scholarly journals Effect of Gait Speed on Recovery Motion from Tripping on a Treadmill

2021 ◽  
Vol 11 (17) ◽  
pp. 7908
Author(s):  
Yasuhiro Akiyama ◽  
Hazuki Miyata ◽  
Shogo Okamoto ◽  
Yoji Yamada
Keyword(s):  
Motion Capture ◽  
Principal Components ◽  
Gait Speed ◽  
Reaction Force ◽  
Force Plate ◽  
Principal Component ◽  
Individual Characteristics ◽  
Healthy Male ◽  
Gait Parameters ◽  
Male Subjects

The analysis of the mechanism of fall avoidance motion is required to prevent fall-related injuries. To investigate the factors that affect fall avoidance motion, tripping was induced among 10 healthy male subjects during treadmill walking at gait speeds of 3.5 and 4.0 km/h. The posture of the subjects and ground reaction force of the recovery steps were recorded using a motion capture system and force plate to analyze the effect of gait speed on recovery motion. The gait parameters of the recovery steps were calculated and compared between gait speeds. Principal component analysis was performed to identify the parameters that represent the recovery motion and the magnitude of the first and second recovery steps, and the balance of recovery steps were extracted as defining characteristics. Of the 18 gait parameters, such as step time, five differed depending on gait speeds. However, the other gait parameters and all four principal components did not differ significantly with respect to gait speeds. Furthermore, the distribution of principal components and gait parameters across subjects and gait speeds suggested that the variability between trials was greater than the effect of gait speed and individual characteristics on recovery motion.

Energetics and mechanics of human running on surfaces of different stiffnesses

2002 ◽  
Vol 92 (2) ◽  
pp. 469-478 ◽  
Author(s):  
Amy E. Kerdok ◽  
Andrew A. Biewener ◽  
Thomas A. McMahon ◽  
Peter G. Weyand ◽  
Hugh M. Herr
Keyword(s):  
Reaction Force ◽  
Force Plate ◽  
Metabolic Cost ◽  
Running Economy ◽  
Leg Length ◽  
Kinematic Data ◽  
Surface Stiffness ◽  
Leg Stiffness ◽  
Compliant Surfaces ◽  
Male Subjects

Mammals use the elastic components in their legs (principally tendons, ligaments, and muscles) to run economically, while maintaining consistent support mechanics across various surfaces. To examine how leg stiffness and metabolic cost are affected by changes in substrate stiffness, we built experimental platforms with adjustable stiffness to fit on a force-plate-fitted treadmill. Eight male subjects [mean body mass: 74.4 ± 7.1 (SD) kg; leg length: 0.96 ± 0.05 m] ran at 3.7 m/s over five different surface stiffnesses (75.4, 97.5, 216.8, 454.2, and 945.7 kN/m). Metabolic, ground-reaction force, and kinematic data were collected. The 12.5-fold decrease in surface stiffness resulted in a 12% decrease in the runner's metabolic rate and a 29% increase in their leg stiffness. The runner's support mechanics remained essentially unchanged. These results indicate that surface stiffness affects running economy without affecting running support mechanics. We postulate that an increased energy rebound from the compliant surfaces studied contributes to the enhanced running economy.

BIOMECHANICAL CHARACTERISTICS IN YOGA SIRSASANA

2017 ◽  
Vol 17 (03) ◽  
pp. 1750053 ◽  
Author(s):  
YO CHEN ◽  
CHO-WEI LEE ◽  
YU-LAN CHEN ◽  
HUI-TING LIN ◽  
JIA-HAO CHANG
Keyword(s):  
Pressure Distribution ◽  
Surface Area ◽  
Motion Capture ◽  
Reaction Force ◽  
Force Plate ◽  
The Body ◽  
Friedman Test ◽  
Joint Angles ◽  
Males And Females ◽  
The Difference

