Squatting is a common motion in activities of daily living and is frequently used in training programs. Squatting requires a shift of the body in both vertical and anterior-posterior directions. Postural control during squatting is considered a mixed strategy; however, details and roles of the trunk and lower limb joints are unclear. The purpose of this study was to investigate the relationship among the kinematics of the lower limb, the trunk and the center of mass (COM) descent during squatting. Twenty-six healthy young adults performed repeated parallel squats. Lower limb joint and trunk angles and the COM were analyzed using a 3D motion analysis system. We evaluated the relationship between the kinematics and the squat depth by performing correlation analysis and multiple linear regression analysis. The ankle was the first to reach its maximum angle, and the remaining joints reached their maximum angles at the maximum squat depth. The knee joint motion and the squat depth were significantly correlated and there was a correlation between the hip and the ankle joint motion and the anteroposterior displacement of the COM during squatting. Multivariate linear regression analysis indicated that squat depth was predicted by both the knee and ankle motion and that anteroposterior displacement of the COM was predicted by the hip, ankle, and knee joint motion. The knees contributed to the vertical COM motion during squatting, while the hips contributed to the COM motion in the anteroposterior direction. On the other hand, the ankles contributed to COM motions in both the vertical and anteroposterior directions during squatting.

A self-study of International Journal of Exercise Science (IJES) publications from 2008 through 2021 revealed a sex-data gap in participant and corresponding author representation. This finding prompted the creation of the IJES Working Group for Opportunity, Representation, and Diverse Perspectives. We are a collaborative team of authors, reviewers, and editors, spanning both rural and urban teaching- and research-focused institutions, who assembled regularly starting in September 2023. The goal was to contemplate potential challenges and opportunities around diversity, equity, and inclusion (DEI), elicit discourse, and broaden inclusion and representation in exercise science research. Our group identified six main challenges/opportunities: 1) Mixed Definitions and Applications of DEI Principles; 2) Competing Lifeviews and Worldviews; 3) Oversight and Enforcement of DEI Principles in IJES; 4) Oversight and Enforcement of DEI Principles in the Broader Field; 5) IJES is a Home for Developing Scholars; and 6) Lag Time for Creating Change in IJES. As a growing international journal, we depend on a diverse group of authors, reviewers, editors, and readers to achieve our mission. Accordingly, the Working Group encourages impactful, inclusive research that broadens representation within exercise science.

The International Journal of Exercise Science (IJES) Working Group for Opportunity, Representation, and Diverse Perspectives was tasked with developing a position stand to provide guidance in critical areas of inclusion. We present to authors, reviewers, and all readership IJES ideals to utilize in practice. Key points are presented, followed by a deeper look with greater explanation into the areas of inclusive language, diversity and inclusion in research, and accessibility. The same approach is presented for the areas of age, disability status, gender identity and sexual orientation, race, and ethnicity with attention to Indigenous Communities, religion, socioeconomic status, and neurodiversity. Person-first language is encouraged, with the acknowledgment that the preference of different community members may vary. IJES is committed to maintaining an environment that is welcoming to all identities so that they feel valued, respected, and included.

The constrained energy model posits that the increased total daily energy expenditure (TDEE) in response to exercise is often less than the energy cost of the exercise prescribed. The mechanisms behind this phenomenon, coined \"exercise-related energy compensation\" (ExEC), are poorly understood, and it is unknown if ExEC is coupled with metabolic adaptation. Using a randomized controlled 24-week exercise intervention, individuals who demonstrated ExEC were identified. Changes to all components of TDEE and metabolic adaptation were assessed using doubly labeled water over 14 days and room calorimetry over 24-h 48% of individuals exhibited ExEC (-308 ± 158 kcals/day). There were no statistically significant differences in sex, age, or BMI between ExEC and non-ExEC. ExEC was associated with baseline TDEE (r = -0.50, p = 0.006). There were no statistically significant differences in metabolic adaptations for 24 h, sleep, or resting expenditures. These findings reveal that ExEC occurs independent of metabolic adaptation in sedentary components of EE.

