Search results for "Force platform"
showing 10 items of 60 documents
Brain Slow Potentials and Postural Sway Behavior During Sharpshooting Performance.
1999
In the present study, the relation of preparatory brain slow potentials (SPs) to postural body sway during sharpshooting performance was examined. SPs from frontal, left-central, and right-central areas were recorded from 6 elite and 6 non-elite sharpshooters during a realistic simulated shooting task. A force platform technique was used in the recording of postural sway. The results showed that body sway, as indexed by sway amplitude and mean velocity, was associated with the concomitant SP changes. That relationship was dependent on the shooter's expertise level, however. The main finding among the elite shooters was that the reduced amplitude of body sway coincided with reduced frontal p…
Deep learning approach for prediction of impact peak appearance at ground reaction force signal of running activity
2020
Protruding impact peak is one of the features of vertical ground reaction force (GRF) that is related to injury risk while running. The present research is dedicated to predicting GRF impact peak appearance by setting a binary classification problem. Kinematic data, namely a number of raw signals in the sagittal plane, collected by the Vicon motion capture system (Oxford Metrics Group, UK) were employed as predictors. Therefore, the input data for the predictive model are presented as a multi-channel time series. Deep learning techniques, namely five convolutional neural network (CNN) models were applied to the binary classification analysis, based on a Multi-Layer Perceptron (MLP) classifi…
Comparison of lower limb segments kinematics in taekwondo kick. an approach to the proximal to distal motion
2015
Abstract In taekwondo, there is a lack of consensus about how the kick sequence occurs. The aim of this study was to analyse the peak velocity (resultant and value in each plane) of lower limb segments (thigh, shank and foot), and the time to reach this peak velocity in the kicking lower limb during the execution of the roundhouse kick technique. Ten experienced taekwondo athletes (five males and five females; mean age of 25.3 ±5.1 years; mean experience of 12.9 ±5.3 years) participated voluntarily in this study performing consecutive kicking trials to a target located at their sternum height. Measurements for the kinematic analysis were performed using two 3D force plates and an eight came…
Prediction of active peak force using a multilayer perceptron
2017
Both kinematic parameters and ground reaction forces (GRFs) are necessary for understanding the biomechanics of running. Kinematic information of a runner is typically measured by a motion capture system whereas GRF during the support phase of running is measured by force platforms. To analyze both kinematics and kinetics of a runner over several subsequent contacts, an instrumented treadmill or alternatively several force platforms installed over a regulated space are available options, but they are highly immovable, expensive, and sometimes even impractical options. Naturally, it would be highly useful to predict GRFs using a motion capture system only and this way reduce costs and comple…
Fatigue effects of marathon running on neuromuscular performance
2007
Nine experienced endurance runners performed individual marathon runs that involved several tests of neuromuscular performance before, during and after the marathon. The tests were performed with special force platform and dynamometer techniques. The results showed an overall decrease in performance from the marathon. The maximal sprint velocity decreased parabolically during the marathon, reaching the final value of 84% of the pre-marathon one. Similarly, the other test results after marathon indicated that maximal isometric knee extension torque was 78%, the performance in a special rebound test (drop jump) 84% and the 5-jump performance 92% of the pre-marathon values. These reductions we…
A step towards a field based agility test in team sports. A perspective on return to play criteria
2017
Introduction: Agility performance tests can be limited by the requirement for force plates, timing gates and expensive camera systems (Correia et al., 2012; Green, Blake, & Caulfield, 2011) making application into rehabilitation programs practically challenging. The aims of this study were to assess the reliability of a field based 1v1 agility test encompassing perceptualaction performance that could be replicated in applied settings. A secondary aim was to assess the relationship between the 1v1 agility test with a range of physical performance tests including the commonly used Y step test (Paul, Gabbett, & Nassis, 2016). Methods: Twenty-eight male rugby union players volunteered (Mean ± S…
Effect of Motor-Cognitive (Dual Task) Rehabilitation Program on Gait Biomechanics in Parkinson’s Disease: Case Study
2016
In some pathologies with impaired control gait, the dual task execution even worse these gait alterations, as in Parkinson’s Disease (PD) occurs. The aim of this paper is to present the effects of a rehabilitation program that integrates dual tasks in gait rehabilitation and prepare patients to move functionally in complex environments in a person with PD. 3D photogrammetry system and two force platform were used for the registering of kinematic and kinetic parameters, respectively. The main variables that have improved after the proposed program are: speed gait (54.87 %), step length (52.01 %), stride length (43.48 %), double support time (37.36 %), flexo-extension hip range of motion (36.…
Relationships Between Standing Balance and Symmetry Measurements in Patients Following Recent Strokes (≤3 Weeks) or Older Strokes (≥6 Months)
2004
Abstract Background and Purpose. The Functional Standing Balance (FSB) Scale was designed to obtain measurements of standing balance and to identify the problems typically faced by people with stroke. The purpose of this study was to investigate the validity of measurements obtained with the FSB Scale for use in the acute and chronic phases of stroke by comparing the measurements obtained with the FSB Scale with those obtained for postural sway and lateral symmetry by use of a force platform. Subjects and Methods. Measurements were obtained for 26 people with recent strokes (ie, strokes within 3 weeks of data collection) and for 28 people with long-standing strokes (ie, strokes of 6 months'…
AB0929 Balance in fibromyalgia is not related with lower limb strength
2017
Background Postural control, that depends on many sensory contributors and motor skills, is altered in people with fibromyalgia (FM) 1–3. Knowing those contributors that could be impaired in this population is important to design an appropriate balance therapy. Objectives Due to the fact that people with FM use to present a strength loss 7, our main goal was to explore the relation between postural control and lower limb strength in this population. Further, the sensory inputs contributors to the postural control were assessed. Methods A cross-sectional study was conducted in a sample of 40 FM patients. A force platform was used to assess postural control under five bipedal conditions: i) e…
Comparison between the directly measured achilles tendon force and the tendon force calculated from the ankle joint moment during vertical jumps.
1988
Summary The purpose of this study was to compare the relationship between the achilles tendon force and the tendon force estimated from the ankle joint moment (EATF) during vertical jump. A healthy male subject performed the following jumps on the force platform: (a) maximal vertical jump from a squat position without counter-movement; (b) maximal vertical jump from an erect standing position with a preliminary counter-movement; (c) repetitive submaximal hopping on the spot with preferred frequency. The achilles tendon force was measured directly with an implanted tendon transducer in all jumping conditions. In addition the joint moment obtained from the film and ground reaction force was u…