Massey University engineers have developed a new wheelchair that has a propulsion whose innovation means your hands never have to leave the push rim while moving. With it, the creators of the chair hope to reduce the chronic wrist and shoulder problems that develop amongst people who use wheelchairs as well as make travelling uphill easier.
Dr. Claire Flemmer from the university’s School of Engineering and Advanced Technology states that the essential design in conventional manual wheelchairs has not been changed in over a hundred years despite proof showing that upper limb pain develop in users after a year’s use.
These problems mainly arise from a manual wheel chair’s inefficient push effort as only 25% of the efforts put in with the continuous cyclic gripping and pushing of the wheel or inner rim contribute to forward movement. Additionally, this method of propulsion also contributes to imbalanced repetitive strain on the shoulders and wrists and, as a result, chronic pain arises.
The new propulsion system, however, improves stroke efficiency by ensuring the hands remain on the push rim and utilize 100% of the arm movement. The new system is adopted in one of Ezy-Wheels two modes, christened Run Mode. This mode is intended for use with longer distances and terrain that is more challenging. Run Mode also employs the innovation of a three gear system similar to that of a bicycle.
The high gear is for easy paths such as downward slopes and smooth surfaces. Low gear, conversely, is for when you meet roads that are rougher – a ramp or a tarred path. The run mode also does not allow for reversing so as to prevent a user from rolling backwards when down slope. While in standard mode, the chair will act just like any other manual wheelchair and allows for maneuverability indoors but with an extra three gears.
30 Years Worth of Work
The journey, Dr. Flemmer says, started 30 years ago when together, with a colleague named Rory, they watched a woman on a wheelchair struggle to move up a slope. Afterwards, they spent many years pursuing the idea of a four-wheel drive type of chair. With Ezy-Wheels, though, Dr. Flemmer and her team finally have it. Though the chair is still a prototype, Dr. Flemmer reports that plans are in place to use lighter materials in order for the final production model to be more user friendly.
Photo Credit: Massey University