Salim Nasser had dreamed of working at NASA since he was a child, and the dream finally turned to reality in 2007, when he was employed as an Aerospace Engineer at NASA’s Kennedy Space Centre. Since then, he has worked designing and analysing flight and ground hardware for various NASA projects including the Space Launch System (SLS) Program. “I am very lucky to be able to have a career where I am able to work on things that I am so passionate about and love to work on”, he says. 

His story, however, starts some years earlier. Salim was born in Colombia in 1974, but he grew up between his country and The United States. He has been a wheelchair user since the age of 20 as a result of a spinal cord injury.  He had a car accident in Colombia, and his life changed with it: he dropped out of university in Colombia and started living in Miami.

While he was studying Mechanical Engineering at Florida International University, he applied to work at NASA in the Space Centre Houston. This would turn out to be his first step and his first achievement with the Space Centre.

Before he worked at NASA he spent some time developing Rowheels, a wheelchair he designed while he was at university. The idea took off when he met Rimas Buinevicius, and they set up Rowheels Inc, “with the goal of developing the reverse propulsion wheel concept into a commercially viable product”, according with their website.

Nowadays, Salim splits his time between NASA and Rowheels. “I plan to continue working here for the time being. It definitely is not easy trying to juggle my responsibilities at Rowheels and my work at NASA but they are so very different and Rowheels is a labour of love for me so it doesn't even feel like work”.

Salim answered some questions about Rowheels, a mechanical wheelchair designed with new features and the idea to minimize the factors which contribute to shoulder and wrist injury.

How much has the first Rowheels idea been changed since you designed it at university? 

“The first Rowheels wheel concept was similar to what we're developing and bringing to the market currently.  The main difference was that that the original version was a "high gear" design that required less force.  Unfortunately, even though less force is good, it also meant that the user displaces or moves less per stroke which seems to frustrate people.  The great thing about Rowheels is that it involves pulling bio-mechanics which recruit many more upper back and shoulder muscles and this allowed me to change the design to a "low gear" version where a little more force is required but the chair becomes much more responsive, going farther for every stroke”.

How did you meet Rimas Buinevicious, the co-founder of Rowheels?

“After I graduated from graduate school I started working at NASA.  Three years later I decided to enter the Rowheels idea into a design contest hosted by NASA magazine (NASA Tech briefs) and ended up winning the grand prize.  As a result, the story was picked up by the Associated Press and several other online publications such as Engadget and Wired.  Rimas, with whom I co-founded Rowheels, read an article about my design while looking for alternative solutions for Manual wheelchairs.  He had broken his leg, had been in a wheelchair for nine months and had started to feel the aches and pains in the shoulder and wrist that tend to creep up due to prolonged wheelchair use.  He sent me an email offering to help me bring the product to market. We ended up meeting a few days later, came to an agreement and started the company at the end of 2011”.

Why does Rowheels minimize the factors which contribute to shoulder and wrist injury?

“Rowheels implies a pulling motion which uses several of the larger upper back muscles and all of the shoulder muscles in comparison to standard pushing propulsion which basically only uses the top part of your chest and one of your front shoulder muscles.  Because most of the muscles involved in stabilizing the shoulder are active during pulling/rowing propulsion your shoulder is more likely to be stable reducing the possibility of shoulder impingement, which is very common in standard Manual wheelchair users (over 50% of long-term Manual wheelchair users will suffer from shoulder pain and injury).  Because pulling/rowing uses most of the upper back muscles (underused or neglected in standard pushing), users can also experience improvements in upper body posture and strength.  This is important for keeping users active and independent. Pulling bio-mechanics reduce the large compressive impact forces present at the beginning of every pushing stroke. These forces are known to contribute to the occurrence of Carpal Tunnel Syndrome. Rowheels' geared hub was designed such that for every hand-rim revolution, the wheel turns 1.3 times more.  If you combine this with past studies which have shown that pulling uses longer propulsion strokes than pushing, then the net effect could be a reduction in the number of times a user needs to pull to go from A to B, reducing overall revolution which is linked to carpal tunnel syndrome and repetitive stress injuries of the shoulder”.

Who can use Rowheels? Is it especially suited to certain disabilities?

“The rule of thumb for determining whether a user can manoeuver a Rowheels-equipped wheelchair is as follows: If you can comfortably go backwards on a standard manual chair, you are a likely candidate for using Rowheels; If you have limited trunk control, proper set-up of your chair will be required. This will include moving your hips slightly forward for stability and making sure you are sitting comfortably in your chair and can touch the centre of your wheels with your fingers. We are working on developing adaptations to the current design so that users with limited to no hand function will be able to use Rowheels as well”.

Why do you think people overall prefer to use manual wheelchairs?

“Usually, users prefer to use Manual wheelchairs because it keeps them healthy and active, you can easily transfer in and out of cars, they take up less space, and are not dependent on a battery.  In my experience, most people in Manual chairs would prefer not to have to use power chairs and the only reason you will see them switch is if they are no longer able to propel their chair, which is often due to the fact that they are experiencing shoulder and wrist pain/injury.  Personally, as a wheelchair user myself, I think many wheelchair users prefer manual wheelchairs because they draw less attention to our situation”.

What is Rowheels’ most important feature?

“The most important feature of Rowheels's is the pulling/rolling propulsion method that it employs.  The other features involve increased responsiveness, the speed control/breaking system, and quick release capabilities which make it compatible with most lightweight and ultra-lightweight wheelchairs”.

When will people be able to purchase this wheelchair? Could people who don’t live in the United States buy it?

“We are scheduled to have our first round of commercially available wheels by the end of this year.  We are working to develop our provider/dealer network here in the United States and internationally.  We plan to make Rowheels available to European and UK users in 2015”.

You can find more information by clicking here: http://www.rowheels.com/index.html