Validation of a robotic balance system for investigations in the control of human standing balance

Billy L. Luu, Thomas P. Huryn, H. F. Machiel Van der Loos, Elizabeth A. Croft, Jean-Sébastien Blouin

Research output: Contribution to journalArticleResearchpeer-review

27 Citations (Scopus)


Previous studies have shown that human body sway during standing approximates the mechanics of an inverted pendulum pivoted at the ankle joints. In this study, a robotic balance system incorporating a Stewart platform base was developed to provide a new technique to investigate the neural mechanisms involved in standing balance. The robotic system, programmed with the mechanics of an inverted pendulum, controlled the motion of the body in response to a change in applied ankle torque. The ability of the robotic system to replicate the load properties of standing was validated by comparing the load stiffness generated when subjects balanced their own body to the robot's mechanical load programmed with a low (concentrated-mass model) or high (distributed-mass model) inertia. The results show that static load stiffness was not significantly (p>0.05) different for standing and the robotic system. Dynamic load stiffness for the robotic system increased with the frequency of sway, as predicted by the mechanics of an inverted pendulum, with the higher inertia being accurately matched to the load properties of the human body. This robotic balance system accurately replicated the physical model of standing and represents a useful tool to simulate the dynamics of a standing person.

Original languageEnglish
Article number5752250
Pages (from-to)382-390
Number of pages9
JournalIEEE Transactions on Neural Systems and Rehabilitation Engineering
Issue number4
Publication statusPublished - 1 Aug 2011
Externally publishedYes


  • Balance control
  • load stiffness
  • robotics
  • standing

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