Prosthetic foot design optimisation based on roll-over shape and ground reaction force characteristics

2016 ◽  
Vol 231 (17) ◽  
pp. 3093-3103 ◽  
Author(s):  
P Mahmoodi ◽  
S Aristodemou ◽  
RS Ransing ◽  
N Owen ◽  
MI Friswell
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
The Body ◽  
Computational Method ◽  
Prosthetic Foot ◽  
Release Mechanisms ◽  
Heel Contact ◽  
Discretisation Error ◽  
Force Components ◽  
Stiffness Profile

Most prosthetic foot products are adjusted by skilled prosthetists using a variety of gait analysis and information given to them by patients in terms of feel and experience. The design of prosthetic foot has traditionally focused on optimising stiffness to support the body weight and storage/release mechanisms of strain energy from heel contact to push off. As a result of this, the optimisation process of a prosthetic foot is simple and sometimes insufficient. It is proposed that the stiffness and energy release mechanisms of prosthetic feet be designed to satisfy amputee’s natural gait characteristics that are defined by an effective roll-over shape and corresponding ground reaction force combinations. Each point on the roll-over shape is mapped with a ground reaction force corresponding to its time stamp. The resulting discrete set of ground reaction force components are applied to the prosthetic foot sole and its stiffness profile is optimised to produce a desired deflection as given by the corresponding point on the roll-over shape. The robustness of this novel computational method is tested on three prosthetic designs. The mesh sensitivity results and the discretisation error resulting from applying finite number of ground reaction forces are discussed. It is shown that the proposed methodology is able to provide valuable insights in the guidelines for selection of materials for a multi-material prosthetic foot.

Comparisons of Spatiotemporal and Ground Reaction Force Components of Gait Between Individuals with Congenital Vision Loss and Sighted Individuals

2020 ◽  
Vol 114 (4) ◽  
pp. 277-288
Author(s):  
Mahdi Majlesi ◽  
Nader Farahpour ◽  
Gordon E. Robertson
Keyword(s):  
Ground Reaction Force ◽  
Vision Loss ◽  
Reaction Force ◽  
Clinical Importance ◽  
Step Length ◽  
Rehabilitation Program ◽  
Control Group ◽  
Eyes Closed ◽  
Heel Contact ◽  
Force Components

Introduction: The understanding of abnormalities in biomechanical parameters of gait in individuals with vision loss (i.e., blindness or low vision) has clinical importance. The aims of this study were to compare the spatiotemporal and ground reaction force variables of sighted individuals with those with vision loss. Methods: Ten sighted males and 10 young males with congenital vision loss were recruited. A Vicon motion analysis system with four cameras and two Kistler force plates was used to quantify spatiotemporal and ground reaction force components of both groups during walking without shoes. Sighted individuals walked in eyes-open and eyes-closed conditions. Results: Results showed that the stride and step length, walking speed, the vertical and posterior–anterior reaction forces in heel contact and push-off phase, and the impulse of the control group during walking with the open- and closed-eyes conditions were significantly smaller than those in persons with vision loss ( p < .05). Discussion: Vision loss is associated with decreased step and stride length, slower walking, and smaller propulsive reaction force. These kinematic and kinetics alterations suggest an adaptation to a new neuromuscular response for dynamic postural control as a result of lack of vision. These alterations in the long term may result in rigidity and muscle weakness. Implications for practitioners: A rehabilitation program to enhance mobility and strength is suggested for individuals with vision loss.

scholarly journals Conceptual Design of a New Multi-Component Test Bench for the Dynamic Characterization of Running Specific Prostheses

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 75 ◽  
Author(s):  
Nicola Petrone ◽  
Gianfabio Costa ◽  
Gianmario Foscan ◽  
Francesco Bettella ◽  
Gianluca Migliore ◽  
...  
Keyword(s):  
Test Bench ◽  
Reaction Force ◽  
Dynamic Characterization ◽  
Prosthetic Foot ◽  
Load Combination ◽  
Stiffness Properties ◽  
Component Test ◽  
Static And Dynamic Loads ◽  
Force Components

Stiffness properties of running specific prostheses (RSP) for Paralympic runners are fundamental in the selection of the optimal running prosthetic foot (RPF) for sprint and jump events, depending on the athlete’s anthropometry and characteristics. RPFs are J-shaped or C-shaped, clamped to the socket or the pylon of the prosthetic leg. The aim of this work was to develop a test bench suitable for the static and dynamic characterization of a running prosthetic feet (RPF). Based on the evidence that the ground reaction force components change their relative orientation to the pylon or socket during the stance, loads were resolved in the socket reference frame and a multi-component test bench was designed and constructed. Two perpendicular actuators can apply static and dynamic loads to the foot while contacting a surrogate ground inclined at different angles. The preliminary tests show how the alignment, load combination, and ground angle can affect RPF stiffness curves.

