Movement Performance Research Articles

Differential Neuroanatomical, Neurochemical, and Behavioral Impacts of Early-Age Isolation in a Eusocial Insect

Introduction: Social experience early in life appears to be necessary for the development of species-typical behavior. Although isolation during critical periods of maturation has been shown to impact behavior by altering gene expression and brain development in invertebrates and vertebrates, workers of some ant species appear resilient to social deprivation and other neurobiological challenges that occur during senescence or due to loss of sensory input. It is unclear if and to what degree neuroanatomy, neurochemistry, and behavior will show deficiencies if social experience in the early adult life of worker ants is compromised. Methods: We reared newly eclosed adult workers of Camponotus floridanus under conditions of social isolation for 2–53 days, quantified brain compartment volumes, recorded biogenic amine levels in individual brains, and evaluated movement and behavioral performance to compare the neuroanatomy, neurochemistry, brood-care behavior, and foraging (predatory behavior) of isolated workers with that of workers experiencing natural social contact after adult eclosion. Results: We found that the volume of the antennal lobe, which processes olfactory inputs, was significantly reduced in workers isolated for an average of 40 days, whereas the size of the mushroom bodies, centers of higher-order sensory processing, increased after eclosion and was not significantly different from controls. Titers of the neuromodulators serotonin, dopamine, and octopamine remained stable and were not significantly different in isolation treatments and controls. Brood care, predation, and overall movement were reduced in workers lacking social contact early in life. Conclusion: These results suggest that the behavioral development of isolated workers of C. floridanus is specifically impacted by a reduction in the size of the antennal lobe. Task performance and locomotor ability therefore appear to be sensitive to a loss of social contact through a reduction of olfactory processing ability rather than change in the size of the mushroom bodies, which serve important functions in learning and memory, or the central complex, which controls movement.

Magnetic‐Driven Hydrogel Spiral PVA/Fe3O4 Micromotors for Targeted Photothermal Therapy

AbstractPhototherapy has emerged as a promising technique for cancer treatment, offering high efficiency and minimal side effects. Nevertheless, conventional phototherapy agents suffer from low targetability and inefficient delivery. Here, a novel approach is proposed using helical hydrogel motors fabricated by combining polyvinyl alcohol, melamine, water, and Fe3O4 nanoparticles. These magnetic motors are capable of precise therapy on tumor cells driven by an external magnetic field. By converting light into heat upon near‐infrared illumination, the motors elevate the temperature of the targeted region, resulting in a significant therapeutic effect, with over 60% eradication of HeLa cells achieve under 808 nm near‐ infrared light (1.5 W cm−2). These helical micromotors exhibit excellent movement performance and biocompatibility, facilitating their in vivo applications and contributing to the advancement of biomedicine.

Deep learning classification of EEG-based BCI monitoring of the attempted arm and hand movements.

The primary objective of this research is to improve the average classification performance for specific movements in patients with cervical spinal cord injury (SCI). The study utilizes a low-frequency multi-class electroencephalography (EEG) dataset from Graz University of Technology. The research combines convolutional neural network (CNN) and long-short-term memory (LSTM) architectures to uncover neural correlations between temporal and spatial aspects of the EEG signals associated with attempted arm and hand movements. To achieve this, three different methods are used to select relevant features, and the proposed model's robustness against variations in the data is validated using 10-fold cross-validation (CV). The research also investigates subject-specific adaptation in an online paradigm, extending movement classification proof-of-concept. The combined CNN-LSTM model, enhanced by three feature selection methods, demonstrates robustness with a mean accuracy of 75.75 % and low standard deviation (+/- 0.74 %) in 10-fold cross-validation, confirming its reliability. In summary, this research aims to make valuable contributions to the field of neuro-technology by developing EEG-controlled assistive devices using a generalized brain-computer interface (BCI) and deep learning (DL) framework. The focus is on capturing high-level spatiotemporal features and latent dependencies to enhance the performance and usability of EEG-based assistive technologies.

