners.

The present study assessed the impacts of two distinct protocols, static stretching (StS, 4 sets of 30 seconds) and static stretching combined with conditioning contractions (10 repetitive drop jumps) (SC), on neuromuscular response and rate of force development (RFD) in the lower limbs during squat jumps (SJs) at varying initial knee-joint angles (60°,90°,120°). Twelve participants completed three randomized experimental trials (no intervention, StS intervention, and SC intervention). Except for the intervention segments, each trial included standardized warm-ups and SJs at three different angles. Data were collected using a 3-dimensional injury motion capture system, an electromyography (EMG) recording system, and a force platform. The collected EMG data were subjected to amplitude calculations, while force-time data were used for RFD computation. Neither StS nor SC significantly impacted the average or peak EMG amplitudes of the five muscles examined (p>0.05). However, at an initial knee-joint angle of 120°, the StS group demonstrated significantly lower RFD values at three distinct phases (0-50 ms, 50-100 ms, and 0-peakforce) compared to those seen in the SC and control groups (p<0.05). For activities starting with a knee-joint angle of 120°, it is recommended to either avoid StS or combine it with ten repetitive drop jumps to mitigate any potential negative impact on explosiveness.

Although there are some studies that have linked fitness parameters and sports injuries, the literature remains controversial. The aim of the study was to prospectively analyze the influence of initial physical condition parameters on the development of injury in the first three months of the sports season in futsal players. A total of 68 players (24.26±4.63 years old) were assessed before the start of the sports season in relation to certain physical condition parameters, such as body composition (bioimpedance), lower limb power (countermovement jump, CMJ) and muscle strength (isokinetic dynamometer). The injured players showed significantly worse initial performance in the CMJ compared to the uninjured players (p<0.001). There were no significant differences between groups in body composition and muscle strength. Lower power values were associated with a higher risk of injury in the first few months of the sports season (OR=0.92; 95% CI=0.88-0.99). Muscle power was an independent predictor of injury in the first few months of the sports season in futsal players, indicating that improving players' physical condition could help reduce the number of injuries.

Jump actions are common in several sports, and their performance is related to a myriad of biomechanical and physiological factors, with links to athletic performance and imbalances. Currently, a valid, field-based, easy-to-use tool to assess the quality of an explosive jump movement, similar to the required sports movements, is unavailable. Thus, the present study aimed to design and validate a field-based, easy-to-use tool that can be used to assess the quality of movement during an explosive single-leg countermovement jump (SL-CMJ). Ten experts participated in the content validation process for the checklist, including checking item relevance, definition accuracy, and scoring adequacy. Content validity was measured using the Aikens V format. The checklist included the items "Foot orientation," "Knee valgus/varus," "Internal/external hip flexed orientation," "Pelvis tilt," "Thorax tilt," "Thorax rotation," "Foot pronation/supination," "Asymmetrical hip," and "Lumbo-pelvic association". The items achieved a 0.60-0.99 in relevance, 0.70-1.00 in definition accuracy, and 0.80-0.83 in scoring adequacies in the Aikens V proof. The results from the context validation process suggest that the tool may be appropriate to assess athletes' quality of explosive movement. Furthermore, the results derived from such assessments may help to design better and safer training interventions.

It is well known that cardiometabolic dysfunction gradually increases after menopause, and the sedentary lifestyle can aggravate this condition. Therefore, we compared the effects of aerobic exercise training during the premenopausal period and after ovariectomy (OVX) on metabolic, hemodynamic, and autonomic parameters in an experimental rat model of menopause. The female rats were divided into four groups: control (C), sedentary OVX (SO), trained OVX (TO), and previously trained OVX (PTO). The PTO group was trained for 4 weeks prior to+8 weeks after OVX, and the TO group trained only after OVX on a motor treadmill. Autonomic modulation was evaluated, white adipose tissue (WAT) was removed and weighed, and lipolysis was assessed. The citrate synthase activity in the soleus muscle was analyzed. The trained groups prevented the impairment of baroreceptor reflex sensitivity in relation to SO; however, only PTO reduced the low-frequency band of the pulse interval compared to SO. PTO reduced the weight of WAT compared to the other groups; lipolysis in PTO was similar to that in C. PTO preserved muscle metabolic injury in all types of fibers analyzed. In conclusion, this study suggests that exercise training should be recommended in a premenopausal model to prevent cardiometabolic and autonomic menopause-induced deleterious effects.

