Performance and reliability of the Lower Quarter Y Balance Test in healthy adolescents from grade 6 to 11

Effect of low versus high balance training complexity on balance performance in male adolescents

OBJECTIVE

The current study aimed to determine the effects of low (i.e., balance task only) versus high (i.e., balance task combined with an additional motor task like dribbling a basketball) balance training complexity (6 weeks of training consisting of 2 × 30 min balance exercises per week) on measures of static and dynamic balance in 44 healthy male adolescents (mean age: 13.3 ± 1.6 years).

RESULTS

Irrespective of balance training complexity, significant medium- to large-sized pretest to posttest improvements were detected for static (i.e., One-Legged Stance test, stance time [s], 0.001 < p ≤ 0.008) and dynamic (i.e., 3-m Beam Walking Backward test, steps [n], 0.001 < p ≤ 0.002; Y-Balance-Test-Lower-Quarter, reach distance [cm], 0.001 < p ≤ 0.003) balance performance. Further, in all but one comparison (i.e., stance time with eyes opened on foam ground) no group × test interactions were found. These results imply that balance training is effective to improve static and dynamic measures of balance in healthy male adolescents, but the effectiveness seems unaffected by the applied level of balance training complexity.

Investigation of inter-rater and test-retest reliability of Y balance test in college students with flexible flatfoot

BACKGROUND

The Lower Quarter Y Balance Test (YBT-LQ) has been widely used to assess dynamic balance in various populations. Dynamic balance in flexible flatfoot populations is one of the risk factors for lower extremity injuries, especially in college populations in which more exercise is advocated. However, no study has demonstrated the reliability of the YBT-LQ in a college student flexible flatfoot population.

METHODS

A cross-sectional observational study. 30 college students with flexible flatfoot were recruited from Beijing Sports University. They have been thrice assessed for the maximal reach distance of YBT under the support of the lower limb on the flatfoot side. Test and retest were performed with an interval of 14 days. The outcome measures using the composite score and normalized maximal reach distances in three directions (anterior, posteromedial, and posterolateral). The relative reliability was reported as the Intraclass Correlation Coefficient (ICC). Minimal Detectable Change (MDC), Smallest worthwhile change (SWC), and Standard Error of Measurement (SEM) were used to report the absolute reliability.

RESULTS

For inter-rater reliability, the ICC values for all directions ranged from 0.84 to 0.92, SEM values ranged from 2.01 to 3.10%, SWC values ranged from 3.67 to 5.12%, and MDC95% values ranged from 5.58 to 8.60%. For test-retest reliability, the ICC values for all directions ranged from 0.81 to 0.92, SEM values ranged from 1.80 to 2.97%, SWC values ranged from 3.75 to 5.61%, and MDC95% values ranged from 4.98 to 8.24%.

CONCLUSIONS

The YBT-LQ has "good" to "excellent" inter-rater and test-retest reliability. It appears to be a reliable assessment to use with college students with flexible flatfoot.

TRIAL REGISTRATION

This trial was prospectively registered at the Chinese Clinical Trial Registry with the ID number ChiCTR2300075906 on 19/09/2023.

Correlation between hip muscle strength and the lower quarter Y-balance test in athletes following anterior cruciate ligament reconstruction

INTRODUCTION

The lower quarter Y-balance test (YBT-LQ), which measures dynamic postural control, has been reported to be predictive of lower limb injuries in athletes. It requires subjects to control their body while maintaining a single-leg stance, which necessitates sufficient strength of the hip muscles to maintain stability. The purpose of the study was to investigate the correlation between the performance of the YBT-LQ and the hip abductor or extensor muscle strength in athletes following anterior cruciate ligament reconstruction surgery (ACLR).

METHODS

Fifteen athletes with post-ACLR participated in this cross-sectional study. The participants completed the YBT-LQ, followed by isokinetic measurement of the hip abductor and extensor muscles of both the legs. The peak and average torque of the hip abductor and extensor muscles were tallied with the composite score of the YBT-LQ for each limb.

RESULTS

No correlation was found between the strength of the hip muscles and the YBT-LQ composite score in both injured and non-injured limbs at all velocities except for the eccentric hip abductor and concentric hip extensor torques. The eccentric hip abductor average torque is strongly associated with the YBT-LQ (r = 0.663, p = 0.010) at a speed of 180°/s. The concentric hip extensor peak torque was weakly correlated with balance (r = 0.540, p = 0.046) at a speed of 180°/s.

