Distinct Postures Research Articles

A Non-Contacted Height Measurement Method in Two-Dimensional Space.

Height is an important health parameter employed across domains, including healthcare, aesthetics, and athletics. Numerous non-contact methods for height measurement exist; however, most are limited to assessing height in an upright posture. This study presents a non-contact approach for measuring human height in 2D space across different postures. The proposed method utilizes computer vision techniques, specifically the MediaPipe library and the YOLOv8 model, to analyze images captured with a smartphone camera. The MediaPipe library identifies and marks joint points on the human body, while the YOLOv8 model facilitates the localization of these points. To determine the actual height of an individual, a multivariate linear regression model was trained using the ratios of distances between the identified joint points. Data from 166 subjects across four distinct postures: standing upright, rotated 45 degrees, rotated 90 degrees, and kneeling were used to train and validate the model. Results indicate that the proposed method yields height measurements with a minimal error margin of approximately 1.2%. Future research will extend this approach to accommodate additional positions, such as lying down, cross-legged, and bent-legged. Furthermore, the method will be improved to account for various distances and angles of capture, thereby enhancing the flexibility and accuracy of height measurement in diverse contexts.

An Ergonomics Analysis of Archers through Motion Tracking to Prevent Injuries and Improve Performance.

Archery ranks among the sports with a high incidence of upper extremity injuries, particularly affecting the drawing shoulder and elbow, as well as inducing stress on the lower back. This study seeks to bridge the gap by integrating real-time human motion with biomechanical software to enhance the ergonomics of archers. Thirteen participants were involved in four tasks, using different bows with varied draw weights and shooting distances. Through the application of advanced integrative technology, this study highlights the distinct postures adopted by both males and females, which indicate the biomechanical differences between genders. Additionally, an analysis of the correlation between exposed spinal forces and these adopted postures provides insights into injury risk assessment during the key archery movements. The findings of this study have the potential to significantly enhance the application of training methodologies and the design of assistive devices. These improvements are geared towards mitigating injury risks and enhancing the overall performance of archers.

Dimensionality of locomotor behaviors in developing C. elegans.

Adult animals display robust locomotion, yet the timeline and mechanisms of how juvenile animals acquire coordinated movements and how these movements evolve during development are not well understood. Recent advances in quantitative behavioral analyses have paved the way for investigating complex natural behaviors like locomotion. In this study, we tracked the swimming and crawling behaviors of the nematode Caenorhabditis elegans from postembryonic development through to adulthood. Our principal component analyses revealed that adult C. elegans swimming is low dimensional, suggesting that a small number of distinct postures, or eigenworms, account for most of the variance in the body shapes that constitute swimming behavior. Additionally, we found that crawling behavior in adult C. elegans is similarly low dimensional, corroborating previous studies. Further, our analysis revealed that swimming and crawling are distinguishable within the eigenworm space. Remarkably, young L1 larvae are capable of producing the postural shapes for swimming and crawling seen in adults, despite frequent instances of uncoordinated body movements. In contrast, late L1 larvae exhibit robust coordination of locomotion, while many neurons crucial for adult locomotion are still under development. In conclusion, this study establishes a comprehensive quantitative behavioral framework for understanding the neural basis of locomotor development, including distinct gaits such as swimming and crawling in C. elegans.

Exploring injury assessment using motion tracking technology and ergonomic tools in archery performance

Introduction: Archers face a notable annual risk of injury attributed to the repetitive strain exerted on their upper body muscles and joints. This groundbreaking study marks the first utilization of real-time motion tracking combined with ergonomic analysis in archery research, eliminating the need for extensive equipment setups and streamlining data collection.Methods: Thirteen participants were involved, undertaking four tasks with varying draw weights of bows and target positions.Results: The precise recording of human movements revealed distinctive postures adopted by both genders across different tasks. Furthermore, an assessment of exposed spinal force and its correlation with anatomical variables was conducted, providing valuable insights into injury risks during archery performances.

