Sex Differences in Young Gymnasts' Postural Steadiness

Puberty is characterized by large hormonal changes, resulting in both physical and sexual maturation. Intense training and low body fat has been found to delay the onset of puberty in females by altering normal hormonal development. In males, despite evidence that physical activity can also result in hormonal changes, intense gymnastics training has not been associated with changes in the onset of puberty, if body composition is within normal range. PURPOSE To assess sexual maturation, hormonal levels, and body fat among competitive male and female Canadian gymnasts and age-matched controls. METHODS The gymnastics group, comprised of 21 male (13.3 ± 0.3y) and 18 female gymnasts (13.4 ± 0.2y), was compared to 24 age-matched male (13.5 ± 0.3y) and 24 female (13.9 ± 0.1y) controls. Sexual maturation was self-assessed using the Tanner Scale. For the male subjects, testosterone levels were determined from saliva samples. For the female subjects, progesterone and estradiol (17-β) were measured from blood samples. For menstruating subjects, age at menarche was reported and blood draws were performed twice: in the follicular and luteal phase of the menstrual cycle. Relative body fat (%BF) was assessed using bioelectrical impedance analysis. RESULTS There were no significant differences between the male gymnasts and controls in salivary testosterone (43.3 ± 5.8 vs. 38.2 ± 4.1 pg ± ml−1), genital development (stages: 3.2 ± 0.2 vs 3.5 ± 0.1) or pubic hair development (stages: 3.5 ± 0.1 vs. 3.6 ± 0.1). Male gymnasts were similar in size, but had significantly (p≤0.05) lower %BF than the controls. Female gymnasts were significantly (P≤0.01) smaller, and had significantly (P≤0.01) lower body fat than female controls. Twenty-one female controls and one gymnast were menarcheal, with the average age at menarche being 12 ± 0.1y for the controls, and 13 for the menarcheal gymnast. Serum estradiol and progesterone levels for the pre-menarcheal gymnasts were similar to those measured in the controls during the follicular phase, which were significantly lower (P≤0.01) than those measured during the luteal phase. Breast development was delayed in female gymnasts compared to controls (stages: 2.7 ± 0.2 vs 3.8 ± 0.1), while the difference between the groups in pubic hair development did not reach significance (stages: 3.1 ± 0.2 vs 4.0 ± 0.2). CONCLUSION While the intense training by the young male gymnasts resulted in a decreased %body fat, there was no apparent alteration in the timing and extent of their physical and pubertal development. On the other hand, a delayed menarche, reduced physical and sexual maturation, and a low %body fat were found in the females engaged in gymnastics training.

Sports performance is strongly influenced by the athletes’ anthropometric profile. In the specific case of Gymnastics, body weight assumes particular relevance, given the aesthetic character of this sport. Anthropometric data were collected from 309 gymnasts (20.9 ± 4.1 years old) participating in the 2015 European Games: age, body weight and height, from a database of the organization of this competition available online in the 5 disciplines of the Gymnastics included in the competition, namely Men´s and Women´s Artistic Gymnastics, Rhythmic Gymnastics, Acrobatic Gymnastics and Aerobic. Body mass index was calculated. Female gymnasts were significantly younger and lighter than male gymnasts and had a lower body mass index than males (P = 0.000). Female athletes were in the 25th percentile for weight and BMI and in the 15th percentile for height, according to their age. Male gymnasts were in the 25th percentile for weight, height and BMI. Female acrobatic gymnasts were younger and lighter (25th percentile) than other gymnastics disciplines; rhythmic gymnasts presented the lowest BMI (5th percentile). Male artistic gymnasts were the lightest (15th percentile) and with the lowest BMI (25th percentile) within the male participants. BMI was dependent on weight, height and gender, with exception for exclusive-gender disciplines and, surprisingly, also in Aerobics. Gymnasts presented an anthropometric profile with results for body weight, height and body mass index below the normal for their age.

