Does the pregnancy-related adaptation of gait biomechanics after childbirth recover to its pre-pregnancy state?: A systematic review.

BACKGROUND: Although changes in the gait biomechanics during pregnancy are known to occur, it is unclear whether they return to their original state after childbirth. RESEARCH QUESTION: The objective of the current systematic review is to summarize existing literature reporting the biomechanical characteristics of gait in postpartum women and to identify knowledge gaps that calls for future investigations in this population. METHODS: Relevant articles were selected using MEDLINE (PubMed), Scopus (Elsevier), Embase (Elsevier), and Web of Science (Clarivate Analytics). Articles were included if they met the following criteria: They must (1) include postpartum women, (2) report measures related to three-dimensional (3D) kinematics and/or kinetics, (3) have been published after 1990, and (4) have been published in English. RESULTS AND SIGNIFICANCE: The current systematic review included a total of 14 articles, five of which compare the data from postpartum women with nulliparous women or pre-pregnancy data. We observed that gait biomechanics changes of postpartum women could persist for more than 5 years after the childbirth. This review provides novel viewpoints on the biomechanics of postpartum women's gait and recommendations for future studies to fully understand these changes and improve postpartum women's physical and mental wellbeing.

Muscle injuries in athletics during the 2020 Tokyo Olympic Games: differences between heats and finals.

BACKGROUND: The aim of this study was to analyze muscle injuries and their related risk factors during the Athletics events of the 2020 Tokyo Olympic Games including the differences in muscle injury rates between heats and finals. METHODS: We included and analyzed in this study muscle injuries diagnosed by either magnetic resonance imaging, ultrasound, or physical examinations by at least two physicians, from Athletics athletes participating at the 2020 Tokyo Olympic Games. Data from electronic medical records, including sex, nationality, event, and the round (heat vs. final) during which the muscle injury occurred and the air temperature in the stadium, measured every five minutes during the competition were extracted. RESULTS: Among the 1631 athletes who competed, a total of 36 athletes (20 males and 16 females) were diagnosed with a muscle injury during the 2020 Tokyo Olympic Games. Among them, 24 occurred during heats (1.47 per 100 athletes) and 12 during finals (2.20 per 100 athletes) (P=0.25). Logistic regression analysis revealed that the geographic region of athletes' origin was a factor associated with muscle injury, with the highest muscle injury rate being in athletes from Africa (odds ratio [OR]=4.74, 95% confidence interval [CI]) = 1.75 to 12.82) and North America (OR=3.02, 95%CI=1.27 to 7.20). For male athletes, competing in finals was a risk factor to sustain a muscle injury (OR=2.55, 95%CI=1.01 to 6.45). CONCLUSIONS: During the 2020 Olympic Games, muscle injury rate was higher in finals than in heats, reaching statistical significance in male athletes.

Differences in screening and treating relative energy deficiency in sport between the United States of America and Japan.

BACKGROUND: The diagnosis and treatment of relative energy deficiency in sport (RED-S) are challenging owing to variations in symptoms and the absence of specific guidelines. This study aimed to investigate differences in the diagnosis and follow-up of RED-S, its consequences, and related factors among sports medicine physicians with different backgrounds in Japan and the USA and examine the differences between the two countries. METHODS: An anonymous survey regarding the diagnosis and treatment processes of RED-S was distributed to sports medicine physicians via email. Respondents included 58 sports medicine physicians from the USA and 241 from Japan. RESULTS: The findings showed that 77.6% of the US physicians screened athletes for RED-S, whereas 17.5% of their Japanese counterparts did so. Moreover, 98.3% and 36.7% of the US and Japanese physicians, respectively, answered that they screened athletes for eating disorders upon suspicion of low energy availability. Logistic regression analysis revealed that the number of US sports medicine physicians who screened athletes for the female athlete triad (Triad) and RED-S (odds ratio [OR] = 12.78, P<0.001) and adhered to specific criteria for athlete suspension and return-to-play (OR=33.67, P<0.01) was higher than that of their Japanese counterparts. CONCLUSIONS: The prevalence of RED-S-related screening and treatment differed between US and Japanese sports medicine physicians. Educating sports medicine physicians about the diagnosis and treatment of athletes with possible signs of RED-S is important in treating female athletes and further investigations are required to identify why the physicians screened/not screened the athletes.

International study of physicians' opinion on physician-patient sex concordance when treating athletes.