CONCLUSION

Our study demonstrated a positive correlation between the YBT-LQ and eccentric hip abduction and concentric hip extension at higher velocities. This shows the importance of implementing velocity-oriented rehabilitation in an athletic population following ACLR.

The immediate effect of synergistic muscles kinesio taping on function and balance of volleyball players with functional ankle instability: A randomized controlled trial

OBJECTIVES

To determine the immediate effect of synergistic muscles Kinesio taping (KT) on the function and balance of volleyball players with functional ankle instability (FAI).

DESIGN

Parallel, superiority randomized controlled trial.

METHODS

Twenty-six semi-professional volleyball players with FAI were randomly assigned to either the intervention or control group. All participants received KT of fibularis longus, gastrocnemius, and gluteus maximus muscles for one session. The intervention group received KT with 35 % tension, while the control group received KT without tension. The function was assessed using the side hop and single hop distance tests. Dynamic balance was assessed with the Y Balance test. The outcomes were measured at baseline, 20 min after KT, and 24 h after KT. Statistical analyses were performed using Mixed-model repeated measures analysis of variance (ANOVA) and one-way ANOVA.

RESULTS

The interactions of time*group for the outcomes of function using the single hop test and stability in the anterior direction of the Y Balance test were significant (p < 0.05). Within-group comparisons showed after KT, both groups experienced significant improvements in all outcomes compared to the baseline. Results of between-group comparisons revealed that the application of KT with tension compared to no tension significantly improved function and balance in the anterior of the Y Balance test.

CONCLUSIONS

Kinesio taping can be an effective treatment option to improve function and balance in FAI. Additionally, Kinesio taping with tension compared to KT without tension had superiority.

Validity and reliability of upper extremity star excursion balance test in adolescent swimmers

Background

Upper limb balance is one of the important physical fitness parameters for all populations, especially overhead athletes like swimmers. Upper extremity star excursion balance test (UESEBT) is a comprehensive dynamic balance assessment, this study aims to explore the reliability and validity of UESEBT among adolescent swimmers.

Methods

This cross-sectional study recruited 70 adolescent swimmers. All participants were required to complete UESEBT, upper quarter Y-balance test (UQYBT), maximal isometric strength (MIS) tests in upper limb, closed kinetic chain upper extremity stability test (CKCUEST), trunk flexor endurance test (TFET) and lateral trunk endurance test (LTET). The intra- and inter-operator reliability and the correlation of UESEBT with other physical performances were conducted.

Results

For reliability, the intra- and inter-operator reliability of all directions and composite score were high-to-excellent (ICC = 0.706-1.000) among all participants. For validity, the UESEBT has a moderate-to-strong correlation with UQYBT (r = 0.42-0.72, p < 0.001), and a weak-to moderate one with CKCUEST (r = 0.25-0.42, p < 0.05). Furthermore, the UESEBT performance showed weak-to-moderate correlations with MIS (r = 0.24-0.44, p < 0.05). UESEBT was correlated to LTET (r = 0.24-0.33, p < 0.05) whereas no relationship was found with TFET.

Conclusions

UESEBT was a reliable and valid tool to screen upper extremity dynamic balance among adolescent swimmers. UESEBT provides more detailed information in eight directions to assess the upper limb sport performance. Further study should explore the prediction ability of UESEBT for injury.

Comparison of Dynamic Balance and Unilateral Hop Performance Between Women and Men Handball Players After Anterior Cruciate Ligament Reconstruction: A Pilot Study

CONTEXT

After anterior cruciate ligament reconstruction (ACLR), long-term functional deficiencies can occur, with controversial results reported when comparing women and men. Dynamic balance and unilateral hop test performance are considered important indicators for the risk of reinjury of the lower extremity. Although both sexes seem to have a similar risk to experience a second anterior cruciate ligament injury, sex-specific differences of dynamic balance and unilateral hop performance in handball players following ACLR are unknown.

OBJECTIVE

To compare dynamic balance and unilateral hop performance between women and men handball players at least 6 months after ACLR.

DESIGN

Cross-sectional pilot study.

PARTICIPANTS

Ten women (27.6 [4.5] y) and 10 men (26.5 [3.1] y) handball players 6 to 16 months after ACLR.

