Wheelchair equipped with an electrically controlled tilting mechanism for reducing and redistributing interface pressure: proof of concept

Purpose: Adjusting the tilt and recline angles of a wheelchair is recommended as one of the approaches for preventing pressure injuries associated with mechanical loading in wheelchair users. However, maintaining a fixed inclination may increase pressure on other body areas, raising concerns about the time-dependent risk of ulcers. To address this issue, we proposed an electrically powered wheelchair equipped with a mechanism that continuously changes the tilt angle, similar to the motion of a rocking chair, and developed a prototype as a proof of concept. This cross‑sectional study aimed to evaluate the effectiveness of the prototype wheelchair in reducing and redistributing interface pressure. Materials and methods: Eight healthy participants were enrolled in this study. The electrically controlled tilt angle was programmed to cycle from 0° to 30° in 50 s. Reclining angles were set at 0°, 10°, 20°, and 30°. The pressure at the head, back, and buttocks was recorded. Results: The peak pressure in these areas changed dynamically with tilt variation; increasing the tilt angle raised the peak pressure at the head and back while reducing it at the buttocks. Increasing the reclining angle amplified these changes in the head and buttocks but had no effect on the back. Conclusion: Our findings suggest that continuous tilt variation may reduce prolonged exposure to excessive pressure, potentially reducing the risk of ulcers in the buttocks associated with mechanical loading in wheelchair users.