BACKGROUND: The effect of physician-patient sex concordance in medicine has been reported in many studies. Whether physicians believe that the sex concordance between physician and athlete influences treatment has not been investigated. OBJECTIVE: To determine whether physicians believe that the sex concordance between physician and athlete influences treatment. DESIGN: Cross-sectional study. SETTING: Online survey. PARTICIPANTS: One thousand one hundred ninety-three sports medicine physicians in 51 countries. Participants were sports medicine physicians trained in orthopedics (n = 443 [37.1%]) and nonorthopedics (n = 750 [62.9%]). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants were asked to decide whether sex of the physician made them better suited to care for athletes of concordant or different sexes along with their personal background. RESULTS: Orthopedic sports medicine physicians agreed less than nonorthopedic sports medicine physicians regarding the statement "MALE sports medicine physicians are better suited than their female counterparts to care for MALE athletes" (odds ratio [OR] 0.56, 95% confidence interval [CI] 0.35-0.91, p = .02), and compared to sports medicine physicians based in Europe, those based in Asia agreed more to this statement (OR 7.91, 95% CI 4.60-13.60, p < .01). In addition, regarding the statement "FEMALE sports medicine physicians are better suited than their male counterparts to care for FEMALE athletes," compared to sports medicine physicians based in Europe, those based in Asia (OR 9.12, 95% CI 5.63-14.79, p < .01) and North America (OR 2.18, 95% CI 1.46-3.25, p < .01) agreed more and orthopedic sports medicine physicians agreed less than nonorthopedic sports medicine physicians (OR 0.61, 95% CI 0.39-0.93, p = .02) to this statement. CONCLUSIONS: Sports medicine physicians trained in orthopedics felt sex concordance was less important than physicians trained in other specialties. Asian sports medicine physicians believed sex concordance was more important compared to physicians in other regions.

Athlete Sleep Behavior Questionnaire in Japanese (ASBQ-J): An Adaptation and Validation Study.

Purpose: The Athlete Sleep Behavior Questionnaire (ASBQ) is an 18-item self-reported questionnaire that can be used to screen for sleep disorders in athletes and assess environmental, behavioral, and sports-related factors along with sleep disorders. This study aimed to analyze the reliability and validity of the ASBQ translated into Japanese (ASBQ-J). Patients and Methods: 111 female collegiate athletes completed both the initial test and retest. Independent variables were what kind of sports they perform, level as an athlete, grade (freshman, sophomore, junior, senior), and age. The reliability of the survey was assessed using Cronbach's alpha and intraclass correlation, and Pearson's correlation coefficient was calculated to determine the correlation between the total ASBQ scores and three components which were routine/environmental, behavioral, and sports factors. Results: A total of 37.8% of athletes had ASBQ scores equal or less than 36 indicating good sleep. However, 19.8% of athletes scored more than 42, indicating poor sleep. Cronbach alpha was 0.62 and 0.65 for test and retest, respectively. Intraclass correlation was 0.78 (P < 0.01), indicating sufficient internal consistency and test-retest validity. Mean ASBQ scores were 38.5 ± 5.0 and 37.0 ± 6.5 for test and retest, respectively, and it was not significantly different between the two groups (P = 0.37). The correlation coefficients between the ASBQ-J and component scores were all statistically significant (all P < 0.01). Conclusion: ASBQ-J is a reliable questionnaire for assessing sleep disorders in athletes whose primary language is Japanese.

Prevalence of anemia and iron deficiency and its association with body mass index in elite Japanese high school long-distance runners.

OBJECTIVES: Anemia is a common condition in long-distance runners (LDRs). Recently, not only iron deficiency (ID) but also energy deficiency has been considered as a risk factor for anemia in athletes but no evidence has yet been established. The aim of this study was to investigate the prevalence of anemia and ID and the influence of body mass index (BMI) on anemia in high-school LDRs. METHODS: The participants were 406 male and 235 female elite Japanese LDRs who competed in the All-Japan High-School Ekiden Championship 2019. They submitted their anthropometric data and results of a blood test within five days after the competition. The prevalence of anemia and ID and the influence of BMI on anemia were assessed retrospectively. RESULTS: Mean hemoglobin concentrations (Hb) were 14.8 ± 0.9 g/dl in males and 13.2 ± 0.9 g/dl in females. The prevalence of anemia (Hb < 14 g/dl in males and < 12 g/dl in females) was significantly higher in males (16.3%) than females (6.4%), but males also showed higher prevalence of non-iron deficiency anemia (NIDA) than females (11.6% and 3.0%, respectively). No significant gender difference was found in the prevalence of iron deficiency anemia (IDA) (4.7% in males and 3.4% in females). ID (serum ferritin level < 25 ng/ml) was significantly more prevalent in females (37.4%) than males (18.5%). A binary logistic regression analysis revealed that low BMI was a contributor to anemia in females (odds ratios: 0.577 (95% CI: 0.369-0.901), p = 0.012). CONCLUSION: In Japanese high-school LDRs, one in six males was anemic, but most males did not have ID. Conversely, one-third of females were diagnosed with ID. Lower BMI was identified as a risk for anemia in females, suggesting that leanness may also lead to anemia in females.