OUTCOME MEASURES

Dynamic balance and unilateral hop performance were assessed using the Y-Balance Test and the Single-Leg Hop for Distance Test.

RESULTS

Women players demonstrated significantly better results in the anterior direction of the Y-Balance Test for both legs compared with men players. Hop performance was not significantly different between sexes.

CONCLUSION

Dynamic balance and single-leg hop performance seem not to differ between women and men handball players 6 to 16 months after ACLR. The difference between sexes in the anterior reach direction of the Y-Balance Test should be considered small, rather than representing a true difference.

Assessment of Physical Tests in 6-11 Years Old Children: Findings from the Play Lifestyle and Activity in Youth (PLAY) Study

The purpose was to evaluate selected physical tests in children and to compare the outcomes by sex. A cross-sectional study design was used to evaluate children 6-11 years who completed five physical tests: hand grip, vertical jump, sit and reach, Y-balance, and obstacle course (time and score). The outcome measures including test results were descriptively examined and compared by sex. The study participants consisted of 133 children (62 males and 71 females, with a median age of 7.8 years). Girls showed superior sit and reach performance (p = 0.002) compared with boys. Boys demonstrated better Y-balance scores (p = 0.007) and faster obstacle time (p = 0.042) than girls. Sex comparison within three age groups (6-<8 years, 8-<10 years, and 10-<12 years) showed that girls performed better on the sit and reach compared with boys in the in 6-<8 years (p = 0.009). Boys demonstrated higher Y-balance scores (p = 0.017) and faster obstacle time (p = 0.007) compared with girls in the 8-<10-year age group. These data will serve to guide future efforts to evaluate normative measures of physical literacy and guide targeted training interventions to promote sustained physical activity in children with deficits relative to their age and sex norms.

Comparison of Sensorimotor Integration and Skill-Related Physical Fitness Components Between College Athletes With and Without Forward Head Posture

OBJECTIVE

To evaluate sensorimotor integration and skill-related physical fitness components for participants with forward head posture (FHP) compared with strictly matched controls with normal head alignment.

MATERIAL AND METHODS

We measured FHP, sensorimotor processing, and skill-related physical fitness variables in 50 participants with FHP and in 50 participants matched for age, gender, and body mass index with normal FHP, defined as having a craniovertebral angle >55°. Sensorimotor processing and integration variables were: (1) amplitudes of the spinal N13, (2) brainstem P14, (3) parietal N20 and P27, and (4) frontal N30 potentials. The skill-related physical fitness variables selected for the study were (1) T-test agility, (2) leg power, (3) stork static balance test, and (4) Y-balance test.

RESULTS

There was a statistically significant difference between the FHP group and control group for the sensorimotor integration variable: frontal N30 potentials (P < .05). Additionally, between-group differences were found for the sensorimotor processing variables: amplitudes of spinal N13, brainstem P14, and parietal N20, and P27 (P < .05). Statistically significant differences between groups for the skill-related physical fitness variables were also identified: T-test agility, leg power, stork static balance test, and Y-balance test (P < .05). The magnitude of the craniovertebral angle showed a correlation with all measured variables (P < .05).

CONCLUSION

College athletes with FHP exhibited altered sensorimotor processing and integration measurements and less efficient skill-related physical fitness compared with athletes with normal sagittal head posture alignment.

Reliability of Y Balance Test in Runners With Intellectual Disability

CONTEXT

The Y Balance Test (YBT) is a simple, reliable, cost-effective screening test. It is used to evaluate dynamic balance as well as to determine the potential risk of injury of the lower limbs. The reliability of YBT has been widely reported in the general population. However, there are no studies evaluating the reliability of YBT use in athletes with intellectual disability (ID). The aim of the study was to examine the reliability of the YBT in runners with ID.

DESIGN

A reliability study.

METHODS

Twelve male runners (short-distance running) with ID (age 25.1 [4.50] y, height 169.1 [4.2] cm, weight 69.5 [5.5] kg, and intelligence quotient 60.8 [2.4]). The YBT was used to measure participants' dynamic balance in the anterior, posteromedial, and posterolateral reach directions. The analysis used the normalized values to the relative length of the lower limbs. A 1-way (trial) repeated-measures (5) analysis of variance for each direction was used. Intraclass correlation coefficient, standard error of measurement, and minimal detectable change were computed to assess the reliability of the YBT between trials.

