Acute and chronic effects of stretching on balance: a systematic review with multilevel meta-analysis.

Introduction: Balance is a multifactorial construct with high relevance in, e.g., everyday life activities. Apart from sensorimotor control, muscle strength and size are positively linked with balance performance. While commonly trained for via resistance training, stretch training has emerged as a potential substitution in specific conditions. However, no review has investigated potential effects of stretching on balance, yet. Methods: PubMed, Web of Science and Scopus were searched with inception to February, 2024. Studies were included if they examined acute and/or chronic effects of any stretching type against passive and/or active controls on balance parameters - without any population-related restrictions concerning sex/gender, age, health status, activity level. Methodological quality was assessed using PEDro scale. Meta-analyses were performed if two or more studies reported on the same outcome. Certainty of evidence was determined based on GRADE criteria. Results: Eighteen acute and eleven chronic effect studies were included. Stretching studies exhibited significant improvements for sway parameters with eyes open against passive controls of moderate magnitude for chronic (ES: 0.63, p = 0.047) and of small magnitude for acute studies (ES: 0.21, p = 0.032). Most other subgroups against passive controls as well as actively-controlled comparisons resulted in trivial and/or non-significant effects. Conclusion: Even though some pooled effects slightly reached the level of significance, the overall results are biased by (very) low certainty of evidence (GRADE criteria downgrading for risk of bias, imprecision, publication bias). Moderators suggested by literature (strength, muscle size, flexibility, proprioception) were rarely assessed, which prevents conclusive final statements and calls for further, high quality evidence to clarify potential mechanisms-if any exist.

Side differences in upper quarter mobility/stability are not related to serve velocity in tennis players with different levels of training experience.

OBJECTIVE: Tennis is characterised by repetitive serves and strokes predominately performed with one arm. This can lead to differences in upper quarter mobility/stability between the stroke and non-stroke arm, which could even enlarge with increasing training experience and negatively affect serve velocity. Thus, we determined side differences (i.e., limb symmetry index) in upper quarter mobility/stability and their association with flat and slice serve velocity in advanced (ITN ≤ 4) female and male tennis players (N = 42, mean age = 23.9 ± 9.3 years) with different levels of training experience (< 2 years: n = 14, 2-5 years: n = 17, 6-8 years: n = 11). RESULTS: Y Balance Test-Upper Quarter (YBT-UQ) side difference (i.e., composite score) and performances (i.e., medial reach) were largest in players with the lowest level of training experience (i.e., < 2 years). Further, YBT-UQ performances (i.e., medial reach and composite score) but not side differences were significantly correlated with flat and slice serve velocity, particularly in less experienced players. Our results suggest that significant side differences in upper quarter mobility/stability occur in less experienced players (indicative of increased injury risk) but they are not related to tennis-specific performance (i.e., serve velocity).

Evaluation of hop tests based on Y-Balance test and FMS test outcomes in volleyball and basketball players to identify those prone to injury: a potential predictor of injury.

BACKGROUND: The quest for a reliable and effective method to identify athletes at risk of injury holds the promise of significantly reducing injury rates and improving overall athletic performance. This research delved into the relationship between the Functional Movement Screen (FMS), Y-Balance Test (YBT), and Hop tests (Side hop, Medial triple hop, and Lateral step-down hop), aiming to determine the potential in predicting injuries of hop tests among division 1 volleyball and basketball players. METHODS: This research was conducted with fifty-two participants from the Division 1 league, encompassing both volleyball and basketball players. The study rigorously employed the Functional Movement Screen (FMS), the Y-Balance Test (YBT), and various hop tests (side hop test, medial triple hop test, lateral step-down hop) to measure relevant variables. The data analysis used logistic regression, ensuring a comprehensive approach to the study. RESULTS: Results showed no significant relationship between FMS and Hop test for predicting injuries, but there was a relationship between ΔY and side hop that shows side hop test can predict injury, but there was no relationship between Lateral step down, Medial triple hop, and ΔY. CONCLUSIONS: Based on our findings, side hop, despite the medial triple hop and lateral step-down test, can be used as a sports injury predictor.

Influence of protocol variables on outcomes of the star excursion balance test group (SEBT, mSEBT, YBT-LQ) in healthy individuals: a systematic review.

