1,720,964 research outputs found
From standing posture to vertical jump - Experimental and model analysis of human movement
No full textDalla postura eretta al salto verticale - Analisi sperimentale e modellistica del movimento uman
Ankle moment measurement in biomechanics
No full textBiomechanical movement analysis is based on a set of kinematic measurements, generally obtained through video recordings, and kinetic measurements usually through a force platform. In order to obtain more detailed information for example as regards internal joint forces and moments, a biomechanical model is required. Model inputs are kinematic and kinetic measurement data, while internal forces and moments are its outputs. Particularly interesting when dealing with lower limbs models for describing for example walking, jumping or lifting on tiptoes, is the ankle moment. Usually ankle is the first joint in the model and external forces act on it producing moments that foot and ankle have to withstand with muscles acting on it. The measurement of such moment is critical due to several factors primarily the unknown position of centre of rotation for the foot. Several methods are available to indirectly measure ankle moment, we propose here a comparison of different measurement approaches considering their results for different gestures, commenting pros and cons and giving some practical indications
Probabilistic Framework for Dynamic Measurements for Markovian Models With a Uniform Prior for the Measurand
No full textToward a probabilistic theory of the measuring systems
No full textIn the current debate on measurement science, there is growing interest in identifying some generic framework for the modelling of the measurement system. Recently, we have proposed sufficient conditions for an empirical system to qualify as a measuring system, and have proposed a deterministic framework based on that. Here we consider turning that framework into a corresponding probabilistic one, in other to properly accounting for measurement uncertainty
Measurement of human movement under metrological controlled conditions
No full textThe study and modeling of human movement requires accurate measurement of forces and of kinematic quantities, with proper control and monitoring of measurement uncertainty. The metrological aspects of such experimentation are often overlooked in the biomechanical literature. In contrast, we present here a complete measurement system that combines a double force platform with vision and inertial sensors. Thanks to some degree of instrumental redundancy a cross‐validation of different measuring channels is possible. Therefore the system permits the characterization of a person’s movement, enabling, at the same time, the verification of the acquired experimental data. Details are provided about the system and about the measurement procedure, in order to allow the reproducibility of the experiment, if needed, in other laboratories. Then, as a test case, the experimental study of hopping is considered. Three male subjects performed the tests on several sessions. Experimental results are discussed, with special focus on kinematic quantities, and system performance is discussed, by properly accounting for uncertainty issues
Instantaneous centre of rotation in human motion: Measurement and computational issues
No full textThe instantaneous centre of rotation plays an important role in biomechanical modelling and physical-medical interpretation of human gestures. Therefore, we consider its measurement, based on video-image acquisition and processing of human motion records. Measurement and computational aspects are discussed, including the evaluation of measurement uncertainty and the estimation of the effect of some influence quantities on the determination of the position of the instantaneous centre of rotation
A proposal for a new approach to the GUM
No full textWe propose a new approach to addressing the expression and evaluation of uncertainty in measurement, which at the one hand maintains the same original goals of the Guide to the Expression of Uncertainty in Measurement (GUM), as expressed by the original recommendations from the CIPM, on the other significantly differs in proposing how to implement them, for a closer orientation to the needs of the expected users, supported by a sound theoretical background. We suggest that this new approach may overcome some of the setbacks that have been experimented in the years in the application of the GUM, thus helping a wider diffusion of the practice of evaluating measurement uncertainty, by establishing a close link with the current state of the art of measurement science
- …
