Location Of Body Parts Research Articles

U.S. Coast Guard Academy Injury and Risk Factor Study

Purpose : Injury rates and injury risk factors were examined for the first time among cadets undergoing Summer Warfare Annual Basic (SWAB) training at the U.S. Coast Guard Academy (USCGA). Methods : Participant s were 778 men and 286 women from four years of SWAB training. Before SWAB training, the subjects were administered a Physical Fitness Assessment (PFA) (2-minute maximal effortsit-ups and 1.5 mile run) andfunctionalmovement screening (FMS) test.Heightand weight were measured and, gender, age and ethnicity were obtained from administrative records. Training -related injuries were compiled from student medical records. The diagnosis, body part location, disposition, and limited duty days were recorded foreach clinic visit. Results:During the 8 weeks of SWAB training, 23.8% of the women and 18.4% of the men were injured at least once. Compared to the men, the odds of an overall injury

스키니 진 착용이 인체생리반응과 주관적 압박감에 미치는 영향

The purpose of this study was to analyze and determine the relationship between physiological responses including blood flow rate and garment pressure, and the feeling of restrictive tightness associated with the wearing skinny pants as a popular clothing style. Evaluation was based on material type, posture and activity type, and body part location. Five female college students took part in this research. Five kinds of experimental clothes with waist measurements of 66cm were chosen. An analysis of the selected skinny pants demonstrated the degree of the whole looseness was higher in this order: clothing type A>B>D>C, and E with E being knitted cloth. Garment pressure was the highest in the front knee portions and was lowest in the outside thigh region. Garment pressure was highest in this sequence : clothing type C>=D>A>=B>E. In terms of posture and activity types, garment pressure was the highest when research participants were crouching, and was the lowest when standing. The blood flow rate was highest in this order: clothing type E>D>B>A>C. Type C skinny pants impeded blood flow and demonstrated the tightest and most restrictive relationship. Blood flow rate varied depending on the type of movement and was highest in this order: getting up, rowing, kicking, jumping and O-shaped leg posture. The results of subjective pressure evaluation demonstrated that pressure was highest in this order: E>=C>B>A>D. These results suggests the need to improve on the patterns and the material design in the area of the front knees. The degree of the looseness when wearing skinny pants did not always correspond to garment pressure or subjective sensation.

Quantitative measure of structural and geometric similarity of 3D morphologies

This work describes a new heuristic algorithm that estimates structural and geometric similarity of three-dimensional morphologies. It is an extension to previously developed measure of similarity (Komosinski et al., Theor Biosci 2001, 120, 271–286) that was only able to consider the structure of 3D constructs. Morphologies are modeled as graphs with vertices as points in a 3D space, and edges connecting these vertices. This model is very general, therefore the proposed algorithm can be applied in (and across) a number of disciplines including artificial life, evolutionary design, engineering, robotics, biology, and chemistry. The primary areas of application of this fast numerical similarity measure are artificial life and evolutionary design, where great numbers of morphologies result from simulated evolutionary processes, and both structural and geometric aspects are significant. Geometry of 3D constructs (i.e., locations of body parts in space) is as important as the structure (i.e., connections of body parts), because both determine behavior of creatures or designs and their fitness in a particular environment. In this work, both morphological aspects are incorporated in a single, highly discriminative measure of similarity. © 2011Wiley Periodicals, Inc. Complexity, 2011 © 2011 Wiley Periodicals, Inc.

An implicit body representation underlying human position sense

Knowing the body's location in external space is a fundamental perceptual task. Perceiving the location of body parts through proprioception requires that information about the angles of each joint (i.e., body posture) be combined with information about the size and shape of the body segments between joints. Although information about body posture is specified by on-line afferent signals, no sensory signals are directly informative about body size and shape. Thus, human position sense must refer to a stored body model of the body's metric properties, such as body part size and shape. The need for such a model has long been recognized; however, the properties of this model have never been systematically investigated. We developed a technique to isolate and measure this body model. Participants judged the location in external space of 10 landmarks on the hand. By analyzing the internal configuration of the locations of these points, we produced implicit maps of the mental representation of hand size and shape. We show that this part of the body model is massively distorted, in a reliable and characteristic fashion, featuring shortened fingers and broadened hands. Intriguingly, these distortions appear to retain several characteristics of primary somatosensory representations, such as the Penfield homunculus.