Background: The "SEBT group," which includes the Star Excursion Balance Test (SEBT), its modified version (mSEBT), and the Lower Quarter Y-Balance Test (YBT-LQ), is used to assess the limits of stability. Interestingly, the testing protocol allows users a considerable degree of flexibility, which can affect the obtained results. Therefore, the objective of this systematic review was to analyze the impact of different protocol variants within the "SEBT group" on outcomes. Methods: Data were acquired by searching 4 databases (MEDLINE, ScienceDirect, Wiley, Springer Link) focusing on studies published in English in peer-reviewed journals, empirical in nature, conducted on healthy individuals, and examining the effects of various protocol variants on test outcomes. Study quality was assessed with the NHLBI quality assessment tool for pre-post studies with no control group. Results: The calculation method based on the maximum repetition yields statistically significantly higher results compared to other calculation methods. Allowing unrestricted arm movements during the test results in statistically significantly higher scores compared to the procedure that restricts arm movements. The impact of a warm-up, wearing footwear during testing, and using a dedicated kit remains ambiguous. To obtain reliable results, 4-6 familiarization trials are necessary, though fewer may suffice for athletes experienced in performing the test. Conclusion: This systematic review highlights the significant impact of the calculation method and arm movement restrictions on the outcomes of the "SEBT group." The effects of wearing footwear during testing, warm-up, and using a dedicated test kit remain unclear. The required number of familiarization repetitions may varies depending on biological maturity level of the person being tested. Future research should develop a warm-up protocol tailored to the needs of the "SEBT group," and investigate the impact of heel elevation during testing on outcomes. Systematic review registration: The protocol for this systematic review was prospectively registered in the OSF Registries (https://doi.org/10.17605/OSF.IO/JSKH2).

Relationship between Dynamic Balance and Physical Characteristics and Functions in Elite Lifesaving Athletes.

Balance is important in lifesaving competitions. We aimed to investigate the relationship between dynamic balance and physical characteristics and functions in elite lifesavers by measuring the foot muscle cross-sectional area, ankle joint muscle strength, toe grasp strength, plantar superficial sensation, and dynamic balance (Y-balance test). In this observational study, we measured the foot muscle cross-sectional area, ankle dorsiflexion, plantar flexion, external flexion, isometric muscle strength, toe grasp strength, and superficial foot sensation of 15 adult lifesavers (12 males). The results show that toe grasp strength and ankle plantar flexion isometric muscle strength are particularly important for the dynamic balance of elite lifesavers working on sandy surfaces. Sand training improves intrinsic muscle strength and dynamic balance function. However, high training intensity may reduce plantar surface sensation; this needs to be verified through sand training interventions in the future.

Comparing reach distance between the Y-Balance Test-Lower Quarter and Star Excursion Balance Test: Are practitioners using the correct protocol?

OBJECTIVES: To compare reach distances between the YBT-LQ and SEBT using the correct protocols as outlined by the developers. This will provide an accurate insight on the actual magnitude differences in reach distance between the movement screen tests and will safeguard practitioners on the subsequent use of these outcomes to inform clinical decision making. DESIGN: Observational. SETTING: Laboratory. PARTICIPANTS: Participants included sixteen healthy female subjects from the university and amateur sports teams. MAIN OUTCOME: Reach distances in the anterior direction (ANT), posterior medial (PM) and posterior lateral (PL) between participants on the YBT-LQ and SEBT. RESULTS: The principal findings highlighted that a statistically significantly greater reach distance on the left and right side for the YBT-LQ compared to the SEBT in the ANT, PM, and PL directions (p < 0.0005). CONCLUSION: The results of this study suggest that the YBT-LQ and SEBT are not comparable tests due to the differences in reach distance and methodological differences. Therefore, previous, and future research using the YBT-LQ and SEBT cannot be used interchangeably. Not following developed guidelines questions the applicability of the findings of reach distance scores to infer on performance and assessment of injury risk.

Center of Pressure Velocity and Dynamic Postural Control Strategies Vary During Y-Balance and Star Excursion Balance Testing.

