The Importance of Physical Fitness Parameters in Rhythmic Gymnastics: A Scoping Review

This scoping review presents an overview of physical fitness parameters in rhythmic gymnastics as well as the association of fitness with gymnasts' performance, competitive level, and age. PubMed, Scopus, and Sport Discus databases were searched. Of the 586 records retrieved, 41 studies met the inclusion criteria (n = 1915 participants). The included studies examined flexibility, aerobic capacity, muscle power, muscle endurance, muscle strength, sprint speed, agility, balance, and coordination. Performance was associated with flexibility, aerobic capacity, lower-limb muscle power, agility, muscular endurance, balance, and coordination from a young age. Flexibility, aerobic capacity, and muscle power were, in general, higher in high-level gymnasts than in low-level gymnasts or controls. Older rhythmic gymnasts demonstrated higher scores than the younger ones in flexibility, aerobic capacity, balance, and sport-specific coordination but not in muscle endurance, while some studies reported a decline in muscle power with age. Supplementary physical fitness training improved all physical abilities irrespective of the gymnasts' level. Rhythmic gymnastics training alone improved muscle power, agility, speed, muscular endurance, and balance to a lesser extent than targeted fitness training. Muscular strength, speed, and agility are largely under-researched in rhythmic gymnastics. Emphasis should be given to targeted strength and power training due to the high mechanical loads placed on skeletally immature athletes.

Covid Pandemic Effects on the Physical Fitness of Primary School Children: Results of the German EMOTIKON Project

BACKGROUND

In spring of 2020, the Sars-CoV-2 incidence rate increased rapidly in Germany and around the world. Throughout the next 2 years, schools were temporarily closed and social distancing measures were put in place to slow the spread of the Covid-19 virus. Did these social restrictions and temporary school lockdowns affect children's physical fitness? The EMOTIKON project annually tests the physical fitness of all third-graders in the Federal State of Brandenburg, Germany. The tests assess cardiorespiratory endurance (6-min-run test), coordination (star-run test), speed (20-m sprint test), lower (powerLOW, standing long jump test), and upper (powerUP, ball-push test) limbs muscle power, and static balance (one-legged stance test with eyes closed). A total of 125,893 children were tested in the falls from 2016 to 2022. Primary analyses focused on 98,510 keyage third-graders (i.e., school enrollment according to the legal key date, aged 8 to 9 years) from 515 schools. Secondary analyses included 27,383 older-than-keyage third-graders (i.e., OTK, delayed school enrollment or repetition of a grade, aged 9 to 10 years), who have been shown to exhibit lower physical fitness than expected for their age. Linear mixed models fitted pre-pandemic quadratic secular trends, and took into account differences between children and schools.

RESULTS

Third-graders exhibited lower cardiorespiratory endurance, coordination, speed and powerUP in the Covid pandemic cohorts (2020-2022) compared to the pre-pandemic cohorts (2016-2019). Children's powerLOW and static balance were higher in the pandemic cohorts compared to the pre-pandemic cohorts. From 2020 to 2021, coordination, powerLOW and powerUP further declined. Evidence for some post-pandemic physical fitness catch-up was restricted to powerUP. Cohen's |ds| for comparisons of the pandemic cohorts 2020-2022 with pre-pandemic cohorts 2016-2019 ranged from 0.02 for powerLOW to 0.15 for coordination. Within the pandemic cohorts, keyage children exhibited developmental losses ranging from approximately 1 month for speed to 5 months for cardiorespiratory endurance. For powerLOW and static balance, the positive pandemic effects translate to developmental gains of 1 and 7 months, respectively. Pre-pandemic secular trends may account for some of the observed differences between pandemic and pre-pandemic cohorts, especially in powerLOW, powerUP and static balance. The pandemic further increased developmental delays of OTK children in cardiorespiratory endurance, powerUP and balance.

CONCLUSIONS

The Covid-19 pandemic was associated with declines in several physical fitness components in German third-graders. Pandemic effects are still visible in 2022. Health-related interventions should specifically target those physical fitness components that were negatively affected by the pandemic (cardiorespiratory endurance, coordination, speed).

