scholarly journals Computation of Intersegmental Moments during Standing Posture: Can We Neglect the Horizontal Ground Reaction Force? Results from an Experimental Study

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Solène Prost ◽  
Sébastien Pesenti ◽  
Bertrand Moal ◽  
Vincent Pomero ◽  
Stephane Fuentes ◽  
...  

Background. The development of postural analysis thanks to force and pressure platforms, in order to determine the center of pressure, can be valuable in the setting of spinal malalignment. The purpose of this study was to compare “pressure” and “force” platforms for the evaluation of the center of pressure. In other words, can we neglect the horizontal ground reaction force in the evaluation of intersegmental moments during standing posture? Methods. Postural data from two healthy adult volunteers were analyzed. Analysis of the posture was done according to a protocol providing sagittal intersegmental moments. A set of 36 markers was used to divide the body in 10 segments. Postacquisition calculations were done in order to obtain the sagittal net intersegmental moments. To evaluate the differences in intersegmental moments between force and pressure platforms, the postacquisition calculations were done with a simulated pressure platform. Mean intersegmental moments between each body segment for each volunteer were compared. Findings. There were significant differences between the 2 platforms in intersegmental moments for the lumbo-sacral junction, hips, knees, and ankles (p<0.005). All differences were inferior to intrasubject variability measured with the force platform (p<0.001). Results from intra- and interobserver comparisons showed that differences measured with the pressure platform were all inferior to the standard error obtained with the force platform for every intersegmental moment (p<0.001). Interpretation. The use of a simulated pressure platform to determine intersegmental moments has the same clinical efficiency as force platforms. Moreover, the possibility to set the platform into the radiograph room will allow in a second time a correlation between radiographic parameters and biomechanical constraints applied to the spine.

1993 ◽  
Vol 9 (4) ◽  
pp. 306-314 ◽  
Author(s):  
Ewald M. Hennig ◽  
Thomas L. Milani ◽  
Mario A. Lafortune

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.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Fabian Horst ◽  
Djordje Slijepcevic ◽  
Marvin Simak ◽  
Wolfgang I. Schöllhorn

AbstractThe Gutenberg Gait Database comprises data of 350 healthy individuals recorded in our laboratory over the past seven years. The database contains ground reaction force (GRF) and center of pressure (COP) data of two consecutive steps measured - by two force plates embedded in the ground - during level overground walking at self-selected walking speed. The database includes participants of varying ages, from 11 to 64 years. For each participant, up to eight gait analysis sessions were recorded, with each session comprising at least eight gait trials. The database provides unprocessed (raw) and processed (ready-to-use) data, including three-dimensional GRF and two-dimensional COP signals during the stance phase. These data records offer new possibilities for future studies on human gait, e.g., the application as a reference set for the analysis of pathological gait patterns, or for automatic classification using machine learning. In the future, the database will be expanded continuously to obtain an even larger and well-balanced database with respect to age, sex, and other gait-specific factors.


2007 ◽  
Vol 353-358 ◽  
pp. 2179-2182 ◽  
Author(s):  
Jae Ok Lee ◽  
Young Shin Lee ◽  
Se Hoon Lee ◽  
Young Jin Choi ◽  
Soung Ha Park

The foot plays an important role in supporting the body and keeping body balance. An abnormal walking habit breaks the balance of the human body as well as the function of the foot. The foot orthotics which is designed to consider biomechanics effectively distributes the load of the human body on the sole of the foot. In this paper, gait analysis is performed for subjects wearing the orthotics. In this study, three male subjects were selected. The experimental apparatus consists of a plantar pressure analysis system and digital EMG system. The gait characteristics are simulated by ADAMS/LifeMOD. The COP (Center of Pressure), EMG and ground reaction force were investigated. As a result of gait analysis, the path of COP was improved and muscle activities were decreased with orthotics on the abnormal walking subjects.


2017 ◽  
Author(s):  
Damiana A dos Santos ◽  
Claudiane A Fukuchi ◽  
Reginaldo K Fukuchi ◽  
Marcos Duarte

This article describes a public data set with the three-dimensional kinematics of the whole body and the ground reaction forces (with a dual force platform setup) of subjects standing still for 60 s in different conditions, in which the vision and the standing surface were manipulated. Twenty-seven young subjects and 22 old subjects were evaluated. The data set comprises a file with metadata plus 1,813 files with the ground reaction force (GRF) and kinematics data for the 49 subjects (three files for each of the 12 trials plus one file for each subject). The file with metadata has information about each subject’s sociocultural, demographic, and health characteristics. The files with the GRF have the data from each force platform and from the resultant GRF (including the center of pressure data). The files with the kinematics have the three-dimensional position of the 42 markers used for the kinematic model of the whole body and the 73 calculated angles. In this text, we illustrate how to access, analyze, and visualize the data set. All the data is available at Figshare (DOI: 10.6084/m9.figshare.4525082 ), and a companion Jupyter Notebook (available at https://github.com/demotu/datasets ) presents the programming code to generate analyses and other examples.


