scholarly journals Mechanisms to absorb load in amputee running

2012 ◽  
Vol 36 (3) ◽  
pp. 318-323 ◽  
Author(s):  
Siobhan C Strike ◽  
Oliver Wickett ◽  
Marlene Schoeman ◽  
Ceri E Diss
Keyword(s):  
Angular Displacement ◽  
Reaction Force ◽  
Population Based ◽  
Convenience Sample ◽  
Rigid Condition ◽  
Reaction Forces ◽  
Set Up ◽  
Transtibial Amputees ◽  
Work Done ◽  
Force Characteristics

Background: We aimed to determine if a shock absorbing pylon (SAP) influenced the ground reaction force characteristics and the shock absorbing mechanisms compared to a rigid pylon (Rigid) during the loading phase in running. Objectives: To determine if the SAP influences the mechanisms of loading compared to the Rigid condition. Study Design: A convenience sample of transtibial amputees participated in a laboratory-based study. The prosthetic set-up was randomly altered fd\sdsd. Methods: Five recreationally active male transtibial amputees age: 18–50 years; mean mass: 86.7 ± 17.5 kg; height: 1.77 ± 0.07 m) volunteered from a population-based sample. They completed a within-participant-designed study assessing a SAP and a Rigid condition during running. Kinematic and kinetic data were collected during two sessions following a one-week customization period. Results: Loading rate, peak vertical and horizontal ground reaction forces and the time to each measure along with knee and hip angular displacement, absorbing powers and work done between the SAP and Rigid conditions were not systematically affected by the prosthetic condition. Conclusions: The effect of the SAP was minimal and inconsistent in the loading phase, with only some amputees presenting higher and others with lower values for the tested variables. Clinical relevance The inclusion of a prosthetic shock absorber in the form of a SAP did not systematically alter the kinetic characteristics or shock absorbing mechanisms of the residual joints. It appears that the prescription of a SAP is not justified for these recreationally active amputees.

Some Gait Characteristics of Below-Knee Amputees and Their Reflection on the Ground Reaction Forces

1986 ◽  
Vol 15 (1) ◽  
pp. 27-34 ◽  
Author(s):  
R Seliktar ◽  
J Mizrahi
Keyword(s):  
Reaction Force ◽  
Kinetic Studies ◽  
Human Locomotion ◽  
Rate Of Change ◽  
Ground Reaction Forces ◽  
Test Results ◽  
Small Perturbations ◽  
Gait Characteristics ◽  
Reaction Forces ◽  
Force Characteristics

Human locomotion studies employing cinematography and force plates have been conducted during the last five decades with the goal of producing a clinically acceptable gait evaluation technique. The bulk of information contained in the kinetic studies was the major obstacle in achieving this goal. Our aim in this work was to explore the possibility of representing some locomotor abnormalities solely by their reflection on the ground reaction force characteristics. As a first stage towards the establishment of these relationships, the gait characteristics of below-knee amputees were examined. One hundred and thirty ground force test results as obtained on twenty three below-knee amputees were analysed. Different variables such as time durations of the various phases, peak forces, impulses, rate of change of the forces, and others, were examined. The conclusions suggest that some of these variables are suitable for evaluation of gait and some, such as small perturbations superimposed on the curve, may serve as indicators of specific malfunction of the prosthetic system.

Simulation Research of Top-Hung Mechanism for Open and Close

2014 ◽  
Vol 644-650 ◽  
pp. 416-420
Author(s):  
Xu Zhou ◽  
Ying Wu
Keyword(s):  
Simulation Analysis ◽  
Reaction Force ◽  
Three Dimensional ◽  
Revolute Joint ◽  
Initial Values ◽  
Support Reaction ◽  
Vertical Location ◽  
Optimization Parameters ◽  
Reaction Forces ◽  
Set Up

For the purpose of researching the top-hung mechanism for open and close and the improvement and use of the mechanism, improving the work efficiency, the three-dimensional solid model of the mechanism was established with ADAMS. Each part of the model in ADAMS was set up. Simulation analysis on the working process of the mechanism was achieved. The structure optimization parameters of the mechanism were obtained. The result proves that when the vertical location of the upper endpoint of lid was increased the total support reaction force acting on the lower endpoint of lower rocker by frame reduced. When the horizontal location of revolute joint of lower rocker and frame, the horizontal location of revolute joint of lower rocker and lid were increased the total support reaction forces acting on the lower endpoint of lower rocker by frame added. The sensitivities of the total support reaction forces acting on the lower endpoint of lower rocker by frame on the initial values of the locations of revolute joint of lower rocker and link, the horizontal location of revolute joint of lower rocker and frame are greater. The sensitivities of the total support reaction forces acting on the lower endpoint of lower rocker by frame on the initial values of the vertical location of revolute joint of upper rocker and link, the horizontal location of revolute joint of the lower rocker and lid are smaller. The sensitivity of the total support reaction force acting on the lower endpoint of lower rocker by frame on the initial value of the vertical location of the upper endpoint of lid are least.