Tai chi-muscle power training for children with developmental coordination disorder: a randomized controlled trial

This study compared the effectiveness of tai chi (TC) muscle power training (MPT), TC alone, MPT alone, and no training for improving the limits of stability (LOS) and motor and leg muscular performance and decreasing falls in children with developmental coordination disorder (DCD). One hundred and twenty-one children with DCD were randomly assigned to the TC-MPT, TC, MPT, or control group. The three intervention groups received TC-MPT, TC, or MPT three times per week for 3 months. Measurements were taken before and after the intervention period. The primary outcomes were the LOS completion time and dynamic LOS scores. The secondary outcomes included the Movement Assessment Battery for Children-Second Edition total test score and percentile rank, knee muscle peak force and time to peak force, and the number of falls. None of the interventions affected the LOS test scores. Improvements in the peak forces of the knee extensors and flexors were demonstrated in the TC (p = 0.006) and MPT groups (p = 0.032), respectively. The number of falls also decreased in these two groups (p < 0.001). Thus, clinicians may prescribe TC or MPT for children with DCD to increase their knee muscle strength and reduce their risk of falls.

Sex and Age Comparisons in Neuromuscular And Biomechanical Characteristics of the Knee in Young Athletes

BACKGROUND

The identification of risk factors for injury is a key step for musculoskeletal injury prevention in youth sports. Not identifying and correcting for injury risk factors may result in lost opportunity for athletic development. Physical maturation and sex affect these characteristics, which may indicate the need for both age and sex-based injury prevention programs.

HYPOTHESIS/PURPOSE

This study examined age and sex differences in knee strength, static balance, jump height, and lower extremity landing biomechanics in school- and high school-age athletes.

STUDY DESIGN

Cross-sectional.

METHODS

Forty healthy school aged (10.8±0.8 yrs) and forty high school (16.8±0.8 yrs) athletes completed isokinetic knee flexion and extension strength tests, single-leg static balance and single-leg vertical stop jump tasks.

RESULTS

High school athletes were significantly stronger (~67% and 35% stronger for males and females, respectively) and jumped higher (regardless of sex) compared to school age athletes. High school males had worse balance (~28%) compared to their younger counterparts. High school females had lower strength (~23%) compared to males but had better balance (~46%). Conclusion: Maturation had different effects on the variables analyzed and sex differences were mainly observed after maturation. These differences may be minimized through appropriate age and sex specific training programs.

LEVELS OF EVIDENCE

3a.

CLINICAL RELEVANCE

Neuromuscular and biomechanical differences between sex and age groups should be accounted for in injury prevention and rehabilitation. Inadequate training may be a primary factor contributing to injuries in a young athletic population. When designing training programs for long term athlete development, programs should be dependent on decrements seen at specific time points throughout maturation.What is known about the subject: Generally, both males and females get stronger and jump higher as they get older but the results comparing balance and biomechanics between genders or across age groups have been mixed.What this study adds to existing knowledge: The current study looks at multiple neuromuscular and biomechanical variables in male and female participants at different maturation statuses. The current data supports the significant changes observed in strength and jump height, as both genders age, but the data also demonstrates significant differences in balance between age groups in males and between genders in balance and knee flexion angles.

Deficits in the Star Excursion Balance Test and Golf Performance in Elite Golfers with Chronic Low Back Pain

The purpose of this study was to investigate whether low-handicap elite golfers with chronic low back pain (CLBP) exhibit deficits in dynamic postural control and whether CLBP affects golfers in terms of their golf swing parameters. A total of fifteen Division 1 college golfers were recruited as participants. Of these, six of whom experienced CLBP, while the remaining participants were healthy. In this study, CLBP was defined as experiencing chronic pain symptoms for more than six months. The Star Excursion Balance Test (SEBT) was administered to examine dynamic posture control in both groups. The TrackMan Golf Launch Monitor Simulator was used to collect data on the performance parameters of the swing of the participants. The results for both feet in the medial, lateral, posterior, posteromedial, and posterolateral directions indicated that the CLBP group scored lower than the control group. However, the CLBP group scored higher for the right foot in the anterolateral direction. The parameters for the club speed and ball carry of the CLBP group were lower than those of the control group. Further, the CLBP group exhibited a more upright swing plane relative to the control group. Taken together, our findings suggest that SEBT may be feasible and highly accessible to assess golf swing performance of elite players with CLBP.

Relationships between types of balance performance in healthy individuals: Role of age

BACKGROUND

Balance is considered to be task-specific as indicated by studies reporting only small-sized and non-significant correlations between types of balance (e.g., static, dynamic). However, it remains unclear whether these associations differ by age and the comparability of studies is limited due to methodological inconsistencies.