Background: Dynamic postural control (DPC) describes an individual's ability to maintain balance within their base of support in both anticipatory and reactive balance situations and has been measured using center of pressure (COP) velocity. Common standardized DPC assessments for active adults include the modified Star Excursion Balance Test (MSEBT) and the Y-Balance Test (YBT). Hypothesis/Purpose: The purpose of this study was to explore DPC during performance of the MSEBT, the YBT, and a modified version of the YBT, the MYBT. It was hypothesized that feedback from the YBT/MYBT reach indicator would enhance DPC. Study Design: Cross-sectional study. Methods: Twenty-one participants (9 females, 12 males, mean age 24.5±1.2 years) performed three trials in each direction (anterior-AN, posteromedial-PM, and posterolateral-PL) on each balance test during one session. The YBT frame was placed atop a force plate for all testing. Frontal and sagittal plane COP velocities (COPx and COPy, respectively) were recorded throughout each trial and resultant COP (COPr) velocities were calculated. Results: Significant main effects were present for test (F=4.485, p\<0.001) and reach direction (F=61.594, p\<0.001). Post hoc analyses for test indicated significant differences in COPy between YBT and MSEBT (p=0.034) and between MYBT and MSEBT (p\<0.001), as well as significant differences in COPr between MYBT and MSEBT (p=0.002). Post hoc analyses for reach direction revealed significant differences in COPx between AN and both PM (p\<0.001) and PL (p\<0.001) directions, in COPy between AN and PM (p\<0.001) and PL (p\<0.001) directions, and COPr between AN and PL (p=0.043) directions only. Conclusion: External proprioceptive feedback from the reach indicator improved DPC during the YBT and MYBT when compared to the MSEBT. Sagittal plane COP velocities were reduced when external proprioceptive feedback from the reach indicator was present, while frontal plane COP velocities were not affected in this group of participants. Level of Evidence: 2b.

Immediate Effects of Wearing an Ankle Bandage on Fine Coordination, Proprioception, Balance and Gait in the Subacute Phase of Ankle Sprains.

Ankle sprains are the most frequently occurring musculoskeletal injuries among recreational athletes. Ankle support through bandages following the initial orthotic treatment might be beneficial for rehabilitation purposes. However, the literature is sparse regarding the use of an ankle support directly after the acute phase of an ankle sprain. Therefore, this study investigates the hypothesis that wearing an ankle bandage immediately after an acute ankle sprain improves motor performance, stability and reduces pain. In total, 70 subjects with acute unilateral supination trauma were tested. Subjects were tested five weeks post-injury to assess immediate effects of the ankle bandage. On the testing day, subjects completed rating questionnaires and underwent comprehensive biomechanical assessments. Biomechanical investigations included fine coordination and proprioception tests, single leg stances, the Y-Balance test, and gait analysis. All biomechanical investigations were conducted for the subject's injured leg with and without a bandage (MalleoTrain® Bauerfeind AG, Zeulenroda-Triebes, Germany) and the healthy leg. Results indicated moderate to strong improvements in ankle stability and pain relief while wearing the bandage. Wearing the bandage significantly normalized single leg stance performance (p < 0.001), stance phase duration (p < 0.001), and vertical ground reaction forces during walking (p < 0.05). However, the bandage did not have a clear effect on fine coordination and proprioception. The findings of our study suggest that ankle bandages may play a crucial role in early-stage rehabilitation by enhancing motor performance and reducing pain.

Lower limb balance, ankle dorsiflexion, orofacial tissue pressure, and occlusal force of rugby players.

This cross-sectional study examined the lower limb balance, ankle dorsiflexion, orofacial tissue pressure, and occlusal strength of rugby players. Twenty-six participants were divided into groups: rugby players (n â€‹= â€‹13) and healthy sedentary adults (n â€‹= â€‹13). Participants underwent an analysis of lower limb balance using a composite score (Y-Balance Test). Ankle dorsiflexion was measured using the Lunge Test. The Iowa Oral Performance Instrument was employed to measure orofacial tissue pressure. Bite force was measured with a dynamometer, and T-Scan assessed occlusal contact distribution. Data were analyzed using the t-test (p â€‹< â€‹0.05) and ANCOVA with age and weight as covariates, where it is possible to verify that these factors did not influence the results obtained. Significant differences were observed in the balance of the right (p â€‹= â€‹0.07) and left (p â€‹= â€‹0.02) lower limbs, where rugby players had lower composite scores. There were significant differences in the right (p â€‹= â€‹0.005) and left (p â€‹= â€‹0.004) lunges, with rugby players showing lower values, as well as lower tongue pressure (p â€‹= â€‹0.01) and higher lip pressure (p â€‹= â€‹0.03), with significant differences to sedentary participants. There was no significant difference in molar bite force and distribution occlusal contacts between groups. Rugby seems to reduce lower limb displacement, cause ankle hypomobility, lead to changes in orofacial tissues, particularly the tongue and lips. This study is significant for identifying significant differences between rugby players and sedentary individuals, providing new insights into the impact of rugby on health and performance, which can benefit sports training and injury prevention.

