Effects of track-based stair climbing robot on muscle activity, usability, and psychological anxiety: a preliminary study.

ABSTRACT

This study investigated the effects of using the LiftCar-150 track-based stair-climbing robot on muscle activity, usability, and psychological anxiety. While stair-climbing robots enhance mobility for individuals with physical disabilities, existing research has predominantly focused on engineering perspectives, with limited attention to user-centered outcomes. Ten healthy participants and an 80 kg dummy rider completed stair-climbing tasks at slow (5 m/min) and fast (7 m/min) speeds. Muscle activity in the middle trapezius (MT), erector spinae (ES), multifidus (MF), gluteus maximus (Gmax), gluteus medius (Gmed), and anterior deltoid (AD) muscles was recorded by electromyography. Usability was evaluated in terms of safety, efficiency, and satisfaction using a 5-point Likert scale, while psychological anxiety was assessed with a visual analog scale (VAS) ranging from 0 to 10. Results showed that during stair ascent, activities of the back extensors (ES and MF) and gluteus muscles (Gmax and Gmed) significantly increased compared to descent, while anterior deltoid activity was higher during descent. Usability scores averaged 4.05 for stability, 4.1 for efficiency, and 3.7 for satisfaction. Perceived psychological anxiety scores were 4.2 ± 0.3 and 5.4 ± 0.5 at slow speed, and 3.5 ± 0.2 and 5.7 ± 0.4 at fast speed during ascent and descent, respectively. While operators recognized the robot's stability and efficiency, satisfaction levels were neutral, and specific muscle activation was increased. These findings provide essential insights into optimizing the design and usability of stair-climbing robots to better address user needs.

The proposed user-centered approach in this study can be used to improve performance and user satisfaction of a wide range of mobility device.To reduce extensor muscle activity caused by forward bending during initial stair climbing, it is necessary to modify the fixed handle design to allow adjustable handle height.Additionally, exploring options for weight reduction and repositioning the power button may further optimize the LiftCar-150, contributing to increased usability and satisfaction for operators.