Anchor system contribution to stability control during tandem gait on the floor and on the balance beam in young and older adults

Abstract

The addition of haptic information through the anchor system improves postural control and this effect appears to be more effective in more challenging postural tasks, since in these tasks there is a greater need for integration and effective use of the additional information. Although the previous study carried out by the student has shown a reduction in the variability of the trunk when using the anchor system, this effect was not continued after withdrawal of the anchor system. The few practice trials or the lack of challenge of the task can explain this result. In the present study, the focus will be to investigate the anchor system contribution during walking with different levels of difficulty. Performing tandem gait on a balance beam is more challenging than on the ground, increasing trunk lateral instability. Therefore, the aim of this study is to evaluate the contribution of additional haptic information provided by the anchor system on locomotor stability of young and older adults while tandem walking on the floor and on a balance beam. We will invite 15 young adults (18-30 years) and 15 older adults (65-85 years) to participate in this study. They will be invited to walk on two different surfaces: floor and balance beam. In both surfaces, they will perform two conditions: with and without the anchor. Six reflective markers will be placed bilaterally on the 5th metatarsal, the lateral malleolus and the calcaneus to calculate gait spatiotemporal parameters: step length, step duration, step speed, single and double support time. The displacement of these markers will be tracked by eight cameras (Vicon). In addition, two accelerometers will be placed in the 7th cervical vertebra and the 2nd lumbar vertebra to record the acceleration of the trunk. For each step, RMS (root mean square) of the acceleration in the medial-lateral direction was computed to quantify the variability of trunk movement. The data will be analyzed using parametric statistics, with a significance level set to 0.05.