Browse Topic: Foot

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Biofidelity of THOR 5th Percentile Female ATD in Ankle Eversion and Inversion2020-01-05284/14/2020
Females have higher frequency and risk of foot and ankle injuries in motor vehicle collisions than similar-sized males. Therefore, lower extremity biofidelity and accurate injury prediction of female ATDs is critical. This paper aims to compare the THOR 5th percentile female (THOR-05F) anthropomorphic test device (ATD) response with male and female PMHS data of various sizes under ankle inversion and eversion. The THOR-05F lower extremity was subjected to dynamic inversion and eversion ankle loading with a constant 2000N axial force applied through the tibia. Twelve THOR-05F tests (3 inversion and 3 eversion on both, left and right legs) were performed with boundary conditions consistent with previous post-mortem human subject (PMHS) lower extremity tests. The biofidelity of THOR-05F ankle stiffness was evaluated via comparison of measured and equal-stress equal-velocity scaled data (using mass-based scale factors) from previous PMHS datasets with mid-size males, small females and larger females. THOR-05F ankle moment-angle response falls within the range of previous mid-sized male and larger female PMHS test data for eversion, when scaled to a small female. However, when compared to PMHS response measured on small female subjects, the THOR-05F response was less stiff in both inversion and eversion. The THOR-05F moments were 65% and 90% less stiff in eversion and inversion respectively, when compared to the average of the measured small female PMHS dataset at 250 ankle rotation. Because ATD stiffness differs from measured PMHS ankle stiffness, care should be taken when applying PMHS-based injury risk functions (IRF) to the THOR-05F ankle.
Kulkarni, Shubham, Roberts, Carolyn, Foltz, Patrick, Forman, Jason
Unpowered, Lightweight Ankle ExoskeletonTBMG-3571712/1/2019
A lightweight, low-profile, inexpensive ankle exoskeleton could be widely used among elderly people, those with impaired lower-leg muscle strength, and workers whose jobs require substantial walking or running.
Biologically Inspired Artificial Skin Improves Sensory Ability of RobotsTBMG-3561112/1/2019
Inspired by human skin, a system was developed that combines artificial skin with control algorithms. The system was used to create the first autonomous humanoid robot with full-body artificial skin.
Engineers Develop More Stable, Efficient Prosthetic FootTBMG-348057/1/2019
Engineers have developed a more stable prosthetic leg — and a better way of designing them — that could make challenging terrain more manageable for people who have lost a lower leg. The cornerstone of the new design is a kind of tripod foot that responds to rough terrain by actively shifting pressure between three different contact points. As important as the foot is, the team also developed a tool for quickly emulating and improving their prototypes.
Residual Injury Situation and Accident Characteristics of Severe Motorcycle Accidents2019-01-06384/2/2019
The total number of persons severely and fatally injured in road traffic accidents has reduced considerably in recent decades. However, the number of motorcyclists involved in accidents has not reduced to the same extent, and some countries have even recorded an increase. The aim of this study is to analyse the circumstances of motorcycle accidents in Germany involving vehicles with a cubic capacity of over 125 cm3 with particular reference to severely or fatally injured riders. An analysis is to be made of the characteristics and patterns of injuries suffered by the most severely injured motorcyclists and proposals developed for injury prevention. The study included accident data from 464 motorcycle accidents collected in Hanover and Dresden between 2010 and 2015 by an academic research team in the course of the GIDAS project (German In-Depth Accident Study). This data represents a statistically representative sample from real accidents occurring in Germany. The analysis of the current injury situation shows that motorcyclists are often severely injured, i.e. suffered injuries of grade MAIS 3+ (so called serious injuries) in 16.9% of cases and thus around 9 times more frequently than car occupants. Motorcyclists wearing helmets suffered head injuries in approx. 20 % of cases. The serious injuries sustained were in particular skull fractures, including base of the skull and traumatic brain injuries are rare. Severe thoracic injuries included in particular rib and shoulder/clavicle fractures, often accompanied by injuries to internal organs. In terms of spinal injuries, the most common serious injuries were fractures of the thoracic spine, followed by fractures of the lumbar spine and cervical spine. In the abdominal area there were often severe injuries in the form of fractures in the pelvic area and accompanying injuries to internal organs. Arm injuries included, besides minor injuries (grazes, bruises, etc.), most commonly fractures of the hands/fingers and forearms, followed by elbow and upper arm fractures. Leg injuries seen in particular were femoral fractures as well as injuries to the muscles and tendons around the knee, also fractures of the shin and calf bones. Around the feet there were many fractures and dislocations of the wrist and ankle joints, as well as toes. The causes of the injuries, which were recorded in detail in the study for the various regions of the body and individual injuries, were most often caused by impact with the road and collision with objects and solid vehicle structural elements of cars and trucks. Serious injuries are linked with high energy respectively high relative impact speed.