Effect of Verbal Encouragement on Postural Balance in Individuals with Intellectual Disabilities.

This study investigated the effect of verbal encouragement (VE) on static and dynamic balance in individuals with intellectual disabilities (IDs). A total of 13 mild IDs and 12 moderate IDs participants underwent static balance tests (bipedal stance on firm surface, under open eyes (OEs) and closed eyes (CEs), and foam surface, unipedal stance on firm surface) and dynamic balance assessments (Y Balance Test (YBT) and Expanded Timed Up-and-Go Test (ETUGT)) under VE and no VE (NO/VE) conditions. VE significantly reduced center of pressure mean velocity (CoPVm) values for mild IDs in firm bipedal CEs conditions. The mild IDs group exhibited improved YBT scores and enhanced ETUGT performances for both groups under VE. Incorporating VE as a motivational strategy in balance training interventions can positively impact static and dynamic balance in individuals with mild IDs, especially in challenging conditions like unipedal stances on firm surfaces.

What is the influence of biomechanical variables on the Y balance test performance in recreational runners?

BACKGROUND: Asymmetries and poor Y balance test (YBT) performance are associated with an increased risk of injuries in athletes. The aim of this study was to investigate the association between YBT performance with biomechanical variables in runners. METHODS: The runners underwent the YBT, followed by the assessment of center of pressure, plank position, muscle strength (MS) of hip flexors, extensors, abductors, and external rotators, knee extensors, ankle dorsiflexion range of motion (ROM), Q angle, forefoot alignment, and passive hip internal rotation. Associations between variables were examined using multiple linear regression models with the Bayesian Information Criterion. RESULTS: 122 cases were analyzed. The R2 values were 0.38; 0.05; 0.06; and 0.15 for the anterior, posteromedial, posterolateral and composite directions models, respectively. The anterior reach in the YBT was associated with ankle dorsiflexion ROM [Sß 95%IC: 0.43 (0.32-0.55)], passive hip internal rotation [Sß 95%IC: 0.35 (0.24-0.47)], MS of the hip extensors [Sß 95%IC: 0.19 (0.07-0.31)] and forefoot alignment [Sß 95%IC: 0.14 (-0.25-0.02)]. The posteromedial and posterolateral reach were associated with MS of the hip flexors [Sß 95%IC: 0.23 (0.09-0.37) and 0.24 (0.11-0.38)], respectively. The composite score was associated with MS of the hip flexors [Sß 95%IC: 0.31 (0.18-0.45)], ankle dorsiflexion ROM [Sß 95%IC: 0.24 (0.10-0.37)] and Q angle [Sß 95%IC: 0.18 (0.04-0.31)]. CONCLUSION: YBT performance in different directions demonstrated specific associations with key biomechanical factors.

Ankle dorsiflexion range of motion and hip abductor strength can predict Lower Quarter Y-Balance Test performance in healthy males.

OBJECTIVES: The aim of the study was to assess whether strength and range of motion (ROM) of the hip and ankle are the factors determining performance in the Lower Quarter Y-Balance test (YBT-LQ). DESIGN: Cross-sectional study. PARTICIPANTS: 66 healthy males (age: 25.2±6.8 years) participated in this study. MAIN OUTCOME MEASURES: Participants underwent assessments of ankle dorsiflexion (DF) ROM, hip internal rotation (IR) ROM, external rotation (ER) ROM and isometric strength of hip abductor (ABD), extensor (EXT) and external rotators (ERS) muscles together with YBT-LQ for both legs. A forward 2-steps multiple linear regression analysis was conducted to examine the relationship between the predictor variables and the criterion variable. RESULTS: Ankle DF ROM predicted anterior (ANT) reach (R2 = 0.49; R2 = 0.33; p < 0.001). The model with hip ABD strength and ankle DF ROM explained posteromedial (PM) reach variance for stance leg (R2 = 0.35; p < 0.001), while only hip ABD strength was included for kicking leg (R2 = 0.19; p = 0.007). The model with ankle DF ROM and hip ABD strength explained posterolateral (PL) reach for stance leg (R2 = 0.41; p < 0.001). Hip ABD was the only predictor for kicking leg PL reach (R2 = 0.15; p < 0.001). YBT-LQ composite score was explained by ankle DF ROM and hip ABD strength for both legs (R2 = 0.44; p < 0.001) and (R2 = 0.25; p = 0.002). CONCLUSION: Hip ABD strength and ankle DF ROM can determine performance in the YBT-LQ. Strength of hip EXT, ERS as well as ROM of hip IR and ER did not predict YBT-LQ performance.

