Design, fabrication, and validation of a portable perturbation treadmill for balance recovery research

Abstract

Trips and falls are a major concern for older adults. The resulting injury and loss of mobility can have a significant impact on quality of life. An emerging field of study, known as Perturbation Training, has been shown to reduce injury rates associated with trips and falls in older adults. In a typical training session, the user stands or walks on a treadmill and is subject to sudden, unexpected accelerations, simulating a trip or slip, in a safe environment. This training aims to improve the user's ability to maintain and recover balance in situations that can often lead to falls. Treadmills traditionally used for Perturbation Training are large instrumented devices that are rigidly bolted to the floor. This presents a problem for older adults with limited mobility or those who live far away from Perturbation Training facilities. A portable treadmill would be able to serve a larger portion of the at-risk population then current methods have allowed. We developed a portable, low-cost perturbation treadmill capable of high-intensity training. The system can perform trip and slip perturbations from a stationary or walking state. It features a tandem belt configuration, a small gap between belts, and individual belt control. The belt speed is digitally controlled, dictated by a custom human-machine-interface and software suite, which allows operators with no programming experience to control the device. When connected to a 240-volt power supply, the maximum belt speed is approximately 3.6 m/s. The treadmill was designed to accommodate a user of up to 118 kg and provide a maximum acceleration of 12 m/s 2 under full load. The treadmill weighs approximately 180 kg and can be moved like a wheelbarrow, with handles in the back and wheels in the front. The design has been validated and was used in multiple locations in a clinical trial.