Imitation of an action course in preschool and school-aged children: a hierarchical reconstruction.

Imitation is commonly considered as a hierarchical process. The current study explored the reproduction of a multi-task course in deferred imitation. Eighty-five children between 3.

Imitation of a bimanual task in preschool- and school-age children: a hierarchical construction.

The present study examined the development of bimanual interaction during the imitation of a live demonstration. To this end, children of five different age groups observed an adult model performing in an object manipulation task consisting to open a box with one hand, taking out an object with the other hand, and closing the box again, before they were asked to imitate this motor task under different imitation conditions. The children's responses were videotaped, coded in dichotomous data, and then transformed in percentage scores.

Influence of vision and motor imagery styles on equilibrium control during whole-body rotations.

To investigate the influence of vision and motor imagery styles on equilibrium control, displacements of the supporting foot during spontaneous whole-body rotations ("pirouette") by expert female ballet dancers were analyzed using three-dimensional kinematics. Four turn types were defined according to direction (clockwise, CW vs. counterclockwise, CCW) and supporting foot (SF, left vs.

Preschool-aged children's jumps: imitation performances.

Imitative behavior underlaid by perception and action links during children's development in complex locomotor skills has been the object of relatively few studies. In order to explore children's motor coordination modes, 130 children divided into five age groups from 3.5 to 7.

Right hemisphere in visual regulation of complex equilibrium: the female ballet dancers' experience.

Objective: To analyse the interaction between visual restrictions and somatosensory disturbances on unipedal control equilibrium with or without classical dance training.

Methods: The support (computerized force platform) was disturbed during roll and pitch sways in association with restriction of the left and right visual hemifields (selective nasal and temporal hemiretina goggles). The effect of training by comparing spontaneous dynamic equilibrium (spectral analysis of body sways) between 14 healthy female right-sided untrained and expert dancers was assessed.

Precocity of fine motor control and task context: hitting a ball while stepping.

To determine if children under 5 years were able to intercept a moving object while stepping, the authors had 9 3-year-olds hit a ball that the authors dropped from a ramp from 5 heights (1.5, 2.0, 2.

Effects of mental imagery styles on shoulder and hip rotations during preparation of pirouettes.

To analyze individual behavior in spatial navigation especially for pirouette preparations (complete whole-body rotations), the authors studied horizontal shoulder-hip interactions under 2 constraints: postural (right and left supporting legs [SL]) and spatial (clockwise [CW] and counterclockwise [CCW]). They performed kinematic analysis at the start and end of the shoulder-hip horizontal rotations (run-up) with regard to imagery of motor actions. On the basis of the Vividness of Movement Imagery Questionnaire, they classified 8 female expert ballet dancers and 7 untrained female participants according to their movement imagery style (kinesthetic and visual).

Spontaneous whole body rotations and classical dance expertise: how shoulder-hip coordination influences supporting leg displacements.

The link between supporting leg stability and individual trunk strategies used during spontaneous whole-body rotations was studied according to visual and kinesthetic imagery styles for classical dancers and untrained female participants. Shoulders-hip angles in the horizontal plane and supporting leg (SL) displacements were analyzed with three-dimensional kinematic at the beginning and end of the four turns, identified according to their SL (left vs. right) and turn direction (clockwise, CW vs.

Spatio-temporal constraints on upright children's coordination when hitting a moving target.

To determine if the spatial and/or temporal context affected the coordination patterns of children under five in upright interceptive tasks, 3-year-olds hit a ball dropped from a ramp from five heights (1.5, 2, 2.5, 3, and 3.

Dynamic balance sensory motor control and symmetrical or asymmetrical equilibrium training.

Objective: Determine whether symmetrical or asymmetrical equilibrium training can enhance the proprioceptive input of the left versus right supporting leg (SL) motor control.

Methods: Proprioceptive input was tested using a seesaw platform through a cross-sectional study. The total spectral energy was recorded and divided into 0-2 and 2-20Hz frequency bands.

Contribution of neck proprioception to subjective vertical perception among experts in physical activities and untrained women.

The purpose of this study was to investigate the influence of physical training on subjective vertical perception with the different head positions in order to explore the involving of the neck proprioception. Visual field dependence was assessed using a rod and frame test on women practising judo or dance (international level) or no specific physical activity. Tests were performed with head upright or tilted head to disturb the Z-axis egocentric reference frame.

Does footedness or hemispheric visual asymmetry influence centre of pressure displacements?

To isolate the footedness contribution from the hemispheric visual asymmetry contribution to the upright postural control, seven right and six left-footed healthy women were asked to balance on each unipodal stance on an unstable platform for each visual hemispaces. We compared lateral deviations of the centre of pressure when balancing on the left leg and on the right leg in three visual conditions: normal and restricted to each hemifields. Whatever the visual conditions, left-footers displaced the centre of pressure towards the outside of the supporting foot, whereas right-footers displaced it towards the right side for the two feet.

Unipodal performance and leg muscle mass in jumping skills among ballet dancers.

We examined the vertical jump performance of each leg among 10 right-footed female ballet dancers with 1 yr. of international professional experience (quadrilles: Opera ballerinas). Their mean age was 17.