Comparison of the Effect of Sportsmetrics Soccer Training on Movement Performance in Soccer Players with and without Anterior Cruciate Ligament Reconstruction

Comparison of the Effect of Sportsmetrics Soccer Training on Movement Performance in Soccer Players with and without Anterior Cruciate Ligament Reconstruction

Return volatility of Asian stock exchanges; a GARCH DCC analysis with reference of Bitcoin and global crude oil price movement

PurposeThis study aims to investigate the conditional volatility of the Asian stock market concerning Bitcoin and global crude oil price movement.Design/methodology/approachThis study uses the newest Dynamic Conditional Correlation (DCC)-Generalized Autoregressive Conditional Heteroskedasticity (GARCH) model to examine the conditional volatility of the stock market for Bitcoin and crude oil prices in the Asian perspective. The sample stock market includes Chinese, Indian, Japanese, Malaysian, Pakistani, Singaporean, South Korean and Turkish stock exchanges, with daily time series data ranging from 4 April 2015−31 July 2023.FindingsThe outcome reveals the presence of volatility clustering on the return series of crude oil, Bitcoin and all selected stock exchanges of the current study. Secondly, the outcome of DCC, manifests that there is no short-run volatility spillover from crude oil to the Malaysian, Pakistani and South Korean and Turkish stock markets, whereas Chinese, Indian, Japanese, Singapore stock exchanges show the short-run volatility spillover from crude oil in the short run. On the other hand, in the long run, there is a volatility spillover effect from crude oil to all the stock exchanges. Thirdly, the findings suggest that there is no immediate spillover of volatility from Bitcoin to the stock markets return volatility of China, India, Malaysia, Pakistan, South Korea and Singapore. In contrast, both the Japanese and Turkish stock exchanges exhibit a short-term volatility spillover from Bitcoin. In the long term, a volatility spillover effect from Bitcoin is observed in all stock exchanges except for Malaysia. Lastly, based on the outcome of conditional variance, it can be concluded that there was increase in the return volatility of stock exchanges during the period of the COVID-19 pandemic.Research limitations/implicationsThe analysis below does not account for the bias induced due to certain small sample properties of DCC-GARCH model. There exists a huge literature that suggests other methodologies for small sample corrections such as the DCC connectedness approach. On the other hand, decisive corollaries of the conclusions drawn above have been made purely based on a comprehensive investigation of eight Asian stock exchange economies. However, there is scope for inclusive examination by considering other Nordic and Western financial markets with panel data approach to get more robust inferences about the reality.Originality/valueMost of the empirical analysis in this perspective skewed towards the Nordic and Western countries. In addition to that many empirical investigations examine either the impact of crude oil price movement or Bitcoin performance on the stock market return volatility. However, none of the examinations quests the crude oil and Bitcoin together to unearth their implication on the stock market return volatility in a single study, especially in the Asian context. Hence, current investigation endeavours to examine the ramifications of Bitcoin and crude oil price movement on the stock market return volatility from an Asian perspective, which has significant implications for the investors of the Asian financial market.

Innate Orientating Behavior of a Multi-Legged Robot Driven by the Neural Circuits of C. elegans.

The objective of this research is to achieve biologically autonomous control by utilizing a whole-brain network model, drawing inspiration from biological neural networks to enhance the development of bionic intelligence. Here, we constructed a whole-brain neural network model of Caenorhabditis elegans (C. elegans), which characterizes the electrochemical processes at the level of the cellular synapses. The neural network simulation integrates computational programming and the visualization of the neurons and synapse connections of C. elegans, containing the specific controllable circuits and their dynamic characteristics. To illustrate the biological neural network (BNN)'s particular intelligent control capability, we introduced an innovative methodology for applying the BNN model to a 12-legged robot's movement control. Two methods were designed, one involving orientation control and the other involving locomotion generation, to demonstrate the intelligent control performance of the BNN. Both the simulation and experimental results indicate that the robot exhibits more autonomy and a more intelligent movement performance under BNN control. The systematic approach of employing the whole-brain BNN for robot control provides biomimetic research with a framework that has been substantiated by innovative methodologies and validated through the observed positive outcomes. This method is established as follows: (1) two integrated dynamic models of the C. elegans' whole-brain network and the robot moving dynamics are built, and all of the controllable circuits are discovered and verified; (2) real-time communication is achieved between the BNN model and the robot's dynamical model, both in the simulation and the experiments, including applicable encoding and decoding algorithms, facilitating their collaborative operation; (3) the designed mechanisms using the BNN model to control the robot are shown to be effective through numerical and experimental tests, focusing on 'foraging' behavior control and locomotion control.

