Force Measurements during Cross-Country Skiing

1987 ◽  
Vol 3 (4) ◽  
pp. 370-381 ◽  
Author(s):  
Paavo V. Komi
Keyword(s):  
Functional Significance ◽  
Force Platform ◽  
Ground Reaction Forces ◽  
Force Measurements ◽  
Experimental Conditions ◽  
Reaction Forces ◽  
Cross Country Skiing ◽  
Cross Country ◽  
Platform System ◽  
Component Force

To understand cross-country (X-C) siding it is important to record and identity forces of skis and poles separately and together. They both contribute to the forward progression, but their functional significance may be more complex than that of the ground reaction forces in running and walking. This report presents two methods to record forces on skis and poles during normal X-C skiing. A long force-platform system with four rows of 6-m long plates is placed under the snow track for recording of Fz and Fy forces of each ski and pole separately. This system is suitable especially for the study of diagonal technique under more strict experimental conditions. The second system consists of small lightweight Fz and Fy component force plates which are installed under the boot and binding. These plates can be easily changed from one ski to another, and telemetric recording allows free skiing over long distances and with different skiing techniques, including skating. The presentation emphasizes the integrated use of either system together with simultaneous cinematographic and electromyographic recordings.

scholarly journals An algorithm to decompose ground reaction forces and moments from a single force platform in walking gait

2014 ◽  
Vol 36 (11) ◽  
pp. 1530-1535 ◽  
Author(s):  
David Villeger ◽  
Antony Costes ◽  
Bruno Watier ◽  
Pierre Moretto
Keyword(s):  
Force Platform ◽  
Ground Reaction Forces ◽  
Walking Gait ◽  
Reaction Forces ◽  
Single Force

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.

scholarly journals The dynamics of walking using the hip guidance orthosis (hgo) with crutches

1981 ◽  
Vol 5 (1) ◽  
pp. 19-22 ◽  
Author(s):  
R. E. Major ◽  
J. Stallard ◽  
G. K. Rose
Keyword(s):  
Gait Cycle ◽  
Control Mechanism ◽  
Force Platform ◽  
Energy Losses ◽  
Ground Reaction Forces ◽  
Video Recordings ◽  
Reaction Forces

The variation of ground reaction forces with time for a complete hgo gait cycle using crutches has been synthesized from video recordings and force platform data. This has led to an understanding of the dynamics of hgo ambulation. The results show that when a patient uses the orthosis the crutches provide a subtle control mechanism taking maximum advantage of forward momentum and produce small propulsive forces when needed to make up energy losses.

Force treadmill for measuring vertical and horizontal ground reaction forces

1998 ◽  
Vol 85 (2) ◽  
pp. 764-769 ◽  
Author(s):  
Rodger Kram ◽  
Timothy M. Griffin ◽  
J. Maxwell Donelan ◽  
Young Hui Chang
Keyword(s):  
Ground Reaction Force ◽  
Natural Frequencies ◽  
Modular Design ◽  
Reaction Force ◽  
Mechanical Tests ◽  
Force Platform ◽  
Ground Reaction Forces ◽  
Signal To Noise ◽  
Clinical Evaluations ◽  
Reaction Forces

We constructed a force treadmill to measure the vertical, horizontal and lateral components of the ground-reaction forces (Fz, Fy, Fx, respectively) and the ground-reaction force moments (Mz, My, Mx), respectively exerted by walking and running humans. The chassis of a custom-built, lightweight (90 kg), mechanically stiff treadmill was supported along its length by a large commercial force platform. The natural frequencies of vibration were >178 Hz for Fzand >87 Hz for Fy, i.e., well above the signal content of these ground-reaction forces. Mechanical tests and comparisons with data obtained from a force platform runway indicated that the force treadmill recorded Fz, Fy,Mxand Myground-reaction forces and moments accurately. Although the lowest natural frequency of vibration was 88 Hz for Fx, the signal-to-noise ratios for Fxand Mzwere unacceptable. This device greatly decreases the time and laboratory space required for locomotion experiments and clinical evaluations. The modular design allows for independent use of both treadmill and force platform.

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

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3626 ◽  
Author(s):  
Damiana A. dos Santos ◽  
Claudiane A. Fukuchi ◽  
Reginaldo K. Fukuchi ◽  
Marcos Duarte
Keyword(s):  
Center Of Pressure ◽  
Reaction Force ◽  
Three Dimensional ◽  
Force Platform ◽  
Ground Reaction Forces ◽  
Data Set ◽  
Public Data ◽  
Human Balance ◽  
Reaction Forces ◽  
Young Subjects

This article describes a public data set containing the three-dimensional kinematics of the whole human body and the ground reaction forces (with a dual force platform setup) of subjects who were standing still for 60 s in different conditions, in which the subjects’ 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 contain the three-dimensional positions of 42 markers that were placed on each subject’s body and 73 calculated joint 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 presents programming code to access the data set, generate analyses and other examples. The availability of a public data set on the Internet that contains these measurements and information about how to access and process this data can potentially boost the research on human postural control, increase the reproducibility of studies, and be used for training and education, among other applications.

