Although cushions may look similar in design on the outside, the materials used on the inside can have a significant impact on their performance. Understanding how materials perform will improve the clinician's ability to select a cushion based on their client's goals. This article describes materials, their benefits, and the clinical considerations when selecting the most appropriate wheelchair cushion.
Foam is a material which is formed by trapping pockets of gas. It can be a variety of densities, firmnesses, and weights. Based on the uniformity of the cells, they will be more or less rigid.
Closed cell foam has a uniform cell structure which creates rigidity. Open cell foam is softer due to a less uniform cell structure.
The weight of a foam is dependent upon mass, not upon firmness or density. Therefore rigid foam may also be lightweight, whereas softer foam may be heavier.
Memory foam (viscoelastic) has increased viscosity and density which allows it to slowly return to its shape after compression.
Elastomer is a man-made polymer with varying degrees of viscoelasticity.
In wheelchair cushions, an elastomer is often a matrix-like polymer structure.
Immersion is dependent upon the softness of the elastomer. It has a greater durability than foam over time.
Gel is a solid jelly-like material that can have properties ranging from soft and weak to hard and tough.
Although it is mostly liquid, it behaves like a solid. Therefore it has some viscosity, but does not allow for complete immersion.
Gel maintains its shape even when opened or cut.
JAY Flow Fluid is a non-Newtonian fluid. A non-Newtonian fluid remains in a semi-solid or highly viscous state.
In a non-Newtonian fluid, viscosity changes when under force to either more liquid or more solid.
Although a non-Newtonian fluid can take a shape without a container, it will flow with pressure. Therefore it needs to be contained when used in a cushion.
Air is a Newtonian fluid. A Newtonian fluid maintains its viscosity independent of stress. A Newtonian fluid only changes its viscosity in response to temperature.
If you provide a Newtonian fluid with stress, it will remain the same thickness (viscosity), but if you heat it up or cool it down it can become more liquid or more solid.
Newtonian fluids such as air or water cannot maintain a shape without a container. However, if the container is opened, it will spill and be released, thereby negating its efficacy.
Clinical Support Information Citations
DISCLAIMER: FOR PROFESSIONAL USE ONLY. THIS WEBSITE (AND THE DOCUMENTS REFERENCED HEREIN) DO NOT PROVIDE MEDICAL ADVICE. Sunrise Medical (US) LLC (“Sunrise”) does not provide clinician services. The information contained on this website (and the documents referenced herein), including, but not limited to, the text, graphics, images, and descriptions, are for informational purposes only and should be utilized as a general resource for clinicians and suppliers to then use clinical reasoning skills to determine optimal seating and mobility solutions for individual patients. No material on this website (or any document referenced herein) is intended to be used as (or a substitute for) professional medical advice, diagnosis or treatment. Never disregard your professional medical training when providing medical advice or treatment because of something you have read on this website (or any document referenced herein). Clinicians should review this (and any other materials) carefully and confirm information contained herein with other sources. Reliance on this website (and the information contained herein) is solely at your own risk.
Yes, I consent to receive email newsletters about products, services, promotions, news, events and useful resources. What does this mean?
How we use your personal information when subscribing to emails
You are agreeing that Sunrise Medical processes and uses your personal data to send you email newsletters. We do this by using your data to create a profile about you. This includes your name, email and any information that you've provided to us whilst using our website (such as the pages you visit, products you've enquired about and the services you use). We keep your profile secure and never share it with third-parties. We will contact you every 2 years to ensure you are happy to continue receiving email newsletters from us.
How to withdraw your consent
These cookies allow the website to be adapted and personalised to certain general pre-established characteristics, such as the language, the browser used or the region from which it is accessed.
These enable information to be obtained for the statistical analysis of the use that users make of the page. Thus, they make it possible to know the preferences of users in order to improve the services offered and limit the impact of advertising. For example, by analysing the search terms used by users to reach the page, studying the geographical area to which most users belong or limiting the appearance of repeated advertisements on the Website.
These enable the management of existing advertising spaces on the page so that each User is offered advertising content in accordance with their browsing habits and preferences, as well as other information provided during browsing.
Sunrise Medical asks you to accept cookies to personalise website content and analyse traffic. We also use third-party social media and advertising cookies to offer you social media functionalities and personalised ads on other sites. Do you accept these cookies and any processing of personal data involved?