Inter-limb differences in upper quarter mobility/stability are not associated with performance in competitive swimmers.

Background: The Y Balance Test-Upper Quarter (YBT-UQ) is a cost-effective, well-established, closed kinetic chain test to assess inter-limb asymmetries in the upper quarter that could negatively affect swimming performance. Thus, the aim of the present study was to determine YBT-UQ performances and inter-limb differences as well as its association with swimming performance in athletes with diverging levels of expertise. Methods: Forty female and male competitive swimmers (age range: 10-22 years) with different expertise levels (A-squad: n = 9, B-squad: n = 12, C-squad: n = 19) were tested (reach distances for the YBT-UQ) and swimming performance was calculated using the ratio of individual to world best time. Results: YBT-UQ performances (i.e., inferolateral reach direction for the dominant arm: p = .027, ηp2 = .12 and the non-dominant arm: p = .031, ηp2 = .17) but not YBT-UQ inter-limb differences significantly differed between groups and were largest in swimmers with the lowest expertise level (i.e., C-squad). Further, YBT-UQ performances (i.e., inferolateral reach direction [r = -.68 to -.70, both p < .05] and composite score [r = -.65 to -.67, both p < .05] for both arms and medial reach direction for the non-dominant arm [r = -.64, p < .05]) but not inter-limb differences were significantly and negatively correlated with swimming performance among B-squad swimmers. Conclusions: Our results suggest that inter-limb differences in upper quarter mobility/stability are not influenced by the level of expertise and have no significant associations with swimming performance. However, greater reach distances were correlated with lower swimming performance for the B-squad swimmers indicating that a training-related increase in upper quarter mobility/stability could worsen swimming performance in those athletes.

Integrated Rehabilitation Approach Utilizing Swiss Ball Training, Mulligan Taping, and Mobilization With Movement for Simultaneous Management of Sacroiliac Joint Dysfunction and Lateral Ankle Sprain in a Badminton Athlete: A Case Study.

This case report details an integrated rehabilitation plan implemented for a professional badminton player who presented with issues of sacroiliac joint (SIJ) dysfunction and a lateral ankle sprain. The integrated approach aimed to address both musculoskeletal issues, considering their potential reciprocal influences on biomechanics and functional performance. The athlete underwent a thorough initial assessment, including clinical examination, imaging, and biomechanical analysis. Treatment began with targeted interventions for acute ankle sprain management, such as rest, ice, compression, and elevation (RICE) followed by progressive exercises to restore ankle stability and range of motion (ROM). Concurrently, a specialized program was devised to address the underlying sacroiliac joint dysfunction through manual therapy, therapeutic exercises, and core stabilization routines. Throughout the rehabilitation process, the focus remained on integrated exercises that targeted both the ankle and sacroiliac joint, promoting optimal neuromuscular coordination and joint function specific to badminton demands. Regular reassessments guided the progression of interventions, ensuring a personalized and athlete-centric approach. The positive outcome highlights the importance of a holistic rehabilitation strategy in managing complex musculoskeletal conditions in athletes, facilitating efficient recovery, and reducing the risk of recurrence. This case report highlights the effectiveness of an integrated approach in enhancing performance and preventing reinjury in badminton athletes facing multifaceted musculoskeletal challenges.

Effects of Nontraditional Division III Lacrosse Participation on Movement Pattern Quality and Dynamic Postural Control.