Otte, Dietmar
Finger Support Could Help Regain Motor FunctionTBMG-339903/1/2019
A Kennesaw State University engineering professor and her team of students have developed a new finger support that could ultimately help those suffering from finger deformities regain motor function.
Orthopedic Replacement Implants Market: Drivers and DevelopmentsTBMG-324568/1/2018
The global market for minor orthopedic replacement implants exceeded $1.5 billion in 2017. Analysts from The Business Research Company forecast the market value to grow at a rate of over 7 percent and to reach $2.2 billion in 2021 in their report “Minor Orthopedic Replacement Implants.”1 According to the report, the primary reason for this growth is the high incidence of arthritis and fractures. Osteoarthritis and rheumatoid arthritis are the major causes for joint replacement surgery, including minor orthopedic joints. The other cause for joint replacement surgery is failed previous joint replacement surgery. This article examines the trends that are driving this market, including a look at materials, regions, procedures, and regulatory developments that are shaping the future of orthopedic implants.
Effect of Driver Posture on Driving Characteristics when Control is Passed from an Autonomous Driving System to a Human Driver2018-01-11734/3/2018
SAE International defines six levels of autonomous driving system, four of which include a change of control from the system to the driver in certain conditions. When vehicle control changes from the system to a human driver, a safe transition time is necessary. The present study focuses on level 3 automation, in which the system controls driving in ordinary conditions, but the human driver is expected to intervene in emergency situations. The aim of this study was to investigate the relationship between driver posture and transition time. Driver posture included four components: backrest angle, seat position, foot position, and arm position. These were adjusted to investigate a total of 30 posture patterns. In addition, the situation in which the driver was not watching the road, but instead using a tablet computer was investigated. The driver’s braking and steering reaction times were measured for a highway-driving scenario in which a truck dropped cargo in front of the vehicle. Acoustic and optical warnings were presented to the driver when the autonomous driving system was disengaging. The results showed that the driver’s foot position most strongly affected braking reaction time. The driver resting their chin on their hands most strongly affected steering reaction time. This research clarified the effect of relaxed driver posture on reaction time and, thus, transition time.
Suzuki, Kensuke, Gokan, Masato, Oikawa, Shoko, Matsui, Yasuhiro, Hirose, Toshiya
Foot Device Controls Video Game ActionTBMG-251517/28/2016
A group of graduate students from Johns Hopkins University, Baltimore, MD, devised a sandal-like controller that allows a video game player to control the on-screen action with his feet. The team — dubbed GEAR, for Game Enhancing Augmented Reality — created the device for amputees or those with disabilities that inhibit use of their arms or hands.
Students Design Prosthetic Fit for High HeelsTBMG-248746/26/2016
A team of Johns Hopkins University students, working with a Johns Hopkins physician and outside experts, has designed a prosthetic fit for high heels. The "Prominence" foot adapts to popular fashion for heels up to four inches high.
Low-Cost Prosthetic Knee Mimics Walking MotionTBMG-226958/4/2015
Researchers at the Massachusetts Institute of Technology designed a low-cost prosthetic knee that mimics normal walking motion. The MIT team's prototype generates a torque profile similar to that of able-bodied knees, using only simple mechanical elements like springs and dampers. The team is testing the prosthetic knee in India, an area with approximately 230,000 above-knee amputees.
An Improved Human Biodynamic Model Considering the Interaction between Feet and Ground2015-01-06124/14/2015
Nowadays, studying the human body response in a seated position has attracted a lot of attention as environmental vibrations are transferred to the human body through floor and seat. This research has constructed a multi-body biodynamic human model with 17 degrees of freedom (DOF), including the backrest support and the interaction between feet and ground. Three types of human biodynamic models are taken into consideration: the first model doesn't include the interaction between the feet and floor, the second considers the feet and floor interaction by using a high stiffness spring, the third one includes the interaction by using a soft spring. Based on the whole vehicle model, the excitation to human body through feet and back can be obtained by ride simulation. The simulation results indicate that the interaction between feet and ground exerts non-negligible effect upon the performance of the whole body vibration by comparing the three cases.