Effect of Different Body Postures on Prospective Time Perception

Aim: The current study employed the Time Reproduction task within the Prospective Time Perception paradigm. Previous research has indicated that posture has a consequential influence on time perception. To expand upon these observations, we explored the impact of five distinct postures on participants' time perception.
 Methods: During each 8- to 10-minute session, 19 healthy young adults were presented with 50 audio stimuli, which took the form of 'beep' sounds and lasted 0.5, 1, 3, 4, and 6 seconds, in a random order. Participants were instructed to reproduce the duration of the stimuli in five different postures in the following order: sitting, standing, lying supine at 180 degrees, lying head down at -15 degrees (HDT), and lying prone at 180 degrees.
 Results: In all postures, the shorter durations were perceived as longer than they are, and the relatively longer durations were perceived as shorter than they are. Statistically significant differences were found between the postures for all stimuli durations except for 3000 ms (repeated-measures ANOVA, significance level at p < 0.05). The physically and mentally healthy participants perceived time more slowly when they adapted a lying posture (supine, prone, and -15 degrees HDT) without cognitive load.
 Conclusion: The current investigation is the first to examine the influence of these postures (sitting, standing, and the three different lying postures) on the perception of time, with the lying postures, but especially the HDT and prone positions, causing a significant dilation of the perception of time.

Gender Recognition Based on Gradual and Ensemble Learning from Multi-View Gait Energy Images and Poses.

Image-based gender classification is very useful in many applications, such as intelligent surveillance, micromarketing, etc. One common approach is to adopt a machine learning algorithm to recognize the gender class of the captured subject based on spatio-temporal gait features extracted from the image. The image input can be generated from the video of the walking cycle, e.g., gait energy image (GEI). Recognition accuracy depends on the similarity of intra-class GEIs, as well as the dissimilarity of inter-class GEIs. However, we observe that, at some viewing angles, the GEIs of both gender classes are very similar. Moreover, the GEI does not exhibit a clear appearance of posture. We postulate that distinctive postures of the walking cycle can provide additional and valuable information for gender classification. This paper proposes a gender classification framework that exploits multiple inputs of the GEI and the characteristic poses of the walking cycle. The proposed framework is a cascade network that is capable of gradually learning the gait features from images acquired in multiple views. The cascade network contains a feature extractor and gender classifier. The multi-stream feature extractor network is trained to extract features from the multiple input images. Features are then fed to the classifier network, which is trained with ensemble learning. We evaluate and compare the performance of our proposed framework with state-of-the-art gait-based gender classification methods on benchmark datasets. The proposed framework outperforms other methods that only utilize a single input of the GEI or pose.

Hierarchical organization of rhesus macaque behavior.

Primatologists, psychologists and neuroscientists have long hypothesized that primate behavior is highly structured. However, delineating that structure has been impossible due to the difficulties of precision behavioral tracking. Here we analyzed a dataset consisting of continuous measures of the 3D position of two male rhesus macaques (Macaca mulatta) performing three different tasks in a large unrestrained environment over several hours. Using an unsupervised embedding approach on the tracked joints, we identified commonly repeated pose patterns, which we call postures. We found that macaques' behavior is characterized by 49 distinct postures, lasting an average of 0.6 seconds. We found evidence that behavior is hierarchically organized, in that transitions between poses tend to occur within larger modules, which correspond to identifiable actions; these actions are further organized hierarchically. Our behavioral decomposition allows us to identify universal (cross-individual and cross-task) and unique (specific to each individual and task) principles of behavior. These results demonstrate the hierarchical nature of primate behavior, provide a method for the automated ethogramming of primate behavior, and provide important constraints on neural models of pose generation.

