The benefits of the anchor system on different parts of the body for posture control in older adults

ABSTRACT The anchor system is a nonrigid tool that provides additional haptic information. It consists of two malleable cables with 125g loads resting on the floor, whereas the hands hold the other end of the cable (hand anchor). If we consider that light touch of different parts of the body reduces body sway, it is also possible that the use of the anchor system on different parts of the body might be effective. Therefore, this study aimed at investigating the effect of using the anchor system on different parts of the body on older adults’ body sway. Thirty older adults participated in this study. Participants stood on a force platform in a semi-tandem position and maintaining an upright posture for measuring deviations in the location of the center of pressure (CoP). Each participant was exposed to five experimental conditions: no anchor, hand anchor, anchors in hands fastened with straps, anchors in forearms fastened with straps and anchors in shoulders fastened with straps. The results showed a reduction in the area of the ellipse adjusted to the deviation of the CoP and mean sway amplitude in the anteroposterior direction with the anchors positioned on the hands (traditional and strap) and forearms, compared with the condition without the anchor. Thus, the use of the anchor system was effective when the anchors were positioned on the forearm as well as when they were fastened/held in hands. The improvement observed with the use of anchors does not seem to be related to the amount of tactile receptors at the point of contact with the anchor cables.