Fifteen international and domestic consensus statements on methods for sports injury and illness epidemiological study were reviewed. The most widely recognized categorization of definitions of injury and illness is time-loss, medical attention, and any complaint, while the domestic consensus statement recommends the use of time-loss and non-time-loss categories. Acute sudden-onset, repetitive sudden-onset, and repetitive gradual onset are the most comprehensive and clear classification for mode of onset. Reinjury was defined as subsequent injuries to the same location and tissue to the index injury in most literature, and the use of this definition has been recommended because of its clarity. Recently established and updated Subsequent Injury Categorization Model is useful to consider the influence of index injury to the subsequent injuries. The risks of injury and illness are often evaluated with incidence rate. The incidence rate should be calculated with a denominator of 1000 athlete hours when the duration of playing time likely affects the risk of injury occurrence. While planning an epidemiological study, it is critical to review methods that have been already standardized in the past literature because the data produced by studies with consistent methodology can be compared and synthesized to build more reliable evidence.

Sports injury and illness surveillance systems are essential to facilitate the continuous availability of high-quality, longitudinal injury and illness data. There are 15 ongoing sports injury surveillance systems worldwide, based in Europe, the United States, and Australia. The majority of these sports injury surveillance systems operate within professional or elite sports. Contrastingly, a total of five sports injury surveillance systems developed among sports in Japan were included, most of which were based on insurance benefits or condolence payment systems. Therefore, it is necessary to establish club-based or organization-based sports injury and illness surveillance systems suitable for the Japanese sports setting to identify the exact magnitude of sports injuries and illnesses and to implement preventive measures among Japanese athletes.

The Oslo Sports Trauma Research Center Questionnaire is an athletic epidemiological survey questionnaire targeting “all complaint injuries” (all problems with symptoms). The questionnaire includes questions regarding (1) participation, (2) modified training/competition, (3) performance, and (4) pain (symptoms) due to an injury at specific location or health problems at certain intervals. The prevalence and severity of problems are calculated to monitor changes in these parameters. This paper provides an overview of this questionnaire, its procedures, and major previous studies.

In April 2022, the Japanese Society of Clinical Sports Medicine and the Japanese Society for Athletic Training published standardize sports injury and illness surveillance methods in Japan. This proposal summarizes the content of the examination of sports injury and illness surveillance in Japan. In this paper, we summarize evidence-based points to note during investigations in line with the [recommendations for sports injury/injury and disease investigations] described in the proposal.

Epidemiological data in sports injury and illness are expected to not only provide information necessary to develop specific measures to prevent them, but also provide evidence to support the results of athletic trainers’ activities. This paper outlines how to utilize epidemiological data in sports injury and illness, including the relationship with stakeholders involved in sport settings.

The purpose of this study was to investigate the effect of low back pain (LBP) history on the physical characteristics of collegiate male volleyball players. Screening tests included assessment of height, weight, muscle mass, fat mass, body fat percentage, tightness (FFD, SLR, HBD, Thomas Test), trunk muscle strength, and muscle stiffness.

This study showed, back muscle strength and flexibility of hip flexor muscles and in which how they were significantly lower in LBP than in Non-LBP players.

The results indicate that improvement of these items/designated areas or categories and detailed the evaluation of trunk function and how it can help prevent low back pain in collegiate male volleyball players.

BACKGROUND: Reliable and objective methods to measure trunk rotation are not well-established; therefore, simple clinical measures to quantify trunk rotation need to be developed.

OBJECTIVES: In this study, two methods were compared to measure the passive range of motion (ROM) of trunk rotation. The reliability and validity of an iPhone^® application with a caliper were compared with those of three-dimensional motion analysis (3DMA).

METHODS: Passive ROM of trunk rotation was measured in 15 healthy male individuals. Intra- and inter-rater reliabilities were determined by calculating the intraclass correlation coefficients (ICCs). The iPhone^® application with a caliper was validated against 3DMA using Pearson’s correlation coefficient, and agreement levels were identified using Bland-Altman plots and 95% limits of agreement.