Awareness and Knowledge of Medical Issues Related to Female Athletes Among Track and Field Coaches.

Introduction: Little is known regarding medical knowledge pertaining to female athletes among track and field coaches and their interactions with female athletes regarding medical problems. Methods: Participants were track and field coaches (369 males and 43 females) with Japan Sport Association certification and they completed an anonymous survey on their knowledge of medical problems pertinent to female athletes including whether the coaches knew about the female athlete triad and relative energy deficiency in sports; their feelings about female athletes' use of contraceptive pills; whether they speak about menses with the female athletes; and whether they have a gynecologist for consultation regarding their medical problems. Results: Females coaches were significantly more likely to be aware of the triad (odds ratio (OR), 3.44; p = 0.003); to have access to a physician able to address the gynecological problems of female athletes (OR, 9.22; p < 0.001); and to talk to their female athletes about menses (OR, 2.30; p = 0.015) than their male counterparts. Coaches with more experience tended to be aware of the triad and relative energy deficiency in sports compared with those with ≤5 years of experience. Conclusion: Females coaches are aware of the triad, talk about menses with their female athletes, and have access to a physician who can address gynecological problems with compared to male counterparts. Educating all coaches on these problems is essential to provide adequate support to female athletes.

Controlling Behavior, Sex Bias and Coaching Success in Japanese Track and Field.

Coaching athletes is a complex and lengthy process. Recently, attention has been given to coaches over-controlling behavior toward the athletes' personal lives and possible sex bias, but the impact of these behaviors on coaching success is unclear. An anonymous survey was answered by 412 track and field coaches (male: 369; female: 43), comprising questions regarding controlling behaviors, sex bias, and personal background. A Chi-square test and logistic regression were performed to determine the factors related to the coach's characteristics and their success in coaching athletes (to national vs. non-national level). The results showed that controlling behaviors and sex-bias-related beliefs were present. The coaches who coached national-level athletes were more likely to be older, more experienced, and were national level athletes themselves. More national-level coaches reported controlling behaviors but fewer held sex bias beliefs than the non-national level coaches. However, the strength of these beliefs (scores for controlling behavior and sex bias) was not related to the coaching success.

An international study on attitudes and opinions regarding female sports medicine physicians during pregnancy and the postpartum period.

OBJECTIVES: Supporting female sports medicine physicians to simultaneously be mothers and pursue professional careers is crucial to maintain gender diversity in sports medicine physicians. The purpose of this study is to understand the attitudes toward female sports medicine physicians during pregnancy and postpartum. METHODS: An anonymous online survey was distributed to sports medicine physicians practicing in 51 different countries. They were asked how comfortable they felt with female sports medicine physicians working on the sidelines of sporting events during pregnancy, if the female sports medicine physicians were as productive as their male counterparts after giving birth, and how satisfied they were with the percentage of female sports medicine physicians in their country. Data were analyzed using the chi-square test, and multivariate logistic regression analysis was performed to identify independent variables. RESULTS: In total, 1193 physicians (380 [31.9%] female) were included for analysis. Physicians in Asia were the least comfortable with pregnant sports medicine physicians working on the sidelines and those in North America were the most comfortable (odds ratio = 0.28 and 2.51, 95% confidence interval 0.18-0.44 and 1.55-4.06, respectively). More experienced sports medicine physicians (odds ratio = 1.01, 95% confidence interval 1.00-1.03; p < 0.05) and divorced physicians (odds ratio = 0.33, 95% confidence interval 0.12-0.91; p < 0.05) were less comfortable with pregnant female sports medicine physicians working on sidelines, and those trained in orthopedics were less likely to agree that female sports medicine physicians were equally as productive as male counterparts postpartum (odds ratio = 0.29, 95% confidence interval 0.10-0.88; p < 0.05). Female physicians were less satisfied with the percentage of female sports medicine physicians in their country (odds ratio = 0.41, 95% confidence interval 0.27-0.60; p < 0.01) than their male counterparts. CONCLUSIONS: Female sports medicine physicians may experience bias in their practice during pregnancy and postpartum.

Association between Self-reported Overtraining Syndrome and Symptoms in High School Track and Field Athletes.

