An active balance board system with real-time control of stiffness and time-delay to assess mechanisms of postural stability

作者：Cruise Denise R; Chagdes James R; Liddy Joshua J; Rietdyk Shirley; Haddad Jeffrey M; Zelaznik Howard N; Raman Arvind^*

来源：Journal of Biomechanics, 2017, 60: 48-56.

DOI：10.1016/j.jbiomech.2017.06.018

• Human balance control
• Balance board
• Balance model
• Time-delay
• Rehabilitation

Increased time-delay in the neuromuscular system caused by neurological disorders, concussions, or advancing age is an important factor contributing to balance loss (Chagdes et al., 2013, 2016a,b). We present the design and fabrication of an active balance board system that allows for a systematic study of stiffness and time-delay induced instabilities in standing posture. Although current commercial balance boards allow for variable stiffness, they do not allow for manipulation of time-delay. Having two controllable parameters can more accurately determine the cause of balance deficiencies, and allows us to induce instabilities even in healthy populations. An inverted pendulum model of human posture on such an active balance board predicts that reduced board rotational stiffness destabilizes upright posture through board tipping, and limit cycle oscillations about the upright position emerge as feedback time-delay is increased. We validate these two mechanisms of instability on the designed balance board, showing that rotational stiffness and board time-delay induced the predicted postural instabilities in healthy, young adults. Although current commercial balance boards utilize control of rotational stiffness, real-time control of both stiffness and time-delay on an active balance board is a novel and innovative manipulation to reveal balance deficiencies and potentially improve individualized balance training by targeting multiple dimensions contributing to standing balance.

• 出版日期2017-7-26