Visually-induced illusions of self-motion (vection) can be compelling for some people, but they are subject to large individual variations in strength. Do these variations depend, at least in part, on the extent to which people rely on vision to maintain their postural stability? We investigated by comparing physical posture measures to subjective vection ratings. Using a Bertec balance plate in a brightly-lit room, we measured 13 participants' excursions of the centre of foot pressure (CoP) over a 60-second period with eyes open and with eyes closed during quiet stance. Subsequently, we collected vection strength ratings for large optic flow displays while seated, using both verbal ratings and online throttle measures. We also collected measures of postural sway (changes in anterior-posterior CoP) in response to the same visual motion stimuli while standing on the plate. The magnitude of standing sway in response to expanding optic flow (in comparison to blank fixation periods) was predictive of both verbal and throttle measures for seated vection. In addition, the ratio between eyes-open and eyes-closed CoP excursions during quiet stance (using the area of postural sway) significantly predicted seated vection for both measures. Interestingly, these relationships were weaker for contracting optic flow displays, though these produced both stronger vection and more sway. Next we used a non-linear analysis (recurrence quantification analysis, RQA) of the fluctuations in anterior-posterior position during quiet stance (both with eyes closed and eyes open); this was a much stronger predictor of seated vection for both expanding and contracting stimuli. Given the complex multisensory integration involved in postural control, our study adds to the growing evidence that non-linear measures drawn from complexity theory may provide a more informative measure of postural sway than the conventional linear measures.

In previous studies, many evaluation parameters for the center of foot pressure (CFP) in a static standing posture have been proposed, but their reliability and inter-relationships have not been sufficiently examined.The purposes of this study were to examine trial-to-trial reliability and the inter-relationships of various evaluation parameters and to propose useful ones. Thirty healthy young adults were selected as subjects. The measurement of CFP for 1 minute was carried out 10 times with 1 minute rest for each subject. The measurement device was an Anima's stabilometer G5500. The data was recorded every 20 msec. Seventy-six evaluation parameters, excepting composite parameters from 114 parameters proposed in previous studies, were selected from the following domains: distance, center of pres-sure, distribution of amplitude, area, velocity, power spectrum, and vector for body sway. The intraclass correlation coefficients (ICC) for 10 trials were 0.7 or over for all parameters excepting for the X-axis and the Y-axis distribution for body sway, and skewness and kurtosis for body sway speed, but a significant difference between the first trial and the other trials was found in many parameters. Therefore, the ICC was recal-culated by excluding the first trial. As a result, no significant difference was found other than that of the distance of the root of the mean square and the area of the root of the mean square. The ICC was 0.7 or over, excepting for the following parameters: the X-axis and the Y-axis distribution for body sway and skewness and kurtosis for body sway speed, the cross correlations for body sway and body sway speed, the C ratio of the power spectrum area on the X-axis, the A ratio of the power spectrum area on the Y-axis and the root of the mean square-axis. Inter-correlation coefficients between parameters in each domain of distance, center of pressure, distribution of amplitude, area, velocity, power spectrum, and vector for body sway were mostly high values of 0.9 or over. Thus, it was considered that there is a close relationship between theoretically similar parameters and any of them could be selected as useful parameters.Based on the above-stated examination, 60 evaluation parameters shown in Table 5 were finally selected.

Objectives: Young male gymnasts are a frequently injured, yet infrequently studied population. Literature on gymnastics injuries has focused primarily on female gymnasts at elite and collegiate levels. Gymnastics equipment, rules, and training methods have continued to evolve over the past few decades so the previous data likely does not reflect current injury patterns. Our study aimed to provide a description of injury patterns for contemporary club-level, pre-collegiate male gymnasts. Methods: This was a retrospective chart review of 163 gymnastics injuries from 84 male subjects ages 4–19 years. Subjects were seen between 2010 and 2019 in pediatric sports medicine clinics. Gymnast demographics, injury locations, injury types, and gymnastics apparatus were collected as available. Results: Our cohort had a mean age of 12.5 ± 3.0 years, gymnastics participation for 8.1 ± 2.9 years, and gymnastics level of 7.4 ± 1.7. Overuse injuries (59.5%) were more common than acute injuries (40.5%). The most common injury locations were lower extremity (42.3%), followed by upper extremity (32.5%), spine/trunk (19.6%), and head/neck (5.5%). The leading injury types were strains (16.6%) and apophysitis (12.9%). The most common apparatus for injury was floor (25%) followed by vault (20%). Binomial logistic regressions revealed that higher gymnastics level (OR = 5.19, p = .031) and younger age (OR = 4.05, p = .012) were predictors of lower extremity injuries. Conclusion: Our data show that injuries among club-level, young male gymnasts were most frequently located in the lower extremities. This contrasts older studies of primarily elite male gymnasts where injuries were more common in upper extremities. Overuse injuries were most prevalent in our cohort, and the most frequent injury types were strains and apophysitis.

