scholarly journals Fatigue-free operation of most body-powered prostheses not feasible for majority of users with trans-radial deficiency

2017 ◽  
Vol 42 (1) ◽  
pp. 84-92 ◽  
Author(s):  
Mona Hichert ◽  
Alistair N Vardy ◽  
Dick Plettenburg

Background: Body-powered prostheses require cable operation forces between 33 and 131 N. The accepted upper limit for fatigue-free long-duration operation is 20% of a users’ maximum cable operation force. However, no information is available on users’ maximum force. Objectives: To quantify users’ maximum cable operation force and to relate this to the fatigue-free force range for the use of body-powered prostheses. Study design: Experimental trial. Methods: In total, 23 subjects with trans-radial deficiencies used a bypass prosthesis to exert maximum cable force three times during 3 s and reported discomfort or pain on a body map. Additionally, subjects’ anthropometric measures were taken to relate to maximum force. Results: Subjects generated forces ranging from 87 to 538 N. Of the 23 subjects, 12 generated insufficient maximum cable force to operate 8 of the 10 body-powered prostheses fatigue free. Discomfort or pain did not correlate with the magnitude of maximum force achieved by the subjects. Nine subjects indicated discomfort or pain. No relationships between anthropometry and maximal forces were found except for maximum cable forces and the affected upper-arm circumference for females. Conclusion: For a majority of subjects, the maximal cable force was lower than acceptable for fatigue-free prosthesis use. Discomfort or pain occurred in ~40% of the subjects, suggesting a suboptimal force transmission mechanism. Clinical relevance The physical strength of users determines whether a body-powered prosthesis is suitable for comfortable, fatigue-free long-duration use on a daily basis. High cable operation forces can provoke discomfort and pain for some users, mainly in the armpit. Prediction of the users’ strength by anthropometric measures might assist the choice of a suitable prosthesis.

2019 ◽  
Author(s):  
Christoph Julian von Borell ◽  
Tobias L. Kordsmeyer ◽  
Tanja M. Gerlach ◽  
Lars Penke

The theory of facultative calibration, which explains personality differences as responses to variation in other phenotypic traits of individuals, received mixed results throughout the last years. Whereas there is strong evidence that individual differences in human behavior are correlated with the self-perception of other traits, it still needs to be questioned whether they are also adjusted to objective differences in body condition (i.e. formidability). In two independent studies (N1 = 119 men and 124 women, N2= 165 men) we tested hypotheses of facultative personality calibration in an integrative way, assessing various outcomes of previous studies in the same samples (including Anger Proneness, Extraversion, Neuroticism, Narcissism, Shyness, Vengefulness, and Sociosexual Orientation). Formidability was derived from assessments of physical strength and various anthropometric measures from full-body 3D scans and paired with measures of self-perceived and other-rated physical attractiveness (based on rotating morphometric 3D body models and facial photographs). We could replicate positive correlations with self-perceived attractiveness across outcomes, though these were not corroborated by more objective assessments of attractiveness: an effect of other-rated attractiveness was clearly not supported in our results for either sex, regardless of the personality outcome. Anthropometric measures and physical strength were also largely unrelated to personality, with the exception of Extraversion, Utility of Personal Aggression, and Sociosexual Orientation. While the two samples differed in their results for domain-level Extraversion, at least the Extraversion facets Activity and Assertiveness were related to strength and masculinity in men. For Sociosexual Orientation the results of our two samples varied more substantially, a positive association was only present in Study 2. Future studies need to clarify whether formidability, potentially an indicator of genetic quality for males, enhances their orientation and success in short-term mating. Furthermore we propose longitudinal twin-difference studies as means to evaluate the theory of personality recalibration in a more controlled manner.