Diagnosing overtraining syndrome is challenging and it is often correlated with other diseases, especially those related to low energy availability. Therefore, we investigated the prevalence of overtraining syndrome-like symptoms and correlative factors in 389 female and 572 male national-level high school track and field athletes. They were asked to complete a survey regarding their history of overtraining syndrome-like symptoms, injuries, and diseases. The survey results revealed that 13.4% (52/389) of female and 13.3% (76/572) of male athletes had a history of overtraining syndrome-like symptoms. Logistic regression analysis showed that training hours per day (odds ratio, 1.74; 95% confidence interval, 1.12-2.71) was an associated factor in female athletes, while rest days per week (odds ratio, 0.61; 95% confidence interval, 0.37-1.00), skipping meals (odds ratio, 3.73; 95% confidence interval, 1.50-9.29), and having snacks/light meals on a regular basis (odds ratio, 0.46; 95% confidence interval, 0.26-0.83) were the associated factors in male athletes. In conclusion, athletes with overtraining syndrome-like symptoms may be prone to injuries and diseases. Hence, although overtraining syndrome is difficult to diagnose, further attention should be paid to minimize overtraining syndrome-related risks.

Risk Factors for Contracting COVID-19 and Changes in Menstrual and Sleep Cycles in Japanese Female Athletes during the COVID-19 Pandemic.

Although research on COVID-19 is prevalent, risk factors for contracting COVID-19 and lifestyle changes in athletes during the COVID-19 pandemic have not been thoroughly investigated. This study included 254 female collegiate athletes and 107 female non-athletes from Japan, who completed an anonymous survey comprising questions about COVID-19, personal background and lifestyle changes during the pandemic. A total of 6.30% athletes and 6.54% non-athletes had tested positive for COVID-19. The majority reported no change in menstrual cycle (80.31% and 78.50% for athletes and non-athletes, respectively). Wake-up time and bedtime were delayed in some athletes (42.13% and 39.25%, respectively) and non-athletes (46.73% and 31.30%, respectively) during the pandemic. Body mass index (BMI) was significantly higher in COVID-19 (+) athletes than in their COVID-19 (−) counterparts (22.78 ± 3.40 and 21.26 ± 2.06, respectively, p < 0.01) and logistic regression analysis revealed that younger students and those with higher BMI had an increased risk of contracting COVID-19. The proportion of vaccinated students was significantly higher in athletes than in non-athletes (p < 0.01). Whether the student was an athlete or not was not a related factor in contracting COVID-19. Extra attention should be focused on athletes experiencing weight gain or staying up late and experiencing lower quality sleep.

Gender bias in sports medicine: an international assessment of sports medicine physicians' perceptions of their interactions with athletes, coaches, athletic trainers and other physicians.

OBJECTIVES: To evaluate the difference between female and male sports medicine physicians regarding disrespectful attitudes and sexual harassment perceived from athletes, coaches, physicians, athletic trainers (ATs) and organisations/administrations. METHODS AND STUDY DESIGN: anonymous survey was distributed to sports medicine physicians practicing in 51 countries. χ2 analysis was used to detect differences between female and male sports medicine physicians and logistic regression analysis was used to determine the independent variables that affect disrespectful attitudes and sexual harassment from sports participants. RESULTS: 1193 sports medicine physicians (31.9% female) participated from 51 countries. The survey revealed that female physicians, compared with male physicians, perceive significantly more disrespect or have their judgement questioned more by the following categories: male and female athletes, male and female coaches, female physicians with more years of experience, male physicians (regardless of years of experience), male and female ATs and organisation/administrations (all p<0.05). The only category where the frequency of disrespect was perceived equally by male and female physicians was during their interactions with female physicians who have the same or lesser years of experience. Female sports medicine physicians noted more sexual harassment than male physicians during interactions with male athletes, coaches, ATs and physicians (all p<0.001). In the logistic regression, gender was a related factor for perceiving disrespect, especially from male coaches (OR=2.01) and physicians with more years of experience (OR=2.18). CONCLUSIONS: Female sports medicine physicians around the world experience disrespectful attitudes, questioning of their judgement and are sexually harassed significantly more often than male counterparts.

Training and physiological characteristics of American and Japanese female track and field athletes.

