scholarly journals On the mechanical contribution of head stabilization to passive dynamics of anthropometric walkers

2019 ◽  
Vol 39 (4) ◽  
pp. 461-475
Author(s):  
Mehdi Benallegue ◽  
Jean-Paul Laumond ◽  
Alain Berthoz
Keyword(s):  
Mechanical Effect ◽  
The Body ◽  
Upper Body ◽  
Control Parameters ◽  
Vertical Orientation ◽  
Head Stabilization ◽  
Passive Dynamics ◽  
Body Dynamics ◽  
Walking Dynamics ◽  
Head Neck

During the steady gait, humans stabilize their head around the vertical orientation. Although there are sensori-cognitive explanations for this phenomenon, its mechanical effect on the body dynamics remains unexplored. In this study, we take profit from the similarities that human steady gait shares with the locomotion of passive-dynamics robots. We introduce a simplified anthropometric 2D model to reproduce a broad walking dynamics. In a previous study, we showed heuristically that the presence of a stabilized head–neck system has a significant influence on the dynamics of walking. This article gives new insights that lead to understanding this mechanical effect. In particular, we introduce an original cart upper-body model that allows to better understand the mechanical interest of head stabilization when walking, and we study how this effect is sensitive to the choice of control parameters.

scholarly journals Wrist-wearable bioelectrical impedance analyzer with miniature electrodes for daily obesity management

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Myoung Hoon Jung ◽  
Kak Namkoong ◽  
Yeolho Lee ◽  
Young Jun Koh ◽  
Kunsun Eom ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Body Fat ◽  
Bioelectrical Impedance ◽  
The Body ◽  
Upper Body ◽  
Sensor Technology ◽  
Clinical Test ◽  
Obesity Management ◽  
Impedance Analyzer ◽  
Bioelectrical Impedance Analyzer

AbstractBioelectrical impedance analysis (BIA) is used to analyze human body composition by applying a small alternating current through the body and measuring the impedance. The smaller the electrode of a BIA device, the larger the impedance measurement error due to the contact resistance between the electrode and human skin. Therefore, most commercial BIA devices utilize electrodes that are large enough (i.e., 4 × 1400 mm2) to counteract the contact resistance effect. We propose a novel method of compensating for contact resistance by performing 4-point and 2-point measurements alternately such that body impedance can be accurately estimated even with considerably smaller electrodes (outer electrodes: 68 mm2; inner electrodes: 128 mm2). Additionally, we report the use of a wrist-wearable BIA device with single-finger contact measurement and clinical test results from 203 participants at Seoul St. Mary’s Hospital. The correlation coefficient and standard error of estimate of percentage body fat were 0.899 and 3.76%, respectively, in comparison with dual-energy X-ray absorptiometry. This result exceeds the performance level of the commercial upper-body portable body fat analyzer (Omron HBF-306). With a measurement time of 7 s, this sensor technology is expected to provide a new possibility of a wearable bioelectrical impedance analyzer, toward obesity management.

Research on intelligent clustering of male upper body

2021 ◽  
pp. 004051752110001
Author(s):  
Pengpeng Cheng ◽  
Xianyi Zeng ◽  
Pascal Bruniaux ◽  
Jianping Wang ◽  
Daoling Chen
Keyword(s):  
Artificial Bee Colony ◽  
Young Men ◽  
Cuckoo Search ◽  
The Body ◽  
Upper Body ◽  
Intelligent Algorithm ◽  
Density Peak ◽  
Swarm Optimization ◽  
Bee Colony ◽  
Length Width

To study the upper body characteristics of young men, the body circumference, length, width, thickness, and angle of young men aged 18–25 and 26–35 years were collected to comprehensively characterize the concave and convex features of the front, back, and side of the human body. The Cuckoo Search-Density Peak intelligent algorithm was used to extract the feature factors of the upper body of men, and to cluster them. To verify the effectiveness of the intelligent algorithm, the clustering results of Cuckoo Search-Density Peak, Density Peak, Particle Swarm Optimization-Density Peak algorithm, Ant Colony Optimization-Density Peak algorithm, Genetic Algorithm-Density Peak algorithm, and Artificial Bee Colony-Density Peak algorithm were evaluated by Silouette and F-measures, respectively. The results show that the Cuckoo Search-Density Peak algorithm has the best clustering results and is superior to other algorithms. There are some differences in somatotype characteristics and somatotype indexes between young men aged 18–25 and 26–35 years.

