The Click Test: A Novel Tool to Quantify the Age-Related Decline of Fast Motor Sequencing of the Thumb

International audienceAbstract : Background: The thumb plays a critical role for manual tasks during the activities of daily life and the incidence of neurological or musculoskeletal disorders affecting the voluntary movements of the thumb is high in the elderly. There is currently no tool to assess repetitive motor sequencing of the thumb during ageing.Objectives: To report a novel procedure (the Click Test) assessing the effects of ageing on fast motor sequencing of the thumb.Methods : Healthy subjects (n = 252; mean age +/- SD: 49.76 +/- 19.97 years; range: 19-89 years; F/M: 151/101) were asked to perform fast repeated flexion/extension movements of the thumb using a mechanical counter.Results: Motor performances (assessed by the number of clicks during 3 time periods: 15, 30 and 45 sec), significantly decreased as a function of age for both the dominant (age effect; p< 0.0001 for 15, 30 and 45 sec) and the non-dominant hand (p<0.0001 for 15, 30 and 45 sec). The number of clicks was significantly higher in males (gender effect; p<0.001) and was higher on the dominant side as compared to the non-dominant side (handedness effect: p<0.001). The Click Test is characterized by high repeatability (coefficients of variation from 3.20 to 4.47%), excellent intra-rater reliability (intra-class coefficients ICC ranging from 0.89 to 0.98), high inter-rater reproducibility (Pearson’s product correlation ranging from 0.85 to 0.96), high internal consistency (Cronbach alpha coefficient=0.95) and is highly correlated in terms of relative performances with the box and block test and the 9-hole peg test (positive linear correlation with the results of the box and block test: p<0.001 for 15, 30 and 45 sec for both the dominant and the non-dominant hand; negative linear correlation with the results of the 9-hole peg test: p<0.001 for 15, 30 and 45 sec for both the dominant and the non-dominant hand).Conclusion : The Click Test is an entirely novel and very low cost tool to reliably discriminate the ageing effects upon the performances during fast repetitive motor sequencing of the thumb. The potential clinical and research applications for motor functions are multiple, especially in acute and chronic neurological disorders affecting the thumb as well as in the field of rheumatology and orthopedics

Simulating the explosive thermonuclear burning of a stellar gas with the smoothed particle hydrodynamics methods

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Simulating the explosive thermonuclear burning of a stellar gas with the smoothed particle hydrodynamics methods

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Du laboratoire de physique nucléaire à l'explosion des étoiles.

info:eu-repo/semantics/publishe

Unidimensional SPH simulations of reactive shock tubes in an astrophysical perspective

Smoothed Particle Hydrodynamics (SPH) is a Lagrangian method widely used for the modelling of a large variety of astrophysical fluid flows in more than one dimension. Simulations of thermonuclear explosions in stars require, besides the hydrodynamic equations, a realistic equation of state, an energy source term, and a set of nuclear kinetic equations to follow the composition changes of the gas during the explosion. The implementation of a realistic stellar equation of state, and the coupling of hydrodynamics and nuclear burning are investigated in the framework of the simple shock tube geometry. We present and discuss the results of a series of SPH simulations of a detonation in the presence of (1) a single exothermic nuclear reaction, and (2) a restricted network of nuclear reactions. Our results are compared to those of identical simulations performed by other authors using a different hydrodynamic method. © Springer-Verlag 2007.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Régimes basse-vitesse de détonations thermonucléaires dans les supernovae de type Ia

We study the effects of the nuclear network detail and of the flow divergence on the reaction zone of thermonuclear detonations in the 50%-50% Carbon-Oxygen plasma at initial temperature and density 2 × 108 K and 5 × 106 g cm-3. We show that the total or intermediate ideal combustion lengths can be 200 times smaller than with the reduced networks used so far and we identify two low-velocity, curved-detonation regimes with incomplete combustion. To cite this article: A. El Messoudi et al. C. R. Mecanique 335 (2007). © 2007 Académie des sciences.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Hydrodynamical simulations of detonation in superbursts

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Mesure du caractère absorbant ou restitutif des matériaux utilisés en podologie

In order to measure the absorption or restitution property of the materials used in podiatry, an accelerated test measuring the restitutive character of functional orthoses has been designed. It makes an effective distinction between the coefficient of restitution (Cr) of propulsion elastomers such as Jogtene (0.740±0.010) and Dynatene (0.774±0.014). A significant Cr reduction is also detected for a heat treatment of 80°C for Jogtene and 160°C for Dynatene Podiatrists must therefore ensure that the heat treatment parameters are adapted to the materials used.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The electronic counting arm movement test (eCAM test)

A novel transportable electronic platform aiming to characterize the performance of successive fast vertical visually guided pointing movements toward two fixed targets (eCAM test: electronic counting arm movement test) is described and one validation test is presented. This platform is based on an Arduino H micro-controller and a Processing® routine. It records both the pointing performance (number of clicks) and the elapsed time between two successive pointing movements. Using this novel platform, we studied the effects of functional electrical stimulation (FES) applied on the dominant upper limb in 15 healthy volunteers (mean age ± SD: 22.3 ± 4.3 years; 5 males/10 females). The following muscles were stimulated: flexor carpi radialis (FCR), extensor carpi radialis (ECR), biceps brachii (BB), and triceps brachii (TB). The intensities of the stimulation were 2 and 3 mA above the sensory threshold (ST). Movement times were lesser when performed against gravity and pointing performance improved with FES. We provide the first demonstration that low-intensity FES impacts on motor performances during successive vertical goaldirected pointing movements under visual guidance. The eCAM test is currently the sole electronic tool to assess quickly and easily the performances of successive vertical pointing movements. Future potential applications include, in particular, the follow-up of the effects of neurorehabilitation of neurological/ neurosurgical disorders associated with hand-eye incoordination, the functional evaluation of upper limb prosthesis or orthosis, and the analysis of the effects of FES in central or peripheral nervous system disorders.SCOPUS: ar.jinfo:eu-repo/semantics/publishe