UNASSIGNED: Surface electromyography (surface EMG) is a primary technique to detect the electrical activities of muscles through surface electrodes. In recent years, surface EMG applications have grown from conventional fields into new fields. However, there is a gap between the progress in the research of surface EMG and its clinical acceptance, characterized by the translational knowledge and skills in the widespread use of surface EMG among the clinician community. To reduce this gap, it is necessary to translate the updated surface EMG applications and technological advances into clinical research. Therefore, we aimed to present a perspective on recent developments in the application of surface EMG and signal processing methods.
UNASSIGNED: We conducted this scoping review following the Joanna Briggs Institute (JBI) method. We conducted a general search of PubMed and Web of Science to identify key search terms. Following the search, we uploaded selected articles into Rayyan and removed duplicates. After prescreening 133 titles and abstracts, we assessed 91 full texts according to the inclusion criteria.
UNASSIGNED: We concluded that surface EMG has made innovative technological progress and has research potential for routine clinical applications and a wide range of applications, such as neurophysiology, sports and art performances, biofeedback, physical therapy and rehabilitation, assessment of physical exercises, muscle strength, fatigue, posture and postural control, movement analysis, muscle coordination, motor synergies, modelling, and more. Novel methods have been applied for surface EMG signals in terms of time domain, frequency domain, time-frequency domain, statistical methods, and nonlinear methods.
UNASSIGNED: Translating innovations in surface EMG and signal analysis methods into routine clinical applications can be a helpful tool with a growing and valuable role in muscle activation measurement in clinical practices. Thus, researchers must build many more interfaces that give opportunities for continuing education and research with more contemporary techniques and devices.

Posture analysis is important in musculoskeletal disorder prevention but relies on subjective assessment. This study investigates the applicability and reliability of a machine learning (ML) pose estimation model for the human posture assessment, while also exploring the underlying structure of the data through principal component and cluster analyses. A cohort of 200 healthy individuals with a mean age of 24.4 ± 4.2 years was photographed from the frontal, dorsal, and lateral views. We used Student\'s t-test and Cohen\'s effect size (d) to identify gender-specific postural differences and used the Intraclass Correlation Coefficient (ICC) to assess the reliability of this method. Our findings demonstrate distinct sex differences in shoulder adduction angle (men: 16.1° ± 1.9°, women: 14.1° ± 1.5°, d = 1.14) and hip adduction angle (men: 9.9° ± 2.2°, women: 6.7° ± 1.5°, d = 1.67), with no significant differences in horizontal inclinations. ICC analysis, with the highest value of 0.95, confirms the reliability of the approach. Principal component and clustering analyses revealed potential new patterns in postural analysis such as significant differences in shoulder-hip distance, highlighting the potential of unsupervised ML for objective posture analysis, offering a promising non-invasive method for rapid, reliable screening in physical therapy, ergonomics, and sports.

The purpose of this study was the detection and characterization of synergistic muscle activity. Using T2-map MRI, T2 values for 10 forearm muscles in 11 healthy adult volunteers were obtained in the resting state and after isotonic forearm supination and pronation exercises with the elbow extended. T2 was normalized by Z = (T2e-T2r)/SDr, where T2e was T2 after exercise, while T2r and SDr were the reference values of 34 ms and 3 ms, respectively. Using the cumulative frequency curves of Z values (CFZ), we detected 2 and 3 synergistic muscles for supination and pronation, respectively, and divided these into 2 types, one activated by exercise strength dependently, and the other, independent of exercise strength, activated by only a smaller fraction of the participants. We also detected co-contraction for the supination. Thus, CFZ is a useful visualization tool to detect and characterize not only synergistic muscle, but also co-contraction muscle.

Hypertension is a risk factor for cardiovascular disease, and exercise has cardioprotective effects on the heart. However, the mechanism by which exercise affects hypertension-induced myocardial injury remains unclear. Exercise response model of hypertension-induced myocardial injury in mice was analyzed using multiomics data to identify potential factors. The study found that serum Ca2+ and brain natriuretic peptide concentrations were significantly higher in the HTN (hypertension) group than in the control, HTN+MICT (moderate intensity continuous exercise), and HTN+HIIT (high intensity intermittent exercise) groups. Cardiac tissue damage and fibrosis increased in the HTN group, but exercise training reduced pathological changes, with more improvement in the HTN+HIIT group. Transcriptomic and proteomic studies showed significant differences in CACNA2D1 expression between the different treatment groups. HIIT ameliorated HTN-induced myocardial injury in mice by decreasing Ca2+ concentration and diastolizing vascular smooth muscle by downregulating CACNA2D1 via exercise.