2020 ◽  
Vol 9 (2) ◽  
pp. 635-643
Author(s):  
Setiawandari - Setiawandari

Massage stimulation is a traditional therapy of the Indonesian, which combines auditory, visual and tactile kinesthetic stimuli, which can be given from early to unlimited age.  Massage stimulation for preschoolers in addition to relaxing the child is also reducing stress, increasing immunity, stimulating the vagus nerve, also increasing growth by stimulating cell growth. This research aims to determine the effect of massage stimulation on the anthropometric size of preschoolers. This research method uses Randomized Controlled Trial. The results obtained a significant value of p = 0,000 or p <0.05 in the treatment group, but in the two control groups there was no difference in anthropometric measurements of height and head circumference p> 0.05. In conclusion, there was the effect of massage stimulation on body weight, height, upper arm circumference and head circumference. But the height and head circumference were not found differences in the two groups. 


2014 ◽  
Vol 587-589 ◽  
pp. 1364-1369
Author(s):  
Cheng Wu ◽  
Jin Yu Liu ◽  
Shui Xing Zhou

Taking the bare arch deformation under gravity as target alignment, the influence matrix that associates the cable forces with segment deformation is obtained via ANSYS program, and the cable force is quickly calculated by MATLAB quadratic programming toolbox. It is illustrated with an example of Guizhou Zong-xi River Bridge, which is a 360-meter concrete filled steel tube bridge in construction, and the calculation process is given. The results show that, this new method has the advantages of high precision and less number of iterations.


2011 ◽  
Vol 378-379 ◽  
pp. 341-344
Author(s):  
Wei Feng Tian ◽  
Shui Xing Zhou ◽  
Ayad Thabet Saeed Alghabsha

Calculation of cable force under seasonal ambient temperature is the key and difficult problem in the construction of long-span rib arch bridge. It affects the final cable forces and deformations of arch rib after arch closure. Unstressed state control method is introduced in the construction of Daning River Bridge; unstressed qualities of ribs and unstressed length of cables can be obtained by optimization analysis of the maximum cantilever state in construction. According to unstressed state control method, the cable forces of each segment were calculated using the forward-iteration method. These results offer the basis for construction control, and guarantee the arch rib line and cable forces to meet the design requirements, and an arch closure with high precision.


1998 ◽  
Vol 12 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Kassam Mahomed ◽  
Michelle A. Williams ◽  
Godfrey B. Woelk ◽  
Laura Jenkins‐Woelk ◽  
Sarah Mudzamiri ◽  
...  

2009 ◽  
Vol 12 (11) ◽  
pp. 1974-1982 ◽  
Author(s):  
Michel Garenne ◽  
Douladel Willie ◽  
Bernard Maire ◽  
Olivier Fontaine ◽  
Roger Eeckels ◽  
...  

AbstractObjectiveThe present study aimed to compare two situations of endemic malnutrition among <5-year-old African children and to estimate the incidence, the duration and the case fatality of severe wasting episodes.DesignSecondary analysis of longitudinal studies, conducted several years ago, which allowed incidence and duration to be calculated from transition rates. The first site was Niakhar in Senegal, an area under demographic surveillance, where we followed a cohort of children in 1983–5. The second site was Bwamanda in the Democratic Republic of Congo, where we followed a cohort of children in 1989–92. Both studies enrolled about 5000 children, who were followed by routine visits and systematic anthropometric assessment, every 6 months in the first case and every 3 months in the second case.ResultsNiakhar had less stunting, more wasting and higher death rates than Bwamanda. Differences in cause-specific mortality included more diarrhoeal diseases, more marasmus, but less malaria and severe anaemia in Niakhar. Severe wasting had a higher incidence, a higher prevalence and a more marked age profile in Niakhar. However, despite the differences, the estimated mean durations of episodes of severe wasting, calculated by multi-state life table, were similar in the two studies (7·5 months). Noteworthy were the differences in the prevalence and incidence of severe wasting depending on the anthropometric indicator (weight-for-height Z-score ≤–3.0 or mid upper-arm circumference <110 mm) and the reference system (National Center for Health Statistics 1977, Centers for Disease Control and Prevention 2000 or Multicentre Growth Reference Study 2006).ConclusionsSevere wasting appeared as one of the leading cause of death among under-fives: it had a high incidence (about 2 % per child-semester), long duration of episodes and high case fatality rates (6 to 12 %).


