Alternative Drive Controls

Should It Be Switches or Proportional Controls for Kids?

• By Laurie Watanabe
• Jun 01, 2017

Humans are meant to be independently mobile, and a great deal of our learning and development depends on it. That truth can be challenging for children with mobility impairments. But even children with no independent mobility experience can demonstrate the ability to learn it, often with astonishing quickness.

That poses a key question to clinicians and ATPs working with kids: How do you decide on the best driving controls for firsttime power wheelchair users?

Jay Doherty, OTR, ATP/SMS, Senior Clinical Education Manager, East Coast, Quantum Rehab, has worked with young children experiencing independent mobility for the first time. While a child’s physical abilities factor into the equation, Doherty said they’re not the only considerations — far from it. So what other criteria impact the decision-making process?

“I typically will start by looking at what consistent movements the child has before I decide on an input device/drive control,” he said. “The device being proportional or switched will be directly influenced by what movements the child can control consistently throughout the day. Also, the child’s understanding of cause and effect often will impact the device chosen to start with. If cause and effect have not been established, and the team feels that a simple device is needed to evaluate the child’s ability to learn cause and effect, then a single switch that allows the wheelchair to move in a single direction may be chosen.”

A proportional input device might be chosen “if the child understands cause and effect, and the team is trying to allow the child to understand how to manipulate the power wheelchair, and the child has appropriate movement to control a joystick,” Doherty said. “The team needs to keep in mind that there is not an exact formula to follow. The decision can vary per the individual child’s needs.”

Other relevant criteria can include a child’s age, mobility experience, clinical diagnosis and function. “It is a very individual decision,” Doherty added.

Advantage: Switches

For young power chair users, what potential advantages do switch systems offer?

“Switch systems are simpler to use in the way that you press the switch and you will only go in the direction the switch activates, as well as a set speed that is programmed into the system ‘on/off,’” Doherty said. “Since switches represent only one direction of control, they tend to be simpler for children to pick up.

“Proportional devices have multiple directions of control and speed and are more subtle in responsiveness so they can be more complex for a child to understand that the change in direction or speed was a direct result of something they did with the proportional control. The child may not be aware they are fully in control of the mobility system. The team should keep in mind that the best control over a power wheelchair’s speed and direction comes from proportional controls, so although switches are easier to understand, they don’t offer the exact same or extent of control that a proportional input device offers.”

Advantage: Proportional Controls

So would Doherty prefer to try to start children on proportional controls instead?

“I believe that proportional controls should always be the first thing you considered utilizing with children,” he said. “A proportional input device allows a child to have great control over modulating speed and direction while driving a power wheelchair. Proportional control is the most efficient way to drive the wheelchair. Therefore, if we can get a child to start with a proportional, that is where we should start.”

But if the mobility team does decide to start a child on a switch system, is it likely that the child will be “stuck” with that system in the long run?

“A child doesn’t always have to stay with the device they start with,” Doherty said. “Sometimes children will start with a simple system so they can understand cause and effect and just explore movement with no expectation other than allowing the child to experience movement. The movement may be spinning, or playing with stop and go to explore movement. In the case of experiencing movement, a single switch may meet the need.

“The team may also choose to allow the child to feel movement in a variety of different directions with a proportional device. If the child has the movement available to potentially use a proportional input device, the team may decide to start with a proportional input device or graduate to a proportional input device when it is appropriate. A team should never rule an input device out until they know for sure that the child cannot use the device. Often, a device is ruled out because of motoric limitation that a child may present with versus [the fact that the child] just started with switches. The team should always keep in mind that as the child starts to control the power wheelchair movement and is moving towards directed movement and finally independent movement, the input method may need to change and be open to exploring other input methods further.”

Endless Possibilities

Finally, does a child’s lack of independent mobility indicate that switches will likely be a more successful answer?

“Not necessarily,” Doherty said. “I have started many children without any mobility with a proportional input device. If the child has the control to use a proportional input device, it may take them a little longer to understand the device, but once they can use it, they have the best control over the power wheelchair.”

Therefore, Doherty said, a history of previous independent mobility (or lack thereof) doesn’t define a child’s future mobility. “The child with mobility already may have a leg up on the child with no mobility because they have some understanding of moving themselves through space,” he said. “The advantage lies in that they understand mobility already; this doesn’t necessarily provide them with an advantage for using an input device. In my experience, some children who have never experienced independent mobility in any other way and do so for the first time with power, gain a desire to be more independent in other ways as well.”

This article originally appeared in the June 2017 issue of Mobility Management.