Background/Purpose: No studies have observed the effects of a collegiate lacrosse season on movement pattern quality, dynamic postural control, or the accuracy of athletes' perceived movement pattern quality. The purpose was to examine the effects of a nontraditional fall season on movement pattern quality, perceived movement pattern quality, and dynamic postural control in collegiate lacrosse athletes. Design: Cross-sectional laboratory study. Methods: Fifty men's (age=19.38±1.24 years, height=182.63±6.16 cm, mass=82.37±8.46 kg) and 22 women's (age=19.68±1.17 years, height=165.10±6.88 cm, mass=64.09±8.72 kg) lacrosse players were recruited. Outcome measures included individual Functional Movement Screen™ (FMS™) scores, self-reported perceived movement pattern quality scores, lower and upper extremity Y-Balance Test (YBT) measurements, and active dorsiflexion range of motion (ROM) before the start and again at the end of the fall lacrosse season. Pre- and post-season measurements were assessed using paired t-tests and chi-squared analyses. Results: FMS™ composite scores did not significantly change from preseason to postseason for males (p=0.74) or females (p=0.07). Male perceived movement pattern quality was significantly higher than measured for 10 of 12 movements (p<0.05). Female perceived movement pattern quality was significantly higher than measured for four of 12 movements (p<0.05). Asymmetry frequency significantly increased in males in the hurdle step from two individuals to nine (χ21=25.52, p<0.01), inline lunge from 10 to 20 (χ21=12.50, p<0.01), and shoulder mobility from 4 to 21 (χ21=78.53, p<0.01). Asymmetries in male athletes significantly decreased in the active straight leg raise from 26 to 8 (χ21=25.96, p<0.01). YBT composite scores increased in males for the right leg (p=0.001) and left leg (p<0.03). Right dorsiflexion ROM (p<0.001) and left dorsiflexion ROM (p<0.001) significantly decreased in males from preseason to postseason. YBT scores for the right leg significantly increased in females from preseason to postseason (p=0.01). YBT scores for females for the right arm significantly increased from preseason to postseason (p=0.045). Conclusions: A 5-week season may not change overall movement pattern quality of men's or women's lacrosse players, but some individual movement scores diminished. Athletes may overestimate self-reported movement pattern quality and are therefore unlikely to individually address movement deficits. Male dynamic postural control may change throughout a season, resulting in a potential increased risk of injury later in the season due to compensatory patterns or changes in mobility, proprioception, or balance. Level of Evidence: 3b.

Effects of Peroneus Brevis versus Peroneus Longus Muscle Training on Muscle Function in Chronic Ankle Instability: A Randomized Controlled Trial.

Chronic ankle instability (CAI) is a common injury that can occur in daily life or sporting events. Injuries to the anterior talofibular, posterior talofibular, and calcaneofibular ligaments are common, and the core of rehabilitation training involves strengthening the peroneus muscle. Many studies on rehabilitation training have focused on strengthening the peroneus brevis muscle, and few studies have focused on specific training to strengthen the peroneus longus muscle. Therefore, this study aims to investigate changes in the symptoms and functions of patients by applying training to strengthen the peroneus longus and peroneus brevis muscles. Home-based training and mobile monitoring were utilized for 12 weeks, divided into peroneus brevis training (PBT) and peroneus longus training (PLT), in 52 adult males with CAI. Participation was voluntary, with enrollment done through a bulletin board, and intervention training allocation was randomly assigned and conducted in a double-blind manner. This study was registered as a trial protocol (KCT 0008478). Foot and ankle outcome scores (FAOS), isokinetic ankle strength tests, and Y-balance tests were performed before and after the intervention. Both PLT and PBT significantly improved in FAOS, inversion, and eversion at angular velocities of 30°/s and 120°/s and in the anterior and posterolateral directions of the Y-balance test (p < 0.05). Interaction effects by time and group were not significant for the FAOS (p > 0.05). However, PLT improved eversion muscle strength and muscle power to a greater degree, compared with PBT, in the anterior and posterolateral directions of the Y-balance test (p < 0.05). In conclusion, both PLT and PBT were effective for CAI patients; in addition, PLT had greater potential for improving strength and balance.

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.

Association between depressive symptoms and dynamic balance among young adults in the community.

