Seated Dancer, Head in Hands

Hands-free navigation in VR environments by tracking the head

Conventional methods of navigating within a virtual reality environment involve the use of interfaces such as keyboards, hand-held input devices such as joysticks, mice, and trackballs, and hand-worn data gloves. While these devices are mostly adequate, they are rather obstrusive and require some amount of training to use. Researchers have begun investigation into interfaces that have the capab...

Posterior ankle impingement in the dancer.

Dancers spend a lot of time in the relevé position in demi-pointe and en pointe in their training and their careers. Pain from both osseous and soft tissue causes may start to occur in the posterior aspect of their ankle. This article reviews the potential causes of posterior ankle impingement in dancers. It will discuss the clinical evaluation of a dancer and the appropriate workup and radiogr...

Variability in the control of head movements in seated humans: a link with whiplash injuries?

The aim of this study was to determine how context and on-line sensory information are combined to control posture in seated subjects submitted to high-jerk, passive linear accelerations. Subjects were seated with eyes closed on a servo-controlled linear sled. They were asked to relax and received brief accelerations either sideways or in the fore-aft direction. The stimuli had an abrupt onset,...

Galvanic Vestibular Stimulation Elicits Consistent Head-Neck Motion in Seated Subjects

Humans actively stabilize the head-neck system based on vestibular, proprioceptive and visual information. Galvanic vestibular stimulation (GVS) has been used previously to demonstrate the role of vestibular feedback in standing balance. This study explores the effect of GVS on head-neck kinematics and evaluates the approach to investigate the vestibular contribution to head-neck stabilization....

Adaptation of Postural Reactions in Seated Positions and Influence of Head Posture when