scholarly journals A Feasibility Study of Kinematic Characteristics on the Upper Body According to the Shooting of Elite Disabled Archery Athletes

2021 ◽  
Vol 18 (6) ◽  
pp. 2962
Author(s):  
Tae-Whan Kim ◽  
Jae-Won Lee ◽  
Seoung-Ki Kang ◽  
Kyu-Yeon Chae ◽  
Sang-Hyup Choi ◽  
...  
Keyword(s):  
The Body ◽  
Lower Limbs ◽  
Upper Body ◽  
Movement Trajectory ◽  
Phase 2 ◽  
Kinematic Characteristics ◽  
Significant Difference ◽  
Athletes With Disabilities ◽  
Body Center ◽  
Time Required

The purpose of this study is to compare and analyze the kinematic characteristics of the upper limb segments during the archery shooting of Paralympic Wheelchair Class archers (ARW2—second wheelchair class—paraplegia or comparable disability) and Paralympic Standing Class archers (ARST—standing archery class—loss of 25 points in the upper limbs or lower limbs), where archers are classified according to their disability grade among elite disabled archers. The participants of this study were selected as seven elite athletes with disabilities by the ARW2 (n = 4) and ARST (n = 3). The analysis variables were (1) the time required for each phase, (2) the angle of inclination of the body center, (3) the change of trajectory of body center, and (4) the change of the movement trajectory of the bow center by phase when performing six shots in total. The ARW2 group (drawing phase; M = 2.228 s, p < 0.05, holding phase; M = 4.414 s, p < 0.05) showed a longer time than the ARST group (drawing phase; M = 0.985 s, holding phase; M = 3.042 s), and the angle of the body did not show a significant difference between the two groups. Additionally, in the direction of the anteroposterior axis in the drawing phase, the change in the movement trajectory of the body center showed a more significant amount of change in the ARW2 group than in the ARST group, and the change in the movement trajectory of the bow center did not show a significant difference between the two groups.

scholarly journals Cervical intradural extramedullay vascular schwannoma in a thirty eight year old male

2019 ◽  
Vol 6 (7) ◽  
pp. 2634
Author(s):  
Shipra Singhal ◽  
Sufian Zaheer ◽  
Rashmi Arora
Keyword(s):  
Peripheral Nerve ◽  
Peripheral Nerves ◽  
Neck Region ◽  
The Body ◽  
Vascular Changes ◽  
Vascular Tissues ◽  
Clinical Presentations ◽  
Cervical Swelling ◽  
Head Neck

Schwannomas are benign peripheral nerve sheet tumours that may arise almost anywhere in the body but are commonly seen in the head, neck region and in the extremities. They may be associated with variable clinical presentations depending on their location. The peripheral nerves are closely related to vascular tissues morphologically and physiologically and therefore schwannomas may be associated with vascular changes like vascular hyperplasia and vascular dilation. Here authors represent one such case where a 38-year-old patient presented with a cervical swelling which on histopathology was diagnosed as vascular schwannoma.

scholarly journals Fitness and body composition profiling of elite junior South African rugby players

2009 ◽  
Vol 18 (2) ◽  
pp. 38 ◽  
Author(s):  
J Durandt ◽  
S Du Toit ◽  
J Borresen ◽  
T Hew-Butler ◽  
H Masimla ◽  
...  
Keyword(s):  
Body Composition ◽  
South African ◽  
Body Fat ◽  
Age Groups ◽  
Rugby Union ◽  
The Body ◽  
Upper Body ◽  
Cross Sectional ◽  
Sprinting Speed ◽  
Rugby Players

