0000000000064010
AUTHOR
Thierry Paillard
Inter-joint coordination of posture on a seesaw device
Even though specific adjustments of the multi-joint control of posture have been observed when posture is challenged, multi-joint coordination on a seesaw device has never been accurately assessed. The current study was conducted in order to investigate the multi-joint coordination when subjects were standing on either a seesaw device or on a stable surface, with the eyes open or closed. Eighteen healthy active subjects were recruited. A principal component analysis and a Self-Organizing Maps analysis were performed on the joint angles in order to detect and characterize dominant coordination patterns. Intermuscular EMG coherence was analysed in order to assess the neurophysiological mechan…
Les performances posturale et cognitive divergent et varient selon l’état physiologique
Introduction Les effets de l’exercice physique aigu sur le controle postural et les ressources attentionnelles ont ete peu etudies simultanement et les resultats obtenus divergent. Cette etude visait a etudier les effets de l’exercice aigu sur le controle postural dans une position specifique de tir debout associee a une tâche cognitive. Materiel et methodes Dix-neuf soldats masculins (25–40 ans) ont d’abord effectue une tâche posturale simple (TS) en tenant un fusil d’assaut et en restant le plus immobile possible, puis ils ont ensuite effectue la meme tâche en effectuant simultanement une tâche cognitive de tir en reponse a des stimuli (double tâche ou DT). Les deux tâches TS et DT ont et…
Methods and Strategies for Reconditioning Motor Output and Postural Balance in Frail Older Subjects Prone to Falls
In frail older subjects, the motor output of the antigravity muscles is fundamental in resisting falls. These muscles undergo accelerated involutions when they are inactive and the risk of falling increases during leisure and domestic physical activity. In order to reduce their risk of falling, frail older subjects limit their physical activities/exercises. The problem is that the less they exercise, the less they are able to exercise and the greater the risk in exercising. Hence, a vicious circle sets up and the antigravity muscles inevitably continue to deteriorate. This vicious circle must be broken by starting a reconditioning program based on developing the strength of antigravity musc…
The influence of wearing ski-boots with different rigidity characteristics on postural control
External supports that reduce ankle joint mobility such as ski-boots can impair postural control of healthy participants. Although this disruptive effect has been attributed to the rigidity of the external supports, the results remained controversial and no study has been conducted in order to evaluate the influence of ski-boots rigidity. Hence, the question about the influence of ankle support rigidity on postural control remains open. This study was therefore undertaken in order to investigate the effect of ski-boots rigidity on postural control. Ten healthy active participants were recruited. The wearing of soft and rigid ski-boots was compared to barefoot while standing on a seesaw gene…
Rehabilitation and Improvement of the Postural Function
Posture refers to the position of different body segments at a given time which can be modified through joint mobilization and the action of the neuromuscular system. Maintaining balance during bipedal quiet stance requires complex mechanisms from the postural control system in order to keep the vertical projection of the centre of mass (COM) within the base of support [1]. To achieve this aim, the centre of pressure (COP) plays a crucial role to compensate for any deviations of the COM, which can generate imbalance if they move beyond the limits of the base of support. The ability to control the COM depends on internal body representation in space. Internal representation is acquired by me…
Fatigue does not conjointly alter postural and cognitive performance when standing in a shooting position under dual-task conditions
ABSTRACTThis study investigated the effects of fatigue on balance control and cognitive performance in a standing shooting position. Nineteen soldiers were asked to stand while holding a rifle (single task – ST). They also had to perform this postural task while simultaneously completing a cognitive task (dual task – DT). Both the ST and DT were performed in pre- and post-fatigue conditions. In pre-fatigue, participants achieved better balance control in the DT than in the ST, thus suggesting that the increased cognitive activity associated with the DT improves balance control by shifting the attentional focus away from a highly automatised activity. In post-fatigue, balance control was deg…
La difficulté de la tâche posturale accentue les effets de la fatigue sur la stabilité posturale
Introduction La difficulte de la tâche posturale est supposee accentuer les effets de la fatigue sur le controle postural. L’objectif etait de comparer les effets d’un exercice de course fatigant dans 3 conditions posturales de differents niveaux de difficulte : une position bipodale standard avec les yeux ouverts (YO), une position bipodale standard avec les yeux fermes (YF) et une position de tir a la carabine avec les yeux ouverts (TIR). La condition TIR implique de supporter une carabine horizontalement avec les bras et de placer la jambe dominante devant la jambe non-dominante. Materiel et methode Trente-deux soldats masculins ont realise un exercice maximal de course sur tapis roulant…
Ski Boots Do Not Impair Standing Balance by Restricting Ankle-Joint Mobility.
Objective: This study was undertaken in order to provide new insight into sensorimotor control of posture when wearing high-shaft (HS) boots as ski boots. Background: Previous studies into the effects of HS boots on postural control have produced controversial results. Some studies reported postural control impairments with ski boots in bipedal postural tasks due to ankle movement restrictions without quantifying the actual restrictive effect of these boots and specifying the adaptations of the postural control system. Method: Eighteen young healthy subjects took part in the experiment. Bilateral postural control was assessed on stable and unstable surfaces, while standing barefoot or weari…