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Dynamic Rocker Back

Dynamic Rocker Back Interface (DRBi)

The Seating Dynamics Rocker Back Interface is installed between the seat and the back of a wheelchair and provides movement of the back to absorb forces and assist the client back to upright. This movement can protect both the client from injury and the seating system and mobility base from breakage. This movement can also reduce extension and provide movement to reduce agitation, increase alertness, and provide sensory input. Movement can also facilitate functional activities. Finally, movement against resistance in a limited range can increase trunk and head control.

seating dynamics dynamic rocker back

Clinical Application

Tyler demonstrating dynamic back

The Dynamic Rocker Back moves posteriorly in response to client force and assists the client back to an upright starting position.

How does the ability to move affect equipment and the client?

  • Forces are absorbed and diffused, protecting both the client and the wheelchair frame and seating system from harm.
  • Extensor tone is diffused, reducing overall tone and posturing, increasing function, and conserving energy.
  • Movement is provided, which can increase sitting tolerance, decrease agitation, increase alertness, and even increase trunk control.

Benefits of Dynamic Rocker Back (DRBi)

Opens Seat to Back Angle in response to client movement and force
Pivot point follows the natural pivot point of the hip, maintaining the position of the pelvis upon return to upright
Provides Movement
Absorbs and Diffuses Force
Reduces Active Extension and Posturing
Protects Client from Injury
Protects Equipment from Breakage
Increases Sitting Tolerance
Decreases Agitation
Increases Alertness
Increases Trunk Control

Explore the Dynamic Rocker Back Interface

In Their Words

Jace Goh, OT

Linds Rehab

“Darcy loves his new chair! He enjoys being able to move around and be able to leave the house frequently with carers, which he did only occasionally previously due to safety concerns and poor tolerance in his own chair.”

Missy Ball, PT, MT, ATP

PhysioBall Therapy, LLC
Metairie, LA

“Seating Dynamics has excellent dynamic products that are compatible with many frames. In my experience, the dynamic back and footrests have prevented frame damage, allowed for extension of the client but with return of pelvis to effective sitting posture, reduced pressures on back, buttock and foot area, and reduced agitation on clients with SI issues. Dynamic motion has also reduced constipation issues on one of my clients.”

Macara McGregor

St. Amant, Winnipeg, Manitoba

“Great products! I work with kids and adults with developmental disabilities. I’ve had lots of success with their dynamic rocker back interface to address high exterior tone, as well as rocking behavior!”

Watch Me Move


Phillip receives his Seating Dynamics components!

Phillip likes to move, but his current dynamic back was broken and his wheelchair did not incorporate other dynamic components. His forceful movements led to significant wheelchair damage.


Determining if a Dynamic Back is Appropriate

In general, if a client has moderate to significant hip extension, is seeking movement, and/or has a history of equipment breakage, a Dynamic Back may be appropriate. How do you determine if this intervention is appropriate without actually trying it?

Determining if Dynamic Footrests are Appropriate

Dynamic Rocker Back interface demonstration

This video demonstrates how the elastomer is compressed, absorbing forces, and then returns the back to upright.

Technical Information

The Dynamic Rocker Back interface is two self-contained suspension assemblies installed between each of the seat rails and the back canes of a wheelchair. The design incorporates both impact and rebound control using urethane elastomers. Each unit ships with a full set of four different elastomers to allow fine tuning to the individual user’s requirements.

DRBI elastomersResistance

The back is available with 4 different levels of resistance – the client should be able to move the back, yet still return to upright.

For written instructions on changing the elastomers, click here.

Pivot Point

The pivot point is such that the position of the pelvis is maintained upon return to upright.


The back can be latched to lock out this movement. It is our recommendation that the latch plate be in the UNLOCKED position at all times with several exceptions:

  1. When the wheelchair is being transported in a vehicle.
  2. When the wheelchair is being pushed by an attendant on a rough surface to reduce the risk of inducing spasms due to movement of the wheelchair.
  3. Some caregivers report that it has been helpful to latch the DRBi during feeding.

Degree of Movement

The seat to back angle opens approximately 10-15 degrees. This amount of movement leads to a minimal amount of shear, allowing the client to remain in alignment with the contours of the back.


The elastomers should be checked every 6 months for wear and tear. A replacement kit is available. If the optimal level of resistance has already been determined, it is possible to order a replacement kit containing all one color, or level of resistance. Please refer to our Quick Class on this subject here:

For written instructions on changing the elastomers, click here.

Dynamic Rocker Back Resources

Quick Class

Quick Class: Dynamic Seating – General Clinical Indicators

July 26, 2023

Dynamic seating has many potential applications. Dynamic components absorb and diffuse force, protecting the wheelchair user from injury caused by sustained and/or repeated forces and reducing damage to the seating system and wheelchair.

Read More
seating dynamics case study ashley

Ashley – Dynamic Seating: Dystonia & Equipment Breakage

July 17, 2023

Ashley is a 35 year old woman with the diagnoses of cerebral palsy and dystonia. She exhibits large and forceful movements (dystonia) which have led to injury to her legs and damage to the wheelchair. She needs to move and her movements increase when she is agitated or excited.

Read More
Seminar Watch Now

Free CEU: Muscle Tone and Tone Management: General Positioning Strategies for Clients with Increased Tone

July 11, 2023

Join OT Michelle Lange for this Free CEU on Positioning Strategies for Clients with Increased Muscle Tone.

Read More