RESULTS

After 6 practice trials, 3 out of 5 consecutive ones achieved results stabilization for all directions and both legs (P < .05). The intraclass correlation coefficient, standard error of measurement, and minimal detectable change values for all trials ranged from .76 to .87, 5% to <7%, and 11% to <15%, respectively.

CONCLUSION

The YBT is a highly reliable tool to measure the dynamic balance of male runners with ID. Therefore, it is recommended to perform 6 practice trials and 3 measurements in these runners.

Effect of balance training on static and dynamic balance performance in male adolescents: role of training frequency

OBJECTIVE

Previous studies reported significant improvements in static and dynamic balance performance following balance training during adolescence. However, it is unclear how equal training volume but different training frequencies per week affect training-induced adaptations. Thus, the present study investigated the effects of balance training frequency (i.e., 2 × 30 min per week or 3 × 20 min per week) on measures of static and dynamic balance in healthy male adolescents.

RESULTS

Irrespective of balance training frequency, significant pretest to posttest improvements were detected for static (i.e., One-Legged Stance test, standing time duration) and dynamic (i.e., Lower Quarter Y Balance test, reach distance) balance performance. However, no group × test interactions were found. These results imply that balance training is effective to improve static and dynamic balance performance in healthy male adolescents, but the effectiveness seems unaffected by the applied balance training frequency.

No sex-specific effects of balance training on dynamic balance performance in healthy children

Background

Cross-sectional studies in children reported better balance performance for girls than for boys. Thus, balance trainability might be different between female and male children. The aim of the present study was to examine the effects of balance training (BT) on dynamic balance performance in girls compared to boys.

Methods

Seventeen girls (age: 11.1 ± 0.7 years) and 22 boys (age: 11.1 ± 0.8 years) were assigned to either a BT-group or an active control (CON) group. BT was conducted over eight weeks (two sessions/week) while the CON-groups received their regular physical education lessons during the same period. Before and after treatment, dynamic balance performance was assessed by using the Lower Quarter Y-Balance (YBT-LQ) test. A series of three-way analyses of covariance (ANCOVA) were undertaken to test for within-between effects of Test [×2 (pretest vs. posttest)], Group [×2 (BT-group vs. CON-group)] and Sex [×2 (boys vs. girls)].

Results

The three-way ANCOVA yielded a significant main effect of Test (p = 0.002-0.043, η p 2 = 0.122-0.262) and of Group (all p < 0.001, η p 2 = 0.330-0.651) but not of sex for all YBT-LQ reach directions and the composite score. Further, there were significant Test × Group interactions (all p < 0.001, η p 2 = 0.330-0.651) in favor of both BT-groups but neither Test × Sex nor Test × Group × Sex interactions were detected.

Conclusions

We conclude that BT is an effective treatment to improve dynamic balance performance in healthy children regardless of their sex. Consequently, girls and boys can be provided with the same BT regime to enhance their postural control.

Interday Reliability of a Testing Battery to Assess Lateral Symmetry and Performance in Well-Trained Volleyball Players

ABSTRACT

Iglesias-Caamaño, M, Álvarez-Yates, T, Carballo-López, J, Cuba-Dorado, A, and García-García, O. Interday reliability of a testing battery to assess lateral symmetry and performance in well-trained volleyball players. J Strength Cond Res 36(4): 895-901, 2022-This study aimed to determine the relative and absolute interday reliability of a testing battery for lateral asymmetry detection and performance in well-trained volleyball players and to determine whether retaining for analysis the best or the average value of 3 attempts would modulate the interday reliability and the magnitude of asymmetry. Thirteen Superleague-2 male volleyball players performed on 3 different days a 5-test battery composed of 4 tests for assessing muscle asymmetries: active knee extension, Y-balance test (YBT), modified 20-yard shuttle run (M-20Y), and single-leg countermovement jump; and one for volleyball sports performance: attack jump (AJ). The intraclass correlation index and coefficient of variation (CV) together with the standard error of measurement (SEM, %SEM) and the minimum detectable change (MDC, %MDC) were taken to calculate relative and absolute reliability. Two-way repeated-measures analysis of variance was used to establish the differences between the best value and the average value in each session. The low %MDC (<10%) suggests that all the tests that make up the testing battery would have good sensitivity to detect possible asymmetries. All tests have shown an excellent interday absolute reliability (CV <4.5%; %SEM < 5%), both when retaining the best value and the average value of the 3 attempts. In addition, AJ and YBT (on both legs) obtained a good-excellent relative reliability, whereas the M-20Y test seems to show a lower relative reliability. Retaining the best value or the average value to determine the magnitude and direction of asymmetry seems to be equally reliable with no differences between both values.

