Dynamic Seating at the Pelvis
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!
Just like Bread and Butter, Dynamic Backs and Pelvic Positioning Belts go together. Dynamic Backs are designed to allow movement at the pelvis and torso in response to client force and then return the client to a neutral starting position. A key component is the pelvic positioning belt, which is designed to maintain the pelvis in as neutral a position as possible in relation to the seating system. When that seating system moves, the pelvic belt is even more critical in maintaining pelvic position.
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.
The Dynamic Rocker Back Interface (DRBi) is a Dynamic Back that moves in response to client force. The elastomers in this Dynamic Back then return the client to an upright position. Some Dynamic Seating components “lock-out” or “latch” to temporarily render the component static. When should the DRBi be locked out?
Dynamic Seating at the Trunk
Our last blog discussed providing dynamic movement at the pelvis. If the pelvis moves posteriorly, the trunk will move posteriorly as well. So if posterior movement of the trunk is desired, dynamic seating components which allow posterior movement of the pelvis are provided, namely a dynamic back rest, which opens the seat to back angle in response to client movement and force.
Our last blog addressed dynamic seating used to provide posterior movement of the trunk. Anterior movement of the trunk can also be facilitated.
Dynamic Seating at the Legs
Wheelchair footrest hangers are generally static. If the client is able to extend at the knees, the feet move forward off the footplates. This is fine for clients who can easily move their foot back onto the footplate. If the client’s feet tend to leave the footplates and the client cannot return to this starting position, we often add in foot straps and/or shoeholders to maintain this position.
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.
In a recent blog, we discussed how, just like Bread and Butter, use of a Dynamic Back requires the use of a Pelvic Positioning Belt to maintain the position of the pelvis during movement of the Dynamic Back. Well, just like Peanut Butter and Jelly, use of Dynamic Footrests requires the feet to be secured in order for client forces to activate this dynamic component.
Dynamic Seating at the Head
In previous blogs, we have discussed clinical indicators for providing dynamic movement at the hips and knees. Another location dynamic movement can be provided is at the neck through Dynamic head support mounting hardware. Most dynamic options allow movement into neck extension and then facilitate return to an upright and aligned posture. So when is a dynamic head support clinically indicated?
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?
Vince is a young adult with the diagnosis of cerebral palsy. He had significant muscle tone throughout his body and frequently extends in his current wheelchair seating system. We were anxious to explore dynamic seating options to diffuse some of this extensor tone. However, Vince had very little hip flexion or extension beyond his current seated position and, as a result, he could not benefit from a dynamic back which allows movement past this point. He had no knee extension past 90 degrees and his range limitations prevented him using even the telescoping feature of a dynamic footrest. We were unsure if we could provide any dynamic intervention when Vince broke yet another head support.
Seating Dynamics offers 3 Dynamic Seating options – the Dynamic Rocker Back interface, Dynamic Footrests, and Dynamic Head Support Hardware. The last option is available in Single Axis (which moves about 10 degrees posteriorly in midline) and Multi-Axis (which moves about 10 degrees in any direction). The hardware is compatible with a number of manufacturer’s head pads.
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.
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.