Page 24 - Mobility Management, April 2018

ATP Series
Suspensions: Functional Comfort
itself illustrates a shift in focus for suspension. Doherty explains that the suspension system signi cantly reduces vibrations no matter what terrain or obstacle the user traverses.
“In addition, when the wheelchair drops down off a small curb, much of the impact is also absorbed by the suspension system,” he says.
For Sunrise, the newest suspension system in their line-up actually senses “when it’s appropriate to let the suspension move and when the suspension should not move,” Critch eld says. “These active suspensions provide additional stability to the end user when going down declines or off of a curb.”
Paying for the Upgrade
This might come as a bit of a shock. Suspension is so important that it is required on Group 3 and 4 power chairs, Critch eld says.
In fact, the classi cations for power chairs and the reimburs- able rate are very similar to motorcycles. A “hardtail” motorcycle does in fact imply a simpler design, no suspension and a reduced cost. Whereas, a “softail” provides comfort through better suspension, a longer ride and a higher price tag. In essence, a softail is a more complex machine, much like the Group 3 and 4 power chairs.
As such, this class of power chairs comes with certain design
expectations that payors recognize.
“Every Group 3 power wheelchair must have some kind of
vibration-dampening system in the wheelchair, as well as meet minimal climbing capabilities,” Doherty says. “Therefore, most manufacturers meet these requirements through use of a suspension system.”
Peterson says funding sources don’t directly pay for the suspension system per se.
“Simply stated, a Group 3 power wheelchair can climb a larger obstacle than a Group 1 or 2 can,” he says. “Suspension is a key component in determining how large an obstacle a chair can navigate.”
To get funding for a suspension system, the clinician and provider must justify the power base itself, Doherty says.
Access to a power chair suspension system — no matter what type is chosen — ultimately improves the clinical condition of the user.
“Minimizing the exposure to vibrations is important to promoting a power wheelchair user’s overall health, enhancing functional endurance and quality of life,” Bourque says.
Fortunately, power chair suspension systems can de ne the end-user experience through a more comfortable ride, while enabling the user to get out on the highway and stay there longer. Functional comfort and adventure await! m
Research on Wheelchair Vibration Offers Consumer and Clinician Insight
A qualitative study published at the 2015 RESNA conference provided consumer and clinician insight on power wheelchair suspension systems.
The researchers — Carmen DiGiovine, Ph.D., ATP/SMS, RET; Amy Darragh, Ph.D., OTR/L, FAOTA; Theresa Berner, MOT, OTR/L, ATP; and Taylor Duncan, Occupational Therapy Division, all of The Ohio State University — looked at whole-body vibrations
and outlined considerations for future research and development in “The Effect of Whole Body Vibration on Power Wheelchair Mobility: A Focus Group.”
The study analyzed responses from a focus group comprising
15 consumers and nine rehab specialists. Both groups discussed surfaces and obstacles encountered while using power wheelchairs and then described functional and non-functional features on power chairs.
The research indicated the following commonalities among consumers and industry professionals.
• End users encounter more than 30 different surfaces and obstacles that result in vibration. These surfaces include uneven grass, cracked sidewalks, transitions and thresholds, gravel, brick, truncated domes and cobblestone.
• These different surfaces and obstacles take various tolls on the user, resulting in longer trips, loss of wheelchair control, fatigue, pain, discomfort, fear and apprehension, and loss of positioning.
• From the clinician’s perspective, these mobility conditions were more susceptible to the effects of vibration, shock and motion: spinal muscular atrophy, muscular dystrophy, multiple sclerosis, amyotrophic lateral sclerosis (ALS), spinal cord injury, cerebral palsy, spina bi da, stroke, lower-extremity amputations, Friedreich’s ataxia, and brain injury. In individuals with these condi- tions, greater startle re ex, spasticity and hypertonicity/hypoto- nicity were a result of vibration.
• Consumers identi ed the suspension system as the most important feature of a power wheelchair for reducing shock, vibration and motion. The consumers also wanted the ability to turn the suspension system on and off. Clinicians agreed and also wanted more exibility to customize the suspension system to the individual user and environment.
In short, the suspension system of a power wheelchair is important to both consumers and rehab professionals. Both groups recognize the issues caused by vibration.
Find the abstract at www.resna.org. m
24 APRIL 2018 | MOBILITY MANAGEMENT MobilityMgmt.com