Design and evaluation of a multimodal balance training system

Objective: Current balance training systems are designed exclusively for one particular type of training and assessment. Additionally, they comprise monotonous training programs. Therefore, patients in different stages of rehabilitation must use different balance training models from different manufacturers, resulting in high treatment cost. Furthermore, large spaces are required to accommodate the balance training machines, and doctors and physiotherapists have to learn to operate multiple machines. We aimed to design a multimodal balance training and assessment system that can accommodate the assessment and training of static, dynamic, reactive and proactive balance to satisfy individual needs. Methods: The difficulty associated with combining static, dynamic, reactive and proactive balance training in a single system was to use radial and circumferential driving mechanisms together with a clutch mechanism, whereby circumferential and radial drivers were installed in the base of the system to drive a compound foot plate system with interchangeable springs, in order to adjust stiffness using the clutch. Based on the kinematic equation, the influence of system parameters on the change of the body's center of gravity were evaluated. The parameters included the radial offset of the driving mechanism (r), circumferential angle of rotation (theta), height of the base of the balance training system (h), horizontal distance between the body's standing center of gravity and the center of the foot plate (R), thickness of the padding mat (.H) and inclination angle (a). Results: The difficulties associated with combining static, dynamic, reactive and proactive balance training models in a single system were solved using radial and circumferential driving mechanisms together with a clutch mechanism. The foot plate can swing back and forth within +/- 20 degrees around the X-axis, swing left and right within +/- 20 degrees around the Y-axis, swing diagonally within +/- 20 degrees, swing 360 degrees around the Z-axis, and adjust the height along the Z-axis. Furthermore, the inclination angle a, circumferential angle of rotation., and speed (d alpha/dt and d theta/ dt) of the system can be controlled in real time. Conclusion: The developed balance training system is suitable for patients in different stages of rehabilitation. By providing multiple functionalities, this system can ensure high use rates, reduce costs and save space.