Zhang, Weiguo, Ma, Zeyu, Jin, Ankang, Yang, James, Zhang, Yunqing
Microprocessor-Controlled Prostheses Are a Step in the Right DirectionTBMG-218294/1/2015
It’s not always easy to walk in someone else’s shoes. It’s even more difficult if those shoes belong to a person with an artificial leg. However, that’s exactly what a group of scientists, engineers, and clinicians at Orthocare Innovations are doing to help engineer prostheses that respond better to the physical needs of amputees.
User's Manual for the Small Adult Female Hybrid III Test DummyJ2862_201502 (Historical)2/3/2015
This user’s manual covers the small adult female Hybrid III test dummy. It is intended for technicians who work with this device. It covers the construction and clothing, disassembly and reassembly, available instrumentation, external dimensions and segment masses, as well as certification and inspection test procedures. It includes instructions for safe handling of the instrumented dummy, repairing dummy flesh, and adjusting the joints throughout the dummy.
Dummy Testing and Equipment Committee
2014 Create the Future Design: Consumer Products Category WinnerTBMG-2098411/1/2014
Michael Zach, Anirudha Sumant, and Jonathan Moritz EChem Nanowires Stevens Point, WI
Heavy-Duty Vehicle Rear-View Camera Systems2014-01-23819/30/2014
Transport Canada, through its ecoTECHNOLOGY for Vehicles program, retained the services of the National Research Council Canada to undertake a test program to examine the operational and human factors considerations concerning the removal of the side mirrors on a Class 8 tractor equipped with a 53 foot dry van semi-trailer. Full scale aerodynamic testing was performed in a 2 m by 3 m wind tunnel on a system component basis to quantify the possible fuel savings associated with the removal of the side mirrors. The mirrors on a Volvo VN780 tractor were removed and replaced with a prototype camera-based indirect vision system consisting of four cameras mounted in the front fender location; two cameras on either side of the vehicle. Four monitors mounted in the vehicle - two mounted on the right A-pillar and two mounted on the left A-pillar - provided indirect vision information to the vehicle operator. Four commercial drivers were asked to perform a series of tests simulating typical driving scenarios on a closed course test track. The tests included an object identification test, a blind spot comparison test, a coupling and uncoupling test, a quasi-static lane change test, a dynamic lane change test and an evasive manoeuvres test. The tests were performed both with the mirrors and with the camera-based indirect vision system. The results of the study provide an analysis of driver performance while using the mirrors in comparison to driver performance while using the camera-based indirect vision system. Driver acceptance of the camera-based indirect vision system was also analyzed through the use of questionnaires.
McWha, Tyson
Bio-Inspired Robotic Rehabilitation DeviceTBMG-190121/27/2014
A soft, wearable device that mimics the muscles, tendons, and ligaments of the lower leg could aid in the rehabilitation of patients with foot-ankle disorders such as drop foot, said Yong-Lae Park, an assistant professor of robotics at Carnegie Mellon University, Pittsburgh, PA.
Treatment for Space Atrophy Finding Application on EarthTBMG-172799/1/2013
The lack of gravity in space reduces the mechanical loading seen by both the muscles and bones of the body, especially those related to standing and moving. The body adapts to reduced loading by losing bone mass and muscle mass. In long-duration space flights this leads to “disuse atrophy,” and an astronaut may lose up to 20% of their bone mass in one year in space. A countermeasure therapy using passive vibration for neuromusculoskeletal stimulation was originally designed by Jeff Leismer, PhD, founder and CTO, VibeTech, Inc., Sheboygan, WI, to enable longer space flights by reducing atrophy.
Operator Controls on Industrial EquipmentJ297_201307 (Current)7/9/2013
This SAE Standard is intended to improve operator efficiency and convenience by providing guidelines for the uniformity of location and direction of motion of operator controls used on industrial wheeled equipment. The controls covered are those centrally located at the operator's normal position.
HFTC1, Controls, Visibility, Anthropometrics, Accessibility
Hybrid III 50 th Dummy Ankle Performance Study and Proposed Design Modification2013-01-06644/8/2013
The Hybrid III 50th male dummy[1] is used globally in vehicle safety for measuring the damage index of dummy components. This paper focuses on the dummy's ankle structures which have a great effect on its tibia index (TI). It is found that the ankle shaft can be damaged during the regular EURO and China NCAP[2] [3] front offset deformable barrier (ODB) test, which affects the accuracy of TI and the corresponding evaluation score. This paper studies the ankle structure and the component material properties and proposes a design modification to prevent damage to the ankle shaft.