The aim of this study was to understand how to process Yoga headstand and the difference between genders in headstand. Twelve skilled participates were recruited in this study (Males 34.1 [Formula: see text] 3.3 years, [Formula: see text]; Females 36.5 [Formula: see text] 3.9 years, [Formula: see text]). The 10 camera Vicon motion capture system, Kistler force plate, and Medilogic pressure mat were used synchronously to record the movement, ground reaction force, and pressure distribution during headstand. The Mann–Whitney U test and Friedman test ([Formula: see text]) was applied to assess the statistics. The trunk, hip, knee, and ankle joint angles were [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text], respectively, in all subjects. The pressure distribution was 38 [Formula: see text] 19%, 29 [Formula: see text] 12%, and 33 [Formula: see text] 9% on subjects’ heads, right elbows, and left elbows, respectively. The COP trajectory was 31.2 [Formula: see text] 17.4[Formula: see text]cm and surface area was 5.3 [Formula: see text] 1.4[Formula: see text]cm2. No significant differences were found in joint angles, overall force distribution, and COP trajectory and surface area between genders. Both males and females distribute body weight to the supports of head and elbows equally and kept the body straight and erect on the ground during Yoga headstand.

The Variance Needed to Accurately Describe Jump Height from Vertical Ground Reaction Force Data

2014 ◽  
Vol 30 (6) ◽  
pp. 732-736 ◽  
Author(s):  
Chris Richter ◽  
Kevin McGuinness ◽  
Noel E. O’Connor ◽  
Kieran Moran
Keyword(s):  
Principal Components ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Principal Component ◽  
Functional Principal Component Analysis ◽  
Optimal Threshold ◽  
Prediction Errors ◽  
Jump Height ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground

In functional principal component analysis (fPCA) a threshold is chosen to define the number of retained principal components, which corresponds to the amount of preserved information. A variety of thresholds have been used in previous studies and the chosen threshold is often not evaluated. The aim of this study is to identify the optimal threshold that preserves the information needed to describe a jump height accurately utilizing vertical ground reaction force (vGRF) curves. To find an optimal threshold, a neural network was used to predict jump height from vGRF curve measures generated using different fPCA thresholds. The findings indicate that a threshold from 99% to 99.9% (6–11 principal components) is optimal for describing jump height, as these thresholds generated significantly lower jump height prediction errors than other thresholds.

scholarly journals Biomechanical study on axillary crutches during single-leg swing-through gait

1986 ◽  
Vol 10 (2) ◽  
pp. 89-95 ◽  
Author(s):  
J. C. H. Goh ◽  
S. L. Toh ◽  
K. Bose
Keyword(s):  
Weight Bearing ◽  
Reaction Force ◽  
Force Plate ◽  
Primary Objective ◽  
Biomechanical Study ◽  
System A ◽  
Kinematic Study ◽  
Axillary Region ◽  
Male Subjects ◽  
Neurovascular Structures

This paper describes a kinetic and kinematic study on axillary crutches during one-leg swing-through gait. The primary objective is to evaluate the interplay of forces at the crutch and body interfaces and to relate them in the understanding of problems associated with the use of axillary crutches. Ten normal adult male subjects with simulated left leg impairment participated in the study. For data acquisition, the VICON kinematic system, a Kistler force plate and an instrumented crutch (with force transducers at the two upper struts close to the axillary bar and one near the crutch tip) were used. Results showed that the peak ground reaction force on the weight-bearing leg during lower limb stance increased by 21.6 percent bodyweight. The peak reaction force transmitted to the arm during crutch stancc was 44.4 percent bodyweight. These increased loadings could be detrimental to patients with unsound weight-bearing leg and upper extremities respectively. When the crutches were used incorrectly, 34 percent bodyweight was carried by the underarm. This could cause undue pressure over the neurovascular structures at the axillary region.

