Evidence Update: The Effects of Inclination, Hip Abduction, Orientation and Tone on Weight-Bearing in Adaptive Standers
For children with limited ability to walk and stand, adaptive standers are commonly used to encourage weight bearing. To date, only two studies describe the use of an adaptive weight-bearing brace in the pediatric population. Therefore, a great recent study to consider is “Tilt, hip abduction, orientation and tone affect weight bearing in standing devices.”
Although this is a small, exploratory and descriptive study (with fifteen children involved), it is the first to measure weight bearing during standing at different degrees of hip abduction, inclination and orientation of the stander.
The study
The children included in the study were between three and nine years old and were divided into groups according to muscle tone: high tone, low tone and typical tone. Each child was given two opportunities to stand while the amount of weight supported by their feet was measured under random conditions. The variables in standing conditions were written on index cards and previously selected independently by the participants:
- Support type: Jenx Stanz; EasyStandZing; o Prime Engineering HLT Superstand
- Stander Tilt: 0 degrees, 15 degrees or 30 degrees
- Hip abduction (total): 0 degrees, 30 degrees or 60 degrees
- Stand orientation: Prone, supine or upright
Results
Overall, when choosing the best conditions to optimize weight bearing, this study found that muscle tone is a key factor. For children with high tone, the upright, prone position with zero degrees of abduction resulted in the greatest weight bearing. In this same group, the least weight bearing occurred in the supine position with thirty degrees of inclination and sixty degrees of abduction. This suggests that maximal tilt and abduction positions should be avoided in children with hypertonia if the primary goal of using standing is weight bearing.
In contrast, for children with low and typical tone, increased abduction in the upright supine position resulted in the greatest weight bearing. The least weight bearing occurred in the prone position with a thirty-degree inclination and feet together. The following chart provides a good visualization of the study’s findings.
Certainly, this study has limitations, as the authors point out. These include the small sample size and measuring weight bearing solely through the footrests. However, this pilot study is the first to examine the effects of stander angle, type, and abduction on weight bearing and therefore a valuable contribution to guiding best practices in pediatric therapeutic intervention.
Reference
Paleg G, Altizer W, Malone R, Ballard K, Kreger A. Tilt, hip abduction, orientation, and tone affect weight bearing in standing devices. [published online ahead of print, 2021 May 28]. J Pediatr Rehabil Med. 2021;10.3233/PRM-190660. doi:10.3233/PRM-190660