Li, Lihua, Zhao, Youmei, Shen, Guangyong
Navigation Aids Enhance Foot Control UsabilityTBMG-156972/1/2013
The ever-increasing functional capabilities of emerging medical de vices have precipitated new requirements for the multi-function foot controls used to operate the equipment. These foot controls typically consist of multiple actuators, one for each required control function.
Equivalent Temperature - Truck and BusJ2234_201211 (Current)11/9/2012
The scope of this SAE Information Report is to: a Define the Equivalent temperature. b Describe how it can be used to evaluate the performance of a heating and/or air-conditioning system in a vehicle. c Describe how it can be measured.
Truck and Bus Windshield Wipers and Climate Control Comm
Medical Category WinnerTBMG-1511511/1/2012
The Medical winner was simply named Prosthetic Leg Connector. Its simplistic name belies the amount of thought and care that went into the creation of a device to replace the traditional silicone rubber “sock” that is pulled very snugly over a residual limb before attaching an artificial leg.
User's Manual for the Hybrid III Large Male Test DummyJ2860_201209 (Historical)9/27/2012
This SAE Surface Vehicle Information Report identifies and defines the assembly/disassembly and certification procedures relating to the use of the Hybrid III Large Male Test Dummy.
Dummy Testing and Equipment Committee
Improving Balance Function Using Low Levels of Electrical Stimulation of the Balance OrgansTBMG-146189/1/2012
Crewmembers returning from long duration space flight face significant challenges due to the microgravity induced inappropriate adaptations in balance/sensorimotor function. The Neuroscience Laboratory at JSC is developing a method based on stochastic resonance to enhance the brain’s ability to detect signals from the balance organs of the inner ear and use them for rapid improvement in balance skill, especially when combined with balance training exercises. This method involves a stimulus delivery system that is wearable/ portable providing imperceptible electrical stimulation to the balance organs of the human body.
External Cooling Coupled to Reduced Extremity Pressure DeviceTBMG-1136710/1/2011
Although suited astronauts are currently cooled with a Liquid Cooled Ventilation Garment (LCVG), which can remove up to 85 percent of body heat, their effectiveness is limited because cooling must penetrate layers of skin, muscle, fat, bone, and tissue to reach the bloodstream, where its effect is prominent. Vasoconstriction further reduces the effectiveness by limiting arterial flow when exposed to cold (the frostbite response), resulting in a time constant on the order of 20 minutes from application to maximum effect. This delay can be crucial in severe exposure to hypo- or hyper-thermic conditions, compromising homeostasis.
Orthotic Dynamically Adjusts to Changes in Foot Structure and MovementTBMG-81397/1/2010
Kinesthotic© orthotics are made to adapt to the foot by replicating, within footwear, an explicit quality of beach-sand surface dynamics on whatever surface the footwear is used. The resulting support complies with the biomechanically sound and functional supportive principles and demands of each foot. The proprietary semi-fluid One-MinuteFit© molding composite is hermetically sealed within the Kinesthotic retaining envelope aligned on top of the pre-molded dynamic molding chassis.
Implants and Prosthetic Devices: Helping the Body Reach its Full PotentialTBMG-78625/1/2010
Medical technology is currently capable of treating such physical hardships as loss of limb, eyelid paralysis, and chronic osteoarthritis – but researchers are continually finding ways to improve upon the effectiveness of these and other implanted and prosthetic device technologies. What follows is a sample of new technologies and research efforts that hold promise for a future in which human beings are able not just to survive, but thrive in the face of any conceivable physical difficulty.
User's Manual for the 50th Percentile Male Hybrid III DummyJ2856_200909 (Historical)9/17/2009
The purpose of this document is to provide the user with the procedures needed to properly assemble and disassemble the 50th percentile male Hybrid III dummy, certify its components and verify its mass and dimensions. Also within this manual are guidelines for handling accelerometers, repairing flesh and setting joints.