scholarly journals Running ground reaction forces across footwear conditions are predicted from the motion of two body mass components

2019 ◽  
Vol 126 (5) ◽  
pp. 1315-1325 ◽  
Author(s):  
Andrew B. Udofa ◽  
Kenneth P. Clark ◽  
Laurence J. Ryan ◽  
Peter G. Weyand
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Time Patterns ◽  
Foot Strike ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Force Time

Although running shoes alter foot-ground reaction forces, particularly during impact, how they do so is incompletely understood. Here, we hypothesized that footwear effects on running ground reaction force-time patterns can be accurately predicted from the motion of two components of the body’s mass (mb): the contacting lower-limb (m1 = 0.08mb) and the remainder (m2 = 0.92mb). Simultaneous motion and vertical ground reaction force-time data were acquired at 1,000 Hz from eight uninstructed subjects running on a force-instrumented treadmill at 4.0 and 7.0 m/s under four footwear conditions: barefoot, minimal sole, thin sole, and thick sole. Vertical ground reaction force-time patterns were generated from the two-mass model using body mass and footfall-specific measures of contact time, aerial time, and lower-limb impact deceleration. Model force-time patterns generated using the empirical inputs acquired for each footfall matched the measured patterns closely across the four footwear conditions at both protocol speeds ( r2 = 0.96 ± 0.004; root mean squared error  = 0.17 ± 0.01 body-weight units; n = 275 total footfalls). Foot landing angles (θF) were inversely related to footwear thickness; more positive or plantar-flexed landing angles coincided with longer-impact durations and force-time patterns lacking distinct rising-edge force peaks. Our results support three conclusions: 1) running ground reaction force-time patterns across footwear conditions can be accurately predicted using our two-mass, two-impulse model, 2) impact forces, regardless of foot strike mechanics, can be accurately quantified from lower-limb motion and a fixed anatomical mass (0.08mb), and 3) runners maintain similar loading rates (ΔFvertical/Δtime) across footwear conditions by altering foot strike angle to regulate the duration of impact. NEW & NOTEWORTHY Here, we validate a two-mass, two-impulse model of running vertical ground reaction forces across four footwear thickness conditions (barefoot, minimal, thin, thick). Our model allows the impact portion of the impulse to be extracted from measured total ground reaction force-time patterns using motion data from the ankle. The gait adjustments observed across footwear conditions revealed that runners maintained similar loading rates across footwear conditions by altering foot strike angles to regulate the duration of impact.

scholarly journals APPLICATION OF DOMAIN INTEGRATED DESIGN METHODOLOGY FOR BIO-INSPIRED DESIGN- A CASE STUDY OF SUTURE PIN DESIGN

2021 ◽  
Vol 1 ◽  
pp. 487-496
Author(s):  
Pavan Tejaswi Velivela ◽  
Nikita Letov ◽  
Yuan Liu ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Cross Sections ◽  
Design Methodology ◽  
Reaction Force ◽  
Integrated Design ◽  
Total Deformation ◽  
Insertion Force ◽  
Force Reaction ◽  
The Moment ◽  
Work Done

AbstractThis paper investigates the design and development of bio-inspired suture pins that would reduce the insertion force and thereby reducing the pain in the patients. Inspired by kingfisher's beak and porcupine quills, the conceptual design of the suture pin is developed by using a unique ideation methodology that is proposed in this research. The methodology is named as Domain Integrated Design, which involves in classifying bio-inspired structures into various domains. There is little work done on such bio-inspired multifunctional aspect. In this research we have categorized the vast biological functionalities into domains namely, cellular structures, shapes, cross-sections, and surfaces. Multi-functional bio-inspired structures are designed by combining different domains. In this research, the hypothesis is verified by simulating the total deformation of tissue and the needle at the moment of puncture. The results show that the bio-inspired suture pin has a low deformation on the tissue at higher velocities at the puncture point and low deformation in its own structure when an axial force (reaction force) is applied to its tip. This makes the design stiff and thus require less force of insertion.

scholarly journals On Examining the Quality of Spanish Translation in Telephone Surveys: A Novel Test-Retest Approach

