Seating & mobility clinicians and providers who work with
children know that high muscle tone and extraneous movements
can, in time, damage or break equipment such as wheelchair
footplates, armrests and backs.
But even when the equipment does not give way under extreme
forces, there can be a problem.
In those situations, when a child’s tone is causing great force
against, for instance, a wheelchair back, “something has to give,”
says Jay Doherty, OTR, ATP, clinical education manager at Quantum
Rehab. “So the child’s position changes. Typically, back canes are not
going to move because they’re not designed to move. If it’s done over
and over and over to the system, you may have some change in some
parts that allow some minimal shifting, but it’s not going to allow
large movements like a dynamic system will.”
Dynamic seating and components — as seen in products by
Quantum Rehab-owned Kids UP, as well as Miller’s Adaptive
Technologies, Rifton Equipment and Thomashilfen’s Exomotion,
among others — move with the child as the child moves.
“Part of the problem with a child moving within a stationary
system is the pelvis is not going to stay in place,” Doherty says.
“Because of the excessive movement, typically they slide forward
on the seat cushion, so they’re going to go into a posterior pelvic tilt
that’s going to be transferred up to the spine. We’re going to end up
with more of a kyphotic position, which transfers into their head
position and their arm position. It’s kind of a tumbling effect.”
With dynamic seating systems such as Kids UP’s, “the seat and
Dynamic Seating: A Moving Alternative back actually move with the child,” Doherty explains. “They’re
designed to allow the child to go into that extended position so that
the seat and back stay with them, open up to accommodate the hip
angle, and then as the child falls back down into the system and
relaxes, it maintains the pelvis back in the system. The springs and
the pivot point are what allow that to occur.
“Most of your static types of systems don’t allow that motion to
occur, so when the child pushes, what ends up happening is the
pelvis slides forward on the seat. The end result is the force is put
not only on the seating system, but it also has changed the child’s
position. (In a dynamic system) the positioning components move
with the child so it maintains the child’s alignment throughout their
Another dynamic system benefit: Potentially less wear on equipment
and fewer ultimate repairs.
“When you have a solid back cane on there and it’s not moving,
(high tone) certainly puts greater force on those attachment points,”
Doherty says. “So you may have holes that ‘egg’ out a little bit and
provide some movement within the back cane. And certainly any
time you have that movement, and it’s not designed to be there, it
can potentially do more damage to that piece of equipment.”
A dynamic system, in contrast, “allows the child to go through
that extension, but the system absorbs it.”
Could be a win-win for providers looking for a solution to
frequent repairs, and for active kids who are too busy to let broken
equipment slow them down.