Dummy Testing and Equipment Committee
Inverse Dynamic Reconstruction of Truck Cabin Ingress/Egress Motions2009-01-22866/9/2009
This paper investigates the feasibility of calculating joint forces and moments during a whole body truck cabin ingress/egress motion. For such a task, it is difficult to evaluate a future truck instep as the influences of the architecture parameters are complex over the motion and the discomfort feeling. In order to evaluate the future product at an early stage of the design process, Digital Human Models (DHMs) are interesting tools. However, most existing DHM simulation packages can only efficiently evaluate the kinematics of postures where the dynamics of the whole motion is necessary for such a task. The enhancement of DHMs towards a dynamic analysis and modeling is therefore necessary. In this study, the motions of subjects entering and exiting an adjustable truck cabin were measured by mean of an opto-electronic motion capture system and six load sensors. The joint angles were then calculated using an inverse kinematics method. And the joint loads were calculated using a classical Newton-Euler inverse dynamics method during the period when all the contact loads are measured. The comparison of the joint torques and forces at the spine L5/S1 joint calculated from the going up and going down methods show a good consistency and validate the moments and forces calculated at the other joints. In order to evaluate the joint loads when a sensor is missing, two methods are also presented, the first one making no assumption on the missing contact force, and the second one assuming that the center of pressure is known. The results show that more consistent joint loads were obtained using the method with assumption. These results validate the dynamic motion reconstruction method and open the way for a discomfort evaluation of truck cabin ingress/egress based on joint moments and forces.
Monnier, Gilles, Chateauroux, Elodie, Wang, Xuguang, Roybin, Christophe
Characterization of Foot Morphology through 3D Optical Measures2008-01-18806/17/2008
The aims of this work were: the definition of an experimental protocol for foot shape anthropometry characterization through advanced 3D scanning technologies; the assessment of the effects of load and position on foot morphology; the creation of a consistent database of both anatomical and standard shoemaking measures. 3D foot shapes from 89 subjects were captured by using a stereophotogrammetric scanning system. A set of dedicated measures were extracted from each individual foot in 5 different conditions in terms of lower limbs position and load. Results gave some interesting indications concerning foot morphology and suggested that position and load do not seem to deeply affect foot measures.
Preatoni, Ezio, Rodano, Renato, Squadrone, Roberto, Cazzola, Dario, Mazzola, Marco, Moroni, Giancarlo, Andreoni, Giuseppe, Pedotti, Antonio
Laser Scanning System Helps Validate Method for Repairing Space Shuttle Heat ShieldTBMG-14794/1/2007
SLP-330 Laser Scanning Probe Laser Design Minneapolis, MN 952-884-9648 www.laserdesign.com
Stationary Apparatus Would Apply Forces of Walking to FeetTBMG-29010/1/2006
A proposed apparatus would apply controlled cyclic forces to both feet for the purpose of preventing the loss of bone density in a human subject whose bones are not subjected daily to the mechanical loads of normal activity in normal Earth gravitation. The apparatus was conceived for use by astronauts on long missions in outer space; it could also be used by bedridden patients on Earth, including patients too weak to generate the necessary forces by their own efforts.
Strength and Balance Guided Posture Selection during a Battery Maintenance Task2006-01-06984/3/2006
Posture selection during standing exertions is a complex process involving tradeoffs between muscle strength and balance. Bodyweight utilization reduces the amount of upper-body strength required to perform a high force push/pull exertion but shifts the center-of-gravity towards the limits of the functional stability region. Thus balance constraints limit the extent to which bodyweight can be used to generate push/pull forces. This paper examines a two-handed sagittal plane pulling exertion performed during a battery maintenance task on a member of the family of medium-sized tactical vehicles (FMTV). Percent capable strength predictions and functional balance capabilities were determined for various two-handed pulling postures using the University of Michigan's 3D Static Strength Prediction Program (3DSSPP). Through this simulation study, preferred postures that minimize joint torques while maintaining balance were identified. Such preferred postures are important in redesigning the vehicle for improved maintenance.
Hoffman, Suzanne G., Chaffin, Don B., Wagner, David W.
