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Material Selection in Cushions
Although cushions may look similar in design on the outside, the materials used on the inside can havea significant impact on their performance. Understanding how materials perform will improve theclinician’s ability to select a cushion based on their client’s goals. This reference table describes material,
their benefits and the clinical considerations when selecting the most appropriate wheelchair cushion.

Cushion Materials

SolidFluidFOAM

ELASTOMERGELJAY® FLOW FLUIDAIRFoam

ElastomerGel

JAY Flow Fluid

Air(Page 1 of 3)

Material Selection in Cushions
MATERIALDescription
Foam is a material which is formedby trapping pockets of gas. It canbe a variety of densities,
firmnesses and weights. Based on
the uniformity of the cells, they will
be more or less rigid.

Additional
Considerations

Inexpensive and lightweight

Compresses over time

Low maintenanceDiﬃcult to clean andabsorbs moisture

Absorbs impact loads well

May create tension on thetissue depending on thesoftness of the foamOpen cell foam is softer due to aless uniform cell structure.

Soft foam can be used for comfort

May create shear forces on
the tissue depending on thefoam design

The weight of a foam is dependent
upon mass, not upon firmness ordensitiy. Therefore rigid foam may
also be lightweight, whereas softer
foam may be heavier.

Viscoelastic memory foam has
vibration dampening properties

Memory foam (viscoelastic) has
increased viscosity and density
which allows it to return slowly toits shape after compression.

ELASTOMERClinical Benefits

Firm foam can provide a levelbase of support

Closed cell foam has a uniform cellstructure which creates rigidity.

FOAM(Continued)

Various densities can be combined for pressure relief, moving
load from high risk bony prominences to lower risk areas

Memory foam may holdmore heat than standard
foam and it becomes morecompressed over time, withless return
May increase pressure on
bony prominences over time

Elastomer is a man-madepolymer with varying degrees
of viscoelasticity.

Easy to clean

In wheelchair cushions, an elastomer is often a matrix-like polymer structure.

Immersion is dependent upon
the rigidity of the elastomer

Immersion is dependent upon thesoftness of the elastomer. It has agreater durability than foam overtime.

May retain heat in hot
climates and get harder incold climate

Allows some compression

Can be lightweight depending
on design, e.g. honeycomb
structure

Limited displacement
Less immersive than lower
density foam or fluids
More diﬃcult to customize inthe field in response to
specific postural needs

Design may allow airflow which
may improve microclimate
Has shear reduction qualities
due to higher viscoelasticityproperties

Gel is a solid jelly-like material that
can have properties ranging fromsoft 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

Gel maintains its shape even whenopened or cut.

Some movement and viscosity

Heavy

Often easy to cut, modify andput in small places

Temperature sensitive

Can oﬀer good friction/shear
control
Easy to clean

Holds heat but can feel cold
to the touch initially
Limited displacement, lessimmersion than liquid, air, or
most foams used in cushions(Page 2 of 3)

Material Selection in Cushions
MATERIALJAY® FLOW FLUID

AIRDescription(Continued)

Clinical Benefits

Additional
Considerations

Good pressure distribution

Heavier than foam or air

JAY Flow Fluid is a non-Newtonian
fluid. A non-Newtonian fluid
remains in a semi-solid or highly
viscous state.

Conforms to the body

In a non-Newtonian fluid, viscosity
changes when under force to either more liquid or more solid.

Moves with the body

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.

Weighs less than gel

Can help control shear

May require redistribution
following use due to migration
with pressure

Does not respond to load withcounterforce of foam, thereby
extremely good for pressure care
Provides good immersion while
creating a large area of surface
contact to distribute

Air is a Newtonian fluid. A Newtonian fluid maintains its viscosity independent of stress. A Newtonian
fluid only changes its viscosity inresponse to temperature.

LightweightIf you provide a Newtonian fluidwith stress, it will remain the same
thickness (viscosity), but if you heatit up or cool it down it can become
more liquid or more solid.

Pressure distribution

Newtonian fluid, such as air orwater, cannot maintain a shapewithout a container. However, if
the container is opened, it will spilland be released, thereby negating
it’s eﬃcacy.

Needs some maintenanceMoves with the body
Easy to clean

Reduced stability, particularly in an air-only cushion
Risk of puncture

Frequent maintenance toCan be used as entire cushion or ensure proper inflation
within a foam base for stability
Provides good immersion while
creating a large area of surface
contact to distribute

Sensitive to pressurechanges, such as during airtravel

References
1.

Polyurethane Foam Association. (1991, rev 2016). Flexible polyurethane foam: A primer. In Touch,
1(1), 1–7. Retrieved from: https://www.pfa.org/wp-content/uploads/2019/02/IntouchV1.1a.pdf

2.

Sherman, S. (2011, November). Skin Protection and Cushion Materials. Retrieved from:http://www.sunrisemedical.ca/dealer-clinician-tools/education-in-motion/clinical-corner/november-2011/skin-protection-and-cushion-materials

3.

Watanabe, L. (2017, September). Immersion, envelopment and oﬀ-loading. Mobility Management. Retrieved from: https://mobilitymgmt.com/Articles/2017/09/01/Seating-Strategies.aspx

DISCLAIMER: FOR PROFESSIONAL USE ONLY. THIS DOCUMENT (AND THE WEBSITE REFERENCED HEREIN) DO NOT PROVIDE MEDICAL ADVICE.
Sunrise Medical does not provide clinician services. The information contained on this document (and the website 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 thenuse clinical reasoning skills to determine optimal seating and mobility solutions for individual patients. No material on this document (or on the website) isintended to be used as (or a substitute for) professional medical advice, diagnosis or treatment. Clinicians should adhere to their professional medical training andtheir institutionʼs or practiceʼs recommended guidelines. Reliance on this document (and the information contained herein) is solely at your own risk.

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