La compréhension des principes fondamentaux régissant les mouvements observés dans la Nature est un objectif fondamental de la science. Après les travaux pionniers de Newton (1643-1727), la Mécanique a considérablement évolué grâce aux reformulations de Lagrange (1736-1813) et de Hamilton (1805-1865). En invoquant un principe de moindre action, Lagrange a remplacé l'équation de Newton par la recherche ...

Abstract Background: In a changing European agricultural context, diversification of dairy farms is gaining attention. This study seeks to (1) assess musculoskeletal pain prevalence associated with tasks such as butter, yogurt, and cheese production; and (2) analyze associated risks. Methods: Observing 31, mostly female, workers, we utilized the ERGOROM questionnaire, a methodology adapted from ...

When a Hamiltonian system undergoes a stochastic, time-dependent anharmonic perturbation, the values of its adiabatic invariants as a function of time follow a distribution whose shape obeys a Fokker–Planck equation. The effective dynamics of the body’s centre-of-mass during human walking is expected to represent such a stochastically perturbed dynamical system. By studying, in phase space, the ...

Background: Side-stepping is a potential exercise program to reduce fall risk in community-dwelling adults in their seventies, but it has never been tested in nursing home residents. This was a pilot quasi-experimental study to examine the feasibility and potential mobility and balance benefits of an intervention based on voluntary non-targeted side-stepping exercises in nursing home residents ...

wo previous studies showed kinematic differences between novice and experienced performers during unchoreographed movements executed in standing position. However, no study explores if these kinematic differences holds during unchoreographed movements executed in quadrupedal position. The aim of this study is to compare the movement behaviour of experienced and novice performers during an exercise ...

Recent advances in electronics have led to sensors whose sizes and weights are such that they can be placed on living systems without impairing their natural motion and habits. They may be worn on the body as accessories or as part of the clothing and enable personalized mobile information processing. Wearable sensors open the way for a nonintrusive and continuous monitoring of body orientation, ...

We discuss the conditions under which static, finite-energy, configurations of a complex scalar field ϕ with constant phase and spherically-symmetric norm exist in a potential of the form V(ϕ*ϕ, ϕ^N, ϕ^*N) with N ∈ N and N ≥ 2, i.e., a potential with a ZN-symmetry. Such configurations are called ZN-balls. We build explicit solutions in (3 + 1)-dimensions from a model mimicking effective field ...

Editorial de la Special Issue de Sensors, Wearable Sensors Applied in Movement Analysis.

Human walking exhibits properties of both stability and variability. On the one hand, the variability of the interval of time between heel strikes is autocorrelated, i.e., not randomly organized. On the other hand, walking is highly stereotyped and arguments from general mechanics suggest that the stability of gait can be assessed according to invariant properties. This study aims at proposing ...

Nowadays, the better assessment of low back pain (LBP) is an important challenge, as it is the leading musculoskeletal condition worldwide in terms of years of disability. The objective of this study was to evaluate the relevance of various machine learning (ML) algorithms and Sample Entropy (SampEn), which assesses the complexity of motion variability in identifying the condition of low back pain. ...