Limb Dominance Does Not Affect Y-Balance Test Performance in Non-Athlete Adolescents

BACKGROUND

The Lower Quarter Y-Balance Test (YBT-LQ) has been shown to be reliable for assessing dynamic balance in children and adolescents. However, limited research is available about the effects of leg dominance on YBT-LQ performance in adolescents. In addition, there is no consensus on the use of maximum reach or mean reach distance being a better measure of YBT-LQ performance.

HYPOTHESIS/PURPOSE

The purposes of this study were to determine if there is a difference in the YBT-LQ performance between the dominant and non-dominant limbs in non-athlete adolescents, and to compare the reliability of the maximum reach scores to that of the mean reach scores in this population.

STUDY DESIGN

Prospective cohort study.

METHODS

Twenty-six healthy non-athlete adolescents (13.6 ± 1.0 years, 22 girls, 4 boys) performed the YBT-LQ on two separate days while the same investigator scored their performance. Paired t-tests were used to compare reach distances on dominant and non-dominate stance limbs. Intraclass correlation coefficients (ICC3,1) were calculated for the maximum and mean reach distances for three directions (anterior, posterolateral, posteromedial) and the composite scores on each limb.

RESULTS

There was no significant difference in YBT-LQ performance between dominant and non-dominant stance limbs (p > 0.05). Overall, the between-day intra-rater reliability for maximum reach and mean reach scores was moderate-to-good for both limbs (ICC3,1 = 0.59 - 0.83), but was poor for the composite score on the dominant limb (ICC3,1 = 0.42) and maximum anterior reach on non-dominant limb (ICC3,1 = 0.48).

CONCLUSION

Limb dominance does not seem to be a factor for YBT-LQ performance in this population. The YBT-LQ appears to be a reliable tool for dynamic balance assessment in non-athlete adolescents using the individual score of each direction. The use of mean reach measures seems to slightly improve reliability, specifically the anterior reach direction, in this population.

LEVEL OF EVIDENCE

Level 2b.

Effects of Different Balance Training Volumes on Children's Dynamic Balance

Concerning balance training, the most effective design of several load dimensions (e. g., training frequency, volume) is unclear. Thus, we determined the effects of different balance training volumes on dynamic balance in healthy children. Three groups of 20 children (age: 11.0±0.7 years; 47% females) were randomly assigned to a balance training group using a low or a high training volume or an active control group that performed regular physical education lessons. All groups trained for 8 weeks (2 sessions/week), whereby balance training volume amounted to 4 min/session and 18-24 min/session for the low- and high-volume group, respectively. Pre- and post-training, balance performance was assessed using the Lower Quarter Y-Balance Test and the Timed-Up-and-Go Test. Fifty-five children completed the study and significant Test x Group interactions were detected for both outcome measures in favor of the two balance training groups. Additionally, improvements in the high-volume group were significantly larger for some measures (Y-balance test anterior reach distance: p <.001, d =.94; Timed-Up-and-Go time: p =.003, d =.81) compared to the low-volume group. The results indicate that balance training is effective to improve balance performance in healthy children and it seems that a 36-48 min/week compared to an 8 min/week training volume provides additional effects.

Impact of Synchronous Online Physical Education Classes Using Tabata Training on Adolescents during COVID-19: A Randomized Controlled Study

This study aimed to investigate the effects of online physical education classes, using Tabata training, on middle school students’ physical fitness. Fifty-four adolescents were randomly assigned to either the asynchronous online class group (AOCG, n = 24, age: 15.8 ± 0.4 years) or the synchronous online class group (SOCG, n = 24 age: 15.9 ± 0.3 years). The online physical education class lasted two days per week for 10 weeks. Recorded video lectures were conducted for the AOCG, and Tabata training for the SOCG, as real-time lecture methods. Baseline and post-online physical education class measures included muscular strength, muscular endurance, flexibility, balance, and cardiorespiratory fitness tests. The results showed that the synchronous online physical education class had a positive effect on the improvement of muscle mass, ankle strength (dorsiflexion), hip strength (abduction, flexion, extension, and external rotation), knee strength (extension and flexion), and balance (Y-balance test) in adolescents. These findings suggest that the physical fitness of adolescents can be sufficiently improved through appropriate online physical education class methods. Further research should focus on developing and evaluating different types of exercises for synchronous online physical education classes as a precautionary measure for the second wave of COVID-19.