2002 ◽  
Vol 12 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Andreas Hofmann ◽  
Marko Popovic ◽  
Hugh Herr

A three-dimensional numerical model of human standing is presented that reproduces the dynamics of simple swaying motions while in double-support. The human model is structurally realistic, having both trunk and two legs with segment lengths and mass distributions defined using human morphological data from the literature. In this investigation, model stability in standing is achieved through the application of a high-level reduced-order control system where stabilizing forces are applied to the model's trunk by virtual spring- damper elements. To achieve biologically realistic model dynamics, torso position and ground reaction force data measured on human subjects are used as demonstration data in a supervised learning strategy. Using Powell's method, the error between simulation data and measured human data is minimized by varying the virtual high-level force field. Once optimized, the model is shown to track torso position and ground reaction force data from human demonstrations. With only these limited demonstration data, the humanoid model sways in a biologically realistic manner. The model also reproduces the center-of-pressure trajectory beneath the foot, even though no error term for this is included in the optimization algorithm. This indicates that the error terms used (the ones for torso position and ground reaction force) are sufficient to compute the correct joint torques such that independent metrics, like center-of-pressure trajectory, are correct.


2017 ◽  
Author(s):  
Damiana A dos Santos ◽  
Claudiane A Fukuchi ◽  
Reginaldo K Fukuchi ◽  
Marcos Duarte

This article describes a public data set with the three-dimensional kinematics of the whole body and the ground reaction forces (with a dual force platform setup) of subjects standing still for 60 s in different conditions, in which the vision and the standing surface were manipulated. Twenty-seven young subjects and 22 old subjects were evaluated. The data set comprises a file with metadata plus 1,813 files with the ground reaction force (GRF) and kinematics data for the 49 subjects (three files for each of the 12 trials plus one file for each subject). The file with metadata has information about each subject’s sociocultural, demographic, and health characteristics. The files with the GRF have the data from each force platform and from the resultant GRF (including the center of pressure data). The files with the kinematics have the three-dimensional position of the 42 markers used for the kinematic model of the whole body and the 73 calculated angles. In this text, we illustrate how to access, analyze, and visualize the data set. All the data is available at Figshare (DOI: 10.6084/m9.figshare.4525082 ), and a companion Jupyter Notebook (available at https://github.com/demotu/datasets ) presents the programming code to generate analyses and other examples.


1993 ◽  
Vol 17 (2) ◽  
pp. 83-89 ◽  
Author(s):  
J. R. Engsberg ◽  
A. G. Lee ◽  
K. G. Tedford ◽  
J. A. Harder

The purpose of this investigation was to develop normative ground reaction force data for able-bodied (AB) and trans-tibial amputee (TTA) children during running. Two hundred AB (mean age 9.4 years, range 7–12) and 21 TTA (mean age 11.1 years, range 5–17) children ran (2.2 m/s±10%) over a force platform. Ground reaction force data were normalized, averaged within groups and plotted to produce force-time curves characterizing the different leg types (i.e. able-bodied, non-prosthetic and prosthetic). In addition, discrete variables characterizing the leg type differences were determined. One way ANOVA determined significant differences between variables and a TukeyB Post Hoc analysis defined which variables were significantly different (p < 0.05). Results generally indicated differences between the three leg types with the non-prosthetic leg indicating greater forces than the prosthetic and AB legs. The results of this investigation provide normative ground reaction force data for both AB and TTA children during running and can be used for comparison with other groups of children.


1989 ◽  
Vol 67 (4) ◽  
pp. 1692-1698 ◽  
Author(s):  
R. Kram ◽  
A. J. Powell

Muscle, bone, and tendon forces; the movement of the center of mass, and the spring properties of the body during terrestrial locomotion can be measured using ground-mounted force platforms. These measurements have been extremely time consuming because of the difficulty in obtaining repeatable constant speed trials (particularly with animals). We have overcome this difficulty by mounting a force platform directly under the belt of a motorized treadmill. With this arrangement, vertical force can be recorded from an unlimited number of successive ground contacts in a much shorter time. With this treadmill-mounted force platform it is possible to accurately make the following measurements over the full range of steady speeds and under various perturbations of normal gait: 1) vertical ground reaction force over the course of the contact phase; 2) peak forces in bone, muscle, and tendon; 3) the vertical displacement of the center of mass; and 4) contact time for the limbs. In our treadmill-force platform design, belt forces and frictional forces cause no measurable cross-talk problem. Natural frequency (160 Hz), nonlinearity (less than 5%), and position independence (less than 2%) are all quite acceptable. Motor-caused vibrations are greater than 150 Hz and thus can be easily filtered.


2018 ◽  
Vol 15 (146) ◽  
pp. 20180276 ◽  
Author(s):  
Christofer J. Clemente ◽  
Nicholas C. Wu

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.


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