The cliché is, “There’s no need to reinvent the wheel.” This has for the most part held true for ultralight manual wheelchairs, where only a few wheel innovations have dramatically improved performance over the decades. However, there are new wheel technologies that really have reinvented aspects of the wheel — with notable benefits for ultralight wheelchair users.
The Historical Issues with Wheeled Propulsion
In recent decades, as technology and social inclusion increased, ultralight wheelchair use also increased. In the process, the study of biomechanics in manual wheelchair propulsion became a field unto itself. Two primary findings emerged. First, ultralight manual wheelchair propulsion in the long term can be hard on the body, where the traditional forward pushing motion has a correlation to joint strain, especially at the shoulders and wrists. Second, because ultralight wheelchairs traditionally use stiff frames, without suspension, they can prove very jarring, exacerbating such conditions as back pain and muscle spasms. So, how are new wheel technologies addressing these two significant issues?
When Backward Becomes Forward
Since the invention of the manual wheelchair, propulsion has been via a forward push of the drive wheels. After all, if you want to roll a wheel forward, you logically push it forward. This has been the method of mobility for millions, for centuries. However, biomechanically speaking, this hasn’t ultimately proven to be the best form. Primarily, only the triceps are used, and tremendous strain is put on the shoulder and wrist joints.
The engineers behind Rowheel, manufacturers of an aftermarket ultralight wheelchair wheel that can be propelled forward with a pulling motion, evolved a solution that dramatically improves biomechanics. The Rowheel uses sophisticated gearing within an ultralight wheelchair wheel, so that when you pull back on the handrim, the wheelchair propels forward. To steer, you counter-rotate the wheels, but in opposite directions of standard wheels. For braking, you press inward on the handrims. I realize this all may sound a bit counterintuitive, but once you try Rowheels, you will understand a simple reality: they work extremely well.
The magic is in the “rowing” or pulling motion. Instead of using primarily your triceps and straining shoulder and wrist joints, the Rowheel keeps joints stable and uses your biceps, deltoids, traps, and lats — that is, approximately four times more muscles than during a forward push. The result is overall easier propulsion, with less immediate fatigue and better joint health over the years. Additionally, the biomechanics of pulling versus pushing intrinsically improves posture by allowing you to remain upright, with your shoulders thrust back during propulsion.
Beyond the biomechanics of Rowheels, built-in gearing allows approximately one-third farther propulsion per stroke. When you combine the gearing with the biomechanics of Rowheels, the result is dramatically greater efficiency in propulsion.
Rowheels are available in wheel sizes from 22 to 26 inches (in two-inch increments), and can be retrofitted to all major brand ultralight wheelchairs.
Put a Little Padding in Your Push
Another unintended problem that has developed with wheelchair wheels is the general lack of shock absorption. If you’ve spent any time on varied outdoor terrain, you know that no matter how high the quality of your ultralight manual wheelchair, the ride can be rough at best, teeth chattering at worst. For those prone to pain or spasms, the rough ride can exacerbate symptoms. Softwheel, a revolutionary wheel design, ingeniously addresses the need for shock absorption.
The Softwheel replaces traditional spokes with three shock absorbers that connect the hub to the rim. The wheel functions as a normal push wheel until it hits a bump. The shock-spokes then compress, allowing the hub to travel from the center of the wheel, where it absorbs the bump, then returns to the center. The secret to the Softwheel’s success is that it uses a totally rigid rim and handrim, so there’s no flexing or energy loss as you push. It’s only when the wheel itself encounters an obstacle or bumpy surface that the wheel rim compresses the shocks, enabling the hub to travel off center for absorption.
With the Softwheel weighing only 3.5 pounds, you get the benefits of true absorbing suspension without adding bulk to an ultralight wheelchair. Available in 24-inch and 25-inch sizes, the Softwheel is plug-and-play on most ultralight wheelchairs.
Seeing is Believing
Both the Rowheel and Softwheel technologies are so simple in use, yet esoteric in design theory, that they’re among those rare products where seeing is believing. Check out the videos — seeing how they work mechanically is fascinating. Also, if there’s an annual Abilities Expo in your area, that’s a great venue to test them for yourself. After all, when it comes to these mind-boggling technologies that actually improve our lives as wheelers, the one experience better than seeing them, is trying them.
Beware, innovation comes at a steep cost. Rowheels are listed at $5,400 online, though different sites offered them for as low as $3,495. The Softwheel ranges from $2,650 to $2,990.