RESULTS: The iPhone^® application demonstrated moderate-to-good intra-rater (ICC=0.73) and excellent inter-rater reliability (ICC=0.75). A strong and significant correlation was found between measurements obtained using 3DMA and the iPhone^® application with concurrent validity (r=0.87, p<0.01). However, the 3DMA measurements were consistently higher than the iPhone^® application measurements (mean difference 4.74°, p<0.01), and the upper and lower limits of agreement were 11.14° and −1.67°, respectively.

CONCLUSIONS: These results indicate that the iPhone^® application with a caliper can be used to assess passive ROM of trunk rotation.

This study analyzed shoulder strength and throwing motion with the effects of cooling stimulation on the palm while the intermittent load was given mimicking a baseball game. Eight college students volunteered to participate in this study. The maximum isometric muscle strength of shoulder abduction was measured on the right or throwing side for 9 sets of 10 repetitions. Subjects has a 5-minute rest period after each of the sets. The right shoulder abduction angle was measured on the throwing side each of the 9 sets. This protocol was defined as “without cooling. On the other hand, the procedure of cooling the left palm with an ice sac between sets was defined as “with cooling”. Shoulder abduction muscle strength significantly decreased in the latter half with “without cooling”, and there was no significant difference between sets with “with cooling”. The shoulder abduction angle was significantly decreased in all the 8 subjects after loading with “without cooling” while it was significantly decreased only for three subjects with “with cooling” after loading. Cooling the palm during the load may be able to maintain shoulder abduction muscle strength and prevent a decrease in the shoulder abduction angle on the throwing motion.

The peroneal muscles undergo morphological changes and functional decline after an ankle sprain, contributing to recurrence. We reported that different morphological changes occur in the peroneus longus (PL) and peroneus brevis (PB) after an ankle sprain (Arima et al., 2022), and we believe that selective muscle strength train for the PL and PB is necessary. This study aimed to examine whether the morphology of PL and PB is selectively altered by different training methods. Two tasks were performed on separate days: the ball of the foot task in which a Thera-Band was placed on the ball of the foot and pushed out from the contact point, and the fifth metatarsal task in which the Thera-Band was pushed out from the base of the fifth metatarsal. Muscle cross-sectional area (CSA) and muscle echogenicity of the peroneus muscles at 25% and 75% proximal to the line connecting the fibular head and the lateral malleolus, and ankle joint strength were measured before and immediately after the task and at 10, 20, and 30 minutes later. A repeated measures analysis of variance was used to compare each item measured at each time point. In the ball of the foot task, the CSA at the proximal 25% was significantly higher immediately and 10 minutes after the task than before (p<0.05). In the fifth metatarsal task, the CSA increased significantly in the proximal 75% after the task (p<0.05). Transient muscle hypertrophy immediately after training is due to edema caused by muscle injury, indicating an immediate effect of training (Damas et al., 2016). The CSA of the proximal 25% showing PL in the ball of the foot task and the distal 75% showing PB in the fifth metatarsal task increased immediately after the task, suggesting the possibility of selectively training PL and PB in this task.

Stability training is often carried out in the field of sports to improve performance. Appropriate loading is important in sports rehabilitation. Rehabilitation that ignores progressive characteristics can lead to a variety of reactions, including prolonged return to work and recurrence of injury. Therefore, it is desirable to objectively evaluate the load exerted by each training method. However, the degree of change in muscle activity in response to changes in foot ground contact height and stability when performing front bridge was unknown. Thirty-seven healthy subjects performed six different front bridges with varying foot height and instability. Muscle activity was measured and examined during implementation. Surface electromyography was used to measure the activity of the upper trapezius, lower trapezius, serratus anterior, rectus abdominis, external and internal abdominal oblique muscles, rectus femoris, and tibialis anterior. The rectus abdominis, external oblique abdominis, and internal oblique abdominis muscles showed significantly higher activity under conditions of instability of the foot ground contact surface. The upper trapezius, serratus anterior, external oblique abdominis, and tibialis anterior muscles showed significantly higher activity under conditions with a high foot ground contact surface. The upper trapezius, serratus anterior, external oblique abdominis, and tibialis anterior muscles required significantly higher muscle activity under high foot ground contact conditions. It was also suggested that the trunk muscles required significantly higher muscle activity under conditions where the foot ground contact surface was unstable.

