A wearable light-touch contact device for human balance support.

There is an urgent need for the development of ways to address the major issue of falls among today's globally aging population. The authors here outline a new approach referred to as virtual light-touch contact to mitigate postural sway during ambulatory and stationary periods, and propose a wearable light-touch (WLT) system featuring a virtual partition around the user that allows determination of virtual forces resulting from related contact. The data produced are used to create vibrotactile fingertip feedback, which supports comprehensive perception of the partition. Non-impaired subjects were recruited to support evaluation of the prototype system (incorporating tactile stimulation and motion-capture technology), with outcomes showing successful mitigation of postural sway in a heel-to-toe tandem stance. Research performed with 150 able-bodied volunteers to validate the performance of the new set-up (incorporating an acceleration sensor and a voice coil motor to render the light-touch effect) suggested that the proposed WLT approach supports human balance on a level comparable to that of the light-touch effect.

Effects of somatosensory information provision to fingertips for mitigation of postural sway and promotion of muscle coactivation in an upright posture.

This study was conducted to investigate the effects of somatosensory information provision to the fingertips using a device proposed by the authors for mitigation of postural sway and muscle co-contraction in an upright posture, which both increase with aging and result in inefficient postural control. In the research, center of pressure (CoP) fluctuation index values and muscle co-contraction for ankle joint movement were monitored with healthy young adults in a standing position. The results showed that the proposed device helped to reduce the root mean square (RMS) of the CoP and muscle co-contraction in the right ankle joint, thereby suggesting its potential for contribution to the assistance of efficient postural control.

A Standing Function Evaluation System Based on Virtual Light Touch Contact and Factor Analysis.

This paper proposes a standing function evaluation system on the basis of factor analysis for indices related to standing characteristics. For this approach, five standing function factors were checked in a large-scale experiment using the results of extraction from 48 indices based on factor analysis. Five factors were extracted from these indices, and the related score radar charts indicated that most factors changed with age. The evaluation results suggest that the system facilitates intuitive comprehension of standing-related factors based on these charts.

A fundamental study on how holding a helium-filled balloon affects stability in human standing.

Various studies have been conducted in the field of the development/deterioration of standing and walking ability. In standing and walking control strategy, the relationship linking visual/somatosensory/vestibular-system information and physical movement is important. Researchers have previously sought to evaluate attitude control based on human sensory information. The authors have also reported that the body sway of a walking infant is mitigated when the subject holds a helium-filled balloon, with results suggesting that this approach can be applied to extend walking distance. This study was conducted to clarify how holding a balloon influences standing control strategy. A novel system was developed to quantitatively monitor and evaluate the standing state of subjects holding such a balloon. The results of the experiments conducted indicate that attitude control strategy changes in response to somatosensory information provided by the physical connection with the balloon.