Amputee Locomotion: Ground Reaction Forces During Submaximal Running With Running-Specific Prostheses

2016 ◽  
Vol 32 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Brian S. Baum ◽  
Hiroaki Hobara ◽  
Yoon Hyuk Kim ◽  
Jae Kun Shim
Keyword(s):  
Three Dimensional ◽  
Force Production ◽  
Acute Injury ◽  
Ground Reaction Forces ◽  
Control Subjects ◽  
Prosthetic Limbs ◽  
Function Loss ◽  
Reaction Forces ◽  
Musculoskeletal Function ◽  
And Control

Individuals with lower extremity amputation must adapt the mechanical interactions between the feet and ground to account for musculoskeletal function loss. However, it is currently unknown how individuals with amputation modulate three-dimensional ground reaction forces (GRFs) when running. This study aimed to understand how running with running-specific prostheses influences three-dimensional support forces from the ground. Eight individuals with unilateral transtibial amputations and 8 control subjects ran overground at 2.5, 3.0, and 3.5 m/s. Ten force plates measured GRFs at 1000 Hz. Peak and average GRFs and impulses in each plane were compared between limbs and groups. Prosthetic limbs generated reduced vertical impulses, braking forces and impulses, and mediolateral forces while generating similar propulsive impulses compared with intact and control limbs. Intact limbs generated greater peak and average vertical forces and average braking forces than control subjects’ limbs. These data indicate that the nonamputated limb experiences elevated mechanical loading compared with prosthetic and control limbs. This may place individuals with amputation at greater risk of acute injury or joint degeneration in their intact limb. Individuals with amputation adapted to running-specific prosthesis force production limitations by generating longer periods of positive impulse thus producing propulsive impulses equivalent to intact and control limbs.

scholarly journals Ground Reaction Forces of Dressage Horses Performing the Piaffe

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 436 ◽  
Author(s):  
Hilary Mary Clayton ◽  
Sarah Jane Hobbs
Keyword(s):  
Coefficient Of Variation ◽  
Three Dimensional ◽  
Individual Variability ◽  
The Other ◽  
Ground Reaction Forces ◽  
High Coefficient ◽  
Reaction Forces

The piaffe is an artificial, diagonally coordinated movement performed in the highest levels of dressage competition. The ground reaction forces (GRFs) of horses performing the piaffe do not appear to have been reported. Therefore, the objective of this study was to describe three-dimensional GRFs in ridden dressage horses performing the piaffe. In-ground force plates were used to capture fore and hindlimb GRF data from seven well-trained dressage horses. Peak vertical GRF was significantly higher in forelimbs than in the hindlimbs (7.39 ± 0.99 N/kg vs. 6.41 ± 0.64 N/kg; p < 0.001) with vertical impulse showing a trend toward higher forelimb values. Peak longitudinal forces were small with no difference in the magnitude of braking or propulsive forces between fore and hindlimbs. Peak transverse forces were similar in magnitude to longitudinal forces and were mostly directed medially in the hindlimbs. Both the intra- and inter-individual variability of longitudinal and transverse GRFs were high (coefficient of variation 25–68%). Compared with the other diagonal gaits of dressage horses, the vertical GRF somewhat shifted toward the hindlimbs. The high step-to-step variability of the horizontal GRF components is thought to reflect the challenge of balancing on one diagonal pair of limbs with no forward momentum.

Associations between ground reaction force waveforms and sprint start performance

2019 ◽  
Vol 14 (5) ◽  
pp. 658-666 ◽  
Author(s):  
Steffi L Colyer ◽  
Philip Graham-Smith ◽  
Aki IT Salo
Keyword(s):  
Reaction Force ◽  
Statistical Parametric Mapping ◽  
Force Production ◽  
Mass Motion ◽  
Ground Reaction Forces ◽  
Centre Of Mass ◽  
Specific Training ◽  
Force Vector ◽  
Reaction Forces ◽  
External Power

Ground reaction forces produced on the blocks determine an athlete’s centre of mass motion during the sprint start, which is crucial to sprint performance. This study aimed to understand how force waveforms are associated with better sprint start performance. Fifty-seven sprinters (from junior to world elite) performed a series of block starts during which the ground reaction forces produced by the legs and arms were separately measured. Statistical parametric mapping (linear regression) revealed specific phases of these waveforms where forces were associated with average horizontal external power. Better performances were achieved by producing higher forces and directing the force vector more horizontally during the initial parts of the block phase (17–34% and 5–37%, respectively). During the mid-push (around the time of rear block exit: ∼54% of the block push), magnitudes of front block force differentiated performers, but orientation did not. Consequently, the ability to sustain high forces during the transition from bilateral to unilateral pushing was a performance-differentiating factor. Better athletes also exhibited a higher ratio of forces on the front block in the latter parts of unilateral pushing (81–92% of the block push), which seemed to allow these athletes to exit the blocks with lower centre of mass projection angles. Training should reflect these kinetic requirements, but also include technique-based aspects to increase both force production and orientation capacities. Specific training focused on enhancing anteroposterior force production during the transition between double- to single-leg propulsion could be beneficial for overall sprint start performance.