Attentional Distractions Do Not Influence Lumbar Spine Local Dynamic Stability during Repetitive Flexion-Extension Movements

The association between low back pain and lumbar spine local dynamic stability (LDS) appears to be modulated by if and how someone catastrophizes about pain, suggesting that the cognitive perceptions of pain may influence an individual’s ability to control lumbar spine motion. Previous work also demonstrates that directing cognitive resources and attentional focus can influence movement performance. Therefore, we aimed to examine whether distracting attentional focus would influence lumbar spine LDS during repetitive flexion-extension movements. Sixteen participants performed repetitive spine flexion-extension movements under two baseline conditions (pre- and post-), and while attentional focus was distracted by either an external sensory stimulus or a cognitive-motor dual-task, both targeted at the hands. Lumbar spine LDS was examined over 30 continuous movement repetitions using maximum Lyapunov exponents. In comparison to both Baseline and Post-Baseline trials, the perceived mental workload was significantly elevated during the cognitive-motor dual-task trial but not the external sensory stimulus trial. The only statistically significant effect on LDS occurred in the Post-Baseline trial, where LDS was higher than in the cognitive-motor dual-task. In combination with previous work, these findings suggest that distracting attentional focus during repetitive lumbar spine flexion-extension movements does not have a negative influence on lumbar spine LDS.

Power and velocity performance of swing movement in the adolescent male volleyball players – age and positional difference

PurposeThe performance of swing movement during spikes and serves plays a crucial role in determining the outcomes of volleyball matches. This study aims to explore the effects of the participation of the trunk and lower limbs’ involvement on the velocity and power of the swing movement of adolescent male volleyball players, as well as the differences in power and velocity performance of the swing movement among different ages and specific positions.MethodsThe study involved 22 adolescent male volleyball players, with 11 high school students and 11 middle school students. The Kineo Globus equipment was used to assess the swing movement performance involving different segments, including arm swing movement only involving arm limb participation; upper swing movement involving trunk and arm limb participation; and whole body swing movement involving lower limb, trunk, and arm limb participation. The measured parameters included power and velocity performance levels. Before the test, each subject practiced three movement patterns twice.ResultsThe study found that swing movement involving both the trunk and arm limbs had significantly higher average (F = 17.70, p < 0.001) and peak power performance (F = 31.47, p < 0.001), as well as in average (F = 9.14, p = 0.03) and peak velocity performance (F = 23.17, p < 0.001). There were no significant differences in average (F = 17.70; p = 0.46) and peak power (F = 31.47, p = 0.94), as well as in average (F = 9.14, p = 0.99) and peak velocity performance (F = 23.17, p = 0.90) between movements involving the whole body and those involving the trunk and upper limbs. Among different age groups, the swing movement performance of middle school athletes showed significant enhancements in both average (F = 9.20, p < 0.001) and peak power (F = 19.93, p < 0.001), as well as in average (F = 10.75, p < 0.001) and peak velocity (F = 34.35, p < 0.001) when arm swing with trunk involvement was compared to arm swing movement. High school athletes also showed significant improvements in peak velocity (F = 34.35, p < 0.001), peak power (F = 17.31, p < 0.001), and average power (F = 9.41, p < 0.001) during upper swing movements, except for average velocity performance (F = 1.56, p = 0.21), when compared to arm swing movement. The increase rate in average velocity performance of swing movements involving trunk participation was significantly higher in middle school athletes than in high school athletes (p < 0.001). Among athletes in specific positions, Middle Blocker (MB) players exhibited significantly better average power performance in swing movements involving trunk and arm limb participation compared to Outside Hitter (OH) players (p = 0.04). Furthermore, the rate of average (p = 0.01) and peak (p = 0.03) power change during upper swing movements involving lower limb participation was significantly higher among OH players than MB players.ConclusionsThe involvement of the trunk segment has been observed to significantly improve power and velocity in swing movements during spike and serves among adolescent male volleyball players. This underscores the importance of coordination between the trunk and arm in influencing swing movement performance during spikes and serves. High school athletes demonstrate superior power and velocity in arm swing movements compared to middle school athletes. MB exhibits greater power in upper limb swing movements than OH, although OH players show better coordination between the arm, trunk, and lower limb segments in the swing movement. To enhance swing movement performance in adolescent male volleyball players, particularly focusing on the trunk segment was crucial. Specialized physical training programs should target improving both arm strength and rotational power of the trunk simultaneously. This approach would help in consistently enhancing coordination between the trunk and arms, ultimately leading to optimized force generation during swing movements such as spikes and serves.