Time course of stabilometric changes after a strenuous treadmill exercise

Curved walking in hemiparetic patients

Background: It is beneficial for gymnasts to train key lumbopelvic musculature to decrease or prevent low back injury. This study compares lumbopelvic exercises and yoga on lumbar muscle endurance, lumbopelvic stabilization, abdominal strength and balance in adolescent female gymnasts and the effect on low back pain. Material/Methods: 13 participants were randomly allocated to a lumbo-pelvic or yoga group intervention and performed specific exercises for 6 weeks. Biering-Sorensen Test, Lumbopelvic Control Test, Side Bridge Test, and Star Excursion Balance Test were conducted on the participants before and after the 6-week intervention and low back pain logbooks were completed. Results: The Biering-Sorensen Test was significantly greater results for the lumbopelvic group compared to the yoga group. Both groups had significant changes over time with the Lumbopelvic Control Test but no group difference. Both groups had significant improvement with the Side Bridge with the yoga group benefitting more on the left. Out of the six fully completed logbooks, the yoga group showed less occurrence of low back pain compared to the lumbopelvic group. Conclusions: Yoga and lumbopelvic stabilization exercises are equally effective in developing lumbar muscle endurance, lateral stability and front-on stability for young non-elite gymnasts. This is important as they are under-represented in research but overrepresented in participation. This study sets the basis for further research on the incidence of low back pain in young gymnasts and the effects of age-appropriate exercises as a preventative matter.

The purpose of this study was to investigate the trend of eating disorders in competitive male and female artistic gymnasts. The study involved 23 male and 42 female gymnasts, aged 7-27, from sports clubs throughout Greece. The EAT-26 Diet Attitudes scale was used to investigate participants' eating habits. The data collection process included communication with sports organizations throughout Greece on the content and purpose of the research. After consultation, the questionnaire was due to the COVID-19 pandemic provided in an electronic form and also included the consent form for participation in the research. The results of the study indicated that eleven of the sixty-five gymnasts had a total score of >20 on the EAT-26, a rate higher among female gymnasts (~ 24%) compared to male gymnasts (~ 4.4%) (p <.05). Although female gymnasts develop more eating disorders and bulimia than male gymnasts, no significant differences were found in the subscales of the questionnaire (p > .05). Therefore, this finding in combination with the fact that most of the gymnasts were teenagers (15.23 ± 6.35 years old) requires particular importance and attention from coaches and the family environment.

Many studies have analyzed gymnastics-related injuries in collegiate and elite athletes, but there is minimal literature analyzing the epidemiological characteristics of injuries in the greater gymnastics community. A higher incidence of injuries in younger gymnasts between the ages of 6 and 15 years compared with those 16 years and older and a difference in the distribution of injuries between male and female gymnasts. Retrospective cross-sectional study. Level 3. The National Electronic Injury Surveillance System (NEISS) was queried for all gymnastics-related musculoskeletal injuries presenting to the emergency department (ED) between 2013 and 2020. Incidence was calculated as per 100,000 person-years using the weighted estimates provided by NEISS and national participation data. Chi-square and column proportion z-testing was used to analyze where appropriate. The incidence of gymnastics-related musculoskeletal injuries was 480.7 per 100,000 person-years. Most ED visits were children between the ages of 6 and 15 years (84.0%). Younger gymnasts (ages 6 to 10) were most likely to experience a lower arm fracture, while those over the age of 10 years were most likely to experience an ankle sprain (P < 0.01). Men and boys presented with a much greater proportion of shoulder injuries (8.0% vs 3.9%), while women and girls presented with a greater proportion of elbow injuries (9.9 % vs 5.9%) and wrist (10.5% vs 8.3%) injuries (P < 0.01). As hypothesized, most gymnastics-related injuries between 2013 and 2020 were athletes between 6 and 15 years old. Many of these athletes are attempting new, more difficult, skills and are at increased risk of more acute injury when attempting skills they may be unfamiliar with. With increased pressure to specialize at an early age to maintain competitiveness and learn new, higher-level skills compared with their peers, younger athletes are most susceptible to acute injury. New injury prevention strategies could be implemented to help this high-risk population compete and train safely.