RESEARCH QUESTION

Are associations between types of balance performance affected by age in children, adolescents, and young adults?

METHODS

Static, dynamic, and proactive balance performance was assessed in 30 children (7.6 ± 0.6 years), 43 adolescents (14.7 ± 0.5 years), and 54 young adults (22.8 ± 2.8 years) using the same standardized balance tests. Pearson's correlation coefficients (r) were calculated for associations between types of balance and statistically compared to detect differences between age groups.

RESULTS

Except for the association between static (i.e., medio-lateral [M/L] sway) and proactive (Y-balance test) balance performance in young adults (r = .319, p < .05), our analyses revealed small-sized and non-significant associations between measures of static, dynamic, and proactive balance performance in children (-.302 ≤ r ≤ .245, p > .05), adolescents (-.276 ≤ r ≤ .202, p > .05), and young adults (-.120 ≤ r ≤ .161, p > .05). Significant differences between age groups were observed for associations between dynamic and proactive balance, which were lesser in young adults (r = .161) compared to adolescents (r = -.276, p = .017) and children (r = -.302, p = .023) and for associations between static (i.e., M/L sway) and proactive balance, which were larger in young adults (r = .319) compared to adolescents (r = -.131, p = .029).

CONCLUSIONS

Practitioners (e.g., PE teachers) should be aware that associations between types of balance performance are small and hardly affected by age in youth. Therefore, they should be trained and tested individually in children, adolescents, and young adults.

Neuromuscular mechanisms that contribute to gross motor performance in survivors of childhood acute lymphoblastic leukemia

PURPOSE

This study explored neuromuscular mechanisms and clinical measures that contribute to countermovement jump performance in survivors of childhood acute lymphoblastic leukemia (ALL CCS) compared to age- and sex-matched peers.

METHODS

This exploratory cross-sectional observational study examined 12 participants, six ALL CCS and six age- and sex-matched peers (7-16 years). During a countermovement jump, rates of muscle activation of lower leg muscles were measured with electromyography, and joint torques and peak jump height with force plates and a motion capture system. Clinical measures included muscle extensibility, balance, and mobility measured by active ankle dorsiflexion, Bruininks-Oseretsky Motor Proficiency (BOT-2), and Timed Up and Go (TUG) tests.

RESULTS

Compared to peers, ALL CCS demonstrated reduced gastrocnemius muscle extensibility and tibialis anterior rate of muscle activation, decreased jump height, and poorer performance on the BOT-2 and TUG. Jump height was significantly correlated with clinical measures of the BOT-2 and TUG.

CONCLUSION

These ALL CCS demonstrated neuromuscular impairments that may impact jump performance, an essential childhood physical activity. Further research is needed to explore intervention strategies to improve the neuromuscular mechanisms that contribute to high-level gross motor skills in ALL CCS.

Balance Tests in Pre-Adolescent Children: Retest Reliability, Construct Validity, and Relative Ability

Balance is an essential prerequisite for the normal physical development of a child. It consists of the ability to maintain the body’s centre of mass over its base of support, which is enabled by automatic postural adjustments, and maintain posture and stability in various conditions and activities. The present study aimed to determine the measurement characteristics (reliability and concurrent validity) and the relative ability of balance tests and different motor tests in healthy 11-year-olds. We also evaluated the impact of vision on balance ability. Our results showed high interrater reliability (from 0.810 to 0.910) and confirmed the construct validity of the included balance tests. Girls performed significantly better than boys in laboratory tandem stance in following balance components: total sway path with eyes open (BSEO) (t = 2.68, p = 0.01, effect size (ES) = 0.81), total body sway with eyes closed of centre of pressure (CoP) displacement in the a-p direction (BSEC) (t = 1.86, p = 0.07, ES = 0.57), mean velocity of CoP displacements (VEO) (t = 2.67, p = 0.01, ES = 0.83), mean amplitude of CoP displacements in the a-p direction (AapEO) (t = 3.38. p = 0.00, ES = 1.01) and in mean amplitude of CoP displacements in the m-l direction (AmlEO) (t = 3.68, p = 0.00, ES = 1.19). With eyes closed, girls performed significantly better (t = 2.28, p = 0.03, ES = 0.70) than boys did in the mean amplitude of COP displacements in the a-p direction (AapEO) and significantly better (t = 2.37, p = 0.03, ES = 0.71) in the mean amplitude of COP displacements in the m-l direction (AmlEC). Insignificant correlations between different balance tests, except for a correlation between the flamingo test and one-leg stance on a low beam (r = 0.558, p < 0.01), show that each test assesses different aspects of balance ability; therefore, balance cannot be assessed with a single test.