Kinetics Analysis of Instep Soccer Kick in Three Heights

2014 ◽  
Vol 1014 ◽  
pp. 161-164
Author(s):  
Pan Li
Keyword(s):  
Reaction Force ◽  
Force Plate ◽  
Soccer Players ◽  
Healthy Male ◽  
Principal Function ◽  
Kinetics Analysis ◽  
Male College ◽  
Ball Velocity ◽  
Soccer Kick ◽  
Support Leg

Using biomechanics theory to reveal the reaction force of ground of support leg in instep shot in different heights in soccer players. Twelve healthy male college students voluntarily participated in this study. After testing each participant by Kistler force plate and then analyze the collected data, the present study draws the following findings that (1) The reaction force of ground on support leg was independent of the ball velocity,(2) The principal function of support leg was in charge of fixing support, maintaining balance for optimal kicking ball of kicking leg.

884: Phase I, Double-Blind, Placebo-Controlled Study in Healthy Male Subjects to Investigate the Safety, Tolerability, and Pharmacokinetics of DA-8159

2004 ◽  
Vol 171 (4S) ◽  
pp. 234-234 ◽  
Author(s):  
Harin Padma-Nathan ◽  
Jae Seung Pacik ◽  
Byoung Ok Ahn ◽  
Kyung Koo Kang ◽  
Mi Young Bahng ◽  
...  
Keyword(s):  
Phase I ◽  
Controlled Study ◽  
Healthy Male ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Male Subjects

Structuring Assessments of Psychopathology

2006 ◽  
Vol 27 (2) ◽  
pp. 87-92 ◽  
Author(s):  
Willem K.B. Hofstee ◽  
Dick P.H. Barelds ◽  
Jos M.F. Ten Berge
Keyword(s):  
Principal Components ◽  
Personality Assessment ◽  
Clinical Sample ◽  
Principal Component ◽  
Normal Sample ◽  
Normative Sample ◽  
Assessment Data ◽  
Obsessive Compulsive ◽  
Oblique Rotation ◽  
Two Samples

Hofstee and Ten Berge (2004a) have proposed a new look at personality assessment data, based on a bipolar proportional (-1, .. . 0, .. . +1) scale, a corresponding coefficient of raw-scores likeness L = ΢XY/N, and raw-scores principal component analysis. In a normal sample, the approach resulted in a structure dominated by a first principal component, according to which most people are faintly to mildly socially desirable. We hypothesized that a more differentiated structure would arise in a clinical sample. We analyzed the scores of 775 psychiatric clients on the 132 items of the Dutch Personality Questionnaire (NPV). In comparison to a normative sample (N = 3140), the eigenvalue for the first principal component appeared to be 1.7 times as small, indicating that such clients have less personality (social desirability) in common. Still, the match between the structures in the two samples was excellent after oblique rotation of the loadings. We applied the abridged m-dimensional circumplex design, by which persons are typed by their two highest scores on the principal components, to the scores on the first four principal components. We identified five types: Indignant (1-), Resilient (1-2+), Nervous (1-2-), Obsessive-Compulsive (1-3-), and Introverted (1-4-), covering 40% of the psychiatric sample. Some 26% of the individuals had negligible scores on all type vectors. We discuss the potential and the limitations of our approach in a clinical context.

Comparison of Principal Component Solutions in Two Populations

Methodology ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Gregor Sočan
Keyword(s):  
Simulation Study ◽  
Principal Components ◽  
Common Factor ◽  
Principal Component ◽  
Component Model ◽  
Bootstrap Procedure ◽  
Factor Loadings ◽  
Component Loadings ◽  
Principal Component Model ◽  
Two Populations

Abstract. When principal component solutions are compared across two groups, a question arises whether the extracted components have the same interpretation in both populations. The problem can be approached by testing null hypotheses stating that the congruence coefficients between pairs of vectors of component loadings are equal to 1. Chan, Leung, Chan, Ho, and Yung (1999) proposed a bootstrap procedure for testing the hypothesis of perfect congruence between vectors of common factor loadings. We demonstrate that the procedure by Chan et al. is both theoretically and empirically inadequate for the application on principal components. We propose a modification of their procedure, which constructs the resampling space according to the characteristics of the principal component model. The results of a simulation study show satisfactory empirical properties of the modified procedure.

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