scholarly journals Spring-like leg behaviour, musculoskeletal mechanics and control in maximum and submaximum height human hopping

2011 ◽  
Vol 366 (1570) ◽  
pp. 1516-1529 ◽  
Author(s):  
Maarten F. Bobbert ◽  
L. J. Richard Casius
Keyword(s):  
Energy Expenditure ◽  
Muscle Activation ◽  
Mechanical Energy ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Centre Of Mass ◽  
Leg Stiffness ◽  
Reaction Forces ◽  
And Control ◽  
The Relationship

The purpose of this study was to understand how humans regulate their ‘leg stiffness’ in hopping, and to determine whether this regulation is intended to minimize energy expenditure. ‘Leg stiffness’ is the slope of the relationship between ground reaction force and displacement of the centre of mass (CM). Variations in leg stiffness were achieved in six subjects by having them hop at maximum and submaximum heights at a frequency of 1.7 Hz. Kinematics, ground reaction forces and electromyograms were measured. Leg stiffness decreased with hopping height, from 350 N m −1 kg −1 at 26 cm to 150 N m −1 kg −1 at 14 cm. Subjects reduced hopping height primarily by reducing the amplitude of muscle activation. Experimental results were reproduced with a model of the musculoskeletal system comprising four body segments and nine Hill-type muscles, with muscle stimulation STIM( t ) as only input. Correspondence between simulated hops and experimental hops was poor when STIM( t ) was optimized to minimize mechanical energy expenditure, but good when an objective function was used that penalized jerk of CM motion, suggesting that hopping subjects are not minimizing energy expenditure. Instead, we speculated, subjects are using a simple control strategy that results in smooth movements and a decrease in leg stiffness with hopping height.

scholarly journals Compensatory Ground Reaction Forces during Scoliotic Gait in Subjects with and without Right Adolescent Idiopathic Scoliosis

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2372
Author(s):  
Paul S. Sung ◽  
Moon Soo Park
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Stance Phase ◽  
Three Dimensional ◽  
Asymmetry Index ◽  
Ground Reaction Forces ◽  
Significant Group ◽  
Reaction Forces ◽  
And Gender

Although the asymmetries of scoliotic gait in adolescent idiopathic scoliosis (AIS) groups have been extensively studied, recent studies indicated conflicting results regarding the ground reaction forces (GRFs) during gait in subjects with spinal deformity. The asymmetry during the stance phase might be clarified with three-dimensional (3D) compensations of GRFs between similar characteristics of subjects with and without AIS. The purpose of this study was to compare the normalized 3D GRF differences during the stance phase of gait while considering age, BMI, and Cobb angle between subjects with and without right AIS. There were 23 subjects with right convexity of thoracic idiopathic scoliosis and 22 age- and gender-matched control subjects. All subjects were right upper/lower limb dominant, and the outcome measures included the Cobb angles, normalized GRF, and KAI. The mediolateral (M/L) third peak force on the dominant limb decreased in the AIS group (t = 2.58, p = 0.01). Both groups demonstrated a significant interaction with the 3D indices (F = 5.41, p = 0.02). The post-hoc analysis identified that the M/L plane of asymmetry was significantly different between groups. The Cobb angles were negatively correlated with the vertical asymmetry index (r = −0.45, p = 0.03); however, there was no significant correlation with age (r = −0.10, p = 0.65) or body mass index (r = −0.28, p = 0.20). The AIS group demonstrated decreased GRF in the dominant limb M/L plane of the terminal stance phase. This compensatory motion was confirmed by a significant group difference on the M/L plane of the KAI. This KAI of vertical asymmetry correlated negatively with the Cobb angle. The asymmetric load transmission with compensatory vertical reactions was evident due to abnormal loading in the stance phase. These kinetic compensatory patterns need to be considered with asymmetry on the dominant limb when developing rehabilitation strategies for patients with AIS.

scholarly journals A data set with kinematic and ground reaction forces of human balance

2017 ◽  
Author(s):  
Damiana A dos Santos ◽  
Claudiane A Fukuchi ◽  
Reginaldo K Fukuchi ◽  
Marcos Duarte
Keyword(s):  
Center Of Pressure ◽  
Reaction Force ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Force Platform ◽  
Whole Body ◽  
Ground Reaction Forces ◽  
Data Set ◽  
Public Data ◽  
Reaction Forces

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.

scholarly journals A data set with kinematic and ground reaction forces of human balance

2017 ◽  
Author(s):  
Damiana A dos Santos ◽  
Claudiane A Fukuchi ◽  
Reginaldo K Fukuchi ◽  
Marcos Duarte
Keyword(s):  
Center Of Pressure ◽  
Reaction Force ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Force Platform ◽  
Whole Body ◽  
Ground Reaction Forces ◽  
Data Set ◽  
Public Data ◽  
Reaction Forces

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.

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