Search results for "KINEMATICS"

Measurement of take-off forces in ski jumping

2007

The force measuring system constructed under the frost rail inrun track element was used for measurement of take-off forces in ski jumping. Several calibrations of the normal forces made on several days showed no significant differences between the calibration sessions. Loading the different places of the track element showed differences less than 5% between the places for the total 10-m distance and less than 3% for the straight take-off table. Two international-level ski jumpers served as subjects during the testing of the system. Further preliminary results from 2 different performances techniques are presented. The force curves of subjects displayed totally different patterns: Two disti…

Effects of Kinesiotape® taping on plantar pressure and impact acceleration during walking

2014

Summary Objectives The aim of this study was to analyse the plantar pressure pattern, contact time, stride rate and impact acceleration in the shank during walking with and without Kinesio Tape (KT®) placed on two muscle groups: peroneus and triceps surae. Methods Among the subjects, 29 (12 men, 17 women) participated in the study. KT® was placed on the triceps surae and peroneus and participants walked at two different speeds (V1: 0.73 m/s; V2: 1.30 m/s) with and without KT®. The pedobarographic system Biofoot IBV® 6.0 was used to analyse plantar pressure (mean peak pressure [kPa]) in 5 foot areas and the kinematic variables of the study (contact time [s]; stride rate [steps/second]). One …

Modeling and simulation of an offshore crane

2018

This paper presents a mathematical modeling of a crane system using robot modeling theory as well as the numerical simulation of the dynamics of a crane and a marine craft. The simulations are performed in SimulationX and Matlab Simulink. The simulation platform includes a SimulationX-model of the crane, a realistic model of a marine craft using the Marine Systems Simulator(MSS) and the hydrodynamic sea-keeping calculations (VERES program code). The simulation results show a very good picture of the dynamic behavior of the real crane in offshore environment and verify the validation and effectiveness of the presented modeling approach.

Análisis cinético y cinemático de las articulaciones del mediopié durante la marcha en sujetos sanos: consideraciones clínicas

2016

Introducción: No existe todavía suficiente evidencia en estudios clínicos respecto al comportamiento del mediopié en situaciones dinámicas como la marcha o la carrera. El presente estudio pretende analizar el comportamiento mecánico de las articulaciones del mediopié mediante un modelo multisegmental del pie, con especial atención a los momentos articulares y sus repercusiones clínicas. Sujetos y métodos: Se realizó un estudio computarizado de la marcha sobre 30 sujetos adultos sanos (27,13 ± 3,82 a˜nos) con un índice de postura del pie (FPI) neutro (entre 0 y +5). Se estimaron los ángulos y momentos articulares externos en 3 dimensiones mediante un modelo que considera 3 segmentos (antepié…

Using deep neural networks for kinematic analysis: Challenges and opportunities

2020

Kinematic analysis is often performed in a lab using optical cameras combined with reflective markers.\ud With the advent of artificial intelligence techniques such as deep neural networks, it is now possible\ud to perform such analyses without markers, making outdoor applications feasible. In this paper I summarise\ud 2D markerless approaches for estimating joint angles, highlighting their strengths and limitations.\ud In computer science, so-called ‘‘pose estimation” algorithms have existed for many years. These methods\ud involve training a neural network to detect features (e.g. anatomical landmarks) using a process called\ud supervised learning, which requires ‘‘training” images to be …

Validity and reliability of a 3-axis accelerometer for measuring weightlifting movements

2016

The purpose of the current study was to assess the validity and reliability of measures obtained by a 3-axis commercial accelerometer during weightlifting movements in comparison with kinematic data derived from the 3D videography. Kinematic data from 3D videography were obtained from 11 track & field throwers performing 3 trials each one at different loads in power snatch, power clean and jerk from the rack. The results showed that the accelerometer measures were highly correlated with derived acceleration data from 3D videography data in the vertical plane (Z axis) taking up to the pull phase (including first pull, transition and second pull) for power snatch and power clean and up t…

Reliability and concurrent validity of the Velowin optoelectronic system to measure movement velocity during the free-weight back squat

2018

The objective of this study was to explore the reliability and concurrent validity of the Velowin optoelectronic system to measure movement velocity during the free-weight back squat exercise. Thirty-one men (age = 27.5 ± 3.2 years; body height = 1.76 ± 0.15 m; body mass: 78.3 ± 7.6 kg) were evaluated in a single session against five different loads (20, 40, 50, 60 and 70 kg) and three velocity variables (mean velocity, mean propulsive velocity and maximum velocity) were recorded simultaneously by a linear velocity transducer (T-Force; gold-standard) and a camera-based optoelectronic system (Velowin). The main findings revealed that (1) the three velocity variables were determined with a h…

Ensemble Averaging and Multiple Statistical Testing of EMG Activities of Cyclically Repeated Body Motions. A Tool for Muscle Function Analysis in Exp…

2003

Coupled with suitable computerized signal recording and processing methods surface electromyography can be a powerful tool for the analysis of muscle activity in specific body movements. It can be used for this purpose in experimental and in clinical diagnostic orthopaedics as well as in physiotherapy. We describe in this paper a motion analysis system comprising this feature. It has been employed for the diagnosis of the basic angular kinematics and muscle function in human gait and other cyclically repeatable movements of the human locomotive system. Changes in the temporal characteristics of the movements and the muscle activity due to changed physical or experimental conditions can be s…

2015

Previous studies have documented the detrimental effects of microgravity on human sensorimotor skills. While that work dealt with simple, laboratory-type skills, we now evaluate the effects of microgravity on a complex, realistic instrument-control skill. Twelve participants controlled a simulated power plant during the short-term microgravity intervals of parabolic flight as well as during level flight. To this end they watched multiple displays, made strategic decisions and used multiple actuators to maximize their virtual earnings from the power plant. We quantified control efficiency as the participants’ net earnings (revenue minus expenses), motor performance as hand kinematics and dyn…

Fuzzy Control Strategy for Cooperative Non-holonomic Motion of Cybercars with Passengers Vibration Analysis

2021

The cybercars are electric road wheeled non-holonomic vehicles with fully automated driving capabilities. They contribute to sustainable mobility and are employed as passenger vehicles. Non-holonomic mechanics describes the motion of the cybercar constrained by non-integrable constraints, i.e. constraints on the system velocities that do not arise from constraints on the configuration alone. First of all there are thus with dynamic nonholonomic constraints, i.e. constraints preserved by the basic Euler-Lagrange equations (Bloch, 2000; Melluso, 2007; Raimondi & Melluso, 2006-a). Of course, these constraints are not externally imposed on the system but rather are consequences of the equations…