BackgroundBalance disorders in patients diagnosed with Parkinson’s disease (PD) are associated with a change in balance-keeping strategy and reflex disorders which regulate the maintenance of vertical body posture. Center of foot pressure (COP) displacement signals were analyzed during quiet standing experiments to define such changes. The research aimed to apply stock exchange indices based on the trend change analyses to the assessment of a level of the Parkinson disease progression on the grounds of the analysis of the COP signals.Methods30 patients in two stages of PD, 40 elderly participants, and 20 individuals at a young age were studied. Each person was subjected to 3 measurements with open and closed eyes. A technical analysis of the COP displacement signal was performed, and the following quantities were determined: indices related to the number of trend changes (TCI), indices defining a mean time (TCI_dT), and mean displacement (TCI_dS) and mean velocity (TCI_dV) between such changes.ResultsThe results indicate a higher TCI value for PD than for aged-matched control group (p < 0.05). In the case of PD patients, there was also an increase in the TCI_dS value by 2–5 mm, which mainly contributed to the increase in TCI_dV. Statistically significant differences for the TCI_dT values occurred between all groups in which differences in the average COP velocity were noted.ConclusionsThe TCI and TCI_dV results obtained for the healthy participants enabled the development of indices supporting PD diagnostics. The causes of the TCI_dV changes in patients were determined, i.e., whether they resulted from an increase in the TCI_dT or TCI_dS between the moments of trend changes indicated by the developed algorithm. The developed methodology provides new information on the impact of PD on the strategy of maintaining balance, which was impossible to obtain using currently used analyses.Trial registration The conducted research is an observational study and does not include a health care intervention. Participants gave their consent to participate in the research and the procedure was approved by the Institutional Bioethics Committee.

Can osteopathic manipulative treatment modify the posture in elderly people? – A single-case study

Gymnastics is a sport where there always exists a real and present danger of physical injury. Athletic injury, whether temporary or permanent, is a painfully disruptive and uncontrollable interruption in a gymnast's career. Injuries can have profound negative consequences on a gymnast’s balance, with lower limbs injuries constituting the majority of these injuries. The purpose of this study was to assess differences in postural stability between high level male and female artistic gymnasts who suffered ankle sprain injuries (ASI) on either or both legs in the past. Ten female (age = 16.66 ± 3.20 years, mass = 47.30 ± 8.00 kg, height = 158.00 ± 5.75 cm) and ten male gymnasts (age = 22.30 ± 1.77 years, mass = 62.00 ± 3.33 kg, height = 168.50 ± 3.03 cm) volunteered to participate in this single visit study. Participants were measured for Limits of Stability variables (Reaction Time [RT]; Center of Gravity Velocity [MVL]; Directional Control [DCL]; End Point Excursion [EPE]; Maximum Excursion [MXE]) to examine the effect of ASI on postural stability. Limits of Stability (LOS) test were used to examine postural stability of gymnasts using the EquiTest Computerized Dynamic Posturography system. Results indicated that females had significantly less ASI than male gymnasts and recorded significantly lower values in Reaction Time and higher values in Movement Velocity during LOS test. In conclusion, the number of past ASI influence postural control as the musculo-tendinous changes around the ankle lead to a reduction of proprioceptive information and may contribute to the deficient postural control mechanisms after injury. Furthermore, postural control may be affected even after acute ASI resolution

The upright standing posture of human beings is unstable because of the inverted pendulum characteristics of the body. The posture control function is explained in the physiology by the stretch reflexes. The functional properties of the posture control are reflected to the area of body away during standing. Such integrated information as area of body sway and length of locus of body sway is applied to the diagnosis of sensory disabilities affecting posture control and the physical education study, etc. However, there have been few reports on the differential information of body sway. The aim of this study is to propose an extraction method of differential information from the time series of the center of foot pressure (CFP) at standing using an autoregressive model. The differential information proposed here is the velocity, the acceleration, and the wave number of the time series of CFP. It describes the relation between the differential information and integrated information of body sway. The differential information is effective in evaluating the postural reflex during an upright standing task.

This study aimed to determine feasibility and reproducibility of muscular strength measurements in young gymnasts, using hand-held dynamometry in gymnastics-specific body positions. A group of 32 male and female young gymnasts 8–11 years-old, performed different strength tests using a Nicholas Manual Muscle Tester (NMMT). The measurements were collected in 4 major muscle groups (shoulder flexors and extensors, hip flexors and extensors) at 22 different joint angular positions, with the active elbow or knee joint in full extension. The maximal strength was obtained by placing the NMMT in a distal forearm or shank position, with the gymnast in supine or prone position stabilized on a vault. A Myrin goniometer, attached on the sagittal plane near elbow or knee joint, was used to specify the shoulder and hip joint angular positions. In the majority of the measurements (18 out of 22 angular positions) the intra-class correlation coefficients revealed a good level of test-retest reliability (R = 0.80–0.88). In four cases (3 in shoulder flexors and 1 in shoulder extensors) intra-class reliability was fair, with R-values ranging from 0.70 to 0.78. The low coefficients of variation and standard errors of measurements affirmed the reproducibility of measurements. In conclusion, this study showed the feasibility and the reproducibility of shoulder and hip flexor and extensor muscles maximal strength measurements using NMMT in gymnastics-based settings.