On August 4, 2015, Max Mobility started shipping their highly anticipated MX2, the next generation of its SmartDrive power assist for manual wheelchairs. NEW MOBILITY columnist Mark Smith was so impressed with the SmartDrive MX1 that he devoted his entire December 2014 Innovations column to it (see resources). In mid-August I received an MX2 for an extended demo. I found the MX2 does even more with less than the MX1.
For those unfamiliar with the SmartDrive, it is a motor and drive-wheel unit that quick connects onto a hitch mounted on the center of the camber tube on a manual wheelchair. Mark Richter, president of Max Mobility, says the company has adaptations that will fit virtually any variation of rigid or folding chair.
At first glance, the MX2 looks like the MX1, but closer inspection reveals the 8-pound battery, which slid under the seat on the MX1 and required plugging in a pigtail power cord into the drive unit, has been eliminated. This reduces the time it takes to put the unit on or off the chair from about a minute for the MX1, to 5 seconds for the MX2! Total weight of the MX2 is 12.5 pounds.
Another new MX2 innovation is a motion-sensing Bluetooth LE [low energy] sports wristband that communicates drive commands with the power unit. The wristband has a push-button on/off switch and provides feedback about mode and acceleration via a small red/green light and silent buzzes akin to an incoming cell phone call on mute setting. The wristband senses when you push on the rim and holds that push speed — from 0.5 mph to 5.5 mph — like a cruise control, and has a 12-mile range. To disengage the motor, you simply tap the push rim with the wristband hand. Optional “Thumb Throttle” buttons, which fit on the frame, enable starting from a stop by pushing a button. A continuous push will accelerate it up to 1.5 mph, about the speed of a slow walk, a useful feature for starting on ramps or hills.
Richter says a primary goal of the SmartDrive is to prevent overuse damage in shoulders. The idea is for wheelers to get SmartDrive at the first signs of shoulder pain, before damage occurs, and allow shoulders to rest, heal and stay healthy for the long haul. To that end, the MX2 is approved by Medicare and the VA with medical necessity documentation. Some examples of medical necessity include pain in shoulders or wrists, becoming easily fatigued by pushing, or having difficulty pushing over carpet, up ramps or hills. This brings up the importance of seeing a physician if you develop shoulder or wrist issues, to help identify and heal the problem, and for documentation. Anecdotally, I am 55, a T10 complete para, 30 years post-injury. Over the years I’ve had several bouts of lingering shoulder pain. Each time I went to my primary care doc, who did a check-up and gave me a referral to a sports therapy clinic, which helped a great deal. However, as a manual chair user, resting my shoulders to help them heal wasn’t an option.
My MX2 test drive actually started when I first used the MX1, three years ago, at a time when both shoulders had become extremely painful due to overexertion from trying to get back in shape too fast. The MX1 enabled me to rest and heal my shoulders despite a busy work-travel schedule. Without the MX1, I was likely heading for permanent damage.
My first impression of using the MX2 is that the Bluetooth wristband makes controlling the drive unit super easy — although it did take a day or two of wheeling before the wristband signals became instinctive rather than having to rely on “recall.” I also found the MX2 interprets long, smooth push strokes when reading acceleration better than short jerky strokes, a reminder that when I am in a hurry, my push strokes become less efficient. Like the MX1, I don’t notice the MX2 is on my chair when it is in the “off” mode.
Out of curiosity I removed the SmartDrive and counted my push strokes while wheeling the three-quarter mile route from my home to my P.O. Box — exactly 425 push strokes. The next day, the same route with the MX2 took 12 strokes, including stopping and starting at a stoplight and opening the door at the post office.
I also timed how long it took me to unhook the MX2 and load it into my car, then unload and hook the MX2 to the back of my chair — 20 seconds each way. I can see it will also be a huge bonus for airline travel, with one trick to figure out — how to get the power unit to fit in the overhead.
Joe Bohl, 62, in his 28th year as a T4 incomplete para, started having painful twinges in his shoulders 11 years ago that slowly got worse. “Over the last two years my shoulders have become so bad, especially my left one, that I was considering shoulder replacement surgery. So I switched to a ramp van, but my shoulder throbs even from minor pushing, especially climbing the ramp into my home. It was severely affecting my ability to get out of the house and enjoy life,” he says.
In February 2015, Bohl got an MX1 for an extended demo. “It changed my life. It enables me to take Lloyd, my lab/mastiff service dog who needs lots of exercise, on daily 4-mile round trips to the dog park,” he says. “It enabled me to enjoy the summer and cancel shoulder surgery, at least for the foreseeable future.”
Bohl was ready to order an MX1 when he heard about the MX2. “After demoing the MX2 for three days last weekend, I’m sold,” he says. “I’m impressed with the way the Bluetooth wristband works. Being able to tap the push rim to disengage the motor is super easy, convenient and safe, especially in tight spaces like wheeling up the ramp into my van.”
Bohl also appreciates the thumb accelerators. “They saved my shoulder a couple times when I stopped in the middle of my ramp,” he says. “Having to start uphill by push rim would have been excruciating. A simple push on the thumb accelerator made it easy.”
Following the demo, Bohl sent a message to his doc to start the paperwork to order a MX2 through Medicare.
Manufacturer’s suggested retail price remains the same as the MX1: $6,450; minimum advertised price: $5,805