The purpose of this study was to assess the test-retest reliability, overall and sex-specific, of common injury screening tasks using commercially available force plates. Assessments included five repetitions of a weighted/unweighted squat, five countermovement jumps (CMJ), three plyometric push-ups (PPU), and three isometric mid-thigh pulls (IMTP). Testing sessions were separated by 4-weeks, completed by 44 healthy adults (24.3 +/- 5.7 yrs, 170.2 +/- 8.1 cm, 68.9 +/- 11.3 kg, 28 female/16 male). Reliability of 20 routine variables across all tests was extracted from the force plates and assessed with intraclass correlation coefficients (ICCs), standard error of measurement, minimum detectable change, and coefficient of variation (CoV) overall and by sex. Seventeen of the 20 variables demonstrated good to excellent reliability (ICC > 0.75), with questionable reliability for the others (ICC = 0.72-0.74). Reliability of only two variables differed significantly by sex (p < .05). All variables demonstrated acceptable CoV at <= 10%. Common assessments via commercial force plates demonstrate acceptable reliability for most outcomes and minimally differ by sex.
This study aimed to develop a physical literacy (PL) assessment tool and examine the construct validity of two PL models in the context of physical education in Serbia, Bosnia and Herzegovina, and Croatia. The theoretical model, consisting of affective, physical, and cognitive domains, was identified through theoretical analysis. The empirical model was identified through EFA based on data collected using the developed assessment tool on a sample of 719 students aged 12 to 14, revealing a four-factor structure comprising motor competence, physical fitness, motivation and physical self-efficacy, and knowledge and understanding. CFA was used to analyze both models, with results showing that the theoretical model did not achieve a good fit, whereas the empirical model demonstrated acceptable fit. The findings support the use of this school-based PL assessment tool with an empirically derived four-factor structure and provide a valuable framework for understanding PL as a multidimensional construct in school environments.
Device-based measurement of physical activity (PA) is crucial for valid research, but reactivity to these devices can undermine validity. Inconsistent findings in prior reactivity research warrant unique approaches among diverse populations, including those habituated to wearing another device. We aimed to estimate reactivity to ActiGraph GT3X+ via concurrent Fitbit Inspire HR wear among Latina adolescents using a person-day matched cross-sectional design. Fitbit data estimated steps, moderate-vigorous PA, light PA, and sedentary time for all days in the 2 weeks preceding and following matched ActiGraph wear days. Linear models estimated the association of ActiGraph wear day with activity after adjustment for covariates. There were 2987 total days across 107 participants, ~35% classified as ActiGraph wear days. Steps statistically significantly differed (p = .0499) with ActiGraph wear days corresponding to 248 greater average steps. Measurement reactivity to ActiGraph may impact steps among adolescent females. Future research could benefit from concurrent wear strategies if feasible.
The Sports Interests Inventory (SPIT) measures adolescents' and emerging adults' interest in sporting activities. While previous analyses showed promising psychometric properties, revisions to some scales and greater test efficiency were recommended. This study further developed and validated the SPIT. First, additional items were generated to reduce construct-irrelevant multidimensionality and better capture domains of interest, then refined by an expert panel. Second, samples of 245 secondary school and 192 university students were analyzed using classical test theory and item response theory, yielding the 36-item SPIT (SPIT-36). Third, psychometric quality was reexamined in 474 university students. Construct validity was supported by correlations with three validated measures. Gender, age, and several sports-related characteristics were considered in evaluating differential item functioning and criterion validity. Results indicate that the SPIT-36 is a psychometrically sound, efficient instrument suitable for individual and group diagnostics with adolescents and emerging adults.
BlazePod is a portable visual-cognitive training tool that uses light modules and a Bluetooth-connected app to assess and train sport-specific skills such as agility, reaction time, and balance. Despite its increasing use, limited evidence exists on its psychometric properties in standardized agility tests. This study examined the reliability, validity, and agreement of BlazePod during a T-Test of agility in competitive soccer players. Thirty players (mean age 22.1 +/- 4.7 years) completed three T-Test trials per device (BlazePod and photocell timing systems) in a crossover design on separate testing days. Test - retest reliability was assessed using intraclass correlation coefficients (ICC) and repeated measures ANOVA; Pearson correlations and Bland - Altman analysis evaluated validity and agreement. BlazePod showed excellent reliability (ICC = 0.97), strong correlation with photocell measures (r = 0.88-0.92, p < .001), and a positive bias (0.75 s) with limits of agreement ranging from -0.46 to +1.96 s. These results indicate that BlazePod is a reliable and valid tool for assessing preplanned agility in soccer players, providing a practical portable alternative to photocell systems. However, due to the systematic bias, caution is warranted when using BlazePod to monitor subtle longitudinal changes in performance.