Comparison of Lower and Upper Quarter Y Balance Test Performance in Adolescent Students with Borderline Intellectual Functioning Compared to Age- and Sex-Matched Controls

The Lower (YBT-LQ) and Upper (YBT-UQ) Quarter Y Balance Test are well established assessment tools for the examination of dynamic balance and shoulder mobility/stability, respectively. However, investigations on YBT-LQ/UQ performance in students with borderline intellectual functioning (BIF) (i.e., intelligence quotient of 70–84 etc.) are lacking. Thus, the aim of the study was to compare YBT-LQ/UQ performance in students with and without BIF. Thirty students with BIF (age: 13.7 ± 1.2 years) and 30 age-/sex-matched students without BIF (age: 13.7 ± 1.3 years) performed the YBT-LQ and/or YBT-UQ. Normalized maximal reach distances (% leg/arm length) per reach direction and the composite score were used as outcome measures. A univariate analysis of variance was conducted to test for significant group differences. Irrespective of limb and reach direction, students with BIF compared to those without BIF showed significantly worse YBT-LQ (p ≤ 0.001–0.031; Cohen’s d = 0.57–1.26) and YBT-UQ (p ≤ 0.001–0.015; Cohen’s d = 0.68–1.52) performance with moderate to large effect sizes. Due to the poorer performance levels of students with BIF, specifically tailored interventions should be developed that have the potential to improve their dynamic balance and shoulder mobility/stability.

Reliability and Validity of the Y-balance Test in Young Adults with Chronic Low Back Pain

BACKGROUND

Individuals with chronic low back pain (CLBP) may demonstrate reduced ability to perform dynamic tasks due to fear of additional pain and injury in response to the movement. The Y-balance test (YBT) is a functional and inexpensive test used with various populations. However, the reliability and validity of the YBT used for assessing dynamic balance in young adults with CLBP have not yet been examined.

PURPOSE

To determine the inter-rater reliability of the YBT and to compare dynamic balance between young adults with CLBP and an asymptomatic group.

STUDY DESIGN

Reliability and validity study.

METHODS

Fifteen individuals with CLBP (≥ 12 weeks) and 15 age- and gender-matched asymptomatic adults completed the study. Each group consisted of 6 males and 9 females who were 21-38 years of age (27.47 ± 5.0 years). The YBT was used to measure participant's dynamic balance in the anterior (ANT), posteromedial (PM) and posterolateral (PL) reach directions. The scores for each participant were independently determined and recorded to the nearest centimeter by two raters. Both the YBT reach distances and composite scores were collected from the dominant leg of asymptomatic individuals and the involved side of participants with CLBP and were used for statistical analysis.

RESULTS

The YBT demonstrated excellent inter-rater reliability, with intraclass correlation coefficients ranging from 0.99 to 1.0 for the YBT scores of both asymptomatic and CLBP groups. The CLBP group had lower scores than those of the asymptomatic group in the reach distances of the ANT (p = 0.023), PM (p < 0.001), and PL (p = 0.001) directions, and the composite scores (p < 0.001).

CONCLUSIONS

The results demonstrated excellent inter-rater reliability and validity of the YBT for assessing dynamic balance in the CLBP population. The YBT may be a useful tool for clinicians to assess dynamic balance deficits in patients with CLBP.

LEVEL OF EVIDENCE

2b.

Factors associated with musculoskeletal injuries in an infantry commanders course

OBJECTIVES

To evaluate the prevalence of injuries among young combat soldiers as assessed and reported by the military physicians, and to investigate whether parameters such as anthropometric measures, postural balance, proprioceptive ability, and chronic ankle instability are related to injuries during and following an infantry commanders course.

METHODS

In this cross-sectional study, 165 soldiers were tested for anthropometric measurements, proprioceptive ability, and dynamic postural balance (DPB), as well as for their responses to an ankle stability questionnaire (CAIT), on three occasions: pre-course, middle-course, and end-course testing. All musculoskeletal injuries were assessed and recorded in the digital medical file of each participant by specialist military physicians before and during/following the course.

