# A Prototype for an Inexpensive Foot Abduction Brace Using 3D Printing --- For more pictures from this project, [check out the gallery](https://hub.e-nable.org/u/kreeser1/gallery/custom-gallery/view?openGalleryId=87#.jpeg). --- ### Clubfoot On my first day at [Lake Victoria Disability Centre](https://hub.e-nable.org/u/kreeser1/wiki/page/view?title=Lake+Victoria+Disability+Centre+-+Complete+Article "Lake Victoria Disability Centre - Complete Article") (LVDC) in Musoma, Tanzania, I was told that northern Tanzania has a strikingly high number of [clubfoot](https://en.wikipedia.org/wiki/Clubfoot) cases. Clubfoot is a birth defect affecting the bones and muscles in the feet, causing the foot to be twisted inward into an unnatural position. While not generally painful for the child, the condition needs to be corrected through orthotics as soon as possible after birth, or the child will grow to be permanently disfigured and potentially unable to walk.  ###### A diagram showing the physical differences between a normal foot and a clubfoot. ###### Source: [https://kidshealth.org/en/parents/clubfoot.html](https://kidshealth.org/en/parents/clubfoot.html) --- Rajab Hamis, director of the Prosthetics and Orthotics department at LVDC has personally treated more than 150 such cases. Rajab’s treatment for clubfoot in babies and small children generally involves a series of plaster casts over several weeks or months to slowly move the feet into a more natural position.  ###### Repositioning clubfoot with a series of plaster casts. ###### Source: [https://www.mdorthopaedics.com/ponseti-afo-solutions/](https://www.mdorthopaedics.com/ponseti-afo-solutions/) --- Once repositioned, an [ankle-foot orthotic](https://en.wikipedia.org/wiki/Orthotics#Ankle%E2%80%93foot_orthosis) (AFO) brace is fit onto the corrected foot to maintain the right position as the baby grows. Otherwise, the foot can often revert back to its previously twisted position. For the first several months, a brace is kept on the feet constantly. For several years after that, a brace is generally only worn while sleeping. As you can imagine, replacing these orthotic devices regularly as the child grows is necessary, but expensive. A foot abduction brace is often used in addition to, or in place of, the AFO while treating cases of clubfoot. The foot abduction brace is a set of two boots connected through a metal bar.  ###### Source: [https://www.aboutkidshealth.ca/article?contentid=1192&language=english](https://www.aboutkidshealth.ca/article?contentid=1192&language=english) --- The angle that the boots make relative to each other is adjustable, as is the distance between the boots. The foot abduction braces that I was introduced to come in a series of increasing boot sizes (approximately $215.00 USD/pair), while all could be used with the same connecting bar hardware (approximately $60.00 USD). Foot abduction braces are expensive and often donated to the LVDC facility, but due to the high number of clubfoot cases that Rajab treats, he regularly runs out. I immediately saw the potential for 3D printing to contribute to this area of need, and a prototype will be outlined in this article.  ###### Off-the-shelf boot and bar food abduction brace, [which retails for $275.00](https://mdorthopaedics.easyordershop.com/easyorder/index). --- Each off-the-shelf boot was made of a sturdy plastic bottom, a thick rubber insert which makes contact with the foot, and a felt exterior with straps that hold the foot in place. The boots are connected to each other through a metal bar which can be lengthened or shortened to hold the feet an appropriate distance apart. The boots are angled relative to the bar in two dimensions: a fixed rotation due to a bend in the bar (see figure below), and a variable angle at the connection between the boot heel and the bar.  ###### Back view of an off-the-shelf boot and bar foot abduction brace. Note the bend in the bar as it meets the boot. --- ### Creating a Low-Cost Boot We began the project by taking apart an existing off-the-shelf boot, including each [rivet ](https://en.wikipedia.org/wiki/Rivet)holding the felt pieces of the boot together. The boot consisted of 8 separate felt pieces (2 large pieces making up the majority of the exterior, plus 3 straps and three buckles). We could have very easily traced these pieces and cut out our own, but the P&O department at LVDC needed to conserve resources, so we used these original felt pieces in our prototype. We hand-riveted the pieces back together, and replaced one of the original buckles with a different type of buckle as proof-of-concept that our prototype could use different parts. We used contact adhesive to glue the bottom of the main felt piece to a piece of cardboard cut roughly into the shape of the bottom of a shoe. This was not crucial but was done for stability and later positioning when assembling the full boot. Next, a set of sturdy boot bottoms were 3D printed in brown PLA. Rajab explained that is was crucial to have a tall rim around the boot base so that the child’s toes do not come up and over the lip of the rim, causing the foot to sit in a weird position in the boot.  ###### Parts of the low-cost foot abduction brace boot. --- Two holes were drilled into the heel of the 3D printed boot bottom, followed by small bolts being inserted through the holes such that the boots can be attached to a bar later. The bottom of the card board (to which the felt pieces were attached) was then glued to the top of the 3D printed boot bottom using contact adhesive, over the heads of the bolts. ### Making and Installing a Thermoformed Foam Insert As the only part of the boot that makes contact with the child’s foot, the boot insert should be comfortable. A plaster cast of a small foot was used as a form to thermoform a piece of polyethylene foam around.  ###### Thermoforming the foot abduction brace boot insert. --- The thermoformed polyethylene foam was then trimmed to create the insert, which included a back portion, a bottom portion, and wings on the sides which slightly fold over onto the top of the foot when the felt straps are cinched.  ###### Parts of the low-cost foot abduction brace boot. --- Contact adhesive was used to secure the foam insert into place, completing the low-cost foot abduction brace boot.  ###### A side view of the fully assembled, low-cost foot abduction brace boot. --- ### 3D Printed Bar We fabricated a 3D printed bar (brown PLA) to replace the metal bar of the off-the-shelf foot abduction brace. The bar actually contains three separate pieces: two flat rectangular ‘half-bars’, each with one circular end, and a plastic piece that pinches the half-bars together with set screws to maintain a specific overall length for the bar. In our prototype, we re-used the plastic piece that holds the two half-bars together (black), but this piece could be easily reproduced.  ###### The low-cost foot abduction brace bar. --- The circular ends of each flat half-bar contain a central hole, and a set of holes spaced along the circumference of an imaginary circle surrounding the central hole. In this way, the boots can be positioned at a variable angle relative to the bar by inserting the two bolts extending down from the boot heels through both the central hole in the bar, and one circumferential hole. The two half-bars were printed flat, but were then thermoformed using near-boiling water to establish a bend near each circular end, to match the off-the-shelf version as explained above.  ###### A view of the underside of the low-cost foot abduction brace boot, as it connects to the 3D printed bar. ---  ###### The 3D printed bar attached to both low-cost foot abduction brace boots. --- ### Final Assembly of the Prototype Low-Cost Foot Abduction Brace The fully assembled boots were attached to the bar assembly using the bolts and holes. We were satisfied with the result of the prototype, and hoped to test it on a child patient during the time I was at LVDC.  ###### A front view of the fully-assembled, low-cost foot abduction brace. ---  ###### A back view of the fully-assembled, low-cost foot abduction brace. --- Lake Victoria Disability Center had planned an outreach mission to a village several hours away from Musoma during my time there, but those plans fell through when the permits didn’t come in on time. We had planned to take our prototype on the outreach mission to test it on a child. Unfortunately, as the outreach mission fell through, we were not able to test the prototype on anyone. ### Takeaways While the pair of boots and the bar cost around $275.00 USD on the manufacturers website, we estimate the prototype we designed cost us less than $5.00 USD in materials. Perfecting the design and offering low-cost, 3D printed foot abduction braces to P&O professionals in developing countries like Rajab, could be a great use of the time and resources of the e-NABLE community and could affect a lot of young lives for the better. The main felt pieces for the right and left boot are mirror images, so only one template is necessary to create these pieces for both boots. I have tracings of the 8 felt pieces taken from the off-the-shelf boots, as well as sketches of the bars and the bar clamp. Please contact me if you would like me to send you these materials, and I will work to put these into a manipulatable, digital file in the future. While working with Roberto Postelmans at ORTHOLAB in Gatagara, Rwanda, I used ePA-GF (a glass fiber impregnated nylon filament) to great success on multiple projects. This material is a little more expensive than PLA, but is incredibly strong. I believe ePA-GF may be a better material to print the boot bottoms and bars in, and they will be less likely to break if the child stresses the parts or the unit is dropped on the floor. ### e-NABLE Community Call to Action The low-cost foot abduction brace, and a host of additional orthotic devices, could be the next frontier for e-NABLE volunteers around the world. As I mentioned [in another article](wiki:/u/kreeser1/wiki/3D+Printed+Orthotic+Devices%3A+A+Potential+New+Frontier+for+e-NABLE%3F "3D Printed Orthotic Devices: A Potential New Frontier for e-NABLE?"), it is important that trained P&O professionals oversee and implement the use of such devices, but the e-NABLE community could act as a distributed manufacturing ‘army’ to provide low-cost devices to humanitarian P&O professionals all over the world. I call upon the e-NABLE community to look into these and other orthotic devices for ways in which 3D printing might be able to help produce them better, quicker, and/or cheaper.