Injury prevalence and associated factors among Japanese lacrosse collegiate athletes.

Context: Sports injuries have a substantial impact on athletes' performance and health. To reduce the risk of an injury occurring, the prevalence, localization, and severity need to be established. Objective: To examine the prevalence of sports injuries in collegiate lacrosse athletes. Design: Descriptive epidemiological study using online survey design. Setting: Japanese universities associated with UNIVAS. Participants: A total of 1,689 Japanese collegiate lacrosse athletes, 978 females and 701 males. Main outcome measures: Athletes were surveyed on the injuries within the previous year, their severity, localization, and onset characteristics. The support of an athletic trainer and its association with the odds of sustaining an injury was assessed. Factors related to injuries were explored. Results: One-year prevalence of injuries was 42%. Male sex, higher year at the university, and support from an athletic trainer were identified as factors related to higher odds of sustaining an injury and practicing at least 5 days per week was associated with lower odds of sustaining an injury. Conclusions: Male sex athletes, and athletes at the higher year at university are especially at risk of sustaining a lacrosse injury. The aspects of training (e.g., frequency, volume) should be investigated across the athlete development process to address these findings. Further investigation is needed to determine the extent to which the support of athletic trainers affects both the frequency and severity of injuries in lacrosse athletes.

Effectiveness of warm-up and dynamic balance training in preventing anterior cruciate ligament injuries in college gymnasts: a 3-year prospective study for one team.

BACKGROUND: The effect of trunk stability and dynamic balance warm-up exercises on physical functional improvement remains unelucidated. This study examined whether exercises could prevent anterior cruciate ligament (ACL) injury and improve trunk muscle activation and dynamic balance in gymnasts. METHODS: This comparison study, involving gymnastics practice sessions, included 31 university gymnasts and was conducted in two periods: 1 year of observation followed by 2 years of intervention. Participants performed a trunk and dynamic balance warm-up exercise program during the intervention. The effect of exercise on the incidence of ACL injury was evaluated. In addition, the paired t-test was used to compare the Y-balance distance and the changes in muscle thickness associated with trunk muscle activation at rest and during plank. RESULTS: ACL injury risk during the intervention was significantly lower, with a relative risk of 0.23 (P=0.02, 95% CI: 0.06-0.88). Changes in muscle thickness with activation of the transversus abdominis (P<0.01, mean difference 4.1, 95% CI: 9.97-28.07, Cohen's d=0.52), internal oblique (P<0.01, mean difference 5.2, 95% CI: 9.72-21.55, Cohen's d=0.65), and external oblique (P<0.01, mean difference 5.5, 95% CI: 20.44-39.09, Cohen's d=0.71) muscles were significantly higher during the intervention. The Y-balance distance was also significantly greater in the posterior medial reach (P<0.01, mean difference 3.3, 95% CI: 1.56-6.26, Cohen's d=0.46) during the intervention. CONCLUSIONS: Exercise-based warm-up programs may decrease ACL injuries. It can improve physical functions, such as the rate of change in trunk muscle thickness and the posterior medial distance during Y balance.

Estimation of maximal lactate steady state using the sweat lactate sensor.

A simple, non-invasive algorithm for maximal lactate steady state (MLSS) assessment has not been developed. We examined whether MLSS can be estimated from the sweat lactate threshold (sLT) using a novel sweat lactate sensor for healthy adults, with consideration of their exercise habits. Fifteen adults representing diverse fitness levels were recruited. Participants with/without exercise habits were defined as trained/untrained, respectively. Constant-load testing for 30 min at 110%, 115%, 120%, and 125% of sLT intensity was performed to determine MLSS. The tissue oxygenation index (TOI) of the thigh was also monitored. MLSS was not fully estimated from sLT, with 110%, 115%, 120%, and 125% of sLT in one, four, three, and seven participants, respectively. The MLSS based on sLT was higher in the trained group as compared to the untrained group. A total of 80% of trained participants had an MLSS of 120% or higher, while 75% of untrained participants had an MLSS of 115% or lower based on sLT. Furthermore, compared to untrained participants, trained participants continued constant-load exercise even if their TOI decreased below the resting baseline (P < 0.01). MLSS was successfully estimated using sLT, with 120% or more in trained participants and 115% or less in untrained participants. This suggests that trained individuals can continue exercising despite decreases in oxygen saturation in lower extremity skeletal muscles.