Ankle Skeletal Injury Predictions Using Anisotropic Inelastic Constitutive Model of Cortical Bone Taking into Account Damage Evolution2005-22-000711/9/2005
The most severe ankle skeletal injury called pilon fractures can cause long term disability and impairment. Based on previous experimental studies, the pilon fractures are regarded as caused by a high-energy compressive force in the ankle joint and affected by a muscular tension force generated by emergency braking. However, quantitative injury criteria for the pilon fractures are still unknown. More accurate prediction of bone fractures in the distal tibia using a FE model of human lower leg can help us know the quantitative injury criteria. Therefore we newly proposed an anisotropic inelastic constitutive model of cortical bone including damage evolution and then implemented it to a FE code, LS-DYNA. The proposed model successfully reproduced most of anisotropy, strain rate dependency, and asymmetry of tension and compression on material and failure properties of human femoral cortical bone. However, the simplified model using an isotropic elasto-viscoplastic material, which has been used in previous studies, did not reproduce the characteristic features of the cortical bone. Two series of validation on axial impact cadaver tests for the foot and ankle indicate that the proposed model predicts the pilon fractures more accurately than the simplified model. Parametric studies on footwell impacts and pedal impacts for the foot using the proposed model show that the severity of the pilon fractures increases when the foot sustains normal and heel impacts with the impact velocity of 5 m/s and the pedal hits the forefoot with the impact velocity of 3 m/s regardless of the muscular tension force.
Iwamoto, Masami, Miki, Kazuo, Tanaka, Eiichi
Universal Horizontal Field Maintenance Stand for 10,000 pound Weight Class Propulsion Units (48 inch and 30 inch Rail Gage)ARP581A (Historical)10/28/2005
This recommended practice covers a rail concept stand that may be used for horizontal disassembly and reassembly, and maintenance, incorporating certain design features which are defined herein. These features include the rail dimensions and width, length and height of stand to insure compatibility with rail concept type transport and positioning trailers.
AGE-4 Packaging, Handling and Transportability Committee
Stairs on the Moon2005-01-30467/11/2005
This paper is an adaptation from a master’ thesis about the architectural design responses to the body's adaptations to a reduced gravity environment. The thrust of this extraction is to study the architectural and biomechanics of stairs in a 1/6 g environment as opposed to a 1 g environment. This paper discusses the ramifications of going up stairs, ramps, and loping considerations such as head height adjustments. Forces, center of gravity, friction, momentum, biomechanics of the knee and hip, and the height from the ground achieved by loping on the moon are discussed. There is also a discussion of stairs vs. ladders as well as the synthesizing of the two modes of vertical circulation.
Barnes, Annette M.
Estimation of Five Anatomical Landmarks on a Foot Model's Toes Based on Surface Shape2005-01-27306/14/2005
We propose producing a body model consisting of anatomical landmarks used in product design from point clouds from a three-dimensional scanner. We previously proposed producing a foot model automatically by deforming the template of known landmarks using free-form deformation (FFD), but shapes of actual toe tips vary widely from the template. Here we propose extracting five landmarks on the toes of a foot model.
Yahara, Hiroki, Inou, Shinpei, Fukui, Yukio, Nishihara, Seiichi, Mochimaru, Masaaki, Kouchi, Makiko
In Search of Efficient Walking Robots2005-01-08414/11/2005
With the recent conflicts in Afghanistan and Iraq, it is increasingly evident that the demands of warfare are changing and the need for innovative mobility systems is growing. In the rough, unstructured terrain that the soldiers encounter, they have reverted to using mules and donkeys to move stealthily and quickly. In light of the growing need for autonomous systems, the Army is looking at the possibility of legged mobility options such as gasoline powered quadrupeds to traverse the off-road terrain. As technology advances, the era of military bipeds may well be in sight. However, current bipedal robotic technology is far too inefficient for battlefield use. Much of this inefficiency stems from actuated control of each limb's motion throughout the entire gait cycle. An alternative approach is to exploit the passive pendular dynamics of legs and legged bodies for energy savings. This paper compares and contrasts fully-actuated walking with passive walking. Simulations of passive and quasi-passive walking are analyzed to evaluate their stability regions and their initial responses on uneven terrain functions are compared.
Haueisen, Brooke, Muench, Paul, Hudas, Greg, Overholt, James, Adamczyk, Peter, Hulbert, Greg
An Inverse Model Based on Optimization in order to Simulate the Automobile Accessibility Movement – A Pilot Study2004-01-21746/15/2004
An experimental protocol and device were setup in order to record the automobile accessibility movement and a biomechanical human model composed of articulated rigid bodies was proposed to reproduce it. From the trajectories of the hands and the feet, an optimization method is applied to each kinematic chain of the model to find the joint angles. It minimizes, for each phase of the automobile accessibility movement, the Euclidian distance between the real and simulated trajectories of the hands and the feet. The constraints take into account the extremes of the experimental joint angles values and the maximum joint variation between two consecutive instants. The first results show that the simulated trajectories of the end effectors fit to the real trajectories but a difference between the computed and simulated joint angles remains.