2019 ◽  
Vol 8 (4) ◽  
pp. 691-705
Author(s):  
Robert P Agans ◽  
Quirina M Vallejos ◽  
Thad S Benefield
Keyword(s):  
Past Research ◽  
Population Based ◽  
Pilot Test ◽  
Spanish Translation ◽  
Convenience Sample ◽  
Single Item ◽  
Telephone Surveys ◽  
Survey Questions ◽  
Health Related

Abstract Past research has shown that commonly reported cultural group disparities in health-related indices may be attributable to culturally mediated differences in the interpretation of translated survey questions and response scales. This problem may be exacerbated when administering single-item survey questions, which typically lack the reliability seen in multi-item scales. We adapt the test-retest approach for single-item survey questions that have been translated from English into Spanish and demonstrate how to use this approach as a quick and efficient pilot test before fielding a major survey. Three retest conditions were implemented (English-Spanish, Spanish-English, and English-English) on a convenience sample (n = 109) of Latinos and non-Latinos where translated items were compared against an English-English condition that served as our control. Several items were flagged for investigation using this approach. Discussion centers on the utility of this approach for evaluating the Spanish translation of single-item questions in population-based surveys.

scholarly journals Pre-Existing Inequality: The Impact of COVID-19 on Medicare Home Health Beneficiaries

2021 ◽  
Vol 33 (2) ◽  
pp. 130-136
Author(s):  
William Cabin
Keyword(s):  
Mental Health ◽  
New York ◽  
Home Care ◽  
Population Based ◽  
Home Health ◽  
Physical And Mental Health ◽  
Convenience Sample ◽  
Medicare Population ◽  
Home Health Agencies ◽  
The Impact

There is significant data on the adverse impact of COVID-19 on persons who were poor, minorities, had compromised physical or mental health, or other vulnerabilities prior to the COVID-19 pandemic. A significant portion of the overall Medicare population has such vulnerabilities. The Medicare home health beneficiary population is even more vulnerable than the overall Medicare population based on gender, race, income level, living alone status, and number of chronic conditions. A literature review indicates there is only 1 study on the impact of COVID-19 in Medicare home health on home care workers and none on the impact on home health beneficiaries. The current study is a qualitative study based on interviews of a convenience sample of 48 home care nurses from 9 different home health agencies in New York City between April 1 and August 31, 2020. Six major themes emerged: need for social service supports increased; loneliness and depression increased among patients; physical and mental health conditions became exacerbated; substance use and abuse increased; evidence of domestic violence against patients increased; and there was a limited amount of staff and equipment to care for patients.

scholarly journals Factors Influencing SARS-CoV-2 Vaccine Acceptance and Hesitancy in a Population-Based Sample in Italy

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 633
Author(s):  
Marco Del Riccio ◽  
Sara Boccalini ◽  
Lisa Rigon ◽  
Massimiliano Alberto Biamonte ◽  
Giuseppe Albora ◽  
...  
Keyword(s):  
Online Survey ◽  
Adult Population ◽  
Herd Immunity ◽  
Population Based ◽  
Vaccine Hesitancy ◽  
Convenience Sample ◽  
Major Barrier ◽  
Trust In Institutions ◽  
General Adult Population ◽  
High Level

Vaccination against SARS-CoV-2 represents an effective and safe tool to protect the population against the disease; however, COVID-19 vaccine hesitancy could be a major barrier to achieving herd immunity. Despite the severity of the current pandemic, the population’s intention to get vaccinated against COVID-19 is still not clear. The aim of this study was to evaluate the intention to get vaccinated against COVID-19 among a convenience sample of the general population resident in Italy and the factors associated with hesitancy and acceptance of the vaccine in the context of the current pandemic before the rolling out of COVID-19 vaccines. An anonymous online survey was diffused among a general adult population living in Italy. Participants aged 18 or older and living in Italy were considered eligible. Incomplete questionnaires were excluded. Overall, 7605 valid questionnaires were collected. Most of the participants (81.9%) were inclined to get vaccinated; male sex (OR 1.38, 95% CI 1.12–1.71), a high level of trust in institutions (OR 3.93, 95% CI 2.04–7.83), and personal beliefs about high safety of COVID-19 vaccines (OR 56.33, 95% CI 31.57–105.87) were found to be among the significant predictors of COVID-19 acceptance. These data could help design larger studies to address the problem of COVID-19 vaccine hesitancy in the current pandemic.

scholarly journals Ground Reaction Forces and Kinematics of Ski Jump Landing Using Wearable Sensors