Exploring Different Types of Music Cues for Arm Movements in Adults with Parkinson’s

Abstract Music therapists may use auditory cueing to facilitate movement exercises when working on motor goals with adults with Parkinson’s disease (PD). There is minimal research, however, comparing the effects of different auditory cueing techniques on the kinematic parameters of movements in adults with PD. The purpose of this exploratory study was to compare how rhythmic and sonified musical cues impact the smoothness and path variance of a repetitive, volitional arm movement in adults with PD. Seven adults with PD and 10 neurotypical adults completed 3 trials of a repetitive arm-reaching task in each of the 3 auditory cueing conditions. The position of each participant’s wrist was recorded in 3 dimensions using an infrared motion capture system. Data from the motion capture system were processed for normalized jerk (NJ) and spatiotemporal index (STI). No significant differences in STI or NJ were observed between groups in the no cueing condition. Repeated measures analyses revealed no significant differences in NJ or STI for the PD group across conditions. Participant-level analysis of the PD group revealed a trend of less efficient movement performance in the rhythmic cueing condition and improved movement performance in the sonified cueing condition. These findings warrant further research to inform music therapists’ use of auditory-motor cueing.

Insight into the Relationship Between Motor and Cognitive Symptoms in Essential Tremor

Essential tremor (ET) is a heterogeneous disorder characterized by bilateral upper limbs action tremor and, possibly, neurological signs of uncertain significance, including voluntary movement abnormalities and cognitive disturbances, i.e., the so-called ‘soft’ signs configuring the ET-plus definition. While motor and cognitive disturbances often coexist in ET, their interrelationship remains largely unexplored. Here we aim to further investigate the relationship between motor symptoms, objectively assessed through kinematic analysis, and cognitive dysfunctions in ET. Seventy ET patients underwent clinical examination, as well as kinematic recordings of tremor and finger tapping and a thorough cognitive assessment. We then tested clinic-demographic and kinematic differences between patients with and without cognitive abnormalities, i.e., with mild cognitive impairment (MCI). Correlation analysis served to explore potential associations between kinematic and cognitive data. Forty-three ET patients (61.42%) had MCI. ET-MCI patients exhibited reduced movement velocity during finger tapping compared to those with normal cognition (p < 0.001). Lower movement velocity during finger tapping was associated with poorer cognitive performance. Namely, we observed a correlation between movement velocity and performance on the Babcock Story Immediate and Delayed Recall Test (r = 0.52 and r = 0.45, both p < 0.001), as well as the interference memory task at 10 and 30 s (r = 0.3, p = 0.008 and r = 0.2, p = 0.03). In this study, we have provided data for a better pathophysiological interpretation of motor and cognitive signs in ET, including the role played by the cerebellum or extra-cerebellar areas, which possibly underpin both signs.

Deciphering Cognitive Impairments in Huntington's Disease: A Comparative Study of Stroop Test Variations.

Huntington's disease (HD) is a neurodegenerative disorder marked by cognitive impairment, movement abnormalities, and behavioral disturbances. The Stroop Color Word Test (SCWT) is a widely used tool to detect cognitive decline in HD. Variations in SCWT formats-horizontal (original) and vertical (Golden)-may influence performance, given HD's impact on cognitive and oculomotor abilities. This study aimed to compare the effectiveness of the horizontal and Golden vertical SCWT formats in detecting cognitive decline in HD, and to determine how performance may have been influenced by eye movement abnormalities. Forty-five participants with genetically confirmed HD were recruited. Both SCWT formats were administered to each participant in a counterbalanced fashion. Individual performance of all three sections on each format was standardized across 2 different norms. Raw and normed scores on each variation were compared and correlated with eye movement ratings on the Unified Huntington's Disease Rating Scale. The Golden variation elicited significantly slower responses, particularly in the Word Reading section, across two benchmark norms. Statistical analysis revealed significant performance differences between the two formats. Correlations between vertical eye movement ratings and performance on the Golden SCWT were highly significant, highlighting the impact of oculomotor coordination on cognitive assessments in HD. This study underscores the importance of considering test format in cognitive assessments for HD. The Golden vertical SCWT demonstrates increased sensitivity in detecting deficits in HD, possibly linked to vertical saccade abnormalities. These insights are important for improving the sensitivity of cognitive assessments and monitoring disease progression in HD research and clinical practice.