Rethinking adoptionism: An argument for dismantling a dubious category

AbstractThis article argues that adoptionism is an anachronistic category when used to describe texts from the first three Christian centuries, a mirage created by later theological controversies about the relationship between the Father and the Son. I survey the evidence for second- and third-century figures and texts generally identified ‘adoptionist’ in order to show that these figures do not advocate a shared christological stance. Instead, we find a variety of distinct postures that disagree with both each other and with common scholarly definitions of adoptionism. Although metaphors of adoption were theologically productive in early Christianity, to identify early Christian figures, texts and movements as adoptionist implies a theological unity that does not exist. The category itself is a problem. Not only are historical adoptionists absent, but early Christian metaphors of adoption and divine sonship functioned within diverse articulations of Jesus’ identity which do not map onto modern definitions.

Effect of Body Posture on Heart Rate Variability Analysis of ECG Signal

An assessment of cardiac function derived from the ECG signal is known as heart charge variability (HRV). The evaluation of HRV provides ways for analyzing entry into the heart rhythm non-invasively, which can be used to guide treatment. For the prevailing study, records of ten members in two one-of-a-kind frame postures have been taken. Sets of records have been received in sleeping and sitting positions. In addition, The R-peak produced from the ECG is employed in the evaluation of the RR interval. It is also applied for the evaluation of HRV. In the context of coronary heart rate (HR), HRV is linked to tachycardia (HR > 100 bpm) and bradycardia (HR 60 bpm). Linear HRV characteristics with unique time-domain and frequency-domain indices are interpreted into two distinct postures. As a result, it is possible to conclude that the RR interval increases for the supine position during all two poses, as sitting appears to be a more comfortable situation than the alternative one. Also, as the frequency-area evaluation result proposes, the LF/HF ratio is better in the supine position, i.e., better sympathetic has an effect. Consequently, supine has a higher resting circumstance than that sitting. A non-linear Poincare plot has also been incorporated for accessing variability.

Triggering and spreading of lateral tongue posture

Lateral bracing is a tongue posture that is pervasively maintained during speech across languages (Liu et al., in press), released only for a few English sounds ([l] and occasional low vowels; Gick et al., 2017). While bracing is required for many (e.g., coronal) sounds, it is unclear why bracing is maintained during non-lingual sounds (e.g., labial/glottal consonants). Specifically, it is unknown whether bracing is maintained during non-lingual sounds because it is a pervasive default posture for speech (i.e., turned “on” unless actively suppressed, e.g., for /l/) or whether an unbraced posture can be maintained during extended periods. We collected coronal cross-section ultrasound imaging of the dorsal tongue while participants said “hubba-bubba” (a four-syllable sequence of non-lingual consonants and low vowels) in two contexts: surrounded by mandatorily braced sounds (e.g., /s/) versus unbraced sounds (e.g., /l/). Preliminary results show that the lateral tongue stayed in a lowered position throughout “hubba-bubba” when surrounded by unbraced sounds compared to braced sounds. Results suggest the lateral tongue may be held in one of at least two distinct postures whose activation is controlled by “trigger” events. [Work supported by NIH and NSERC.]

Pattern Recognition and Characterization of Upper Limb Neuromuscular Dynamics during Driver-Vehicle Interactions

SummaryIn this work, pattern recognition and characterization of the neuromuscular dynamics of driver upper limb during naturalistic driving were studied. During the human-in-the-loop experiments, two steering tasks, namely, the passive and active steering tasks, were instructed to be completed by the subjects. Furthermore, subjects manipulated the steering wheel with two distinct postures and six different hand positions. The neuromuscular dynamics of subjects' upper limb were measured using electromyogram signals, and the behavioral data, including the steering torque and steering angle, were also collected. Based on the experimental data, patterns of muscle activities during naturalistic driving were investigated. The correlations, amplitudes, and responsiveness of the electromyogram signals, as well as the smoothness and regularity of the steering torque were discussed. The results reveal the mechanisms of neuromuscular dynamics of driver upper limb and provide a theoretical foundation for the design of the future human-machine interface for automated vehicles.

