Study: Frog Legs Soft Roll Wheels help to make maneuvering a manual wheelchair easier

OTTUMWA, Iowa, May 27, 2020 -- Frog Legs Soft Roll (FLSR) wheels showed the best overall performances for straight and zero-radius-turn maneuvers during a study looking at manual wheelchair propulsion costs.

“We have put years into research and testing to make our wheels the best that they can be, understanding how crucial performance is to the well-being of our customers,” said Mark Chelgren, Frog Legs Founder and CEO. “We appreciate this independent validation of what we’ve always known.” 

The results of the study are included in a recently published article in RATE - the Journal of Rehabilitation and Assistive Technologies Engineering. The article, “Manual wheelchair propulsion cost across different components and configurations during straight and turning maneuvers,” was written by Stephen Sprigle and Morris Huang.

The researchers wanted to measure the work required to propel a manual wheelchair configured with three weight distributions, three drive wheels, and four casters over tile and carpeted surfaces. One of the casters used for the study was the 4 x 1.4*-inch Frog Legs Soft Roll (FLSR) wheel. (*The study cited the FLSR as 4 X 1.5-inch.)

A wheelchair user must use effort, often considerable effort, to achieve different speeds and/or directions to maneuver throughout the day. To help prevent fatigue and injury, using the least amount of energy to maneuver a wheelchair is desired.

The project sought to address two research questions: (a) how much does propulsion cost change during straight and turning trajectories with different weight distributions on the wheelchair’s drive wheels and (b) how much does wheelchair propulsion cost differ when configured with different drive wheels and casters?

“The influence of specific casters under the different conditions varied substantially,” according to the article. “The straight and zero radius turning maneuvers can be used to draw inferences about overall performance since these maneuvers highlight caster performance.”

The study found that with respect to casters, “despite the smaller diameter and wider width, the 4 X 1.5 FLSR exhibited a surprising good performance. This may reflect a beneficial material construction and overall design.”

“We’ve taken great care to create our wheels,” Chelgren said. “Our U.S.-made, three-spoke aircraft-grade aluminum hubs are machine-lathed for perfect balance. What’s more, our proprietary high-rebound polyurethane recipe for our treads is designed to minimize energy loss and absorb vibration. To achieve this, we spin-cast our solid urethane treads. This manufacturing technique significantly minimizes air bubbles in the tread, resulting in a denser material, fewer defects, and less tread damage compared to when air bubbles in other wheels are uncovered from wear or impacts. We also opted for a spherical arch tread design to improve pivotability for effortless turns and enhanced stability, much like a ball rotates and spins easily on a surface.”