Prevalence of and Factors Associated with Sports Injuries in 11,000 Japanese Collegiate Athletes.

BACKGROUND: To establish the 1-year prevalence of sports injuries and explore associations of various factors with a sports injury in Japanese collegiate athletes. METHODS: The data were collected through a web-based survey of Japanese collegiate athletes associated with UNIVAS (Japan Association for University Athletics and Sport). The survey questions asked about athletes' personal characteristics, sports participation, and injuries sustained within the previous year. Follow-up questions on the details regarding the three most serious injuries were asked. Differences in proportions of athlete characteristics between males and females and between injured and uninjured were explored with the chi-square test. Factors associated with sustaining an injury were determined with regression analysis. RESULTS: The prevalence of injuries among Japanese collegiate athletes is high, and most of the sustained injuries require athletes to take a considerable time off training and competition indicating their severity. Athletes from year two and higher at the university, overweight or obese, training more often per week, and with longer sports experience were more likely to sustain an injury within the previous year. CONCLUSIONS: There is compelling evidence to suggest that excessive training and insufficient recovery may be contributing to their increased risk of injury. These findings underscore the importance of implementing evidence-based training programs and recovery strategies to mitigate injury risk and optimize performance outcomes among this population.

The Effectiveness of Trunk and Balance Warm-up Exercises in Prevention, Severity, and Length of Limitation From Overuse and Acute Lower Limb Injuries in Male Volleyball Players.

Background: Injuries in volleyball players are most common in the ankles and knees. Many volleyball players suffer from overuse injuries because of the strain placed on the lower extremities from repeated jumping. A characteristic of players who are most at risk for lower extremity injuries is the tendency to display trunk instability during landing, such as lateral flexion and rotation. Research has shown the effectiveness of exercise-based warm-up interventions for acute volleyball injuries. However, comprehensive analyses on the use of lower extremity, trunk, and balance programs to prevent overuse injuries are lacking. Purpose: To examine the effects of trunk and balance warm-up exercises on the prevention, severity, and length of limitation of overuse and acute lower limb injuries in male volleyball players. Study Design: Prospective, single-cohort study. Methods: This study involved the 2019 (control group) and 2021 (intervention group) male volleyball teams. The control and intervention groups were on the same team; however, seven players joined in 2021 through a sports referral program through which different players are recruited. Measurements included injury incidence rate, injury severity, and injury burden. The intervention involved the addition of trunk and balance exercises during the 2021 season. Results: There was no significant difference in injury incidence rates between groups. Injury severity decreased by 3.7 days for overuse injuries (p=0.04). Injury burden decreased by 11.8 (days/1000 player hours) overall and by 7.1 (days/1000 player hours) for overuse injuries. Conclusion: The results show that an exercise-based warm-up aimed at improving trunk posture during landing did not reduce the incidence rate of injury in men's volleyball. However, the addition of this warm-up did significantly reduce the severity of overuse injury. Level of Evidence: Level 3B.

Correction: Comparison between bracing and hollowing trunk exercise with a focus on the change in T2 values obtained by magnetic resonance imaging.

[This corrects the article DOI: 10.1371/journal.pone.0240213.].

Comparison between bracing and hollowing trunk exercise with a focus on the change in T2 values obtained by magnetic resonance imaging.

The purpose of this study was to compare the muscle activity of Bracing and Hollowing trunk exercises by means of T2 values using MRI. Subjects were 19 healthy adult males, of whom 10 (with mean height ± SD: 172.3 ± 4.7 cm, mean weight ± SD: 64.3 ± 5.4 kg, mean age ± SD 21.5 ± 1.9 years) performed hollowing and 9 (with mean height ± SD: 171.3 ± 2.1 cm, mean weight ± SD: 68.5 ± 11.7 kg, mean age ± SD: 23.0 ± 2.6 years) performed bracing. They were assessed using MRI. The imaging was completed using Osirix software, which measured T2 values from the transversus abdominis (TrA), internal oblique (IO), external oblique (EO), and multifidus (MF) muscles. Subsequently, T2 values recorded before the exercise were compared with those recorded after the exercise to evaluate the extent of change effected by exercise on the muscles. MRI T2 values indicated that the TrA and IO regions were activated to a significantly greater degree after bracing. No significant changes occurred in any muscle before and after hollowing. It was determined that the activity of the deeper trunk muscles was higher in bracing than in hollowing on comparing the T2 values obtained in the MRI.