Multiple Force Platform Analysis of the Canine Trot: a New Approach to Assessing Basic Characteristics of Locomotion

1997 ◽  
Vol 10 (03) ◽  
pp. 160-169 ◽  
Author(s):  
D. V. Lee ◽  
R. J. Todhunter ◽  
Wendy S. Foels ◽  
Alma Jo Williams ◽  
G. Lust ◽  
...  
Keyword(s):  
Analytical Techniques ◽  
Force Platform ◽  
Average Force ◽  
In Series ◽  
Reaction Forces ◽  
Multiple Platform ◽  
Basic Characteristics ◽  
Force Time ◽  
Platform System ◽  
Positional Data

SummaryMultiple platforms measure forces on different limbs simultaneously and provide a convenient means of determining locomotion parameters directly from force data. Four force platforms in series were used to measure force and positional data from simultaneous foot contacts of trotting dogs. Proper evaluation of fore and hindlimb forces from a complete stride requires a minimum of four platforms. Stride period, stride length, average velocity during the stride, relative phases of footfalls and duty factors can be determined directly from the force record. Impulse, average force and change in forward velocity can be determined by integrating the summed force/time curves over one stride period. These analytical techniques are illustrated using multiple platform data. Multiple platform analysis provides a comprehensive view of canine locomotion that cannot be achieved with a single platform.A multiple force platform system designed to analyze ground reaction forces of quadrupedal animals is described. This system provides all force and positional data required for the description of each footfall in a full trotting stride. Methods for calculating key locomotion parameters from multiple platforms are reported and their relevance to gait analysis is discussed.

scholarly journals Lower Extremity Stiffness in Collegiate Distance Runners Pre- and Post-Competition

2020 ◽  
Vol 71 (1) ◽  
pp. 69-77
Author(s):  
Jake P. Tavernite ◽  
Matthew F. Moran
Keyword(s):  
Ground Reaction Forces ◽  
Distance Runners ◽  
Countermovement Jump ◽  
Squat Jump ◽  
Leg Stiffness ◽  
Main Effect ◽  
Before And After ◽  
Reaction Forces ◽  
Cross Country ◽  
Post Hoc

AbstractPrevious evidence has suggested that there is a relationship between leg stiffness and improved running performance. The purpose of this investigation was to determine how leg stiffness of runners was influenced in the 24 and 48 hour period following a cross country race. Twenty-two collegiate cross-country runners (13 males, 9 females, 19.5 ± 1.4 yr) were recruited and participated in the study. Leg stiffness was assessed 24 hours before and after a race as well as 48 hours post-race. Three jumping protocols were conducted: 1) a static jump, 2) a countermovement jump, and 3) a vertical hopping test. Two embedded force plates (1000 Hz) were utilized to measure ground reaction forces for each test and a metronome was utilized to maintain hopping frequency (2.2 Hz). A significant main effect was found for a static jump, a countermovement jump and leg stiffness. Leg stiffness was significantly reduced 24 hours post-race (pre-race 36.84 kN·m-1, 24h post 33.11 kN·m-1, p < 0.05), but not 48 hours post-race (36.30 kN·m-1). No significant differences were found in post-hoc analysis for the squat jump, countermovement jump height and the eccentric utilization ratio. Following a cross-country race, leg stiffness significantly declined in a group of collegiate runners in the immediate 24 hours post-race, but returned to baseline 48 hours post-race. Sport scientists and running coaches may be able to monitor leg stiffness as a metric to properly prescribe training regiments.

scholarly journals Consistent inconsistencies in braking: a spatial analysis

2021 ◽  
Vol 11 (5) ◽  
pp. 20200058
Author(s):  
Alexandra G. Hammerberg ◽  
Patricia Ann Kramer
Keyword(s):  
Ground Reaction Forces ◽  
Two Dimensional ◽  
Centre Of Pressure ◽  
Experimental Conditions ◽  
Disease Clustering ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Applied Forces ◽  
Vertical Ground Reaction Forces ◽  
Fatigue Failures

The dynamic system that is the bipedal body in motion is of interest to engineers, clinicians and biological anthropologists alike. Spatial statistics is more familiar to public health researchers as a way of analysing disease clustering and spread; nonetheless, this is a practical approach to the two-dimensional topography of the foot. We quantified the clustering of the centre of pressure (CoP) on the foot for peak braking and propulsive vertical ground reaction forces (GRFs) over multiple, contiguous steps to assess the consistency of the location of peak forces on the foot during walking. The vertical GRFs of 11 participants were collected continuously via a wireless insole system (MoticonReGo AG) across various experimental conditions. We hypothesized that CoPs would cluster in the hindfoot for braking and forefoot for propulsion, and that braking would demonstrate more consistent clustering than propulsion. Contrary to our hypotheses, we found that CoPs during braking are inconsistent in their location, and CoPs during propulsion are more consistent and clustered across all participants and all trials. These results add to our understanding of the applied forces on the foot so that we can better predict fatigue failures and better understand the mechanisms that shaped the modern bipedal form.

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