RESULTS

Ninety-eight soldiers (59.4%) were injured before the course. Forty soldiers (24.2%) incurred an injury during/following the course (with 33 out of the 40 [82.5%] soldiers that were injured during/following the course having also been injured before the course). Sixty soldiers had no injury before/during/following the course. A survival curve showed that half of the soldiers who were injured during/following the course (20 soldiers) were recorded as injured in the first half of the course (during the first 46 days of the 92-day course). Logistic regression showed that the pre-course parameters that were significant among injured soldiers compared with the non-injured soldiers were: low CAIT results (OR = 2.736, 95% CI = 1.178-6.354), high BMI (OR = 1.234, 95% CI = 1.082-1.406) and reduced proprioceptive ability (OR =.858, 95% CI =.797-.924).

CONCLUSION

With a high prevalence of soldiers injured during and following a commanders course, a somatosensory intervention program should be generalized into the practical daily preparation and training routines of the soldiers for improving somatosensory abilities, optimizing military physical readiness, and for preventing future musculoskeletal injuries.

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.

Discriminative validity of the lower and upper quarter Y balance test performance: a comparison between healthy trained and untrained youth

Background

The Lower (YBT-LQ) and Upper (YBT-UQ) Quarter Y Balance Test have been widely used for the assessment of dynamic balance and shoulder mobility/stability, respectively. However, investigations on the validity of the two tests in youth are lacking. Therefore, we performed two studies to determine discriminative validity of the YBT-LQ (study 1) and the YBT-UQ (study 2) in healthy youth.

Methods

Sixty-nine male soccer players (age: 14.4 ± 1.9 yrs) and 69 age-matched untrained male subjects (14.3 ± 1.6 yrs) participated in study 1 and 37 young swimmers (age: 12.3 ± 2.1 yrs) as well as 37 age−/sex-matched individuals (age: 12.5 ± 2.0 yrs) took part in study 2. Absolute (cm) and relative (% leg/arm length) maximal reach distances per reach direction and the composite score of the YBT-LQ/UQ were used as outcome measures. One-way analysis of variance and the receiver operator characteristic curve analysis (i.e., calculating the area under the curve [AUC]) were conducted to assess discriminative validity.

Results

Concerning the relative values, youth athletes showed significantly better YBT-LQ (study 1: p < 0.001, d = 0.86–1.21) and YBT-UQ (study 2: p < 0.001, d = 0.88–1.48) test performances compared to age- and sex-matched untrained subjects. Further, AUC-values indicated a chance of ≥74% (YBT-LQ) and ≥ 71% (YBT-UQ) to discriminate between youth athletes and controls. These findings were confirmed when using the absolute data for analysis.

Conclusions

According to our results, the YBT-LQ and the YBT-UQ seem to be useful test instruments to discriminate trained and untrained healthy youth performance for dynamic balance and shoulder mobility/stability, respectively.

Seasonal Changes in Anthropometry, Body Composition, and Physical Fitness and the Relationships with Sporting Success in Young Sub-Elite Judo Athletes: An Exploratory Study

This exploratory study aimed to monitor long-term seasonal developments in measures of anthropometry, body composition, and physical fitness in young judo athletes, and to compute associations between these measures and sporting success. Forty-four young judoka (20 females, 24 males) volunteered to participate. Tests for the assessment of anthropometry (e.g., body height/mass), body-composition (e.g., lean body mass), muscle strength (isometric handgrip strength), vertical jumping (e.g., countermovement-jump (CMJ) height), and dynamic balance (Y-balance test) were conducted at the beginning and end of a 10-month training season. Additionally, sporting success at the end of the season was recorded for each athlete. Analyses revealed significant time × sex interaction effects for lean-body-mass, isometric handgrip strength, and CMJ height (0.7 ≤ d ≤ 1.6). Post-hoc analyses showed larger gains for all measures in young males (1.9 ≤ d ≤6.0) compared with females (d = 2.4) across the season. Additionally, significant increases in body height and mass as well as Y-balance test scores were found from pre-to-post-test (1.2 ≤ d ≤4.3), irrespective of sex. Further, non-significant small-to-moderate-sized correlations were identified between changes in anthropometry/body composition/physical fitness and sporting success (p > 0.05; -0.34 ≤ ρ ≤ 0.32). Regression analysis confirmed that no model significantly predicted sporting success. Ten months of judo training and/or growth/maturation contributed to significant changes in anthropometry, body composition, and physical fitness, particularly in young male judo athletes.

