Postural stability refers to the continuous process of postural changes during sitting. The capacity to maintain postural stability in sitting position is a prerequisite to perform activities of daily living (ADLs), reduce risk of shoulder injury, reduce risk of falling, and reduce change of pressure injuries. But postural stability is also important for social functioning, satisfaction with equipment, and thus quality of life. Deficits in postural stability can severely limit performance in these aspects of life.1-4 Furthermore, the role of trunk control on shoulder injuries may be an important consideration in mitigating injury and improvement of wheelchair propulsion.
There are several contributing factors to obtaining and retaining postural stability in a sitting position, namely trunk strength, foot supports, large base of support, anterior pelvic tilt, thigh support, back support and wheelchair set-up. Anterior pelvic tilt, thigh support, and a stable sitting surface can all be achieved using an appropriate wheelchair cushion.
Several studies have been aimed to examine the influence of seat cushions on postural stability in sitting. These studies used different cushions: interconnected air cell cushions, contoured foam, flat foam, and Vreede also used compartmented air cell cushions; the Vicair Adjuster O2 and the Vicair Vector O2.5-7 Stability of the wheelchair user can be compromised by the cushions ability to resist medial-lateral or anterior-posterior pelvic rotations caused by shifting center of mass. Sprigle et al. found that the Jay 2, ROHO High Profile (single chamber) and Varilite Evolution could not create a stable base to perform reach6. Both Vicair cushions allowed participants to reach significantly further on seated functional reach tests compared to all the other cushions tested (including a ROHO Quadtro Select locked and unlocked) by Vreede, which is indicative of increase of postural stability7.
Selection of an adequate wheelchair cushion is of utmost importance to ensure a satisfactory quality of life of wheelchair users. Increase in postural stability in a sitting position can be obtained by using a compartmented air cell cushion.
References
- Dean, M., Shepherd, R. B., & Adams, R. D. (1999). Sitting balance II: Reach direction and thigh support affect the contribution of the lower limbs when reaching beyond arm’s length in sitting. Gait and Posture, 10(2), 147–153. https://doi.org/10.1016/S0966-6362(99)00027-2
- Dyson-Hudson, A., & Kirshblum, S. C. (2004). Shoulder pain in chronic spinal cord injury, Part I: Epidemiology, etiology, and pathomechanics. The Journal of Spinal Cord Medicine, 27(1), 4–17. https://doi.org/10.1080
/10790268.2004.11753724
- Riley, O., Benda, B. J., Gill-Body, K. M., & Krebs, D. E. (1995). Phase plane analysis of stability in quiet standing. Journal of Rehabilitation Research and Development, 32(3), 227–235.
- Trefler, , Fitzgerald, S. G., Hobson, D. A., Fitzgerald, S. G., Bursick, T.,
& Joseph, R. (2004). Outcomes of Wheelchair Systems Intervention With Residents of Long-Term Care Facilities. Assistive Technology, 16(1), 18–27. https://doi.org/10.1080/10400435.2004.10132071
- Aissaoui, , Boucher, C., Bourbonnais, D., Lacoste, M., & Dansereau, J.
(2001). Effect of seat cushion on dynamic stability in sitting during a reaching task in wheelchair users with paraplegia. Archives of Physical Medicine and Rehabilitation, 82(2), 274–281. https://doi.org/10.1053/ apmr.2001.19473
- Sprigle, S., Wootten, M., Sawacha, Z., & Theilman, G. (2003). Relationships among cushion type, backrest height, seated posture, and reach of wheelchair users with spinal cord injury. Journal of Spinal Cord Medicine, 26(3), 236–243. https://doi.org/10.1080/10790268.2003.1
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- Vreede, (2018). reach out for stability.
(Master Dissertation, The Hague University of applied Sciences) https://hbo-kennisbank.nl/details/sharekit_hh:oai:surfsharekit. nl:4a413930-2852-43fc-a79c-dc6758556af7?q=vreede&has- link=yes&c=0&p=5 (last accessed on: 12/04/2021)