This study evaluated the validity and reliability of start detection methods for determining 5-m sprint time using a resistance device with an encoder. Seventeen recreationally trained participants completed 12 resisted 5-m sprints across two sessions. Sprint start was identified using three encoder-based methods (position, velocity [MEv], and acceleration), a rear-foot release sensor and hip-marker kinematics (KIN) as a proxy for forward center-of-mass displacement. Reliability was evaluated using intraclass correlation coefficient (ICC), coefficient of variation (CV), typical error (TE), standard error of measurement (SEM), and minimal detectable change (MDC), while agreement was examined using Pearson correlations and Bland-Altman analysis. All methods showed moderate to excellent reliability (ICC = 0.54-0.93; CV <= 11.1%) and strong agreement with KIN (r = 0.90-0.94). MEv showed the smallest bias (-0.00 +/- 0.07 s) and narrowest 95% limits of agreement, and is therefore preferred for sprint start detection in practical settings.
The objective of this study was to improve the validity of the physical activity self-efficacy (PASE) measurement. To accomplish this objective, a latent variable approach commonly advocated, but infrequently used in practice, for determining the internal structure of response patterns to a PASE scale was systematically studied. Data were simulated using Monte Carlo experimental methods under conditions commonly observed in practice (e.g. N; exploratory/confirmatory latent variable models) to maximize potential implications for data analysis in practice. Three sets of outcomes were monitored: convergence issues, model-data fit, and parameter estimates. A one-dimensional model outperformed two-dimensional exploratory and confirmatory models when the population model was one-dimensional. A two-dimensional exploratory model outperformed a two-dimensional confirmatory model and a one-dimensional model when the population model was two-dimensional. These findings provide an initial empirical basis for fuller adherence to the long proposed, but rarely fully followed, validity guidelines for measuring PASE - though experimental-design related limitations exist.
This study aimed to evaluate the accuracy and reliability of the newly developed SomatoMetrics software for somatotype calculation and to compare its performance with existing methods. The study included 132 individuals aged 28-35 years (73 males, 59 females), and anthropometric measurements were obtained using the Heath - Carter method. SomatoMetrics, developed with a Flutter-based frontend and a GoLang-based backend, provides automated error checking, standardized data entry, and graphical outputs. Its accuracy was compared with the Somatot & uuml;rk and Somatotype programs. Reliability was assessed using the intraclass correlation coefficient (ICC), Pearson correlation, Bland - Altman analysis, and Cohen's kappa coefficient. The results demonstrated very high agreement and strong correlations between methods (ICC: 0.999-1.000; Pearson r > 0.99; p < .001), with no systematic bias observed. Cohen's kappa values also indicated excellent agreement. Overall, SomatoMetrics is a fast, accessible, and user-friendly tool that offers high accuracy and reliability in somatotype assessment.
Wrist-worn heart rate (HR) monitors offer convenience but require validation against gold-standard devices. This study evaluated the accuracy of Polar wrist-worn devices using photoplethysmography. A systematic review and meta-analysis were conducted following PRISMA-P guidelines. Ten studies, providing 26 effect sizes, compared Polar wrist-worn devices with Polar chest-worn reference monitors. Accuracy was summarized by estimating the average difference in HR and the range within which most differences fell using a Bland - Altman meta-analytic approach. Subgroup analyses explored differences by age group, activity type, activity intensity, and device model. The overall mean bias was -1.51 bpm, with LoA including zero, suggesting no consistent overestimation or underestimation. Accuracy declined in teenagers and during high upper-body movement activities. Resting conditions and the Vantage V model showed the best agreement. Only the teenage subgroup exceeded 10% mean absolute percent error. Polar wrist-worn devices generally demonstrate acceptable HR accuracy but are less reliable during dynamic conditions.
Based on the tenets of self-determination theory, the satisfaction and frustration of the basic psychological needs of competence, autonomy, and relatedness during school physical education is related to students' behavioral and psychological outcomes. The construct of need dissatisfaction, however, has been studied less extensively within physical education. To facilitate research in Chinese physical education classrooms, we adapted and evaluated measurement scales designed to tap needs satisfaction, dissatisfaction, and frustration. Exploratory and confirmatory factor analyses were conducted in Study 1 (n = 331) and 2 (n = 401), respectively, and results supported the factorial validity of scale scores. In Study 3 (n = 242), nomological validity of scale scores were examined and the expected interrelation between related constructs were found. Overall, results supported the reliability and validity of scale scores. This Chinese scale can be used to study students' psychological needs in physical education, and in turn generate new insights to the study of motivational processes.
