Dynamic Seating Design
Dynamic movement can be provided at various areas of the body where movement is possible from a seated posture. The
dynamic component allows movement beyond the usual seated posture, such as into increased trunk extension, and then assists with the client returning to upright. Ideally, the return to upright does not lead to a loss of position, such as a posterior pelvic tilt.
In our last blog, we discussed clinical indicators and contra-indicators to allowing movement into neck extension using a dynamic head support. Dynamic movement in this area can protect the head support hardware from damage, limit client injury, and reduce overall extensor tone. How does design facilitate these goals?
Allowing movement at the knee is more complicated than it sounds. When a client extends at the knee, this movement is not just in one plane. In other words, the foot doesn’t simply slide forward. The foot follows an arc, forward and upward.
I see a lot of clients for head positioning in their wheelchair seating system. This requires a thorough seating assessment, as well as providing the best product. Even if I choose what I believe to be the very best head support for a client, I find that maintaining the position of that support is a challenge. I continually find that the hardware has moved, often resulting in a sub-optimal head position for the client.
Dynamic Seating Installation
Seating Dynamics Dynamic Rocker Back interface (DRBi) provides movement in response to client forces. These forces are stored and then return the client to a neutral starting position. This Dynamic Back has many clinical applications, but first it must be correctly mounted to a wheelchair base.
The Dynamic Rocker Back Interface (DRBi) moves in response to client force as two elastomers are compressed. The energy stored in the elastomers helps the client to return to an upright starting position. These elastomers can be switched to change the level of resistance.
Seating Dynamics Dynamic Footrests can move in up to 3 directions. First, the footrests can telescope, allowing movement downward. Second, the footrests can elevate, allowing the knee to extend and the foot to move forward. Third, the footplate can move into plantar and dorsi flexion, allowing ankle movement.
This blog is the third in a series on determining the optimal resistance when using dynamic components. The first blog in this series addressed determining resistance in the Dynamic Rocker Back Interface (DRBi) and the second blog addressed finding the optimal resistance when using Dynamic Footrests. In this final blog, we shall turn to the Dynamic Head Support Hardware.
The Dynamic Head Support Hardware absorbs client forces and then returns the client to an upright and neutral head position. The purpose of this dynamic component is to protect the client from harm, prevent the mounting hardware from breaking, and to reduce overall extension tone. This hardware can be used with nearly any head pad to best meet an individual’s needs.
Dynamic Seating Maintenance
Most items need a certain level of maintenance. I have to get the oil changed in my car and fertilize my lawn, for example. What about Dynamic Seating components? The answer is, “Yes!”
This is the story of J and the flattened elastomers. J is a young man with an incredibly strong extensor tone pattern that usually initiates in his hips. He uses a Seating Dynamics Dynamic Rocker Back to absorb these forces. He resides in a long term care facility and has multiple caregivers who have known him for many years.
Dynamic Seating and Durability
Dynamic Seating is often used to prevent equipment breakage, specifically the wheelchair frame and seating system. The Dynamic components absorb strong, repeated, sudden, and/or sustained forces, hence protecting vulnerable areas of the seating and mobility base. This was addressed in two prior Blogs (Dynamic Seating to Prevent Equipment Breakage, part 1 and part 2). But what about the Dynamic Components themselves? Just how durable are these?
Whenever I recommend complex rehab equipment for a client, I need to be aware of the cost of my recommendations. Why? One reason is that my documentation must often include why something less costly will not meet the client’s needs. I often hear from team members who are considering Dynamic Seating interventions but are concerned about the cost of these components and if the equipment is justified, as a result.
Dynamic Seating has many clinical benefits for wheelchair users and those benefits are our primary justification. From there, I do believe we can look at the cost-benefit analysis and find additional justifications.
Dynamic Seating and Shear
Can a Dynamic Back be used with any type of seat? Does the movement allowed by this component limit what seating surface can be used? This is an important consideration. A seat or cushion is typically designed to support the pelvis and provide pressure distribution when the client is in a static position. Dynamic seating gets things moving!
Oil and water don’t mix well and we often assume that molded seating and movement don’t mix either. Why? Well, a molded seat or back provides very intimate contact with the client’s body. If, for example, the seat to back angle changes, this can change the alignment of the client in relation to these intimate contours.