A Fenomenologia de Heidegger e Sartre em suas diferenças

The aim of this paper is to describe Heidegger and Sartre's ontologies in their approximations and differences, taking some themes as analyzers, such as the meaning of phenomenon and phenomenology, the theory of knowledge and the question of science, the sense of being and the relation ontic-ontological. Heidegger and Sartre depart from common phenomenological assumptions, both of which are critical of the metaphysics of tradition and the imprisonment that Phenomenology itself has undergone. However, they establish such criticisms from different points of view, supporting singular conceptions about the analyzed themes. Thus stand out the radically distinct postures between the two phenomenologists: whereas for Heidegger concerns about concrete subject are considered metaphysical vices and reflect the concealment of the truth of being, for Sartre it is precisely the break with an abstract philosophy, detached from reality and the starting point of his dialectical ontological understanding. It is important to reflect on these approximations and differences, as the ontological and epistemological propositions of these two authors appear as the two main pillars of existential approaches in the field of psychology and psychopathology.

How different effectors and action effects modulate the formation of separate motor memories

Humans can operate a variety of modern tools, which are often associated with different visuomotor transformations. Studies investigating this ability have shown that separate motor memories can be acquired implicitly when different sensorimotor transformations are associated with distinct (intended) postures or explicitly when abstract contextual cues are leveraged by aiming strategies. It still remains unclear how different transformations are remembered implicitly when postures are similar. We investigated whether features of planning to manipulate a visual tool, such as its visual identity or the environmental effect intended by its use (i.e. action effect) would enable implicit learning of opposing visuomotor rotations. Results show that neither contextual cue led to distinct implicit motor memories, but that cues only affected implicit adaptation indirectly through generalization around explicit strategies. In contrast, a control experiment where participants practiced opposing transformations with different hands did result in contextualized aftereffects differing between hands across generalization targets. It appears that different (intended) body states are necessary for separate aftereffects to emerge, suggesting that the role of sensory prediction error-based adaptation may be limited to the recalibration of a body model, whereas establishing separate tool models may proceed along a different route.

The effect of body posture on available habitat and activity-time in a lizard: Implications for thermal ecology studies

Ectothermic animals contend with variable environmental temperature through behavioral thermoregulation, including selection of activity-times and microhabitat spaces with suitable operative temperatures. Thus, an important component to understanding the influence of temperature on animals is through the assessment of thermal constraints on time and space usage. Thermal ecologists have recognized that postural adjustments are an important part of behavioral thermoregulation. However, the impact of postural adjustments on available space and time has received little attention. We hypothesized that postural adjustments would significantly affect the thermal availability of space and time for surface activity. To test our hypothesis, we used data collected over a four-year study of the thermal ecology of Eastern Collared Lizards (Crotaphytus collaris) in Arkansas. We used a novel approach to model three distinct postures used by C. collaris, and to assess the impact of posture on available space and time. For our study species and habitat, posture had a significant impact on several indices of available space and time including: a) a 13% increase in length of the reproductive activity season, b) a 35% increase in the frequency distribution of habitat within active body temperature range and c) a 42% increase in average thermal quality index. We conclude that posture can significantly impact space and time available for surface activity in species that employ it for thermoregulation. Thus, a clearer understanding of the thermal constraints on time-space usage in ectotherms requires consideration of the impact of posture on the spatiotemporal distribution of thermally suitable microhabitats.

HECUBA SUCCUMBS: WORDPLAY IN SENECA'STROADES

Hecuba's grief upon learning of Hector's death in Hom.Il. 22.430‒6 and in the presence of his corpse later on inIl. 24.747‒59 seems to foreshadow the queen's miserable fate in the aftermath of the fall of Troy. In the subsequent literary tradition, the character of Hecuba ends up merging with the destiny of her city: as Harrison points out with reference to Seneca'sTroades, Hecuba, the Latin counterpart of Greek Hekabe, functions as a metaphor for the fall of Troy (118), even represents the fallen Troy itself (128). In turning into an exemplar of maternal grief, she also comes to embody the vicissitudes of fortune. In these pages, I am interested in exploring a possible wordplay on the queen's name in Seneca'sTroades, which may have originated, as I suggest, from Hecuba's distinctive posture in Euripides’ diptychHecubaandTrojan Women(for convenience's sake I will employ the Latin form of the name throughout these pages with the exception of a few passages, in which the Greek form ‘Hekabe’ will be used in order to bring to the fore an etymological connection I will discuss below).