This study evaluated the validity and reliability of the 6-minute pegboard and ring test (6PBRT) in individuals with spinal cord injury (SCI). Thirty-four individuals with SCI participated in this study. Upper limb function was assessed using the 6PBRT, alongside digital dynamometry for muscle strength (shoulder flexors, abductors, elbow extensors, flexors) and hand grip strength. Functional capacity was measured via the 20-meter propulsion test (MWPT20m) and modified functional reach test (mFRT). The 6PBRT demonstrated excellent test - retest reliability (ICC = 0.958) and reproducibility (Bland-Altman limits: 28.09 to -14.79 rings). Moderate correlations were observed with shoulder flexor (r = 0.538-0.560), shoulder abductor (r = 0.553-0.591), and elbow flexor (r = 0.65-0.661) strengths, and mFRT (r = 0.525). Strong correlations were found with hand grip strength (r = 0.702-0.705) and MWPT20m (r = -0.743). These findings confirm the 6PBRT as a valid, reproducible, and reliable instrument for assessing upper extremity function and exercise capacity in individuals with SCI.
Accelerometry is widely used in physical activity research, but processing approaches differ across studies. This study evaluated the agreement among raw use preprocessing in the entire document metrics (Activity Counts, Activity Index, Euclidean Norm Minus One - ENMO, Mean Amplitude Deviation - MAD, and Monitor Independent Summary Unit - MIMS) derived from two devices. Participants wore ActiGraph (wGT3X-BT) and Google Pixel Watch 2 devices (50-100 Hz) on their non-dominant wrist for 24 h. Data were converted to minimum acceleration of the most active minutes (MX) for each metric across 1-60-s epochs. Agreement between device-paired MX values was assessed using mean absolute percent error (MAPE) and Bland - Altman analysis. Data from 16 participants (25.4 +/- 8.9 years) showed strong agreement for MAD and MIMS MX with MAPE of 6.8% +/- 7.0% and 7.1% +/- 3.5%. Only MIMS showed lowest bias and consistent MAPE across epochs without compounded error, supporting its use for device-agnostic assessment. Larger samples and additional device configurations may strengthen generalizability.
This study evaluated the validity of the SENS motion (R) system (SENS) for classifying activity intensity (sedentary, light, moderate-to-vigorous [MVPA]) and type (sedentary, standing, walking, running, cycling) across four wear locations: thigh, hip, non-dominant, and dominant wrist. In healthy adults (n = 62), SENS classifications were compared to activity intensity from compendium-derived MET levels for structured activities in a laboratory setting. The thigh placement showed excellent agreement for classifying activity intensity (kappa=0.89, 95% CI: 0.86-0.93, p < .001; 90.9% agreement) and type (kappa=0.81, 95% CI: 0.76-0.86, p < .001; 90.5% agreement). Sedentary and MVPA activities were classified with excellent accuracy (means = 97.7% and 83.8%, respectively), while light activities showed mixed results (42.6-87.9%). In contrast, the hip and wrist placements showed fair-to-slight agreement (kappa <= 0.30) and poor accuracy for light activities. These findings support the thigh as the optimal wear location and identify performance reductions for other locations. Further research should validate the SENS in free-living conditions and diverse populations.
This study aimed to update and validate regression models for estimating body fat percentage (BF%) in Chinese women using anthropometric measures. A total of 630 women aged 20-79 yr. underwent dual-energy X-ray absorptiometry (DXA) and standardized anthropometric assessments. Development of experimental models and cross-validation of the published equations were done on the entire sample. The final prediction models developed from this study are Total BF% = 5.76 + 0.666 & times;BMI + 0.180 & times;Waist (RMSE = 3.47 +/- 0.36); and Android BF% = -13.3 + 0.711 & times;BMI + 0.475 & times;Waist (RMSE = 5.81 +/- 0.64). Although models with higher complexity improved prediction accuracy, simpler models using waist circumference, BMI, or WtHR were nearly as effective. Among published equations, the Rush et al. (1997) model from a Western sample surprisingly outperformed equations derived from Asian samples. These findings support the use of circumference-based models as accessible, low-cost alternatives to DXA for estimating BF% in Chinese and potentially multiethnic female populations.