Lempereur, M., Pudlo, P., Lepoutre, F.-X., Gorce, P.
Automatic Landmarking based on 3-D Foot Database using the FFD Method2004-01-21976/15/2004
An auto-landmarking method for foot measurement was developed. With most of the conventional methods, landmarks of the face and the body were estimated using the curvature, textures and statistics information of body dimensions. In this method, landmarks of the foot were estimated by deformation of the generic foot model. Variation of foot shape was represented by the spatial distortion based on the Free Form Deformation (FFD). The generic foot model was deformed and fit into a new measured foot. Landmarks on the deformed generic foot model were projected to the surface of the measured foot. The mean absolute error of the estimated landmarks was 2.8 [mm]. The error of this method is appropriate to distinguish foot shapes for selecting shoes on a retail store, however it is insufficient for anthropometric database.
Mochimaru, Masaaki, Kouchi, Makiko, Yahara, Hiroki, Fukui, Yukio
Improvement of Foot FE Model Based on the Movement of Bones during Heel Impact2004-01-03133/8/2004
Frontal vehicle collisions often result in foot injury of the front seat occupant. Therefore, it is very important to understand the mechanism of the foot injury. For that purpose, several impact experiments have been conducted using a partial human lower extremity. In addition, recently several impact response analyses using a human FE model have been conducted to understand the mechanism. In the present circumstances, a verified FE model is needed, and the verification of kinematical biofidelity is very important in the first place. In this connection, a foot FE model (based on an existing human FE model) was improved to create a foot FE model, which can be used for study of foot injury mechanism in this research. And the kinematics of foot bones of the model was verified by comparing the bone movements of the FE model with the movement of human foot during heel impact. The sequential X-ray pictures were used to verify the movement of bones, and the bone locations in the improved FE model was compared with X-ray pictures. Improving the model resulted in the movement of calcaneus, talus and navicular in the model correlating well with the human foot.
Morimoto, Junya, Yamazaki, Kunio
Visualizing the Postural Stability of a Digital Human in Working2003-01-22226/17/2003
The purpose of this study is to develop an evaluation method for the postural stability using a digital human model. Experiments were carried out to measure two kinds of stability limits defined in this study. Based on the results new software was developed to visualize the postural stability of the digital human model Jack (EDS). Using the model a methodology was proposed to judge easily whether the human body in any working postures could be maintained with effort or not. It was also demonstrated that the postures unsafe to work could easily be found.
Kawano, Tsuneo, Onosato, Masahiko, Iwata, Kazuaki
The Effects of Axial Preload and Dorsiflexion on the Tolerance of the Ankle/Subtalar Joint to Dynamic Inversion and Eversion2002-22-001311/11/2002
Forced inversion or eversion of the foot is considered a common mechanism of ankle injury in vehicle crashes. The objective of this study was to model empirically the injury tolerance of the human ankle/subtalar joint to dynamic inversion and eversion under three different loading conditions: neutral flexion with no axial preload, neutral flexion with 2 kN axial preload, and 30° of dorsiflexion with 2 kN axial preload. 44 tests were conducted on cadaveric lower limbs, with injury occurring in 30 specimens. Common injuries included malleolar fractures, osteochondral fractures of the talus, fractures of the lateral process of the talus, and collateral ligament tears, depending on the loading configuration. The time of injury was determined either by the peak ankle moment or by a sudden drop in ankle moment that was accompanied by a burst of acoustic emission. Characteristic moment-angle curves to injury were generated for each loading configuration. Neutrally flexed ankles with no applied axial preload sustained injury at 21 ± 5 Nm and 38° ± 8° in inversion, and 47 ± 21 Nm and 28° ± 4° in eversion. For ankles tested in neutral flexion with 2 kN of axial preload, inversion failure occurred at 77 ± 27 Nm and 40° ± 12°, and eversion failure occurred at 142 ± 100 Nm and 41° ± 14°. Ankles dorsiflexed 30° and axially preloaded to 2 kN sustained inversion injury at 62 ± 31 Nm and 33° ± 4°, and eversion injury at 140 ± 53 Nm and 40° ± 6°. Survival analyses were performed to generate injury risk curves in terms of joint moment and rotation angle.
