Interpretation of navigation information modulates the effect of the waist-type Hanger Reflex on walking

The Hanger Reflex is a phenomenon in which the head rotates unintentionally when force is applied via a wire hanger placed on the head. This phenomenon is caused by physical pressure on the skin, and the direction of the Hanger Reflex modulated by the direction of skin deformation. A previous study examined the use of the head-, waist-, and ankle-type Hanger Reflex on walking navigation without interpretation of navigation information, and found that the waist-type Hanger Reflex had the strongest effect on walking. However, the existing waist-type Hanger Reflex device is passive; i.e. must be operated by the user, which leads to the necessity of developing a new active type device for use as part of a navigational system. In this paper, we developed a controlled waist-type Hanger Reflex device with four pneumatic actuators. We investigated different interpretations of navigation information on the effect of our device on walking. Our interpretation conditions included “Natural”, in which users did not attempt to interpret the navigation information, “Follow”, and “Resist”, in which they actively followed, or resisted the navigation information, respectively. We confirmed that our waist-type Hanger Reflex device could control the walking path and body direction, depending on user's interpretation of the navigational information.