Effect of aging on the association between ankle muscle strength and the control of bipedal stance

Previous studies reported a significant association between postural control and lower-limb strength of several muscle groups, however, they were focused especially on knee muscles and ankle plantar and dorsal flexors. The aim of the present study is to examine the correlation between the muscle strength of ankle invertors, evertors, plantar flexors, and dorsal flexors and the control of bipedal stance in young and older adults. Thirty one young (aged 22.8 ± 2.6 years) and thirty one older adults (aged 70.5 ± 7.2 years) voluntarily participated in this study. Ankle muscle strength was evaluated by an isokinetic dynamometer. Normalized peak torque and work were averaged for four repetitions and for both lower limbs. The control of bipedal stance was evaluated by the sample entropy derived from an accelerometer placed on the lumbar spine while the subject stood on a foam pad with eyes open. Results showed significant age-related differences in ankle muscle strength and sample entropy in medial-lateral direction. More interestingly, the correlation between ankle muscle strength and the sample entropy was significantly different between young and older adults. Indeed, no significant correlation was observed in the younger adults. Conversely, in the older adults, the work of the ankle evertors positively correlated with sample entropy in the medial-lateral direction during bipedal stance (r = 0.36), whereas the peak torque and work of the dorsal flexors were significantly correlated with sample entropy in the anterior-posterior direction during bipedal stance (r = 0.44 for both variables). In the young adults, results suggest that, standing on foam with eyes open is a relatively easy postural task that does not require the full ankle muscle strength capacity. Taken together, the present findings suggest that older adults have a different association between ankle muscle strength and the sample entropy during bipedal stance.

Dynamic Postural Control in Children: Do the Arms Lend the Legs a Helping Hand?

There is growing empirical evidence lending support to the existence of an "upper body strategy" to extend the ankle and hip strategies in maintaining upright postural stability among adults. Both postural stability and arm movement functions are still developing in children. Therefore, enquiry concerning arm contribution to postural stability among children is needed. This proof of concept study seeks to determine whether the arms play a functionally relevant role in dynamic postural control among children. Twenty-nine children (girls, n = 15; age, 10.6 ± 0.5 years; height, 1.48 ± 0.08 m; mass, 42.8 ± 11.4 kg; BMI, 19.2 ± 3.7 kg/m²) completed three dynamic balance tests; (1) Y Balance test^®, (2) timed balance beam walking test, (3) transition from dynamic to static balance using the dynamic postural stability index (DPSI). Each test was performed with free and restricted arm movement. Restricting arm movements elicited a marked degradation in the Y Balance reach distance (all directions, P ≤ 0.001, d = -0.85 to -1.13) and timed balance beam walking test (P ≤ 0.001, d = 1.01), while the DPSI was the only metric that was not different between free and restricted arm movements (P = 0.335, d = -0.08). This study provides direct evidence that the arms play a functionally relevant role in dynamic balance performance among children. These findings may provide the impetus to develop training interventions to improve the use of the arms in activities of daily living.

The association of childhood sleep problems with the prevalence of traumatic dental injury in schoolchildren

BACKGROUND/AIM

Sleep quality exerts an influence on attention level and motor skills and is associated with accidental injuries in children. The aim of this study was to evaluate the association between traumatic dental injury and sleep behaviour in children.

MATERIAL AND METHODS

A cross-sectional study was conducted in a small city in southern Brazil with a representative sample of schoolchildren aged 8-10 years (n = 537). Weight and height were measured, and examinations were performed for the determination of clinical occlusion and traumatic dental injury. The parents answered the Sleep Behaviour Questionnaire and questions addressing socio-demographic characteristics.

RESULTS

The prevalence of traumatic dental injury was 22% (95% CI: 19-26) and was higher among children who woke three to four times per night (PR = 3.30; 95% CI: 2.47-4.39), those who fell asleep in the parental bed (PR = 1.41; 95% CI: 1.09-1.83), those who were not in a good mood on waking up in the morning (PR = 1.30; 95% CI: 1.02-1.65), those who became sleepy while sitting and/or studying (PR = 1.57; 95% CI: 1.09-2.24) and while watching TV (PR = 1.41; 95% CI: 1.0005-1.97) and those who had bad dreams (PR = 1.35; 95% CI: 1.04-1.76). The Poisson multiple regression model with a multilevel approach revealed that the prevalence of traumatic dental injury was 1.51-fold higher among children with daytime drowsiness (PR = 1.51; 95% CI: 1.11-2.04) after adjusting for socio-demographic, occlusal and anthropometric variables.

