SURVEYOR'S NOTEBOOK

The Unpredictability of Innovation in Wheelchair Use

By Rik van Hemmen

Standard wheelchairs have not changed in decades. It is a chair with wheels and has foot pads to support a person’s feet and to keep them from dragging on the ground.

The foot pads are actually quite complicated, because they need to flip away when the person is being seated or stands up and they need to be removable for various more complex iterations when a person is being moved from bed to chair or from car to chair.

As a matter of fact, these foot pads are a pain in the butt, because they require a caregiver to lean over to do the flipping and removing.

As caregivers, we had just shifted Anne to the car to take her from New Jersey to Harlem for a doctor’s visit, and, when we arrived, we realized we had left the foot pads at home.

The distance from the parking spot to the hospital is a substantial distance over NY sidewalks and streets and without foot pads the transit would either be all wheelie, to keep Anne’s feet off the ground, or would have to be backwards with her feet dragging.

I searched the minivan for a solution and found a dog leash. I slung it under Anne’s feet and tied it to the armrests and Anne had her feet comfortably suspended. Problem solved.

When we got to the hospital, the Doctor commented on the foot sling and said: “That is pretty neat, she is exercising her weak left leg with her stronger right leg by swinging the legs together.”

By the time we were going home we realized that Anne could place her right foot in the sling herself and then swing her left foot off the ground with the sling. (In physical therapy they called that foot hooking, but it never worked all that well with Anne)

Loading her in the car we realized we did not have to swing the foot pads out of the way. One less bending motion for the caregiver, and no need to struggle with the securing mechanism.

When I got home, I decided to modify Anne’s transfer chair with a foot sling.

I had a beautiful red padded cargo strap and wanted to fit that, but Abby felt it should be color coordinated, so I decided to use the transfer chair seat belt as the foot sling. I unscrewed it from the back of the seat and transferred it to the screws at the front of the seat.

And it did not work. Anne could not get her foot in easily and it was difficult to swing her foot up.

I suppose this is where engineering training becomes significant in design. I took me a minute, but I then realized that the swing attachment point needs to be above knee level. Our emergency modification on the wheelchair had the most obvious attachment point high near the armrest, while on the transfer chair there was no such obvious attachment point.

I had to take a dive into my marine hardware bucket and with some hose clamps and shackles I managed to create a reasonably attractive solution.

We are now well in the product testing and evaluation phase and can provide some interesting observations.

Standard footrest problems:

  1. 1. Increases turning radius of the wheelchair.
  2. 2. Rigid footrests cause damage to walls and doors.
  3. 3. Footrests do not prevent a person from sliding down (slouching) in their seat unless the footrests are elevated (delivery table style).
  4. 4. A paralyzed foot needs to be secured to a footrest to keep it from falling off when transiting door sills or rough pavement.
  5. 5. Footrests require bending and stooping by the caregiver during transfer.
  6. 6. Footrests may require removal when moved in small cars.
  7. 7. Footrests are heavy and can get lost when removed.
  8. 8. Footrests are complex pieces of equipment ($$$).
  9. 9. Footrests are passive equipment. They do not allow an occupant to be involved in the use of the equipment.

It is a rare day when a design improvement can provide so many benefits.

This is what we have observed:

1. It is easier to maneuver a person in tight quarters with the foot sling.

2. The soft sling cannot damage walls and doors (the wheels still will though).

3. Since the strong foot and leg is restrained above the knee, the occupant can push herself back into the seat and slouching is much reduced and even eliminated.

4.  The picture provides some reference, but, in effect, the good foot secures the bad foot in the sling and the weak foot stays in place much better than being isolated on a horizontal foot pad. (We had some concerns with foot pinching, but in long wheelchair runs Anne will wear shoes which reduces pinching, and at home she will simply take her foot out if she becomes uncomfortable.)

5. As a caregiver it is so nice to not to have to worry about those foot rests. No removing feet no hinging foot rests out of the way and no flipping pads (when the pads have been flipped up many times they no longer stay up by themselves either, since the fit has loosened. Talk about frustrating holding a person and trying to get the pad to stay up). With a foot sling you pull up to the car and, at worst, you help the occupant to take her foot out of the sling, which can be done by lifting at knee level.

6. You get the person in the car, you move the chair, fold it and dump it in the trunk. Seamless, and it is much less bulky to store.

7. The foot sling never needs to be removed, if necessary you simply tuck it under the pillow. The footrests can still be used if there is a specific need. (I don’t know if they were designed for it, and worry about their strength, but a two person chair lift consists of one person lifting at the handles and one at the foot rest frame.)

8. A foot sling is significantly less expensive than the foot rests.

9. It is no fun to be wheelchair bound, and any small change that makes a wheelchair user feel more involved in their activities is a very important psychological improvement. Just to make a wheelchair user feel a little bit better is priceless.

10. In Anne’s case there is another very interesting therapeutic effect. She has to wear a boot that prevents her from developing a drop foot in her weak foot. Just by positioning her weak foot in the right position in the sling her foot is pressed up at the toe and the need for the boot is much reduced.

I have been involved in design for a long time, and was amazed that no such device had been invented earlier. So I searched the internet (Googled: wheelchair support feet in a sling)  and the design exists, but it is not marketed for the purposes provided above. It simply exists to converts a rolling walker into a pushable device.

Interestingly, I see an immediate flaw in the design, since the rigid foot pad is much too wide. The pad should be no wider than two narrow feet, since the side straps should function as foot securings, and the wide pad provides no such security. Moreover, a wide foot pad reduces tight quarter maneuverability. However, for the cost of it (in the context of medical devices at $49 not bad, but actually many multiples of the cost to manufacture), I certainly see no reason to patent our invention and to market it. I just hope that it will become better known to help the wheelchair bound community. A chair with a foot sling should actually be less expensive than a chair with conventional foot rests, a truly rare occurrence in the medical industrial complex, but I am not holding my breath that in the future chairs can be purchased without those foot rests.