The head bone's connected to the neck bone: when do toddlers represent their own body topography?

Developments in very young children's topographic representations of their own bodies were examined. Sixty-one 20- and 30-month-old children were administered tasks that indexed the ability to locate specific body parts on oneself and knowledge of how one's body parts are spatially organized, as well as body-size knowledge and self-awareness. Age differences in performance emerged for every task. Body-part localization and body spatial configuration knowledge were associated; however, body topography knowledge was not associated with body-size knowledge. Both were related to traditional measures of self-awareness, mediated by their common associations with age. It is concluded that children possess an explicit, if rudimentary, topographic representation of their own body's shape, structure, and size by 30 months of age.

Where are your body parts? A pure case of heterotopagnosia following left parietal stroke

We studied the involvement of the parietal cortex in interpersonal body representation in a left parietal stroke patient. We used tasks assessing different types of body representations and localization of object parts. The patient performed normally on all tasks of body knowledge. However, she was unable to locate body parts on another person or on body representations. In contrast, she pointed correctly to the same body parts on herself or object representations. The data support the important role of the left parietal cortex in the transformation of intrinsic spatial coding of body parts localization in extrinsic body part coordinates.

Optokinetic stimulation induces illusory movement of both out-of-the-body and on-the-body hand-held visual objects

The coding of body part location may depend upon both visual and proprioceptive information, and allows targets to be localized with respect to the body. The present study investigates the interaction between visual and proprioceptive localization systems under conditions of multisensory conflict induced by optokinetic stimulation (OKS). Healthy subjects were asked to estimate the apparent motion speed of a visual target (LED) that could be located either in the extrapersonal space (visual encoding only, V), or at the same distance, but stuck on the subject's right index finger-tip (visual and proprioceptive encoding, V-P). Additionally, the multisensory condition was performed with the index finger kept in position both passively (V-P passive) and actively (V-P active). Results showed that the visual stimulus was always perceived to move, irrespective of its out- or on-the-body location. Moreover, this apparent motion speed varied consistently with the speed of the moving OKS background in all conditions. Surprisingly, no differences were found between V-P active and V-P passive conditions in the speed of apparent motion. The persistence of the visual illusion during the active posture maintenance reveals a novel condition in which vision totally dominates over proprioceptive information, suggesting that the hand-held visual stimulus was perceived as a purely visual, external object despite its contact with the hand.

EARS: A System for Geometric and Anthropometric Evaluation of Human Body Scans

AbstractWe present the Enhanced Anthropometric Rating System (EARS), an automated system for evaluating the quality of 3D human body scans. EARS is able to detect and classify both the geometric and anthropometric features of a given mesh and rates its quality. These features and corresponding operations include the roughness of the scanned surface, the fairness of vertex location, area and position of missing body parts, anthropometrically guided segmentation, detection of landmarks, and wrinkles in clothing. The system ranks these features and operations based on their importance as determined by Anthropologists who have specific requirements with respect to understanding the anthropometry of the soldier of the 21st century. The data scans contain more than 100,000 vertices and over 300,000 facets. The system is able to provide real-time feedback on whether the mesh is suitable for downstream applications. The system will be used by the U.S. Army to do statistical studies on their large human body dataset.