CONCLUSION

Sleep problems were associated with a higher prevalence of traumatic dental injury among the children analysed.

Associations Between Types of Balance Performance in Healthy Individuals Across the Lifespan: A Systematic Review and Meta-Analysis

Background: The objective of this systematic review and meta-analysis was to quantify and statistically compare correlations between types of balance performance in healthy individuals across the lifespan. Methods: Literature search was performed in the electronic databases PubMed, Web of Science, and SPORTDiscus. Studies were included if they investigated healthy individuals aged ≥6 years and reported measures of static/dynamic steady-state, proactive, and/or reactive balance. The included studies were coded as follows: age group, gender, and balance type, test, parameter. Pearson's correlation coefficients were extracted, transformed (i.e., Fisher's z-transformed r _z -value), aggregated (i.e., weighted mean r _z -value), back-transformed to r-values, classified according to their magnitude, and statistically compared. The methodological quality of each study was assessed using the Appraisal tool for Cross-Sectional Studies. Results: We detected twenty-six studies that examined associations between types of balance and exclusively found small-sized correlations, irrespective of the age group considered. More specifically, the weighted mean r _z-values amounted to 0.61 (back-transformed r-value: 0.54) in old adults for the correlation of dynamic steady-state with proactive balance. For correlations between dynamic and static steady-state balance, the weighted mean r _z-values amounted to 0.09 in children (r-value: 0.09) and to 0.32 in old adults (r-value: 0.31). Further, correlations of proactive with static steady-state balance revealed weighted mean r _z-values of 0.24 (r-value: 0.24) in young adults and of 0.31 (r-value: 0.30) in old adults. Additionally, correlations between reactive and static steady-state balance yielded weighted mean r _z-values of 0.21 (r-value: 0.21) in young adults and of 0.19 (r-value: 0.19) in old adults. Moreover, significantly different correlation coefficients (z = 8.28, p < 0.001) were only found for the association between dynamic and static steady-state balance in children (r = 0.09) compared to old adults (r = 0.31). Lastly, we detected trivial to considerable heterogeneity (i.e., 0% ≤ I² ≤ 83%) between studies. Conclusions: Our systematic review and meta-analysis showed exclusively small-sized correlations between types of balance performance across the lifespan. This indicates that balance performance seems to be task-specific rather than a "general ability." Further, our results suggest that for assessment/training purposes a test battery/multiple exercises should be used that include static/dynamic steady-state, proactive, and reactive types of balance. Concerning the observed significant age differences, further research is needed to investigate whether they are truly existent or if they are caused by methodological inconsistencies.

Reliability of Ankle⁻Foot Complex Isokinetic Strength Assessment Using the Isomed 2000 Dynamometer

For quantifying muscle strength in clinical and research practice, establishing the reliability of measurements, specifically to the procedures used, is essential for credible findings. The objective was to establish the reliability of isokinetic measurement of ankle plantar and dorsal flexors (PF/DF) and invertors and evertors (INV/EV) on an IsoMed 2000 dynamometer. Twenty healthy subjects (10 males, 10 females, mean age: 23.1 ± 3.1 years) completed an isokinetic measurement session. The intraclass correlation coefficient (ICC) and standard error of measurement were assessed for peak torque and work of ankle PF/DF (concentric and eccentric) and INV/EV (concentric) for the preferred and nonpreferred limb. Standardized isokinetic measurements of reciprocal PF/DF and INV/EV muscle actions were associated with ICC ranging from 0.77 to 0.98 for the majority of observed parameters. The exception was work in the eccentric mode in the ankle DF and peak torque in the concentric mode in the ankle INV on the preferred limb, where ICC ranged from 0.64 to 0.71. The IsoMed 2000 isokinetic dynamometer can be reliably employed in future studies for reciprocal ankle PF/DF and INV/EV assessment in healthy adult subjects after implementation of a familiarization session.

