Wheelchair ‘Rowing’ Design Could Reduce Shoulder Injuries

A breakthrough invention in manual wheelchair design offers the opportunity of reducing upper-body, repetitive stress injuries while increasing mobility. Developed by Salim Nasser, an engineer from Merritt Island, Florida, the Rowheel Wheelchair Propulsion System won the $20,000 grand prize in the “Create the Future” Design Contest 2010, an annual competition by the publishers of NASA Tech Briefs magazine that attracts nearly 1,000 global entries each year.

The concept behind the Rowheel system is that by pulling on a wheel –rather than pushing– wheelchair users can utilize larger, stronger muscles in the bicep and upper back, generating greater ease of maneuverability, while cutting down on user fatigue and injuries to the shoulder, elbow and wrist brought on by repetitive motion.

In an interview with New Mobility magazine, director of Human Engineering Research Laboratories, Rory Cooper, Ph.D. says, “On shoulder repair –an ounce of prevention is worth a pound of cure.” Himself a T7-8 complete para, who races wheelchairs, swims and handcycles, Cooper adds, “The keys to keeping shoulders healthy are: Don’t gain extra weight (this puts stress on the joints); stretch and stay flexible; and develop the best, most efficient wheelchair stroke possible.” With 75 percent of all wheelchair users being manual wheelchair users, that means a lot of people risking serious repetitive stress injuries every year.

The Rowheel design could potentially prevent a great number of those injuries and the costly, painful surgeries required to fix them. According to Nasser:

The key feature of the Rowheel design involves adapting a planetary gear system at the center of the wheel, which reverses the pulling motion of the user into a forward motion of the chair. The unique change from pushing to pulling along with the mechanical advantage created by the use of the gear system will provide an overall increase in user endurance and range.

Nasser, who is himself a wheelchair user, currently works as an engineer at NASA’s Kennedy Space Center, where he performs analysis for flight hardware and ground support equipment. He developed the concepts behind a “Pulling Wheel System for Wheelchairs” as his senior engineering design project while attending Florida International University.

Creating the Rowheel system for the “Create the Future” contest took 4-1/2 months from original concept to prototype to complete. It has similar specifications to those of existing manual wheelchair wheels and great care was taken in incorporating standard, universal parts where necessary, so that modification of existing wheelchair frames is not required.

“I thought it was a great design and that someone would be able to use for their own health” says Nasser. “It would be the ultimate satisfaction to see your design come to life and be used by other people.”