Synthesis of Silhouettes and Visual Hull Reconstruction for Articulated Humans

In this paper, we propose a complete framework for improved synthesis and understanding of the human pose from a limited number of silhouette images. It combines the active image-based visual hull (IBVH) algorithm and a contour-based body part segmentation technique. We derive a simple, approximate algorithm to decide the extrinsic parameters of a virtual camera, and synthesize the turntable image collection of the person using the IBVH algorithm by actively moving the virtual camera on a properly computed circular trajectory around the person. Using the turning function distance as the silhouette similarity measurement, this approach can be used to generate the desired pose-normalized images for recognition applications. In order to overcome the inability of the visual hull (VH) method to reconstruct concave regions, we propose a contour-based human body part localization algorithm to segment the silhouette images into convex body parts. The body parts observed from the virtual view are generated separately from the corresponding body parts observed from the input views and then assembled together for a more accurate VH reconstruction. Furthermore, the obtained turntable image collection helps to improve the body part segmentation and identification process. By using the inner distance shape context (IDSC) measurement, we are able to estimate the body part locations more accurately from a synthesized view where we can localize the body part more precisely. Experiments show that the proposed algorithm can greatly improve body part segmentation and hence shape reconstruction results.

Why are out-of-body experiences interesting for philosophers?: The theoretical relevance of OBE research

After decades of only sparse scientific interest, we are currently witnessing a renaissance of empirical research into out-of-body experiences (OBEs) and full-body illusions. Being a philosopher of mind, I obviously have only a limited judgment of how good this research actually is from a purely scientific point of view. What I can do, however, is to draw attention to a series of theoretical aspects that make OBEs a particularly relevant target of investigation in the ongoing search for the neural correlate of self-consciousness and in the wider context of an empirically grounded theory of the human mind. Firstly, and most basically, this type of research has a great potential for conceptual differentiation. By more clearly distinguishing different types of neurological disorders affecting the sense of self, it will help to improve the taxonomy of selfrelated disorders. Introducing more fine grained conceptual distinctions will have diagnostic, and perhaps also therapeutic value, because it contributes to our taxonomy of hallucinations and deviant forms of self-modeling (see Metzinger, 2003, chapter 7) involving dimensions like ‘‘self-location’’ and ‘‘selfidentification’’. The four main types are autoscopic hallucination, heautoscopy, OBE, and the feeling of a presence – all due to multisensory disintegration and damage to temporo-parietal and temporo-occipital cortex (Blanke and Mohr, 2005; Blanke and Castillo, 2007). Autoscopic phenomena show that not only identification with and localization of body parts, but also of the global conscious representation of the entire body can be disturbed. In autoscopic hallucinations and heautoscopy patients see a second own illusory body in extrapersonal space, but the two phenomena differ in terms of self-identification

Point Zero: A Phenomenological Inquiry into the Seat of Consciousness

Does consciousness have a spatial "location" that can be scientifically investigated? Using a novel phenomenological method, when people are encouraged to explore the question introspectively they not only can make sense of the idea of their consciousness being "located," but will readily indicate its exact position inside the head. The method, based on Francisco J. Varela's work, involves a structured interview led by an expert mediator in which preliminary questions are asked of untrained volunteers about the location of objects and body parts, and then they are questioned about the location from which they are experiencing these objects. 83% of volunteers located with confidence a precise position for the I-that-perceives in the temporal area of the head centred midway behind the eyes. The same results were obtained with blind subjects (congenitally or later) and with non-Westerners. The significance of this subjective source of the experience of the location of perception is discussed linking it to neurological correlates of self-referred conscious activities and of conscious awareness in memory. Further investigations are suggested with trained volunteers and with individuals with psychiatric disorders.

