Introduction: Miniature Pediatric Posterior Walker
Jace is happy and curious 2-year old who has achondroplasia, a form of dwarfism. His physical therapist wanted a way to support him as he learned to walk independently, but there are no walkers on the market that are small enough for him.
His physical therapist wanted a reverse walker for Jace, where he held handles but the support of the walker was behind him. We did some research and discovered it is also called a posterior walker. "For kids challenged with mobility impairments, pediatric posterior walkers provide several distinct advantages over other types of walkers. They deliver a comprehensive array of physical and psychological benefits, along with encouraging improved eye-to-eye interaction because the support is placed behind the child, rather than blocking their access in front (RehabMart)."
This Instructable will go through the steps we took to custom-build a tiny reverse walker for Jace.
Supplies
- 2 swivel Caster Wheels
https://www.coolcasters.com/cool-casters-175-ball-...
-2 threaded Casters Wheels
https://www.lowes.com/pd/TITAN-2-in-Rubber-Rigid-C...
-1 Electrical Tape
https://www.lowes.com/pd/Scotch-Super-33-37-5-ft/3...
- 3 Metal tubing: 1-inch diameter tubing for walker main structure
https://www.grainger.com/product/GRAINGER-APPROVED...
- 1 Foam:
https://www.amazon.com/FoamTouch-Upholstery-Foam-D...
-Paint
https://www.amazon.com/Rust-Oleum-7579838-Professi...
-Fun stickers:
https://www.amazon.com/Stickers-50-500Pcs-Colorfu...
-Screws, Nuts, bolts:
(Provided In lab) N/A
- 1 Special bending 3D Filament:
Step 1: Meet With Your Customer
We met with Jace's physical therapist to learn more about Jace's body and needs, and she took his measurements that would help us custom-build a walker for him.
She explained about current walker options, like the NIMBO Walker and why no commercially-available walkers met Jace's needs because they were all too large for him.
We also got to spend time with Jace and his family to get to know them more. They talked about things he liked to do, and how he wanted to move around like his big brother and sister, but wasn't able to keep up yet. They were very excited for a walker for Jace to help him get around independently and play like a typical kid.
Step 2: Initial Design Phase
The best way to develop a product or service that meets a customer's needs is to co-design it with the person who is intended to use it. By involving your potential customers early in the process, you will understand their challenges and needs, and they will help you create something that is truly valuable for them.
So based on our customer, it was determined that aluminum tubes were perfect for this project as it is lightweight and is strong for our weight restrictions because we also wanted to make sure that it is easy to carry for the parents.
Initial mockup was constructed as shown in the CAD model using Fusion 360 (but any suitable CAD software can be used, such as CATIA, AutoCAD, Solidworks, etc) to give us an idea of how to build and design the walker.
Special emphasis was given to the fact that it needed to be simple enough to build with minimum joints and complications so as it can be replicated in most standard workshops without much expertise on metalwork or woodwork by students, hobbyists, and parents who might need the product.
Step 3: Prototype for Your Customer
We obtained some tubing to practice tube bending and make our first prototype.
For our team, the main area of concern was the tubing, to create a good tubing structure we had to be sure to cut and bend the tubes accurately.
This is the mantra of, "measure twice, cut once", but don't be scared if you make a couple of mistakes along the way, learn from them for your future tubes!
For our measurements of the side tube pillars, now that you've cut some tube, and bent it into the orientation you like, you'll need to build some kind of inserts to be able to screw in the casters at the end(pocket out the ends to ensure a tight fit if solid tubing is used, which is not recommended due to weight concerns and price)
In our case, we chose to fit in a wooden dowel inside the tube with epoxy and also insert a metal insert into the wooden dowel for our casters to be screwed in.
- Cut out an appropriate length of a wooden dowel (1-2inch should be sufficient)
- Once your dowels are made, you'll need to bore out a hole for the future screws.
- Now that your holes for the screws are made, friction fit them into your tubing!
- Now you'll need to get the screws into place, this can be tricky because you'll have to close off both ends of the hole, so make sure it's where you want it!
- After this, ensure the screws are in an adequate resting position and use some epoxy to set the screws.
- Let the epoxy cure
For our connecting rods at the back, similar methods were used as for the side tubings.
Appropriate-sized holes were cut to fit it in between the 2 side tubings. Then similarly as above, wooden dowels were inserted, but this time, a bolt was screwed into the wooden dowels and use epoxy to set the dowel and bolt in place. It would be later fastened with wingnuts so as to be easy to be disassembled by hands.
Step 4: Collect Feedback on Your Prototype
After creating an initial mockup of the idea, we presented this to Jace's physical therapist and the family. Doing so allows for feedback and iteration as necessary. In our team's case, we had to add some finishing touches to the prototype to create a finalized solution. Some of the changes were to make sure that the side tubings are parallel to each other and not bent on an angle. Also, the metal edges needed to be sanded down to make sure to not accidentally hurt the child.
Step 5: Create a Higher Fidelity Prototype
Now that you have feedback, create a better prototype! We did this by adding the finishing casters, painted it, and added handle grips.
Step 6: Deliver Final Product
Jace took some time getting used to his new reverse walker but had fun decorating it with dinosaur stickers. Once he got it home on his own turf he began using it to help him walk independently.
The happy ending in this story is that Jace learned to walk within a few months of using the walker and no longer needs to use the it--we even gpt to see him running after brother and sister! Now the walker will be gifted to a different family who needs it next.
