Influence of Visual and Haptic Cues on Motor Learning: Insights from Tennis Skill Acquisition in Children.

Underdevelopment of cognitive abilities in children, such as memory and attention, may make the use of verbal instructions difficult for learning new motor skills. The objective of this study was to evaluate whether visual and haptic cues which emphasize certain instructions facilitate skill acquisition in young tennis players. Twenty children were distributed in 2 groups: experimental (EXP) and control (CON).

Finger force sharing during an adapted power grip task.

This study analyses the finger force sharing using power grip task with adapted experimental conditions. This paradigm limits as much as possible the external constraints when the Index (I), Middle (M), Ring (R) and Little (L) fingers act simultaneously: the thumb did not oppose the other fingers and no secondary moments were applied to the wrist. The motor control of these two parameters was limited in contrary to the previous paradigms of the literature.

Degraded postural performance after muscle fatigue can be compensated by skin stimulation.

It has been shown that the ability of humans to maintain a quiet standing posture is degraded after fatigue of the muscles at the ankle. Yet, it has also been shown that skin stimulation at the ankle could improve postural performance. In the present study, we addressed the issue of the interaction of these two effects.

Time course of neuro-mechanical changes underlying stretch-shortening cycle during intermittent exhaustive rebound exercise.

This study analysed the time course of neuro-mechanical changes underlying stretch-shortening cycle during intermittent exhaustive rebound exercise. On a sledge apparatus, ten subjects repeated until exhaustion a series of 30 unilateral submaximal rebounds, with intermediate 3-min rest periods. Rebound height, ground reaction force, 3D tibial acceleration and electromyographic activity of major lower limb muscles were recorded.

Characterization of the mechanical properties of backpacks and their influence on the energetics of walking.

The objectives of the experiment were (i) to characterize the mechanical properties of backpacks and (ii) to study the influence of a flexible backpack on the energetics and kinematics of walking. Twelve subjects walked at different speeds on a treadmill with each of two backpacks loaded with 25% bodyweight, with either a rigid or a flexible link between the body attachment and the suspended loads. A single degree of freedom linear model of the link between the pack and the trunk was used to calculate the stiffness and damping coefficient of the two backpacks.

Effects of hiking pole inertia on energy and muscular costs during uphill walking.

Introduction/purpose: The purpose of the present study was to investigate the effects of using hiking poles with different inertia on oxygen cost (V O2) and muscular activity.

Methods: Eleven subjects walked at 3 km.h on a treadmill inclined at 20% grade.