BACKGROUND: Accurate and timely assessment of children\'s developmental status is crucial for early diagnosis and intervention. More accurate and automated developmental assessments are essential due to the lack of trained health care providers and imprecise parental reporting. In various areas of development, gross motor development in toddlers is known to be predictive of subsequent childhood developments.
OBJECTIVE: The purpose of this study was to develop a model to assess gross motor behavior and integrate the results to determine the overall gross motor status of toddlers. This study also aimed to identify behaviors that are important in the assessment of overall gross motor skills and detect critical moments and important body parts for the assessment of each behavior.
METHODS: We used behavioral videos of toddlers aged 18-35 months. To assess gross motor development, we selected 4 behaviors (climb up the stairs, go down the stairs, throw the ball, and stand on 1 foot) that have been validated with the Korean Developmental Screening Test for Infants and Children. In the child behavior videos, we estimated each child\'s position as a bounding box and extracted human keypoints within the box. In the first stage, the videos with the extracted human keypoints of each behavior were evaluated separately using a graph convolutional networks (GCN)-based algorithm. The probability values obtained for each label in the first-stage model were used as input for the second-stage model, the extreme gradient boosting (XGBoost) algorithm, to predict the overall gross motor status. For interpretability, we used gradient-weighted class activation mapping (Grad-CAM) to identify important moments and relevant body parts during the movements. The Shapley additive explanations method was used for the assessment of variable importance, to determine the movements that contributed the most to the overall developmental assessment.
RESULTS: Behavioral videos of 4 gross motor skills were collected from 147 children, resulting in a total of 2395 videos. The stage-1 GCN model to evaluate each behavior had an area under the receiver operating characteristic curve (AUROC) of 0.79 to 0.90. Keypoint-mapping Grad-CAM visualization identified important moments in each behavior and differences in important body parts. The stage-2 XGBoost model to assess the overall gross motor status had an AUROC of 0.90. Among the 4 behaviors, \"go down the stairs\" contributed the most to the overall developmental assessment.
CONCLUSIONS: Using movement videos of toddlers aged 18-35 months, we developed objective and automated models to evaluate each behavior and assess each child\'s overall gross motor performance. We identified the important behaviors for assessing gross motor performance and developed methods to recognize important moments and body parts while evaluating gross motor performance.

UNASSIGNED: Children with chronic ankle instability (CAI) frequently experience ankle unsteadiness, causing trips, falls, and ankle sprain injuries resulting in poor quality of life. A specific exercise program focused on physical and psychological purposes in children with CAI is needed.
UNASSIGNED: The purpose of this study was to investigate the feasibility of a 4-week home-based exercise training program using active video games (AVGs) for balance, motor proficiency, foot and ankle ability, and intrinsic motivation in children with CAI.
UNASSIGNED: Sixty children with CAI (mean age 10, SD 2 years) were randomly assigned to an experimental group (AVG group; n=30) or a control group (CG; n=30). The AVG group played 2 selected video games, Catching Fish and Russian Block, while the CG received the traditional exercise program for CAI. Both programs were scheduled for 30 minutes per day, 3 times per week, for 4 weeks at home. The single-leg stance test was used to assess static balance. The walking forward on a line and standing long jump tests were used to assess motor proficiency. The Foot and Ankle Ability Measure (FAAM) and the Intrinsic Motivation Inventory questionnaire were used to assess foot and ankle ability and intrinsic motivation, respectively. Assessments were conducted at baseline and after 4 weeks.
UNASSIGNED: In the AVG group, the single-leg stand test (eyes open; on floor and on foam conditions), the FAAM (activities of daily living subscale), and intrinsic motivation (interest/enjoyment, pressure/tension, and value/usefulness dimensions) were improved compared with the CG (all P<.05). Motor proficiency did not differ between the 2 groups at the end of the 4-week program (P=.31 for the walking forward on a line, P=.34 for the standing long jump test).
UNASSIGNED: A 4-week home-based exercise training program using AVGs can be beneficial and may be an effective approach for improving balance, foot and ankle ability, and enhancing positive motivation by increasing the interest/enjoyment and value/usefulness dimensions and lowering the pressure/tension dimension in children with CAI that require long-term rehabilitation sessions.