While some funding programs may have an automatic period of time when a person becomes eligible for a new wheelchair cushion or back support, other funding programs may require justification for seeking approval for new seating. How can we tell when a cushion or a back support requires replacement? Several circumstances warrant a review of an individual's seating needs. These include:
- Change in size
- Change in positioning needs
- Change in risk for pressure injury
- Wear in seating system
Let's review each of these conditions.
Change in Size
Children tend to grow longer before they grow wider and some pediatric wheelchair cushions are designed to allow for some growth in depth (e.g., one inch depth growth) to account for this anticipated growth. Some therapists also try to build growth into a cushion by prescribing a cushion that may be an inch or so greater in depth than initially required and securing the cushion through the back canes of the wheelchair at the time of initial dispensing. As the child grows, the cushion can be brought forward on the seat pan of the wheelchair and secured in a new position that accommodates the growth. The hardware on the back support also may be adjusted to create the depth needed in the cushion.
While it might be tempting to try to build growth into the width of a cushion for a child who is still growing, caution should be advised. The correct width of a wheelchair frame and cushion is important for positioning and postural alignment. If the wheelchair is too wide, the child may need to abduct the shoulders excessively to position the upper extremities on both arm supports or may lean to one side to support the upper extremities and trunk. If a child propels a manual wheelchair independently, access to the rear wheels would be suboptimal in a wheelchair that is too wide, making the push stroke inefficient and more difficult for the child. Depending upon the postural needs of the child and the contour of the existing back support, there may be some "tricks" that can be applied with the hardware on the back support and wheelchair back canes to gain some additional width. This should be done only if the child's trunk still fits within the contact surface of the back support. When a child inevitably grows more than what can be accommodated in the current seating system, it is time to review the need for a new cushion and back support.
For an adult, a change in size such that the wheelchair no longer adequately fits the individual – whether shrinking or growing – means that a replacement of the cushion and back support is required.
Change in Positioning Needs
At the time of the assessment, we do our best to anticipate the client's positioning needs. Sometimes, a client's needs change over time and their current seating system does not provide adequate positioning for the individual. If modifications cannot be made to the current system, a new cushion and/or back support may be required to provide positioning to prevent deterioration in posture and to enhance function.
Change in Risk for Pressure Injury
If the client's risk for pressure injury changes, or indeed if the client has begun to develop a pressure injury, the client's current seating system should be evaluated. If, for example, the client develops a pressure injury at an ischial tuberosity while sitting on a foam cushion, consideration should be given to replacing the cushion with one that is made with material that is designed for pressure management, such as air or fluid. Also be aware of positioning needs that may contribute to pressure at the bony prominence. If the wheelchair cushion is changed, the back support should be assessed to determine if an adjustment is needed in its placement on the wheelchair back canes, particularly if the profile, or height, of the new cushion is different from the initial one.
Of course, part of the assessment for pressure injury risk should include what occurs over the 24 hour period, such as transfers, and the frequency, duration and quality of weight shifting while using the wheelchair. These are topics that are beyond the scope of this article, but remain important when addressing pressure injury prevention.
Wear in Seating System
When a cushion or a back support is worn, it is time to consider replacement. How can we tell if seating is worn? Visual and tactile inspection give a lot of clues. First, look at the cover. Damaged fabric or torn seams can be a sign of wear. It does not necessarily mean that what is underneath the cover requires replacement. Sometime it is simply the cover itself that needs to be replaced. Most seating manufacturers sell replacement covers as a part and that may be all that is required.
The next step in assessing the wear of the cushion or back support is to remove the cover and to look underneath. For foam, look for signs of foam compression, granulation or changes in stiffness. For fluid or air bladders, look for visual signs of damage, such as a puncture. Air bladders may show stress lines or may have damage to the valve.
After looking at the cushion or back support, it's time for the touch test. Check the evenness of the springiness throughout an open-cell foam material. For fluid cushions, feel the viscosity of the fluid and assess the fluid level. Any changes from the original state of the cushion may mean replacement is required. Lastly, for an air cushion or insert, check for leakage by submerging the cushion in water or wetting the cushion or insert with soapy water to look for signs of air bubbles. If the air cushion cannot be repaired, it should be replaced.
One final thought on wear in wheelchair cushions and back supports – how often seating requires replacement will depend on the factors that contribute to wear in seating products. These factors include:
- Number of daily transfers
- Type of transfer (e.g., sliding board, "uncontrolled")
- Activities completed (e.g., curb jumps, sports)
- Environmental exposure (e.g., moisture, incontinence, temperature extremes)
How often a particular individual needs to replace their seating due to wear will depend on these various factors.
A wheelchair cushion and/or back support may require replacement prior to the need for a new wheelchair. Circumstances under which new seating should be considered include a change in size, positioning needs or pressure injury risk and wear in the cushion or back support. Several visual and tactile clues help us to determine when a person's seating may need to be replaced due to wear.
Please send your comments, questions, and suggestions for Clinical Corner topics to Sheilagh Sherman, OT Reg. (Ont.) at Sheilagh.Sherman@sunmed.com. Thank you!
Note: The content of this article is not meant to be prescriptive; rather, it is meant as a general resource for clinicians to then use clinical reasoning skills to determine optimal solutions for individual clients. Sheilagh is unable to answer questions from members of the general public. Members of the general public are directed to their own therapists or other health care professionals to ask questions regarding needs.
This article is © Sunrise Medical, Inc., 2021 and cannot be copied, distributed, or otherwise reproduced in whole or in part without the express written permission of Sunrise Medical Canada.