Characterization of Driver Neuromuscular Dynamics for Human–Automation Collaboration Design of Automated Vehicles

In order to design an advanced human–automation collaboration system for highly automated vehicles, research into the driver's neuromuscular dynamics is needed. In this paper, a dynamic model of drivers’ neuromuscular interaction with a steering wheel is first established. The transfer function and the natural frequency of the systems are analyzed. In order to identify the key parameters of the driver–steering–wheel interacting system and investigate the system properties under different situations, experiments with driver-in-the-loop are carried out. For each test subject, two steering tasks, namely the passive and active steering tasks, are instructed to be completed. Furthermore, during the experiments, subjects manipulated the steering wheel with two distinct postures and three different hand positions. Based on the experimental results, key parameters of the transfer function model are identified by using the Gauss–Newton algorithm. Based on the estimated model with identified parameters, investigation of system properties is then carried out. The characteristics of the driver neuromuscular system are discussed and compared with respect to different steering tasks, hand positions, and driver postures. These experimental results with identified system properties provide a good foundation for the development of a haptic take-over control system for automated vehicles.

A novel balance training system using multimodal biofeedback.

BackgroundA biofeedback-based balance training system can be used to provide the compromised sensory information to subjects in order to retrain their sensorimotor function. In this study, the design and evaluation of the low-cost, intuitive biofeedback system developed at Gyeongsang National University is extended to provide multimodal biofeedback for balance training by utilization of visual and haptic modalities.MethodsThe system consists of a smartphone attached to the waist of the subject to provide information about tilt of the torso, a personal computer running a purpose built software to process the smartphone data and provide visual biofeedback to the subject by means of a dedicated monitor and a dedicated Phantom Omni® device for haptic biofeedback. For experimental verification of the system, eleven healthy young participants performed balance tasks assuming two distinct postures for 30 s each while acquiring torso tilt. The postures used were the one foot stance and the tandem Romberg stance. For both the postures, the subjects stood on a foam platform which provided a certain amount of ground instability.ResultsPost-experiment data analysis was performed using MATLAB® to analyze reduction in body sway. Analysis parameters based on the projection of trunk tilt information were calculated in order to ascertain the reduction in body sway and improvements in postural control. Two-way analysis of variance (ANOVA) showed no statistically significant interactions between postures and biofeedback. Post-hoc analysis revealed statistically significant reduction in body sway on provision of biofeedback. Subjects exhibited maximum body sway during no biofeedback trial, followed by either haptic or visual biofeedback and in most of the trials the multimodal biofeedback of visual and haptic together resulted in minimization of body sway, thus indicating that the multimodal biofeedback system worked well to provide significant (p < 0.05) assistance in postural control.ConclusionsA multimodal biofeedback system can offer more customized training methods and hence provide therapists with a comprehensive solution for a diverse array of patients. It is necessary to identify the long-term effects of this novel biofeedback system. In the future, the balance training schemes for individuals with upright balance issues will be studied.

A Face Recognition System using PCA and AI Technique

In this paper a proficient posture invariant face recognition framework utilizing PCA and AI has been proposed. The peculiarities of an image under test have been extracted utilizing PCA then neuro fuzzy based framework ANFIS is utilized for recognition. The primary reason for this paper is to decrease the computational complexities in the face recognition framework. The proposed framework will perceive the face images under an assortment of stance conditions by utilizing AI based system. The preparation face image dataset will be handled by PCA procedure to register the score esteem, which will be then used in the recognition process. The score values from the distinctive posture images will be given as data to the Neuro-Fuzzy based ANFIS System. The Neuro-Fuzzy based ANFIS System will achieve the recognition transform by taking the info score estimations of the data images and perceive the information face images with the assistance of predefined limit esteem. The proposed face recognition system with Neuro-Fuzzy based ANFIS System will perceive the information face images productively with high recognition proportion. The proposed methodology will be actualized in the MATLAB stage and it will be assessed by utilizing an assortment of database images under different posture invariant conditions. Accordingly, proposed framework will effectively perceive the face images focused around the blend of scores acquired from the posture invariant procedure.