Skeletal muscle is the largest organ system in the human body and plays critical roles in athletic performance, mobility, and disease pathogenesis. Despite growing recognition of its importance by major health organizations, significant knowledge gaps remain regarding skeletal muscle health and its crosstalk with nearly every physiological system. Relevant public health challenges like pain, injury, obesity, and sarcopenia underscore the need to accurately assess skeletal muscle health and function. Feasible, non-invasive techniques that reliably evaluate metrics including muscle pain, dynamic structure, contractility, circulatory function, body composition, and emerging biomarkers are imperative to unraveling the complexities of skeletal muscle. Our concise review highlights innovative or overlooked approaches for comprehensively assessing skeletal muscle in vivo. We summarize recent advances in leveraging dynamic ultrasound imaging, muscle echogenicity, tensiomyography, blood flow restriction protocols, molecular techniques, body composition, and pain assessments to gain novel insight into muscle physiology from cellular to whole-body perspectives. Continued development of precise, non-invasive tools to investigate skeletal muscle are critical in informing impactful discoveries in exercise and rehabilitation science.

The aim of this study was to determine the effects of subtetanic neuromuscular electrical stimulation combined with voluntary exercise between repeated Wingate tests on sprint exercise performance and blood lactate accumulation during sprint interval training. Fifteen healthy young males volunteered. After 1-min baseline, participants underwent the Wingate test twice. They performed a 4-min intervention between tests: neuromuscular electrical stimulation with free-weight cycling or voluntary cycling alone [43.6 (8.0) watts], which matched oxygen consumption with neuromuscular electrical stimulation with free-weight cycling. The blood lactate concentration was assessed at the end of the baseline, at 3-min intervention, and on recovery at 1, 3, 5, and 10 min after the second Wingate test. Peak and mean blood lactate concentration during recovery were significantly greater with neuromuscular electrical stimulation with free-weight cycling than voluntary cycling alone (P>0.036 and P=0.011, respectively). Peak power, mean power, and rate of decline (fatigue index) were not significantly different between conditions in both Wingate tests (condition/interaction all P>0.300, partial η²<0.1). Subtetanic neuromuscular electrical stimulation combined with voluntary exercise indicated similar exercise performance and fatigue levels during Wingate tests, but enhanced blood lactate accumulation compared to oxygen consumption-matched voluntary cycling during sprint interval training.

The purpose of this study was to analyze the association and predictive capacity between the acute:chronic workload ratio (ACWR) and non-contact injuries in a semiprofessional football team. Seventeen football or soccer players from a Spanish Third Division football team participated voluntarily in this study. A prospective longitudinal study was developed during the 2020/2021 season. Twenty-four weeks were analyzed from October to March, including a regenerative microcycle due to the absence of competition during Christmas. Rate of perceived exertion (RPE) and session-rate of perceived exertion (sRPE) were registered for every training and game session. Afterward, acute and chronic workloads were calculated, and ACWR was subsequently derived from them. Furthermore, non-contact injuries were registered during the period mentioned. The main findings were that there is a poor correlation between the ACWR and non-contact injuries (r=0.069 (p<0.05)), and the use of the ACWR by itself is insufficient to predict the occurrence of non-contact injuries in a semiprofessional football team. Consequently, the ACWR is not an useful predictive tool for injuries in semiprofessional football teams.

The study aimed to identify athlete-reported reasons for not returning to pre-injury sports level after anterior cruciate ligament reconstruction (ACLR) and to identify the factors associated with these reasons. Ninety-one athletes with 2 years post-ACLR indicated whether or not they had returned to their pre-injury sport level (same frequency, duration, and intensity). Athletes who did not return were asked to provide the reasons. Athletes' characteristics and injury-related factors were used to determine factors associated with the reasons for not returning. Only nine athletes (10%) returned to pre-injury sport level after ACLR. The most common reasons for not returning were lack of confidence or concerns about re-injury (48.8%), followed by continued post-surgical impairments in the reconstructed knee (39%). Having episodes of the knee giving way after ACLR was the only significant predictor of post-surgical impairments (48.8%; OR=8.3, 95%CI=2.48-27.42, p=0.001). Lack of confidence, concerns about re-injury, or post-surgical impairments in the reconstructed knee were the most frequently reported reasons for not returning to pre-injury sports level with 2 years post-ACLR. Reported dynamic knee instability was the only factor associated with ongoing post-surgical knee impairments after ACLR. Rehabilitation programs should address athletes' psychological responses and resolve knee impairments to optimize return to pre-injury sport level after ACLR.