BACKGROUND: Intensive training without appropriate recovery can predispose athletes to injury. Balancing these two facets - training and recovery - is crucial for keeping athletes at their highest possible performance level while lowering their risk of training-related injury. Cultural differences may also affect athletes' training and daily routines, but research investigating the effects of cultural background on female track and field athletes is lacking. METHODS: In total, 49 Japanese and 28 American track and field athletes competing at the national level were included in this study. Their body composition was evaluated and eating attitudes test (EAT-26) and a survey regarding training schedules, recovery practices, and performance levels were conducted. RESULTS: Compared with the Japanese athletes, the American athletes had significantly higher height, weight, and Body Mass Index measurements, although their performance levels did not differ. Japanese athletes trained for significantly longer hours both on school days and non-school days and spent significantly fewer days per week on weight training. The Japanese athletes slept, on average, for 1 hour less per day than the American athletes, and their EAT-26 scores were significantly higher than those of the American athletes (both P<0.01). The number of days off per week was positively correlated with performance, but training hours on school days and fat mass percentage were negatively correlated with performance (P<0.05). Further, days off per week and nationality were correlated with EAT-26 scores (both P<0.05). CONCLUSIONS: The American and Japanese athletes performed similarly, but the Japanese athletes were achieving their performance level with less sleep, longer training hours, and a higher risk of developing an eating disorder.

Factors that affect menarche in Japanese national-level track-and-field athletes.

OBJECTIVES: The minimum body mass index (BMI) required to menarche and the relationship between the training onset age of sports and menarche is not fully understood. The aim of this study is to elucidate the minimum BMI required to attain menarche in female adolescent athletes competing at a national level, and to determine how the occurrence of menarche is associated with training onset age in track-and-field athletes. METHODS: Overall, 134 sprinters and 44 long-distance (LD) runners of ninth-grade females at a national level were enrolled and an anonymous questionnaire was administered. RESULTS: As BMI increased, the proportion of athletes who had attained menarche increased. The BMI cutoff values for menarche were 17.3 and 17.1 kg/m2 for sprinters and LD runners, respectively. Menarche had not occurred in almost 50% of the LD runners who began training at elementary school, and among LD runners, those who began training at elementary school had 18.4 higher odds of not attaining menarche until the age of 15 years as opposed to those who started training after elementary school. CONCLUSIONS: The BMI cutoff values could be an indicator for menarche in sprinters and LD runners. For LD runners, starting to compete at elementary school could be a risk factor for delayed menarche.

Bone parameters of elite athletes with oligomenorrhea and prevalence seeking medical attention: a cross-sectional study.

INTRODUCTION: Since the definition of secondary amenorrhea is cessation of regular menses for more than 3 months, it is likely that athletes with irregular menstrual cycles, including oligomenorrhea, do not consider the condition as serious. However, the consequences of untreated oligomenorrhea have not been investigated in elite track and field athletes. MATERIALS AND METHODS: The cohort consisted of 91 elite-level track and field athletes. Body compositions, including bone parameters and bone turnover markers (BTMs), were measured. RESULTS: Among the 91 participants, 52 were eumenorrheic and 33 were oligomenorrheic. The eumenorrheic athletes had significantly higher bone mineral density (BMD) and bone mineral content (BMC) of the lumbar spine, lower extremities, and whole body than had the oligomenorrheic athletes (p < 0.01). There were no significant differences in BTMs between the two groups, but oligomenorrheic athletes had significantly lower percent body fat. CONCLUSION: More than 40% of the elite-level female track and field athletes in this study reported menstrual disorders with oligomenorrhea as the most common. However, none sought medical attention. As compared to the eumenorrheic athletes, the oligomenorrheic athletes had lower BMC and BMD. Hence, if an athlete is oligomenorrheic, bone parameter measurements are considerably important.

Bone Metabolism, Bone Mineral Content, and Density in Elite Late Teen Female Sprinters.

With intensive training, bone injuries are a major concern for athletes. To assess bone condition, we often measure bone turnover markers, bone mineral content and density; however, in junior athletes, it is not easy to distinguish changes caused by bone injuries from those caused by growth, because the metabolism is increased in both cases. Moreover, although some studies have examined female endurance athletes, knowledge regarding changes in static and dynamic bone conditions in late teen athletes is limited. In this study, we measured the bone mineral content and density, as well as bone turnover markers, in 40 elite female sprinters in their late teens. Whole body mode dual-energy X-ray absorptiometry was performed to measure bone mineral content and density. Blood samples were collected to determine bone resorption and formation markers at the end of track season in 2016 and during the same period of the following year. Body weight and bone mineral content significantly increased, and tartrate-resistant acid phosphatase type 5b, bone-type alkaline phosphatase, and osteocalcin significantly decreased after a year. Furthermore, the rate of change in bone mineral content was higher in younger athletes, indicating that bone growth approaches completion in the late teen years and that bone metabolism accordingly decreases.