Cushion and

Back Support Modifications

Custom Cushion Modifications for Wheelchair Seating

Cushion Modifications

The following is an at-a-glance reference to a few cushion modifications available through Matrix Seating Systems.

Seat Positioning Tray

The seat positioning tray is an ABS rigid base that mimics the cushion’s underside and velcros securely into the seat pan. Side and rear tabs guide the cushion back into proper alignment after removal, ensuring consistent positioning relative to the back support. The rigid base also helps prevent seat-sling hammocking, maintaining a stable and supportive seating surface.

Seat Positioning Tray with T-nut Upgrade

An upgrade is available that uses T-nut bolts to integrate hardware with a seat-to-back bracket.

Lateral Thigh Support Reinforcement

Lateral thigh support reinforcement adds ABS to the outer edges of a custom foam cushion, increasing the rigidity of the lateral adductors and enhancing overall postural stability

Integrated Rigidizer

The integrated rigidizer is a reinforcement added to the bottom of a cushion to act as a rigidizer, improving stability, maintaining cushion shape, and reducing seat-sling hammocking. In the AIREZ cushion line, this platform is 3D printed directly into the base of the cushion, while in the Posture-Fit foam line, it is an ABS layer securely bonded to the underside of the cushion.

Tapered Cushion

A tapered cushion is designed so the front or rear of the cushion narrows to better fit the wheelchair frame and match the client’s individual body dimensions.

Digital Relief

A digital relief is a precisely designed area of off-loading created within a 3D printed or digitally modeled cushion to reduce pressure over sensitive or high-risk anatomical regions.

Notching the Cushion

A modification in which small cutouts or recessed areas are created to accommodate wheelchair components such as back canes, seat belt straps, or seat rails. This allows the cushion to sit fully and securely on the seat pan without interference, preventing displacement and ensuring proper alignment with the back support.

Notches can be added to the rear or front corners, on the sides for a seat belt, or along the side bottom edges of the cushion.

Pelvic Obliquity Build up

A pelvic obliquity build-up is a customized adjustment added to one side of a cushion to correct or accommodate uneven pelvic height. It helps level a reducible obliquity or safely support a non-reducible one to improve alignment, comfort, and pressure distribution.

Notching the Cushion

A modification in which small cutouts or recessed areas are created to accommodate wheelchair components such as back canes, seat belt straps, or seat rails. This allows the cushion to sit fully and securely on the seat pan without interference, preventing displacement and ensuring proper alignment with the back support.

Notches can be added to the rear or front corners, on the sides for a seat belt, or along the side bottom edges of the cushion.

Cushion Modification Decision Tree

Cushion Modification Options

BACK SUPPORT MODIFICATION
AND ACCESSORY OPTIONS

The following is an at-a-glance reference to a few back support accessory modifications available through Matrix Seating Systems.

Universal Headrest Mount

The Universal Headrest Mount provides a stable, standardized interface for attaching most industry headrest systems. Designed for seamless compatibility and easy installation, it allows clinicians to position the headrest precisely for optimal comfort, alignment, and support. Ideal for users requiring consistent head and neck positioning throughout the day.

Accessory Mounting Rails
(on Headrest Mount)

Accessory Mounting Rails offer a clean, integrated solution for attaching secondary supports and equipment to the back support. These rails eliminate the need for drilling and allow easy installation of items such as lateral supports, communication devices, oxygen tank brackets, and custom hardware. They offer clutter-free hardware integration.

Shoulder Harness Guides

Shoulder Harness Guides ensure proper strap routing for chest and shoulder harnesses. Positioned on the back support to maintain ideal strap angle and prevent slippage, these guides promote safer, more effective trunk control. They help keep the user aligned and secure during mobility, transfers, and everyday activities.

Shoulder Harness T-Nut Pattern Upgrade

The Shoulder Harness T-nut Pattern Upgrade includes factory-installed T-nuts placed in standard harness-mounting locations. This upgrade eliminates drilling, simplifies installation, and ensures consistent alignment of shoulder harness guides. A time-saving, durable solution for clinicians and suppliers who install harnesses frequently.

Custom T-Nut Pattern

The Custom T-nut Pattern option allows clinicians to specify unique T-nut locations* on the back support to accommodate specialized harness setups, adaptive accessories, or non-traditional mounting positions. Ideal for complex postural presentations or unique user needs, this customizable option enhances flexibility and clinical precision.

*Location is specified on the shape capture or in the order form clinical notes. T-nut location is marked on the shape capture bag with a circled X as shown.

Digital Relief

A Digital Relief is a precisely modeled off-loading zone built into a custom back support to accommodate bony prominences such as a gibbus deformity or rib hump. By selectively removing material in the relief area, it reduces localized pressure, improves comfort, and helps prevent skin breakdown while maintaining proper spinal alignment. Digital reliefs are fully customizable and can be shaped, sized, and positioned** during the design phase.

**Shape, size, and location are specified on the shape capture bag with an R surrounded by a line indicating the shape and size as shown.

POST-DELIVERY BACK SUPPORT MODIFICATIONS

Lateral Width

Lateral width shaping allows you to bring the laterals inward for a more intimate, supportive fit or outward, to widen laterals to increase comfort and better accommodate trunk width.

How To Video

Lumbar Adjustments

Lateral trimming involves removing or reducing material along the sides of the back support to improve clearance, prevent rubbing or interference with the user’s arms or trunk, and achieve a more comfortable, tailored fit.

How To Video

Edge Relaxation
(Flair in and out)

Trimming, softening, or reshaping the edges of the back support to prevent irritation, improve clearance around the trunk or arms, or accommodate tight spaces within the wheelchair frame.

How To Video

Lateral Trimming

Lateral trimming involves removing or reducing material along the sides of the back support to improve clearance, prevent rubbing or interference with the user’s arms or trunk, and achieve a more comfortable, tailored fit

How To Video

Scapular Relief

Creating additional clearance or contour behind the scapula to allow free shoulder movement, reduce pressure on bony prominences, and prevent discomfort or skin irritation during propulsion or reaching.

*Achieved with the same method as Lumbar Adjustments listed above.

Back Modification & Accessories Guide

Shape Capture Mark Up Guide