Objective. The aim of this study was to describe the body composition, strength and speed characteristics of elite junior South African rugby players. Design. Cross-sectional. Setting. Field study. Subjects. Rugby players (16 and 18 years old, N = 174) selected for the South African Rugby Union National Green Squad. Outcome measures. Body composition, 10 m and 40 m speed, agility, 1RM bench press, underhand pull-ups, push-ups, multistage shuttle run. Results. The under-16 players were on average shorter (175.6 ± 5.7 v. 179.2 ± 6.7 cm), weighed less (76.5 ± 8.2 v. 84.8 ± 8.3 kg) had less upper body absolute strength (77.1 ± 11.8 kg v. 95.3 ± 16.7 kg) and muscular endurance (41 ± 12 v. 52 ± 15 push-ups) and aerobic fitness (87.1 ± 19.4 v. 93.5 ± 15.3 shuttles) than the under-18 players. There were no differences in body fat, sprinting speed (10 m and 40 m) or agility between the two age groups. There were differences between playing positions, with the props having the most body fat, strongest upper bodies, slowest sprinting speed, least agility and lowest aerobic capacity compared with players in the other positions. Conclusion. This study provides data for elite junior rugby players and can be used to monitor the progression of players after intervention while also assisting with talent identification for the different playing positions. South African Journal of Sports Medicine Vol. 18 (2) 2006: pp. 38-45

scholarly journals Automated Analysis of Body Movement in Emotionally Expressive Piano Performances

2008 ◽  
Vol 26 (2) ◽  
pp. 103-119 ◽  
Author(s):  
Ginevra Castellano ◽  
Marcello Mortillaro ◽  
Antonio Camurri ◽  
Gualtiero Volpe ◽  
Klaus Scherer
Keyword(s):  
Emotional Expression ◽  
Temporal Dynamics ◽  
Body Movement ◽  
Music Performance ◽  
The Body ◽  
Head Movements ◽  
Automated System ◽  
Upper Body ◽  
Musical Score ◽  
Motion Cues

EMOTIONAL EXPRESSION IN MUSIC PERFORMANCE includes important cues arising from the body movement of the musician. This movement is related to both the musical score execution and the emotional intention conveyed. In this experiment, a pianist was asked to play the same excerpt with different emotionally expressive intentions. The aim was to verify whether different expressions could be distinguished based on movement by trying to determine which motion cues were most emotion-sensitive. Analyses were performed via an automated system capable of detecting the temporal profiles of two motion cues: the quantity of motion of the upper body and the velocity of head movements. Results showed that both were sensitive to emotional expression, especially the velocity of head movements. Further, some features conveying information about movement temporal dynamics varied among expressive conditions allowing emotion discrimination. These results are in line with recent theories that underlie the dynamic nature of emotional expression.

Working a half-stone of an old man

2021 ◽  
Vol 2 (3/S) ◽  
pp. 356-360
Author(s):  
Javli Kudratov
Keyword(s):  
Human Body ◽  
The Body ◽  
Lower Limbs ◽  
Characteristic Points ◽  
Human Figure ◽  
Head Neck

The most important parts of the human body are divided into the head, neck, shoulders, chest area of   the body, waist and upper and lower limbs.  The structure of the human body is manifested in many different personalities, in many complex and unusual combinations. Drawing a human figure is the student's perspective, proportion, plastic anatomy, to have a deeper knowledge of the forms of movement and the principle of the main characteristic points and reference lines  the pin requires more reliable, more accurate application.

Biodynamic Characteristics of Upper Limb Reaching Movements of the Seated Human Under Whole-Body Vibration

2013 ◽  
Vol 29 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Heon-Jeong Kim ◽  
Bernard J. Martin
Keyword(s):  
Right Hemisphere ◽  
Whole Body Vibration ◽  
The Body ◽  
Upper Body ◽  
Whole Body ◽  
Vibration Transmission ◽  
Body Vibration ◽  
Body Segments ◽  
Human Movements ◽  
Reach Movements

Simulation of human movements is an essential component for proactive ergonomic analysis and biomechanical model development (Chaffin, 2001). Most studies on reach kinematics have described human movements in a static environment, however the models derived from these studies cannot be applied to the analysis of human reach movements in vibratory environments such as in-vehicle operations. This study analyzes three-dimensional joint kinematics of the upper extremity in reach movements performed in static and specific vibratory conditions and investigates vibration transmission to shoulder, elbow, and hand along the body path during pointing tasks. Thirteen seated subjects performed reach movements to five target directions distributed in their right hemisphere. The results show similarities in the characteristics of movement patterns and reach trajectories of upper body segments for static and dynamic environments. In addition, vibration transmission through upper body segments is affected by vibration frequency, direction, and location of the target to be reached. Similarities in the pattern of movement trajectories revealed by filtering vibration-induced oscillations indicate that coordination strategy may not be drastically different in static and vibratory environments. This finding may facilitate the development of active biodynamic models to predict human performance and behavior under whole body vibration exposure.

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