Dive into Design: Human Centered Design & the GRIT Freedom Chair

We are often asked how many designs of the GRIT Freedom Chair exist and how did the current chair design come to be? Well, the short answer: Design, prototype, test, repeat. As engineers do, we cycled through that process dozens of times as we developed the GRIT Freedom Chair. Prototype after prototype was tested with wheelchair riders around the world, and we gathered key feedback to make the chair better and better each time around.

We knew from the outset of our research that mobility devices are essential for many individuals, but many manual wheelchairs are hard on the body. And those that are easier on the body, tend to be harder on the wallet ($$$$). Similarly, more often than not, most chairs on the market are incredibly difficult to transport making it harder for one to enjoy their favorite activities, and even the chairs that claim to be all-terrain, can be faulty on surfaces that are anything but perfect. We also heard these three issues echoed from our riders and prospective riders: manual chairs are hard to take off-road, they are hard to transport, and they can be expensive. We knew that these were our challenges to overcome.

So, taking all of this into account, we set out to build a chair that was rooted in the philosophy known as "human-centered design." This customer-centric approach involves iterative prototyping and careful consideration of the entire product experience. We didn't want to just make a pretty product. We wanted to make a product that met important user needs and addressed their concerns. We wanted to make a product that would help people achieve great things.  Little by little, we progressed to the current model of the GRIT Freedom Chair, which we're proud to stand behind. 

Hop on the engineering train! We're diving into 3 areas of our design: the lever drive system, ease of transportability and usage of bike parts. 1-2-3….let’s go!

  1. Lever Drive equals Efficiency

While at MIT, GRIT’s founders started the Mobility Lab and researched the ideal upper body movements to maximize power. The innovative and patented lever design uses larger muscle groups and simpler movements than push rims. No other product has the published peer reviewed research on the efficacy of their lever design.  Comparing the Freedom Chair to their regular wheelchair over a typical mixed terrain commute:

  • Riders were faster. 76% faster than a wheelchair over the same terrain.

  • Riders used less energy. 41% more efficient.

  • Riders tackled obstacles easier. 51% higher peak propulsion force.

In practice this means you can push yourself independently further, whether you are a outdoors person hoping to complete a longer hike or, like Nate, who uses his Freedom Chair to get exercise in his backyard and, for the first time, can move a “manual wheelchair independently”. The lever drive is our answer to the chief complaint that a standard manual chair simply can’t handle vast terrains.

2. Transportability and Storage

Early on in the design process (and continuously throughout) individuals told us about the importance of being able to take the GRIT Freedom Chair with them. There are lots of trails to be explored that don't start at your front door, and we knew that a huge part of the GRIT experience was being able to get outside in the fresh air! Many other pieces of adaptive equipment are great for the specific purpose, but hard to transport. Take for example, handcycles and tank chairs, which can oftentimes require a trailer for transport.

We designed the GRIT Freedom Chair to disassemble (in under a minute) without any tools to fit in the trunk of a small car - that’s the difference maker! We know many people have vans and trucks, but we wanted to the GRIT Freedom Chair to be accessible for everyone, regardless of trunk size. We decided to disassemble rather than fold, so that we could maintain the structural integrity on the trail, and to make it each piece that has to be lifted incrementally lighter. While one hand tool-less quick release wheels are a common feature of everyday chairs, it is not in other manual devices you may be considering in the market, in fact this innovative design was granted another GRIT patent.

Fun fact: One founder of GRIT has been known to put two Freedom Chairs in a old 2 seater convertible.

3. Bike parts and the GRIT Freedom Chair

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From early on, we recognized the benefits of taking advantage of the bike industry. Parts are manufactured in an order of magnitude larger quantities than with wheelchair components. As such, innovations in the bike industry have been realized decades before they reached the wheelchair world. We thought “Hey, if we could bridge the gap between the two worlds we would have a real winner in our hands.” Why? Well, for one it’s more economic (aka saves you, the rider, some moolah), two, it is easier maintenance and servicing, and three, these parts are already appropriately engineered for human forces.

As such, we made every rotating wear component a bike standard interface (and the footrest and parking brake adjustments of seat post standards, to boot). From the drivetrain and caster to mountain bike wheels, we think the bike parts are one of the greatest features of our all-terrain wheelchair. The best part? These are all commonly available and affordable to service at any bike shop. Can our competitors say the same?

Read Nerissa’s experience at a local bike shop here.

Design, prototype, test, repeat.

We are continuing to use this process as we develop not only accessories for the GRIT Freedom Chair, but new chairs themselves (check out our Push model and the Freedom Chair Spartan). We always have terrain, transportability, and cost on our mind, and continually find new ways to ensure that the GRIT Freedom Chair excels in all of these categories. Thank you to our riders and supporters for their constant feedback. We always welcome and appreciate your questions, concerns, and ideas, as they help us make the product better for everyone. 

Time to hit the road!

The GRIT Freedom Chair is the most versatile chair on the market, designed from the ground up to handle any terrain. From trails to grass to snow, the Freedom Chair is built for you to push yourself. Born out of research at MIT, the Freedom Chair's patented easy-push levers reduce shoulder strain and put you in control of your mobility. Learn more about the GRIT Freedom Chair at www.gogrit.us