Associations Between Measures of Balance and Lower-Extremity Muscle Strength/Power in Healthy Individuals Across the Lifespan: A Systematic Review and Meta-Analysis

BACKGROUND

It has frequently been reported that balance and lower-extremity muscle strength/power are associated with sports-related and everyday activities. Knowledge about the relationship between balance, strength, and power are important for the identification of at-risk individuals because deficits in these neuromuscular components are associated with an increased risk of sustaining injuries and falls. In addition, this knowledge is of high relevance for the development of specifically tailored health and skill-related exercise programs.

OBJECTIVES

The objectives of this systematic literature review and meta-analysis were to characterize and, if possible, quantify associations between variables of balance and lower-extremity muscle strength/power in healthy individuals across the lifespan.

DATA SOURCES

A computerized systematic literature search was performed in the electronic databases PubMed, Web of Science, and SPORTDiscus up to March 2015 to capture all relevant articles.

STUDY ELIGIBILITY CRITERIA

A systematic approach was used to evaluate the 996 articles identified for initial review. Studies were included only if they investigated healthy individuals aged ≥6 years and tested at least one measure of static steady-state balance (e.g., center of pressure [CoP] displacement during one-legged stance), dynamic steady-state balance (e.g., gait speed), proactive balance (e.g., distance in the functional-reach-test), or reactive balance (e.g., CoP displacement during perturbed one-legged stance), and one measure of maximal strength (e.g., maximum voluntary contraction), explosive force (e.g., rate of force development), or muscle power (e.g., jump height). In total, 37 studies met the inclusionary criteria for review.

STUDY APPRAISAL AND SYNTHESIS METHODS

The included studies were coded for the following criteria: age (i.e., children: 6-12 years, adolescents: 13-18 years, young adults: 19-44 years, middle-aged adults: 45-64 years, old adults: ≥65 years), sex (i.e., female, male), and test modality/outcome (i.e., test for the assessment of balance, strength, and power). Studies with athletes, patients, and/or people with diseases were excluded. Pearson's correlation coefficients were extracted, transformed (i.e., Fisher's z-transformed r z value), aggregated (i.e., weighted mean r z value), back-transformed to r values, classified according to their magnitude (i.e., small: r ≤ 0.69, medium: r ≤ 0.89, large: r ≥ 0.90), and, if possible, statistically compared. Heterogeneity between studies was assessed using I2 and Chi-squared (χ2) statistics.

RESULTS

Three studies examined associations between balance and lower-extremity muscle strength/power in children, one study in adolescents, nine studies in young adults, three studies in middle-aged adults, and 23 studies in old adults. Overall, small-sized associations were found between variables of balance and lower-extremity muscle strength/power, irrespective of the age group considered. In addition, small-sized but significantly larger correlation coefficients were found between measures of dynamic steady-state balance and maximal strength in children (r = 0.57) compared with young (r = 0.09, z = 3.30, p = 0.001) and old adults (r = 0.35, z = 2.94, p = 0.002) as well as in old compared with young adults (z = 1.95, p = 0.03).

LIMITATIONS

Even though the reported results provided further insight into the associations between measures of balance and lower-extremity muscle strength/power, they did not allow us to deduce cause and effect relations. Further, the investigated associations could be biased by other variables such as joint flexibility, muscle mass, and/or auditory/visual acuity.

CONCLUSIONS

Our systematic review and meta-analysis showed predominately small-sized correlations between measures of balance and lower-extremity muscle strength/power in children, adolescents, and young, middle-aged, and old adults. This indicates that these neuromuscular components are independent of each other and should therefore be tested and trained complementarily across the lifespan. Significantly larger but still small-sized associations were found between measures of dynamic steady-state balance and maximal strength in children compared with young and old adults as well as in old compared with young adults. These findings imply that age/maturation may have an impact on the association of selected components of balance and lower-extremity muscle strength.

Risk factors for traumatic dental injuries in the primary dentition: concepts, interpretation, and evidence