The rubber hand illusion in action

In the well-known rubber hand illusion (RHI), watching a rubber hand being stroked while one's own unseen hand is synchronously stroked, induces a relocation of the sensed position of one's own hand towards the rubber hand [Botvinick, M., & Cohen, J. (1998). Rubber hands ‘feel’ touch that eyes see. Nature, 391(6669), 756]. As one has lost the veridical location of one's hand, one should not be able to correctly guide one's hand movements. An accurate representation of the location of body parts is indeed a necessary pre-requisite for any correct motor command [Graziano, M. S. A., & Botvinick, M. M. (1999). How the brain represents the body: Insights from neurophysiology and psychology. In D. Gopher, & A. Koriat (Eds.), Attention and performance XVII—Cognitive regulation of performance interaction of theory and application (pp. 136–157)]. However, it has not yet been investigated whether action is indeed affected by the proprioceptive drift towards the rubber hand, nor has the resistance of visual capture in the RHI to new proprioceptive information been assessed. In the present two kinematic experiments, we show for the first time that action resists the RHI and that the RHI resists action. In other words, we show a dissociation between illusion-insensitive ballistic motor responses and illusion-sensitive perceptual bodily judgments. Moreover, the stimulated hand was judged closer to the rubber hand for the perceptual responses, even after active movements. This challenges the view that any proprioceptive update through active movement of the stimulated hand erases the illusion. These results expand the knowledge about representations of the body in the healthy brain, and are in line with the currently most used dissociation between two types of body representations so far mainly based on neuropsychological patients [Paillard, J. (1991). Knowing where and knowing how to get there. In J. Paillard (Ed.), Brain and space (pp. 461–481); Paillard, J. (1999). Body schema and body image: A double dissociation in deafferented patients. In G. N. Gantchev, S. Mori, & J.Massion (Eds.), Motor control, today and tomorrow (pp. 197–214)].

Generic temporal segmentation of cyclic human motion

A method is proposed for the temporal segmentation of cyclic human motion from video sequences. The proposed method is divided into three processing steps. Once silhouettes and body part locations are obtained, a set of individual 1-D signals representing motion trajectories of body parts is extracted for the entire sequence. The second step performs the individual segmentation of all signals in the set in order to localize their periodic segments. In the final step, all individual segmentations are coherently merged into a global segmentation for the entire sequence and set of signals. The proposed approach has been successfully tested on a variety of sequences containing cyclic activities such as aerobic exercises and walking along different directions.

Progress in Understanding Spatial Coordinate Systems in the Primate Brain

A new study in this issue of Neuron shows that when monkeys reach to a visual target, neurons in the dorsal premotor cortex compare the location of the target, the hand, and the point of visual fixation. The neurons therefore encode space through a combination of eye-centered and hand-centered coordinates.

Injuries in Naval Special Warfare Sea, Air, and Land Personnel: Epidemiology and Surgical Management

Several epidemiologic studies are described in the literature on all different types of sporting activities as well as military personnel. No studies to our knowledge have investigated the injury patterns and treatment of United States Naval Special Warfare personnel. The purpose of this study is to present the injuries of the Naval Special Warfare community that presented to the combined orthopedic/human functional performance clinic during a 3-year period, as well as the surgical management of these injuries. Medical records generated during a 3-year period yielded diagnoses that were stratified according to body part and location. The surgical procedures were divided by body part location and were correlated to the initial diagnosis. A calculation was then made based on the percent of patients who eventually progressed on to surgical intervention. Injuries were most frequent to the back/neck, knee, and shoulder in order of decreasing frequency. Surgical management was highest for the knee, followed by the shoulder and foot/ankle. A primary diagnosis involving the knee led to surgery 33% of the time. Similarly, a primary shoulder diagnosis involving the shoulder progressed to surgery 32% and with the foot/ankle 18% of the time. The varied injury and surgical management patterns suggest that the Naval Special Warfare community is composed of truly “unique” athletes, not easily categorized into any previously described sporting activities.

The role of human left superior parietal lobule in body part localization.

Electrophysiological data in primates suggest that the superior parietal lobule integrates the position of the limbs to construct complex representations of postures. Although in humans the neural basis of these mechanisms remains largely unknown, neuropsychological studies have implicated left superior parietal regions. We devised a simple functional magnetic resonance imaging paradigm aimed at exploring this hypothesis in healthy humans. Strong activation was obtained within the left but not the right superior parietal lobule, providing additional evidence that this structure may play a key role in body part localization processing.