Effects of Balance Training on Balance Performance in Youth: Are There Age Differences?

Purpose: In youth, cross-sectional studies reported age differences in balance performance that were in favor of adolescents. Thus, trainability of balance performance might be different in children compared to adolescents. The purpose of this study was therefore to compare the effects of balance training (BT) on balance performance between children and adolescents.Method: Thirty children (7.5 ± 0.5 years) and 42 adolescents (14.7 ± 0.5 years) participated in this study and were assigned to either a BT-group or a control (CON) group. In both age groups, BT was conducted over five weeks while the CON-groups received their regular physical education lessons. Pre- and posttests included the assessment of mobility, static steady-state, proactive, and reactive balance.Results: Significant Test × Group × Age interactions were found for static steady-state balance (i.e., CoP displacements during single leg stance) and mobility (i.e., 10-m gait velocity). For both measures, post hoc analysis revealed larger improvements (+16-37%, 0.001 ≤ p ≤ 0.033, 0.65 ≤ d ≤ 2.24) for children compared to adolescents. For proxies of proactive and reactive balance, we could not detect significant Test × Group × Age interactions.Conclusions: We conclude that trainability of static steady-state balance and mobility seems to be higher in children than in adolescents indicating larger adaptive reserves in children compared to adolescents. However, there were no age differences in adaptations to BT with respect to proactive and reactive balance.

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.

Lower Quarter Y Balance Test performance: Reference values for healthy youth aged 10 to 17 years

BACKGROUND

The Lower Quarter Y Balance Test (YBT-LQ) has been widely used to register dynamic balance performance in children and adolescents. However, studies evaluating age- and sex-specific normative data to assess and classify YBT-LQ performance for these age-cohorts are missing.

OBJECTIVE

Thus, we investigated YBT-LQ performance in healthy youth to provide age- and sex-specific reference values.

METHODS

Six-hundred and sixty-nine individuals (286 female, 383 male) aged 10-17 years performed the YBT-LQ with their left and right leg. Normalized maximal reach distances (% leg length) for all three directions (i.e., anterior, posterolateral, posteromedial) and the composite score were calculated. Further, age- and sex-specific percentile values (i.e., 10th to 90th percentile) were computed and plotted.

RESULTS

In boys, the oldest age group (16-17 years) performed better than the younger ones (14-15, 12-13, and 10-11 years). In girls, the youngest age group (10-11 years) often achieved better values compared to the 12-13-year olds. Further, 16-17-year old boys compared to the same aged girls showed better YBT-LQ performance in all but one measure (except left leg reach in posterolateral direction). For both sexes, curvilinear shaped curves were detected for percentile values across the reach directions.

CONCLUSIONS

The generated age- and sex-specific reference values for the YBT-LQ can be used by practitioners to evaluate dynamic balance performance in healthy youth aged 10-17 years.

Unilateral and bilateral patellofemoral pain in young female dancers: Associated factors

Aiming to evaluate the prevalence of unilateral/bilateral patellofemoral pain (PFP) among young dancers, and to investigate whether different factors are associated with PFP in young dancers, 132 dancers aged 12-14 years were assessed for PFP. Anthropometric parameters, proprioception ability, dynamic postural balance (DPB), and muscle strength were measured. PFP was found in 64.1% of the dancers. No significant differences in the prevalence of dancers with no, unilateral, or bilateral PFP at different ages were found. Significant age effects were found for anthropometric and developmental measurements, and for intensity of training. PFP effect was found for DPB asymmetry, ankle proprioception, and leg-length %height. A higher hip abductor/adductor ratio was associated with PFP in 14-year-old dancers. Binomial logistic regression showed that increased number of hours per day (h/day) and decreased number of hours per week (h/week), low proprioception scores, greater leg length as %height, and more anterior DPB asymmetry were significant predictors of PFP. In conclusion: unilateral/bilateral PFP is common among young dancers. Body morphology, reduced ankle proprioception ability, DPB asymmetry, and increased h/day of practice are associated with PFP. Dance teachers should start monitoring the impact of training and implement injury modification/prevention strategies when their students are at a young age.