The purpose of this comprehensive review is to explore the main concepts related to quantification and interpretation of risk factors and investigate characteristics associated with traumatic dental injuries (TDI) in the primary dentition. Initially, the main concepts related to causality and risk factors were summarized, including how to measure, express, and compare risk as well as interpret statistical significance. Based on a structured search through PubMed, original research articles regarding TDI and associated factors in the primary dentition were then reviewed by two examiners. Studies with a sample size of at least 300 children aged between 0 and 6 years were summarized according to journal, country, study design, and type of statistical analysis. Variables associated with TDI in primary teeth were identified from studies with multivariable analysis. Measures of effect size and P values were presented. Thirty-two studies were retrieved: most were cross-sectional in design and only 17 (53.1%) performed multivariable analysis. Most investigations did not find an association between gender and socioeconomic variables with TDI. Increased overjet was the only factor consistently identified as an associated factor. Behavioral characteristics have been recently investigated and suggested as potential risk factors for TDI in the primary dentition. In conclusion, increased overjet is undoubtedly associated with TDI in the primary dentition. As behavioral factors may be targeted by preventive strategies, their role on TDI occurrence should be clarified in future cohort studies. Clinicians should understand the terms and measures described in studies on risk factors to properly apply knowledge and benefit patients.

Test-retest reliability of the Star Excursion Balance Test in primary school children

BACKGROUND

Dynamic balance has been considered a fundamental skill at all ages and is required for normal daily tasks, such as walking, running, or other sports activities. The Star Excursion Balance Test (SEBT) has been widely used in recent years to identify dynamic balance deficits and improvements and to predict the risk of lower extremity injury. However, no study has demonstrated the reliability of the SEBT in children while they are performing the test in a physical education session. Reliability is needed in all measurement tools in order to provide repeatable and consistent data.

OBJECTIVE

To evaluate the reliability of the SEBT in primary school students in the school setting.

METHODS

Twenty-four healthy children with typical development were tested twice, 2 weeks apart. The tests were conducted by the same single rater and were performed during the physical education class. The test was performed under standardized conditions during the 2 testing sessions and was performed by each subject with both limbs in the 3 directions (anterior, posteromedial, and posterolateral). Four practice trials were performed in each direction before selecting 3 additional distances reached. The best value of these 3 additional measured trials was selected. The paired t test was used to ensure the absence of any systematic bias. Intraclass correlation coefficient, standard error of measurement, 95% confidence intervals (CIs), and minimal change values were calculated to assess reliability and measurement error.

RESULTS

The paired t tests revealed no significant differences between test-rest scores. Test-retest reliability for all distances reached was moderate to good.

CONCLUSIONS

Reliability values suggest that the SEBT is suitable for primary school students. However, it may be more practical and feasible during extracurricular sports participation due to the time constraints and difficulties in using the test in the school setting.

Socioeconomic, behavioral, and anthropometric risk factors for traumatic dental injuries in childhood: a cohort study

AIM

To investigate risk factors for the occurrence of traumatic dental injuries (TDI) at 4 years of age.

DESIGN

Prospective cohort study.

METHODS

A birth cohort (n = 500) was recruited from the public healthcare system in São Leopoldo, Brazil. Demographic, socioeconomic, anthropometric, and behavioral variables were collected at 6 months, 1 year, and 4 years of age. Clinical examinations at 4 years of age were carried out by a single examiner using the Andreasen classification. Poisson regression was used to determine risk factors for the occurrence of TDI at 4 years of age.

RESULTS

A total of 23.7% of the children (80/337) exhibited TDI at 4 years of age. The risk of TDI was 35% lower among children who had been breastfeed for ≥6 months relative risk (RR 0.65; 95% CI 0.43-0.97) and more than twofold higher among those who were bottle fed ≥ three times a day (RR 2.37; 95% CI 1.10-5.11) at 12 months of age. Higher household income in the first year of life and greater height at 4 years of age were significantly associated with the outcome.

CONCLUSIONS

The identification of behavioral, socioeconomic, and anthropometric risk factors for TDI in early childhood can contribute to the elaboration of prevention strategies.

Relationship between strength, balance and mobility in children aged 7-10 years

The purpose of this study was to investigate the association between variables of lower extremity muscle strength, balance, and mobility assessed under various task conditions. Twenty-one healthy children (mean age: 9±1 years) were tested for their isometric and dynamic strength as well as for their steady-state, proactive, and reactive balance and mobility. Balance and mobility tests were conducted under single and dual task conditions. Significant positive correlations were detected between measures of isometric and dynamic leg muscle strength. Hardly any significant associations were observed between variables of strength and balance/mobility and between measures of steady-state, proactive, and reactive balance. Additionally, no significant correlations were detected between balance/mobility tests performed under single and dual task conditions. The predominately non-significant correlations between different balance components and mobility imply that balance and mobility performance is task specific. Further, strength and balance/mobility as well as balance under single and dual task conditions seem to be independent of each other and may have to be tested and trained complementarily.