Exploration of Eye Fatigue Detection Features and Algorithm Based on Eye-Tracking Signal

Eye fatigue has a fatiguing effect on the eye muscles, and eye movement performance is a macroscopic response to the eye fatigue state. To detect and prevent the risk of eye fatigue in advance, this study designed an eye fatigue detection experiment, collected experimental data samples, and constructed experimental data sets. In this study, eye-tracking feature extraction was completed, and the significance difference of eye-tracking features under different fatigue states was discussed by two-way repeated-measures ANOVA (Analysis of Variance). The experimental results demonstrate the feasibility of eye fatigue detection from eye-tracking signals. In addition, this study considers the effects of different feature extraction methods on eye fatigue detection accuracy. This study examines the performance of machine learning algorithms based on manual feature calculation (SVM, DT, RM, ET) and deep learning algorithms based on automatic feature extraction (CNN, auto-encoder, transformer) in eye fatigue detection. Based on the combination of the methods, this study proposes the feature union auto-encoder algorithm, and the accuracy of the algorithm for eye fatigue detection on the experimental dataset is improved from 82.4% to 87.9%.

Experiencing the body as play: Cultivating older adults’ exergame experiences using embodied metaphors and multimodal feedback

Physical activity (PA) is promising in increasing active life for older adults, but its repetitive and fatigue-inducing nature greatly harms older adults’ motivation to participate. Recently, there has been a growing interest in applying exergames to improve older adults’ PA adherence and engagement. To better support body-based interactions, embodied metaphors and multimodal feedback are suggested to ensure effective and meaningful mapping between elderly players’ input actions and exergame responses, but their effectiveness have not been fully investigated. After developing a list of embodied and ontological metaphors based a series of user-centered approaches, two experiments were conducted to investigate how embodied metaphors and multimodal feedback impact older adults'’ playing experience of PA exergames, among fifty-nine and twenty-five older adults, respectively. Regarding the embodied metaphor design, the results indicated that a higher embodiment level significantly and positively influenced the participants’ acceptance behavior in terms of their attitudes toward the exergame, and a higher information richness level demonstrated significantly positive effects on familiarity perception and all aspects of acceptance behavior. For the multimodal feedback design, the results indicated that 3D visual feedback better facilitated the participants’ sense of embodiment and immersion, as well as their acceptance behavior, compared to 2D visual feedback. Furthermore, constant tactile feedback in a continuous-only or continuous-and-augmented way significantly improved the participants’ PA movement performance and sense of embodiment, rather than instant feedback. Accordingly, a list of design guidelines for PA exergame development is proposed, with the possible contributions and limitations of this research addressed.

A Protocol for Comprehensive Analysis of Gait in Individuals with Incomplete Spinal Cord Injury.

This is a protocol for comprehensive analysis of gait and affecting factors in individuals with incomplete paraplegia due to spinal cord injury (SCI). A SCI is a devastating event affecting both sensory and motor functions. Due to better care, the SCI population is changing, with a greater proportion retaining impaired ambulatory function. Optimizing ambulatory function after SCI remains challenging. To investigate factors influencing optimal ambulation, a multi-professional research project was grounded with expertise from clinical rehabilitation, neurophysiology, and biomechanical engineering from Karolinska Institutet, the Spinalis Unit at Aleris Rehab Station (Sweden's largest center for specialized neurorehabilitation), and the Promobilia MoveAbility Lab at KTH Royal Institute of Technology. Ambulatory adults with paraplegia will be consecutively invited to participate. Muscle strength, sensitivity, and spasticity will be assessed, and energy expenditure, 3D movements, and muscle function (EMG) during gait and submaximal contractions will be analyzed. Innovative computational modeling and data-driven analyses will be performed, including the identification of clusters of similar movement patterns among the heterogeneous population and analyses that study the link between complex sensorimotor function and movement performance. These results may help optimize ambulatory function for persons with SCI and decrease the risk of secondary conditions during gait with a life-long perspective.