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2011 ◽  
Author(s):  
Bessone ◽  
Petrat ◽  
Schwirtz
Keyword(s):  
Wearable Sensors ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Inertial Motion ◽  
Jump Landing ◽  
The Past ◽  
Landing Biomechanics ◽  
Reaction Forces ◽  
The Hill ◽  
Kinematics And Kinetics

In the past, technological issues limited research focused on ski jump landing. Today, thanks to the development of wearable sensors, it is possible to analyze the biomechanics of athletes without interfering with their movements. The aims of this study were twofold. Firstly, the quantification of the kinetic magnitude during landing is performed using wireless force insoles while 22 athletes jumped during summer training on the hill. In the second part, the insoles were combined with inertial motion units (IMUs) to determine the possible correlation between kinematics and kinetics during landing. The maximal normal ground reaction force (GRFmax) ranged between 1.1 and 5.3 body weight per foot independently when landing using the telemark or parallel leg technique. The GRFmax and impulse were correlated with flying time (p < 0.001). The hip flexions/extensions and the knee and hip rotations of the telemark front leg correlated with GRFmax (r = 0.689, p = 0.040; r = −0.670, p = 0.048; r = 0.820, p = 0.007; respectively). The force insoles and their combination with IMUs resulted in promising setups to analyze landing biomechanics and to provide in-field feedback to the athletes, being quick to place and light, without limiting movement.

Transducer-based comparisons of the prosthetic feet used by transtibial amputees for different walking activities: a pilot study

2012 ◽  
Vol 36 (2) ◽  
pp. 203-216 ◽  
Author(s):  
Edward Schreiber Neumann ◽  
Kartheek Yalamanchili ◽  
Justin Brink ◽  
Joon S Lee
Keyword(s):  
Clinical Decision Making ◽  
Research Question ◽  
Case Series ◽  
Clinical Decision ◽  
Residual Limb ◽  
Convenience Sample ◽  
Loading Patterns ◽  
Prosthetic Feet ◽  
Transtibial Amputees ◽  
Resultant Forces

Background: Knowledge of transtibial residual limb force and moment loading during gait can be clinically useful. The research question was whether a transducer attached between the socket and pylon can be used to detect differences in loading patterns created by prosthetic feet of different design and different walking activities in real-world environments outside the gait lab. Objectives: To develop methods for obtaining, processing, analyzing and interpreting transducer measurements and examining their clinical usefulness. Study Design: Case series design. Methods: A convenience sample of four K3-K4 transtibial amputees and a wireless tri-axial transducer mounted distal to the socket. Activities included self-selected comfortable speed walking, and ascending and descending ramps and steps. Measurements taken about three orthogonal axes were processed to produce plots of normalized resultant force versus normalized resultant moment. Within-subject differences in peak resultant forces and moments were tested. Results: Loading patterns between feet and subjects and among the activities were distinctly different. Optimal loading of peak resultant forces tentatively might occur around 25% and 69% to73% of stance during self-selected comfortable walking. Ascending and descending ramps is useful for examining heel and forefoot response. Conclusions: Force-moment plots obtained from transducer data may assist clinical decision making. Clinical relevance A pylon-mounted transducer distal to the socket reveals the moments and forces transmitted to the residual limb and can be used to evaluate the loading patterns on the residual limb associated with different foot designs and different everyday activities outside the gait lab.

Development of Foot Structure for Humanoid Robot Using Topology Optimization

2018 ◽  
Vol 29 ◽  
pp. 34-45
Author(s):  
Van Tinh Nguyen ◽  
Daichi Kiuchi ◽  
Hiroshi Hasegawa
Keyword(s):  
Topology Optimization ◽  
Humanoid Robot ◽  
Differential Evolution Algorithm ◽  
Optimization Method ◽  
Gait Pattern ◽  
Surface Model ◽  
Foot Structure ◽  
Adaptive Differential Evolution ◽  
Reaction Forces ◽  
Set Up

This paper addresses the development of a foot structure for 22-Degree of Freedom (DoF) humanoid robot. The goal of this research is to reduce the weight of the foot and enable the robot to walk steadily. The proposed foot structure is based on the consideration of cases where the ground reaction forces are set up in different situations. The optimal foot structure is a combination of all the topology optimization results. Additionally, a gait pattern is generated by an approximated optimization method based on Response Surface Model (RSM) and Improved Self-Adaptive Differential Evolution Algorithm (ISADE). The result is validated through dynamic simulation by a commercially available software called Adams (MSC software, USA) with the humanoid robot named KHR-3HV belonging to Kondo Kagaku company.

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