Fan engagement extends beyond the competitive season, yet existing measures largely focus on in-season behaviors. This study conceptualizes off-season fan engagement (OFE) as a distinct form of engagement that sustains fans' psychological connection to a sport team during periods without live competition. Following a multi-stage scale development procedure, we developed and validated a measure of OFE. Qualitative online focus groups were conducted to explore off-season fan behaviors, and an initial item pool was generated and refined through expert evaluation. Rasch model analysis (n = 211) supported appropriate item functioning and response category performance. Confirmatory factor analysis (n = 244) validated a three-dimensional structure, demonstrating strong reliability as well as convergent and discriminant validity. A subsequent validation test (n = 257) provided additional support for criterion-related validity through positive associations between OFE dimensions and team identification. The findings highlight the unique processes underlying off-season fan engagement and introduce a psychometrically sound instrument for examining and enhancing fan engagement beyond the competition season.
We aimed to compare the concurrent validity of force-velocity (F-V) profiling using two low-cost and accessible jump height (JH) calculation methods: flight time method (FT) and modified FT (FTM). Forty-two male athletes performed unloaded, moderate-, and high-loaded squat jumps and countermovement jumps on force plates while recorded with a high-speed smartphone camera. JH was calculated using the impulse-momentum method (IM), FT, and FTM, and values were subsequently used to derive F-V profile variables. The FT significantly overestimated some F-V profile variables of the countermovement jump. Conversely, all F-V profile variables calculated using the FTM did not differ significantly from those derived using the IM. Moreover, F-V profile variables derived using the IM were more strongly correlated with those calculated using the FTM than those calculated using the FT. In conclusion, the FTM demonstrates higher concurrent validity for assessing F-V profiles than the FT.
Gait reflects multisystem integrity and predicts morbidity and functional decline, underscoring its growing recognition as a "sixth vital sign." This study developed and validated a transparent multivariable regression equation to estimate healthy step length in adults, incorporating age, sex, height, weight, and habitual walking speed. Data from 252 healthy adults (ages 18-90 years) were analyzed using multiple linear regression with 5-fold cross-validation to assess predictive accuracy and model stability. The final model demonstrated strong performance (adjusted R2 = 0.83; RMSE = 2.88 cm). The resulting equation was: step length (cm) = -16.14 - 0.06 & centerdot;Age +0.31 & centerdot;Height - 0.04 & centerdot;Weight + 0.02 & centerdot;Sex +0.30 & centerdot;Walking speed. Individualized 95% prediction intervals defined normative ranges for clinical and research applications. This empirically derived model provides a reproducible and interpretable reference for assessing gait health, enabling early detection of deviation and supporting fall prevention, rehabilitation, and digital health monitoring across diverse adult populations.
The purpose of this study was to analyze the intra- and inter-evaluator reliability hip adduction (HAD), internal rotation (HIR) and external rotation (HER) range of motion (ROM) tests as well as the level of agreement between evaluators with different experience levels in young adults. Fifty-four physically active adults participated. Passive HAD, HIR and HER ROM were assessed using the ROM-SPORT I method on four occasions. ROM was measured with an inclinometer by two evaluators (expert and novice). Good-to-excellent intra- and inter-evaluator reliability was observed for all tests (ICC = 0.81-0.97; TEM = 1.09 degrees-2.60 degrees; CVTE = 3.3-6.0%; MDC95 = 2.99 degrees-7.1 degrees). Agreement analyses showed low systematic bias and acceptable limits of agreement between evaluators, indicating good measurement consistency. Overall, the ROM-SPORT I method provides reliable and consistent passive hip ROM assessment in physically active adults, even when applied by evaluators with different levels of experience.
The rapid expansion of online physical education (PE) has made it difficult to assess students' engagement in psychomotor activities. The flow scale used in this study was originally developed for face-to-face PE classes; its suitability for online instruction has not yet been tested. This study evaluated the scale's psychometric properties for online PE lectures using Rasch analysis of survey data from 416 South Korean university students enrolled in psychomotor PE lectures. Analyses of item fit, rating-scale functioning, item difficulty, person separation reliability, and differential item functioning supported a 27-item version with clear unidimensional structure and appropriate category use. The validated scale enables instructors and researchers to monitor students' engagement in online PE lectures, compare engagement across lectures or groups, and evaluate the impact of instructional strategies and technologies. These findings provide a measurement foundation for designing, refining, and researching online PE curricula.