Ground Reaction Forces in Children’s Gait

1989 ◽  
Vol 1 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Nancy L. Greer ◽  
Joseph Hamill ◽  
Kevin R. Campbell
Keyword(s):  
Sex Differences ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Force ◽  
Reaction Forces ◽  
Braking Force ◽  
Force Components ◽  
Age Range ◽  
Minimum Force

Ground reaction force patterns during walking were observed in 18 children 3 and 4 years of age. The children walked barefoot at a self-chosen walking pace. Selected variables representing the vertical, anteroposterior, and mediolateral force components were evaluated. The results indicated that children in this age range contact the ground with greater vertical force measures relative to body mass than do adults. In addition, the minimum vertical force was lower, the transition from braking to propulsion occurred earlier, and the mediolateral force excursions were higher than typically found in adults. When the children were divided into groups on the basis of sex, differences were observed between those groups. The boys exhibited a greater difference in the vertical peak forces, a lower minimum force, a greater braking force, and a higher mediolateral force excursion value. The results indicated that children display a different ground reaction force pattern than do adults and that differences between boys and girls may be observed as early as ages 3 and 4 years.

scholarly journals Effect of Textured Foot Orthoses on the Ground Reaction Force Components in the Older Adults During Walking

2020 ◽  
Vol 7 (1) ◽  
pp. 23-32
Author(s):  
Aydin Valizadeorang ◽  
Arefe Mokhtari MalekAbadi ◽  
Aydin Valizade Orang ◽  
◽  
◽  
...  
Keyword(s):  
Older Adults ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Foot Orthoses ◽  
Force Components

Gait Phase Detection Using Foot Acceleration for Estimating Ground Reaction Force in Long Distance Gait Rehabilitation

2012 ◽  
Vol 24 (5) ◽  
pp. 828-837 ◽  
Author(s):  
Kazuya Kawamura ◽  
◽  
Yuya Morita ◽  
Jun Okamoto ◽  
Kohei Saito ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Vertical Axis ◽  
Gait Rehabilitation ◽  
Phase Detection ◽  
Long Distance ◽  
Axis Direction ◽  
Acceleration Data ◽  
Heel Contact ◽  
Gait Phase

In gait rehabilitation, achieving a gait analysis method using a simple system during long-distance walking is important. This method is required to measure all gait parameters in a single measurement. In addition, it is required that the measurement system is not spatially constrained. Therefore, we have been developing a gait tracking system with acceleration sensors for long-distance gait rehabilitation. In this paper, we describe a gait phase detection method using foot acceleration data for estimating ground reaction force during long-distance gait rehabilitation. To develop this method, we focused on the jerk of each foot in vertical axis direction. Using two accelerometers mounted on the left and right feet, we carried out three experiments. First, we measured the jerk of each foot during a free gait to verify the relation with the walking speed. Second, we measured the jerk of each foot during walking faster than normal for each subject. We then compared these results with the results of first experiments. Finally, we measured the jerk of each foot during left-right asymmetrical walking. The results confirmed that gait phase could be detected using the jerk of each leg, calculated from acceleration data in vertical axis direction. In particular, the timing of Heel-contact / Toe-off could be obtained with an average error of 0.03 s. And as a preliminary study, we estimated the ground reaction force using the one of the results.

scholarly journals Body and tail-assisted pitch control facilitates bipedal locomotion in Australian agamid lizards

2018 ◽  
Vol 15 (146) ◽  
pp. 20180276 ◽  
Author(s):  
Christofer J. Clemente ◽  
Nicholas C. Wu
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Angular Acceleration ◽  
The Body ◽  
Bipedal Locomotion ◽  
Temporal Asymmetry ◽  
Pitch Control ◽  
Force Profile ◽  
Torque Moment ◽  
Modelling Studies

Certain lizards are known to run bipedally. Modelling studies suggest bipedalism in lizards may be a consequence of a caudal shift in the body centre of mass, combined with quick bursts of acceleration, causing a torque moment at the hip lifting the front of the body. However, some lizards appear to run bipedally sooner and for longer than expected from these models, suggesting positive selection for bipedal locomotion. While differences in morphology may contribute to bipedal locomotion, changes in kinematic variables may also contribute to extended bipedal sequences, such as changes to the body orientation, tail lifting and changes to the ground reaction force profile. We examined these mechanisms among eight Australian agamid lizards. Our analysis revealed that angular acceleration of the trunk about the hip, and of the tail about the hip were both important predictors of extended bipedal running, along with increased temporal asymmetry of the ground reaction force profile. These results highlight important dynamic movements during locomotion, which may not only stabilize bipedal strides, but also to de-stabilize quadrupedal strides in agamid lizards, in order to temporarily switch to, and extend a bipedal sequence.

Use of Ground Reaction Force Parameters in Predicting Peak Tibial Accelerations in Running

1993 ◽  
Vol 9 (4) ◽  
pp. 306-314 ◽  
Author(s):  
Ewald M. Hennig ◽  
Thomas L. Milani ◽  
Mario A. Lafortune
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
The Body ◽  
Force Platform ◽  
Good Prediction ◽  
Vertical Force ◽  
Force Peak ◽  
Power Frequency ◽  
Initial Force ◽  
Force Data

Ground reaction force data and tibial accelerations from a skin-mounted transducer were collected during rearfoot running at 3.3 m/s across a force platform. Five repetitive trials from 27 subjects in each of 19 different footwear conditions were evaluated. Ground reaction force as well as tibial acceleration parameters were found to be useful for the evaluation of the cushioning properties of different athletic footwear. The good prediction of tibial accelerations by the maximum vertical force rate toward the initial force peak (r2 = .95) suggests that the use of a force platform is sufficient for the estimation of shock-absorbing properties of sport shoes. If an even higher prediction accuracy is required a regression equation with two variables (maximum force rate, median power frequency) may be used (r2 = .97). To evaluate the influence of footwear on the shock traveling through the body, a good prediction of peak tibial accelerations can be achieved from force platform measurements.

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