Enhanced Design of a Tai Chi Teaching Assistance System Integrating DTW Algorithm and SVM

Physical education using technology has enabled traditional practices like Tai Chi, a martial art known for its multiple health benefits and meditative aspects, to set coordinated goals. This research presents an intelligent Tai Chi Teaching Assistance System supported by the integration of the Dynamic Time Warping algorithm and Support Vector Machine, in which can practitioners providing real-time feedback to improve Tai Chi learning and quality. In the system, the DTWA Dynamic Time Warping Algorithm was used to accurately compare a practitioner’s complex body movements with the Tai Chi standard movements dataset, taking into account execution speed deviations and others. Meanwhile, the SVM was employed to classify the movement as to quality and correctness, thereby being able to provide precise, individual feedback. This hybrid approach ensures a high-motion recognition accuracy rate while also adhering to nuanced Tai Chi requirements. The system was evaluated through detailed testing with various levels of Tai Chi experience. Evaluation showed that the students’ performance and understanding of most Taijiquan movements and related physical exercises improved significantly. It indicates the system has a practical application value for also beginners and intermediate and last expert, respectively. It also shows the effectiveness of combining DTW and SVM to support learners ‘body movement trajectory in a physical learning environment, opening them up to additional technology-assisted physical training applications. This provides implications for a more promising generation of future physical education involving the incorporation of complex AI technology.

Motor Control in Parkinson’s Disease During the Performance of Multi-Joint Reversal Movements

We tested if the movement slowness of individuals with Parkinson’s disease is related to their decreased ability to generate adequate net torques and linearly coordinate them between joints. This cross-sectional study included ten individuals with Parkinson’s disease and ten healthy individuals. They performed planar movements with a reversal over three target distances. We calculated joint kinematics of the elbow and shoulder using spatial orientation. The muscle, interaction, and net torques were integrated into the acceleration/deceleration phases of the fingertip speed. We calculated the linear correlations of those torques between joints. Both groups modulated the elbow and shoulder net torques with target distances. They linearly coupled the production of torques. Both groups did not modulate the interaction torques. The movement slowness in Parkinson’s disease was related to the difficulty in generating the appropriate muscle and net torques in the task. The interaction torques do not seem to play any role in movement control.

Studying Motor Praxis in Children With Varying Levels of Developmental Coordination Disorder

Background and Aims This research aimed to examine the gesture production ability of motor praxis among children with developmental coordination disorder (DCD) and children on the verge of developing DCD and compare it to typical children of the same age and younger. Methods For this reason, 91 boys (6-12 years old) were selected as sample size and divided into five groups (20 children with typical development, 14 children with DCD, 17 children on the verge of developing DCD, 20 typically-developed children aged 8-9 years, and 20 typically-developed children aged 6-7 years). To find the children with DCD, we employed the developmental coordination disorder questionnaire 7th edition (DCDQ-7) and the Bruininks–Oseretsky test of motor Proficiency. The Dewey gesture production test was performed to investigate motor praxis. Data analysis was performed using variance analysis and an independent t test. Results Comparing the subjects’ performance in different conditions showed that their performance in transitive motor praxis was better than intransitive one (P&lt;0.05). Also, the comparison of verbal command and imitation position showed that between the two DCD groups, the performance in the imitation movements was significantly better (P&lt;0.05). While in the same age control group, no significant difference was seen between motor praxis in two conditions (P&gt;0.05). The between-group comparisons showed that the performance of two DCD groups was disrupted compared to that of the control group at the same age. The performance of the DCD group compared to lower-age children with typical development (8-9 years old) was not different at the verbal command condition. In the imitation position condition, the DCD group performed significantly better than the lower-age children groups (P&lt;0.05). Conclusion These results show that DCD subjects have developmental delays in performing motor praxis under verbal command.

