Conventional orthopaedic and dental device materials are made of metallic materials such as stainless steel (SUS316L), titanium alloy (Ti-6Al-4V), and cobalt-chrome (Co-Cr). Those materials have the disadvantage of mechanical properties and anti-corrosion behavior. Bulk metallic glasses (BMGs), which are also called amorphous alloys, are metallic materials with metastable glassy states and have a higher strength, higher elasticity, higher failure resistance, and lower Young’s modulus compared with crystalline alloys. There are several types of BMGs. Among them, Zr-based BMGs and Ti-based BMGs have excellent mechanical properties. In addition, they have good corrosion resistance and are promising for orthopaedic and dental device materials. In this review article, in vitro and in vivo studies regarding Zr and Ti-based BMGs applications as biomaterials, especially in orthopaedic and dental device materials, are reviewed.

Background: In recent years, there has been a trend in badminton toward more specialized training at an earlier age. Accompanying this trend is the increased frequency of injuries in young players. Ankle injury is the most common injury in pediatric sports; however, its influence on subsequent injuries is rarely considered. Purposes: To evaluate the incidence of ankle, knee, and shoulder injuries in youth badminton and to investigate the influence of ankle injuries on subsequent ankle, knee, and shoulder injuries. Study Design: Descriptive epidemiology study; Level of evidence, 3. Methods: A custom-designed questionnaire was used to survey Japanese players 7 to 12 years of age who attended national elementary school–level badminton tournaments between May and September 2019. Information including the players’ characteristics, training history, injuries in the previous 12 months, and ankle injury histories were collected. Logistic regression was used for analysis. Results: A total of 478 players were included in the study, with 71 ankle injuries, 74 knee injuries, and 48 shoulder injuries reported. The injury incidence rates (per 1000 hours of play) were 0.23 (95% CI, 0.18-0.29) for the ankle, 0.24 (95% CI, 0.19-0.30) for the knee, and 0.16 (95% CI, 0.11-0.20) for the shoulder; 90.1% of ankle injuries, 25.7% of knee injuries, and 33.3% of shoulder injuries were acute. Previous ankle injury was significantly associated with subsequent ankle injury (adjusted Odds Ratio (OR), 3.05; 95% CI, 1.54-6.07; P < .05), knee injury (adjusted OR, 2.03; 95% CI, 1.12-3.69; P < .05), and shoulder injury (adjusted OR, 2.46; 95% CI, 1.26-4.83; P < .05). Conclusion: The study results indicated that previous injury to the ankle significantly increased the occurrence of subsequent ankle, knee, and shoulder injuries. Emphasizing protection and prevention of ankle injuries may help lower future injury risk in young badminton players.

Reproductive-aged women experience somatic and affective symptoms of premenstrual syndrome (PMS) which affect their daily life and work, but there are limited tracking data on senior high school-age female students. To investigate the characteristics and incidence of PMS, and to detect the relationship between physical exercise participation and PMS in female students of senior high school. A prospective study was conducted among senior high school female students aged 14–16 years. The participant was asked to finish two questionnaires. One questionnaire collected information about demographic data and PMS symptoms which were recorded on a daily calendar named Daily Record of Severity of Problems (DRSP) per day. Another questionnaire was physical exercises participation questionnaire, collecting times of physical education (PE) class participation, exercise times, exercise type participation in morning exercise and recess exercise, times of morning exercise, times of recess exercise per week, recess exercise time, and autonomous exercise participation of students. The data were prospectively recorded for three consecutive months. Odds ratio (OR) with 95% confidence intervals (CI) was performed for results of the multivariate logistic regression analysis model. A total of 233 participants completed the prospective study, 78 (33.5%) participants experienced PMS. The incidence of the participants with mild PMS was 20.2% while moderate PMS was 11.6% and severe PMS was 1.7%. The most common somatic symptom was fatigue while the most common affective symptom was cannot concentrate. Participants with PE classes less than 2 times per week were 4.43 times (OR 4.43, 95% CI 1.18–16.6, p < 0.05) more possible to experience PMS than those with 2 times PE classes per week. PMS is a frequent phenomenon in senior high school female students. Female students with 2 times PE classes per week show a lower incidence of PMS. This study encouraged senior high school-age females to take more physical exercises per week and could be helpful to create a no-pharmacology coping strategy.

Badminton-related injury is thought to happen with increasing incidence among badminton players. Literature shown injury incidence across age is scarce. The objective was to investigate the epidemiological characteristics of badminton-related injuries among badminton players broken down by age and sex. This epidemiology study is a retrospective design in 7–22-year-old badminton players at a national competitive tournament with a questionnaire from 2018 to 2023. An injury was defined as somatic complaint with time loss and/or medical care. Badminton-related injuries were normalized to rate per 1000 training-hours calculated by Poisson distribution in the collected data according to age and gender. Among all the 711 badminton players, 60.3% (429 players) suffered from at least one badminton-related injury. Regardless of gender, the most frequently injured anatomical site was knee (male: 18.8%, female: 18.6%), followed by ankle (male: 13.4%, female: 13.4%) and lower back (male: 12.3%, female: 10.0%). In male badminton players, the shoulder (7.6%) ranked fourth as the plantar (6.7%) ranked fourth in female badminton players. The rate per 1000 training-hours of badminton-related injuries showed that male players peaked at age 15–16 years and female players peaked at age 17–18 years, with 3.24 injuries and 3.52 injuries per 1000 training-hours, respectively. In 7–22-year-old badminton players, knee, lower back, and shoulder injuries frequently occurred and were significantly associated with the incidence of badminton-related injuries. The peak incidence of badminton-related injuries was in 15–16-year-old male badminton players while the peak incidence was in 17–18-year-old female badminton players. These data have the potential to help target the most at-risk anatomical sites and the most at-risk badminton players precisely for injury prevention programs.

Body pain, often considered as an early sign of injury in young players, warrants thorough study. This study aimed to examine the distribution of badminton-related pain and prevalence in pre-adolescent and adolescent badminton players. Profiles of badminton-related pain were surveyed using a questionnaire among 366 pre-adolescent and adolescent badminton players aged 7–12 years. The distribution of badminton-related pain was described, and the pain incidence was calculated. Proportions of pain per 1000-training-hour exposures were the main outcome measures. The analysis considered various age groups (7–8, 9–10, and 11–12 years) and years of badminton experience (≤2, 2–3, and > 3 years). In total, 554 cases of badminton-related pain were reported. The ankle was the most common site, followed by knee, plantar, shoulder, and lower back. The overall pain rate per 1000-training-hour exposure was 3.06. The 11–12-year-old group showed the highest pain rate, significantly greater than the 7–8-year-old group and the 9–10-year-old group. Additionally, the prevalence of pain exhibited an increasing trend with age. Finally, regardless of the age groups, participants with 2–3 years of badminton experience had the highest pain rate. These findings might help inform targeted interventions to reduce the high prevalence of pain in various body regions across pre-adolescent and adolescent badminton players.