A System that Adjusts Chair Configuration for Desired Postural Change

Paul van Geffen, Birgit Molier, Jasper Reenalda, Peter Veltink, PhD and Bart Koopman, PhD


Subjects who cannot reposition themselves adopt a passive sitting posture and often suffer from physical discomfort in long-term sitting. To regulate body load and to prevent seating related mobility problems, we developed a system that adjusts body posture in the sagittal and frontal plane. We describe this concept and evaluate whether it is applicable to control body posture. Eighteen healthy male subjects participated in the experiment. Quasi-static actuated chair movements were performed in which chair configuration and body posture were measured using an infrared-camera motion capturing system and an accelerometer attached on the pelvis. Strong significant relations were found between chair adjustments and body segment rotations, leading to an algorithm that predicts chair configuration from desired sitting postures. Although the experiment only involved healthy subjects, we assume that the described concept for postural adjustments is clinically applicable to control sitting posture.


wheelchair adjustment, posture control, pelvis, body segments, postural alignment


This study was partly funded by the Dutch Ministry of Economic Affairs, SenterNovem. The authors would like to thank the engineering company Demcon (Oldenzaal, the Netherlands) for their contribution in the design and development of the experimental simulator chair. 


Paul van Geffen, Institute for Biomedical Technology (BMTI), Laboratory of Biomechanical Engineering, Department of Engineering Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands, Telephone: +31 53 489 3649, Email: P.vanGeffen@ctw.utwente.nl