Estimation of STEADI performance using inertial measurement unit

IntroductionFalls present a significant public health concern in the United States as a primary cause of unintentional injury-related deaths among older adults. A fall risk assessment toolkit STEADI developed by the CDC has been shown to predict future falls. However, STEADI has issues with accurate evaluations due to the disagreement on cut-off scores in functional assessments and history-taking questionnaires. Wearable sensor technology offers a practical and quantifiable alternative for assessing an individual's movement performance in real-world environments. The use of Inertial Measurement Units (IMUs) offers considerable potential to enhance fall risk screening. PurposeThe primary aim of this study is to test the agreement of STEADI functional assessment performance measured by the IMUs in comparison to human-based measurements. Method27 participants (Age: 74.37 ± 7.21) performed STEADI, including the Four-Stage Balance Test (4SBT), Timed Up & Go Test (TUG), 30-second Chair Stand (30sCS) with IMU placed at the fifth lumbar vertebra which is the proxy location of whole-body Center of Mass. By adopting an equivalent test, the STEADI agreement was tested between the human rater and IMU measurements, giving α = 0.05. ResultBetween the results from evaluators and IMU, the difference in TUG is -0.23 s, and the difference in 30sCS is 0.37, which is equivalent to within 4 % and 8 % for TUG and 30sCS, respectively. The difference in single-leg stance during the 4SBT is 0.59 s; however, the calculated equivalence zone is larger (22.7 %). ConclusionThis study demonstrates the feasibility of using IMU sensors to enhance fall risk screening protocols based on the STEADI. Future refinement may still need to enable broader application and effective screening practices on a larger scale of the population.

The Impact of Cardiorespiratory and Metabolic Parameters on Match Running Performance (MRP) in National-Level Football Players: A Multiple Regression Analysis

The aim of the study was to examine the association between cardiorespiratory and metabolic parameters and match running performance (MRP) in highly trained football players. The sample of participants consisted of 41 national-level football players (aged 23.20 ± 3.40 years, body height 182.00 ± 5.15 cm, and body mass 76.86 ± 6.06 kg) from the Serbian Super league. For the purposes of this research, the following measurements were applied. A maximal multistage progressive treadmill test, with a direct measurement of maximal oxygen consumption (VO2max) (using Fitmate MED, Cosmed, Rome, Italy) was conducted, alongside continuous heart rate monitoring. Capillary blood samples were taken from the hyperemic area using specific test strips, and, after sample collection, lactate concentration was immediately determined using a lactate analyzer. MRP variables were analyzed according to the BioIRC model of motion structure analysis, based on existing standards for profiling movement intensity. The results of multiple regression analysis indicated an association between cardiac parameters and total distance (R2 = 54.3%, p = 0.000), high-speed running (R2 = 46.4%, p = 0.000), and jogging (R2 = 33.6%, p = 0.004). Regression analysis revealed an association between cardiorespiratory parameters and total distance (R2 = 24.8%, p = 0.014), and high-speed running (R2 = 20%, p = 0.039). Meanwhile, no association was found between lactate concentration and running performance. The explanation for these regression analysis results is based on the observation that functional abilities represent significant potential for expressing movement performance, a crucial condition for success in football.

Collective queuing motion of self-propelled particles with leadership and experience

The coordinated and ordered collective behavior arising from dispersed and local self-organizing interactions among individuals is widely observed in many biological communities. For populations engaging in group foraging or migration, complex societies with multiple hierarchical levels are common. A prevalent scenario involves two dominant levels, one corresponding to leaders and the other composed of followers. In this paper, we explore how a group can be influenced by a set of leaders to organize and move in a coordinated manner towards a preferred direction. Specifically, we balance social interactions among group members through two weighted factors, corresponding to the leadership and experience of leaders. Through computer simulations, we observe a linear relationship between the proportion of leaders guiding group movement and the group size, with larger groups requiring a higher proportion of leaders while maintaining initial density. Additionally, we identify an optimal leadership interval where group movement performance enhances with increasing leadership up to a certain point, beyond which it starts to decline. Similar patterns are observed concerning individual visual field, indicating the existence of an optimal interval for visual angle. Our findings not only contribute to understanding collective motion in natural biological systems but also provide new insights into effective leadership mechanisms in artificial swarm systems.