The purpose of this study was to clarify awareness regarding the prevention of exertional heat illness among high school baseball athletes and coaches and to examine the issues to be addressed in promoting exertional heat illness prevention in the future. The survey included questions about knowledge, attitude, and practice (KAP) of exertional heat illness prevention, and the facilitators and barriers in the prevention practice. The results showed that both athletes and coaches had good attitudes, but insufficient knowledge and practice. In addition, since there was a difference in KAP scores between athletes and coaches, suggesting that the practice of exertional heat illness prevention is influenced by the presence of others, it would be effective not only to strengthen education but also to increase communication and common awareness between athletes and coaches. It is thought that this will help to strengthen the prevention of exertional heat illness.

In order to evaluate correctly the physical characteristics and motor abilities of youth soccer players, it is necessary to take into account the state of maturity. In this study, we investigated the timing that the variations of the physical characteristics and motor abilities happen on youth elite soccer players in their PHA period with a mixed longitudinal study. Both the thigh circumference and the distance of 5-step bounding of youth elite soccer players show significantly large variations after PHA compared to before PHA (p<0.05). It was also revealed that both height and the time of 50-m sprint show significantly large variations before PHA compared to after PHA (p<0.05).

A single-leg drop landing test was conducted in 71 junior male soccer players. While there was no difference in the center of pressure (COP) trajectory length for the first 200 ms after contact among subjects of different grades, it tended to be shorter in the upper grades 5 seconds after contact. The maximal vertical ground reaction force was 5.19 to 6.82 times the body weight, and its time to peak tended to be shorter in the lower grades.

The coronavirus pandemic has affected sports activities. The athletes experienced unprecedented circumstances of the cancellation of club activities, which affected them physically and psychologically, and may have been related to the occurrence of injuries. The purpose was to investigate the injuries that occurred after the period of restraint in club activities, and to explore the characteristics of the players who were injured after the period of restraint. This study was a cross-sectional survey. The target was students at the University of sports club activities who refrained from club activities for two months. The survey items were the type and location of injuries that occurred after the restraint period, the time difference in practice, the apathy score, WHO-5 during and after restriction. The total number of respondents was 148, and the number of injuries was 52. Sprains occurred in 11 cases, and the most common location of injury was the lower extremity with 36 cases. The number of the injured group was 40, and the number of the uninjured group was 108. The time difference in practice time during and after restraint was significantly greater in the injured group (p<0.05). There was no significant difference in apathy score and WHO-5.

The aim of this study was to investigate the effect of changes in the living environment caused by the emergency declaration issued by the COVID-19 pandemic on the swimmers’ range of activities and mental health, and to examine the differences between swimmers with and without disabilities. The participants were 39 competitive swimmers, including 10 male para-swimmers, 10 female para-swimmers, 10 male swimmers, and 9 female swimmers. The online questionnaire was conducted twice: during the state of the emergency period, and after the period. The differences in the Life-Space Assessment (LSA) and Japanese Apathy Scale (JAS) between para-swimmers and able-bodied swimmers, by gender, were analyzed using a two-way repeated-measures ANOVA during and after the period. Concerning LSA, a significant main effect was shown only in the period related to the state of emergency (p<0.01). Among the female participants, there was a significant interaction effect of JAS (p<0.05). Female para-swimmers may be more susceptible to experiencing changes in mental health following their circumstances. Therefore, it is important to create opportunities for exercise in place of swimming by planning exercises that could be done on the spots, and to consider measures that consider mental health from the aspect of sex and disabilities.