By Duangporn Suriyaamarit and Sujitra Boonyong

Sit-to-stand movements, where an individual rises from a chair to a standing position, are common daily functional actions. Previous research has demonstrated that the design and dimensions of the chair used can influence the performance of the sit-to-stand task. For instance, getting up from a chair with higher height and an anterior tilted seat surface is usually easier. No evidence has been presented to date, however, in children with cerebral palsy for whom sit-to-stand movements are a constant challenge. This research therefore sought to draw comparisons between performance levels in terms of mechanical work, movement time, kinematics, and kinetics while getting up from chairs with varying seat angles and heights, for children with cerebral palsy.

Experiments were carried out involving 12 children with cerebral palsy under three conditions. The control condition used a low and horizontal seat (low-flat). The other two conditions were a low seat with anterior inclination (low-tilted), and a high horizontal seat (high-flat). Under both low-tilted and high-flat conditions, there was a significant reduction in movement time and mechanical work during sit-to-stand, in comparison to the low-flat control condition. We also found that at the start of the sit-to-stand movement in the low-tilted, there was better trunk alignment, and reduced pelvic motion. Meanwhile, the high-flat showed a reduction in the range of movement for the knee, hip, and ankle joints, and in the maximal hip and knee extension moments in comparison to the low-flat.

Our findings indicate that both a high seat and anterior inclination can improve sit-to-stand performance in children with cerebral palsy, although these two chair types provide different benefits. The low-tilted chair improves trunk alignment with the pelvis as the sit-to-stand task commences. Anterior inclination should therefore be employed for children with cerebral palsy whose primary problem lies in trunk and pelvis alignment even though they have sufficient muscle strength in the lower legs to facilitate standing. We also found that the high-flat chair reduced hip, knee, and ankle joint excursion and lowered the maximal hip and knee extension moment. A higher chair may therefore be helpful for children with cerebral palsy whose primary problems concern the lower extremities, or who are still in the initial stages of training for sit-to-stand movements. The findings presented here may help clinicians determine which type of chair design is more appropriate for a specific child with cerebral palsy.

Figure: The three different chairs and corresponding movement time and mechanical work during the sit-to-stand task.



Suriyaamarit, D., & Boonyong, S. (2020). Comparison of the effects of chair height and anterior seat inclination on sit-to-stand ability in children with spastic diplegic cerebral palsy. Journal of Biomechanics, 113, 110098.

About the Author

Duangporn Suriyaamarit

Duangporn Suriyaamarit

Department of Physical Therapy, Faculty of Allied Health Sciences, Chulalongkorn University, Thailand

Duangporn’s expertise is in biomechanics, motor control, and movement analysis. Her current research aims to study the biomechanical factors to detect falls in older adults with mild cognitive impairment.

Sujitra Boonyong

Sujitra Boonyong

Department of Physical Therapy, Faculty of Allied Health Sciences, Chulalongkorn University, Thailand

 Sujitra is an Assistant Professor at the Department of Physical Therapy, Faculty of Allied Health Sciences, Chulalongkorn University; and Head of the human movement performance enhancement research unit. She is providing teaching and doing research on motor control and human movement performance.


© 2021 by the author. Except as otherwise noted, the ISPGR blog, including its text and figures, is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. To view a copy of this license, visit

ISPGR blog (ISSN 2561-4703)

Are you interested in writing a blog post for the ISPGR website?  If so, please email the ISGPR Secretariat with the following information:

  • First and Last Name
  • Institution/Affiliation
  • Paper you will be referencing