Representations of the human body in the production and imitation of complex movements

Previous investigations suggest that there are at least three distinct types of representation of the human body. One representation codes structural information about body part location (body structural description), the second codes knowledge about body parts (body semantics or body image), and the third provides a dynamic mapping of the current positions of body parts relative to one another (body schema) (Buxbaum & Coslett, 2001; Schwoebel, Coslett, & Buxbaum, 2001; Sirigu, Grafman, Bressler, & Sunderland, 1991). In this study we used an influential "two route" model of gesture performance (Gonzalez Rothi, Ochipa, & Heilman, 1991) to derive predictions about the body representations expected to underlie the production and imitation of meaningful and meaningless movements. The relationships between these measures were examined in 55 patients with unilateral left-hemisphere lesions. Multiple regression analyses demonstrated that performance on body semantics and body schema tasks were significant and unique predictors of meaningful gesture performance, whereas the body schema measure alone predicted imitation of meaningless movements. Body structural descriptions did not enter into any of the models. These findings are consistent with performance of meaningful actions via a semantic route that accesses body semantics and other action knowledge, and performance of meaningless movements via a "direct" route that bypasses this information.

Human Body Model Acquisition and Tracking Using Voxel Data

We present an integrated system for automatic acquisition of the human body model and motion tracking using input from multiple synchronized video streams. The video frames are segmented and the 3D voxel reconstructions of the human body shape in each frame are computed from the foreground silhouettes. These reconstructions are then used as input to the model acquisition and tracking algorithms. The human body model consists of ellipsoids and cylinders and is described using the twists framework resulting in a non-redundant set of model parameters. Model acquisition starts with a simple body part localization procedure based on template fitting and growing, which uses prior knowledge of average body part shapes and dimensions. The initial model is then refined using a Bayesian network that imposes human body proportions onto the body part size estimates. The tracker is an extended Kalman filter that estimates model parameters based on the measurements made on the labeled voxel data. A voxel labeling procedure that handles large frame-to-frame displacements was designed resulting in very robust tracking performance. Extensive evaluation shows that the system performs very reliably on sequences that include different types of motion such as walking, sitting, dancing, running and jumping and people of very different body sizes, from a nine year old girl to a tall adult male.

Effects of Level of Automation on Errors and Consistency in Two- and Three-Dimensional Anthropometry

This study investigated some potential sources of error, and their consequences, across different types of anthropometric measurement methods. The measurement methods included use of traditional anthropometric instruments, as well as two versions of an electromechanical approach that recorded three-dimensional locations of body parts. Several errors were hypothesized to be from aspects related to human information processing and their interaction with differing methods. Measurements obtained with the traditional approach and two versions of the electromechanical approach were then compared for two experienced anthropometrists who each took 72 measurements on a cadaveric forearm while it was clothed and unclothed. ANOVA demonstrated that there were differences in measurement consistency between individuals, measurement methods and clothing conditions. This study was an initial attempt to investigate the potential sources of error within anthropometric measurements via focusing on the information presented to the measurer and the application of this information to the consistency of measurement. The findings provide information about the causes of error and the saviors of consistency.

Nonstationary color tracking for vision-based human-computer interaction

Skin color offers a strong cue for efficient localization and tracking of human body parts in video sequences for vision-based human-computer interaction. Color-based target localization could be achieved by analyzing segmented skin color regions. However, one of the challenges of color-based target tracking is that color distributions would change in different lighting conditions such that fixed color models would be inadequate to capture nonstationary color distributions over time. Meanwhile, using a fixed skin color model trained by the data of a specific person would probably not work well for other people. Although some work has been done on adaptive color models, this problem still needs further studies. We present our investigation of color-based image segmentation and nonstationary color-based target tracking, by studying two different representations for color distributions. We propose the structure adaptive self-organizing map (SASOM) neural network that serves as a new color model. Our experiments show that such a representation is powerful for efficient image segmentation. Then, we formulate the nonstationary color tracking problem as a model transduction problem, the solution of which offers a way to adapt and transduce color classifiers in nonstationary color distributions. To fulfill model transduction, we propose two algorithms, the SASOM transduction and the discriminant expectation-maximization (EM), based on the SASOM color model and the Gaussian mixture color model, respectively. Our extensive experiments on the task of real-time face/hand localization show that these two algorithms can successfully handle some difficulties in nonstationary color tracking. We also implemented a real-time face/hand localization system based on such algorithms for vision-based human-computer interaction.