Background: Detecting and addressing depression symptoms at their outset can reduce the burden on individuals and society; however, it has a limitation in that such evaluations mainly rely on self-reports. Several studies have demonstrated a strong association between motor symptoms and early depression. We aimed to associate body balance measured by the Lower Quarter Y Balance Test (YBT-LQ) with depressive symptoms among young adults in the community, to confirm the current evidence that depression negatively influences body balance. Research question: Is the YBT-LQ an objective tool for measuring and evaluating young adults' depression risks, as well as assessing whether depression negatively influences body balance? Methods: Our participants comprised 36 young adults. We assessed their depressive symptoms using the Center for Epidemiological Studies Depression Scale (CES-D) via a Google survey, measured their body balance with the YBT-LQ, and analyzed data with Spearman's rank-order correlation coefficient test, using SPSS version 27.0. Results: We found that the right leg's anterior, posteromedial, and posterolateral scores- Z = -2.129, p = .033; Z = -2.181, p = .029; and Z = -2.250, p = .024, respectively-and composite scores-Z = 73.00, p = .027 -were significantly lower in the group with risk for clinical depression compared to the normal group. The CES-D total score had a negative association with all YBT-LQ scores, except for the anterior score of the left leg. Among the CES-D sub-factors, somatic and retarded activity showed negative correlations with all the YBT-LQ scores. Significance: Our findings revealed that depressive symptoms have a negative association with balance, and that the YBT-LQ can be a reliable tool for measuring motor symptoms of depression, specifically among young adults.

The Effects of a Short Virtual Reality Training Program on Dynamic Balance in Tennis Players.

This study aimed to analyze the effects of a 5 min virtual reality training program (VR) on dynamic balance in tennis players. Fifty-eight college tennis players (mean age 22.9 ± 3.1 years, weight 73.9 ± 10.8 kg, height 176.6 ± 8.4 cm) were allocated to either the control group (placebo) (CG, n = 20) or the right-handed experimental group (RTG, n = 20) and left-handed experimental group (LTG, n = 18), both of which took part in the 5 min VR intervention program. Pre-tests included anthropometric measures and the Y Balance Test (YBT), and the post-test was the Y Balance Test (YBT). Three YBT trials were performed in anterior (ANT), posterolateral (PL), and posteromedial (PM) directions. After the training intervention, in the right-handed experimental group (RTG), significant differences were observed for two variables: anterior reach (right foot) (p = 0.00) and posterior medial reach (right foot) (p = 0.03). In other analyzed variables, there were no significant differences. Additionally, the effect size was small. In the left-handed experimental group (LTG), statistically significant improvements were identified in five out of six analyzed variables: anterior reach (left foot) (p = 0.00), posterior medial reach (left foot) (p = 0.00), posterior lateral reach (left foot) (p = 0.00), posterior medial reach (right foot) (p = 0.00), and posterior lateral reach (right foot) (p = 0.00). The effect size ranged between small and medium. No significant changes were observed in the control group (CG) after the training intervention. Moreover, for all variables, the time*group interaction is determined. Anterior reach (left foot), posterior medial reach (left foot), posterior medial reach (right foot), and posterior lateral reach (right foot) showed significant interactions (F = 3.04, p = 0.05; F = 3.50, p = 0.03; F = 6.08, p = 0.00; and F = 4.69, p = 0.01). The outcome of this study leads us to a further understanding that if a player were to partake in VR activity, it could show a positive effect on their dynamic balance performance.

Novel Multi-View RGB Sensor for Continuous Motion Analysis in Kinetic Chain Exercises: A Pilot Study for Simultaneous Validity and Intra-Test Reliability.

As the number of musculoskeletal disorders caused by smartphone usage, sedentary lifestyles, and active sports activities increases, there is a growing demand for precise and accurate measurement and evaluation of issues such as incorrect compensation patterns, asymmetrical posture, and limited joint operation range. Urgent development of new inspection equipment is necessary to address issues such as convenience, economic feasibility, and post-processing difficulties. Using 4DEYE®, a new multi-view red, green, and blue (RGB) sensor-based motion analysis equipment, and the VICON® ratio, which are infrared-based markers, we conducted a comparative analysis of the simultaneous validity of the joint angle (trajectory) and reliability. In this study, five healthy participants who could perform movements were selected for the pilot study and two movements (Y-balance and side dip) were analyzed. In addition, the ICC (Intraclass Correlation Coefficient) was analyzed using the SPSS (Statistical Package for the Social Sciences) V.18 while the number of data frames of each equipment was equalized using the MATLAB program. The results revealed that side dips, which are open kinetic chain exercises (intraclass correlation coefficient ICC(2.1), 0.895-0.996), showed very high concordance with the Y-balance test, a closed kinetic chain exercise (ICC(2.1), 0.678-0.990). The joint measurement results were similar regardless of the movement in the open or closed kinetic chain exercise, confirming the high reliability of the newly developed multiview RGB sensor. This is of great significance because we obtained important and fundamental results that can be used in various patterns of exercise movements in the future.