2020 ◽  
pp. 1-10
Author(s):  
Laura Moore ◽  
Sinead O’Mahony ◽  
Mark Shevlin ◽  
Philip Hyland ◽  
Hatty Barthorp ◽  
...  

Abstract Objectives: To determine (i) whether distinct groups of infants under 6 months old (U6M) were identifiable as malnourished based on anthropometric measures and if so to determine the probability of admittance to GOAL Ethiopia’s Management of At Risk Mothers and Infants (MAMI) programme based on group membership; (ii) whether there were discrepancies in admission using recognised anthropometric criteria, compared with group membership and (iii) the barriers and potential solutions to identifying malnutrition within U6M. Design: Mixed-methods approaches were used, whereby data collected by GOAL Ethiopia underwent: factor mixture modelling, χ2 analysis and logistic regression analysis. Qualitative analysis was performed through coding of key informant interviews. Setting: Data were collected in two refugee camps in Ethiopia. Key informant interviews were conducted remotely with international MAMI programmers and nutrition experts. Participants: Participants were 3444 South-Sudanese U6M and eleven key informants experienced in MAMI programming. Results: Well-nourished and malnourished groups were identified, with notable discrepancies between group membership and MAMI programme admittance. Despite weight for age z-scores (WAZ) emerging as the most discriminant measure to identify malnutrition, admittance was most strongly associated with mid-upper arm circumference (MUAC). Misconceptions surrounding malnutrition, a dearth of evidence and issues with the current identification protocol emerged as barriers to identifying malnutrition among U6M. Conclusions: Our model suggests that WAZ is the most discriminating anthropometric measure for malnutrition in this population. However, the challenges of using WAZ should be weighed up against the more scalable, but potentially overly sensitive and less accurate use of MUAC among U6M.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Yan-feng Li ◽  
Xing-long Sun ◽  
Long-sheng Bao

A model test and finite element analysis were conducted in this study to determine the distribution law of shear lag effect in the main beam section, a box girder, during the cable-stayed bridge construction process. The experimental and theoretical results were compared in an example of loading the control section. The stress value of the cable tension area of the main beam upper edge was found to markedly change when tensiling the cable force and was accompanied by prominent shear lag effect. After a hanging basket load was applied, the main beam of certain sections showed alternating positive and negative shear lag characteristics. The shear lag distribution law in the box girder of the single-cable-plane prestressed concrete cable-stayed bridge along the longitudinal direction was determined in order to observe the stress distribution of the girder. The results show that finite element analysis of the plane bar system should be conducted at different positions in the bridge under construction; the calculated shear lag coefficient of the cable force acting at the cable end of the cantilever reflects the actual force. In the beam segments between the cable forces, the shear lag coefficient determined by the ratio of the bending moment to the axial force reflects the actual stress at the cable force action point. In the midspan beam section between the action points of cable forces, the shear lag coefficient of the bending moment reflects the actual stress. The section shear lag coefficient can be obtained by linear interpolation of the beam section between the cable action point and the middle of the span.


Author(s):  
Senhao Hou ◽  
Xiaoqiang Tang ◽  
Yuheng Wang ◽  
Dianjun Wang

Abstract During the landing and detection missions of the Moon, Mars, and asteroids, due to the complexity and unpredictability of the landing process, it is necessary and critical to carry out simulation tests on the ground to simulate the stress state during the separation of the backshell from the lander. A high-speed cable-driven mechanism adopted. The cable force is different at the end actuator and the drum. There are many factors causing this difference, such as high acceleration, cable stiffness, cable density, cable length. In this paper, the cable force transmission of spacecraft during high-speed separation is studied. The dynamic model of high-speed cable-driven mechanism is established based on Newton principle, then the trial function is introduced, and the second-order partial differential equation is solved by using the method of space discretization. The force relationship of the cable in the process of motion is obtained, and the influencing factors of the cable force are explored. Finally, the correctness of the research content in this paper is verified by numerical simulation and experiment. The results show that the model can accurately simulate the force state of the cable, and it has guiding significance for the active high-speed separation test of spacecraft.


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