Funk, James R., Srinivasan, Sreebala C. M., Crandall, Jeff R., Khaewpong, Nopporn, Eppinger, Rolf H., Jaffredo, Anna S., Potier, Pascal, Petit, Philippe Y.
Rotary Tool and Retractable Foot for Walking RobotTBMG-727511/1/2002
A mechanism has been developed to serve as an end effector for one of the legs of the Legged Excursion Mechanical Utility Robot (LEMUR) — a walking robot designed for demon- strating robotic cap- abilities for maintenance and repair. [The LEMUR was described in “Six-Legged Experimental Robot” (NPO-20897), NASA Tech Briefs, Vol. 25, No. 12 (December 2001), page 58.] Through controlled actuation of this mechanism, the tip of the leg can become either (1) a foot for stable support during walking or (2) the robotic equivalent of a simple hand tool — a ballend hexagonal driver for a standard hexagonal-socket machine screw. More specifically, the foot can be extended to enable walking, or can be retracted to enable cameras that are parts of the robot to view the insertion of the tool bit in a socket. Retraction of the foot also enables the tool to be used in confined spaces in which the foot cannot fit.
Intuitive Control System for a Dexterous RobotTBMG-719510/2/2002
The Full Immersion Telepresence Testbed (FITT) is an experimental anthropomorphic-robot remote-control system that is so named because it gives a human control operator some of the sensations of the remote environment as though the operator were in that environment in place of the robot. In comparison with older telerobotic control systems, the FITT provides robotic sensory feedback better suited to the operator’s senses and enables the operator and robot acting together to respond, with more nearly natural, humanlike motions, to changes in the remote environment. In particular, correlating the operator’s movements (principally of the head, arms, and hands) with movements of the robot creates a more intuitive method of teleoperating robotic manipulators. Moreover, the use of an operator’s own movements to control the robot provides the operator with useful kinesthetic feedback. The FITT and other systems like it are expected to reduce training time and costs, task-completion times, and operator workloads and errors. Because the FITT concept mates human intelligence with the durability of robots, it is potentially useful for performing complex tasks in harsh environments; for example, cleaning up radioactive and toxic wastes.
Comfort Management in Rest and Exercise Conditions in an Innovative Shortened Liquid Cooling/Warming Garment2002-01-24117/15/2002
Comfort management in extreme environments is complex, requiring temperature stabilization of the body core and distal parts of the extremities. Examination of the capability of body zones to absorb and release heat can facilitate a solution to this problem. Using an experimental shortened liquid cooling/warming garment (LCWG), heat transfer effectiveness of different body zone combinations was assessed in rest and exercise conditions, at different levels of body heat deficit and intensities of physical exertion. Comfort stabilization in terms of minimum changes in core (Tc) and finger (Tfing) temperatures was achieved in exercise (200-400 W) at 18-22°C inlet water temperature in the following zonal combination: a portion of the torso, the internal thigh area covering the femoral artery, the forearm, neck, and part of the head.
Coca, Aitor, Koscheyev, Victor S., Leon, Gloria R.
Six-Legged Experimental RobotTBMG-2952612/1/2001
The figure depicts the Legged Excursion Mechanical Utility Robot (LEMUR) - a six-legged robot for demonstrating robotic capabilities for assembly, maintenance, and inspection. LEMUR is designed to be capable of walking autonomously along a truss structure and to perform other operations.
Three-Fingered Robot Hand With Self-Adjusting GripTBMG-2952712/1/2001
The figure depicts a tendon-driven, three-fingered robot hand (or foot, depending on one's perspective) designed to be installed on the end of the left front leg of the six-legged robot described in the preceding article. This hand, which was undergoing development at the time of reporting the information for this article, is intended to satisfy the need for a small, lightweight mechanism that can grasp objects of various shapes (e.g., balls or cylinders of differing diameters), without need for an elaborate electronic control system or for multiple actuators. The hand also houses rudimentary sensors: the terminal optics of a fiber-optic camera are incorporated into the palm of the hand, and the housing for the optics doubles as a contact-sensor switch.
Some Notes on the Issue of Anthropometrical Accuracy in Digital Human Modeling Manikins2001-01-21076/26/2001
This paper addresses some aspects of the issue of anthropometrical accuracy in digital human modeling manikins as expressed in a proposed European draft prEN ISO 15536. Some problems and possible solutions are illustrated by comparing two computer manikin systems available in our School of Industrial Design Engineering.
Hoekstra, Pyter N.
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