Effects of kinesthetic haptic feedback on standing stability of young healthy subjects and stroke patients.

BackgroundHaptic control is a useful therapeutic option in rehabilitation featuring virtual reality interaction. As with visual and vibrotactile biofeedback, kinesthetic haptic feedback may assist in postural control, and can achieve balance control. Kinesthetic haptic feedback in terms of body sway can be delivered via a commercially available haptic device and can enhance the balance stability of both young healthy subjects and stroke patients.MethodOur system features a waist-attached smartphone, software running on a computer (PC), and a dedicated Phantom Omni® device. Young healthy participants performed balance tasks after assumption of each of four distinct postures for 30 s (one foot on the ground; the Tandem Romberg stance; one foot on foam; and the Tandem Romberg stance on foam) with eyes closed. Patient eyes were not closed and assumption of the Romberg stance (only) was tested during a balance task 25 s in duration. An Android application running continuously on the smartphone sent mediolateral (ML) and anteroposterior (AP) tilt angles to a PC, which generated kinesthetic haptic feedback via Phantom Omni®. A total of 16 subjects, 8 of whom were young healthy and 8 of whom had suffered stroke, participated in the study.ResultsPost-experiment data analysis was performed using MATLAB®. Mean Velocity Displacement (MVD), Planar Deviation (PD), Mediolateral Trajectory (MLT) and Anteroposterior Trajectory (APT) parameters were analyzed to measure reduction in body sway. Our kinesthetic haptic feedback system was effective to reduce postural sway in young healthy subjects regardless of posture and the condition of the substrate (the ground) and to improve MVD and PD in stroke patients who assumed the Romberg stance. Analysis of Variance (ANOVA) revealed that kinesthetic haptic feedback significantly reduced body sway in both categories of subjects.ConclusionKinesthetic haptic feedback can be implemented using a commercial haptic device and a smartphone. Intuitive balance cues were created using the handle of a haptic device, rendering the approach very simple yet efficient in practice. This novel form of biofeedback will be a useful rehabilitation tool improving the balance of stroke patients.

Aposematism and crypsis in a rodent: antipredator defence of the Norwegian lemming

Aposematism is unusual in herbivorous mammals, and exceptions help clarify its ecology and evolution. The Norwegian lemming differs from other rodents in colouration and behaviour. One hypothesis is that its black, yellow and white colours, loud calls and ferocious defence reduce predation by conspicuous aposematism. Another hypothesis is that the colouration is cryptic. These alternatives are tested in a detectability experiment comparing lemmings and sympatric grey-sided voles. All 18 observers detected a higher proportion of the lemmings, corroborating conspicuousness. Unlike smaller rodents, Norwegian lemmings often call from a distance at predators. The aposematism hypothesis predicts that cryptically coloured Alaskan brown lemmings will not call. In the field, Norwegian lemmings gave antipredator calls at a human observer in 36 of 110 encounters, but brown lemmings did so in only 1 of 39 cases. Most Norwegian lemmings called if surprised within a few metres but froze or fled silently farther away, relying on crypsis against distant predators. Small juveniles called as often as adults, a possible case of auto-mimicry. In an earlier experiment, Norwegian lemmings, in contrast with grey-sided voles, aggressively resisted attacks by a major avian predator of rodents. The tests corroborate the hypotheses that (1) distinctive, contrast-rich colouration, antipredator calls and threat postures of the Norwegian lemming form a multimodal suit of aposematic traits, warning predators that this is a more dangerous prey than the smaller sympatric voles, and (2) discriminability from undefended species is an important adaptive reason for conspicuous distinctness of many aposematic signals.