by Christin Krey
Children with spinal cord injury or dysfunction (SCI/D) are more than just “small people” and therefore, require more than just a “small wheelchair” for their seating and mobility needs. Although some of the goals of seating and mobility prescription are the same as adults, there are different needs and concepts that are unique to the prescription and design of pediatric wheelchairs.
Children with SCI/D, like adults, must be provided with a seating and mobility system that provides orthopedic support, pressure reduction, comfort, and a means of efficient, independent activity. Unique to children however are growth requirements that must be addressed. Therefore, it is imperative to build a wheelchair and seating system that is modular enough to meet their growing needs. This system must last them an average of 3 to 5 years, primarily because of insurance reimbursement. It may be possible however, to justify new seating on an annual basis.
How Is the Child Growing?
When evaluating a child for a manual wheelchair that is adjustable to meet their growing needs, one must consider what type of growth will be most necessary for that specific child: changes in seat width, seat depth, or both. During the interview phase of the evaluation, there are several points to address which will help determine what kind of growth adjustability will most likely be required for this particular patient:
• Consider the age of the child, whether they just recently went through a growth spurt or if one is yet to come, as well as genetic tendencies.
• Consider the diagnosis of the child. Children with a greater amount of spasticity burn a lot of their calories, they barely gain any weight or girth, but typically grow in height, which translates to a need for an increase in seat depth. Children with spina bifida, on the other hand, have stunted growth below the level of the meningiocele, and therefore, do not typically grow as quickly in seat depth. Generally, they tend to lead a more sedentary life, do not control their diets well, and subsequently, require more growth availability in width than depth. There are plenty of children with spina bifida however, that participate in numerous wheelchair sporting activities. Therefore, overall activity level of the child is a major consideration.
• Consider the patient-to-wheelchair weight ratio. An average adult of 150 pounds who pushes a 30-pound manual wheelchair is pushing at an approximate ratio of 5:1. A child weighing 30 pounds who pushes a 30-pound chair however, is pushing at a 1:1 ratio. Add backpacks or other bags hung off the back of the wheelchair and the ratio tips even further away from their favor. Children, therefore, need an ideal set-up, even more than adults, to maximize the biomechanics and propulsion efficiency.
How Does the Chair Allow for Growth?
There are several options to choose from when it comes to prescribing a pediatric wheelchair that will allow for growth. The designs of some pediatric wheelchair frames have inherent growth, while others have a more custom build. These custom-built wheelchairs typically have a lack of (or minimal) adjustability, but they do have a growth program available. Owners can trade in the current wheelchair frame for a new, larger frame while retaining the original axles, wheels, casters, anti-tippers, and so forth. With the growth/trade-in program however, new seating must be ordered to accommodate the change in size.
Wheelchairs with inherent growth typically feature a depth-adjustable frame: several holes running along the side frame for placing the back canes to increase the depth. Special care must be taken to ensure that there is not too much depth built into the frame, particularly with the younger children. Unfortunately, there is no magic number to determine how much depth adjustability is too much. It is individual for each child.
For example, there might be a chair for a child whose seat depth measures 10 inches (so you would set the seat depth at 8 or 9 inches) and the wheelchair adjusts as deep as 16 inches. There are several issues with this set up that can be detrimental.
The seating system in such a chair could end up being set very forward on the frame. This tends to create an imbalance on the wheelchair frame, which loads the front casters and not only places the child at risk for tipping forward, but also makes the wheelchair more difficult to propel. A more properly positioned seating system will distribute weight more toward the back, over the axle, improving the ease of propulsion.
An excessively long frame is difficult for the child to propel for several additional reasons. If a frame is too long, even the most forward axle position-and the more forward the axle the better for children-does not allow for efficient wheelchair propulsion. The wheel would still be too far behind the child, decreasing the amount they have access to for propulsion, and the chance would increase for rear wheel interference with the travel of the front caster. A long frame can also result in excessive weight behind the child.
When building growth into a wheelchair through the seat frame, remember to build some growth into the seating system as well. Depth adjustability in the seating system can be completed quickly, without having to change anything on the wheelchair frame. The way this is typically accomplished is by “notching” the seat cushion by several inches. This allows for several inches of the cushion to sit behind the back canes when mounted on the wheelchair. This portion will eventually be utilized as the seat depth increases.
A second way to build growth in the seat depth of a wheelchair is through depth-adjustable back hardware. This technique usually allows approximately 1 to 2 inches of seat depth adjustment (depending on what kind of back or back hardware is utilized) and allows a clinician to adjust the seat depth without having to adjust the back canes. One can simply adjust the position of the back hardware to move the seat back more on the wheelchair frame.
Growth in seat width is slightly more difficult. Folding wheelchair frames typically have about 1 to 2 inches of seat width growth in the cross brace. If your frame does not, a growth kit can be ordered from the manufacturer, which typically provides a new cross frame and footplates. Many pediatric rigid frames have growth built into the width through telescoping cross tubes, which allows the clinician to easily grow the width of the chair. Anytime the seat width is increased through the frame of the wheelchair, a new seating system must be ordered to accommodate the new size.
It is widely recognized that children grow and change. It is imperative for children who utilize a manual wheelchair for independent mobility to have an appropriate wheelchair and seating system that is just as modular as the children are dynamic.
Christin Krey is SCI program coordinator at the Philadelphia Shriners Hospital for Children.
