# 3D Printed Orthotic Devices: A Potential New Frontier for E-NABLE? --- On my first day at Lake Victoria Disability Center (LVDC) in Musoma, Tanzania, I was told that northern Tanzania has a strikingly high number of 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.  ###### 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. Once repositioned, a 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. Rajab now uses his 3D printer to make 3D printed ankle-foot orthoses (AFOs), one of several options for foot bracing after the casting stage. The 3D printed AFO is worn either with a sock on the foot, or wearing a shoe, so the design of the 3D printed AFO takes this into account on a case-by-case basis. After 3D printing the brace, it is completed by attaching straps which will be used to secure the brace to the patient. I think Rajab has stumbled on a very important use-case for humanitarian 3D printing, and I was on the lookout for additional inspiration thereafter. AFOs were the first of several widely-used orthotic devices I was introduced to during my time in Africa. I’ll detail the others below. When I first saw this off-the-shelf orthotic, I immediately saw potential in it for use as a swimming aid for children and adults with upper limb amputations. It turns out, the anti-spasticity ball splint is an orthotic device that maintains the fingers spread while keeping the palm and fingers in a neutral position. The purpose of this device is to prevent flexion of the fingers and wrist and limit damage to the tendons of the hand during spastic episodes. This orthotic device is used to position a user’s hand in a more natural way, often after a radial nerve injury causing drop wrist. Drop wrist can be uncomfortable and may cause someone suffering from it to be self-conscious. There is potential in creating a manipulatable design for this type of orthotic device, both in utility and for the cosmetic potential 3D printing allows for. The 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. 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, while all could be used with the same connecting bar hardware. Foot abduction braces are expensive and often donated to the 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 another article. Below are examples of traditionally made rigid AFOs, which are created by forming warm polypropylene over a plaster cast of the patient’s foot under vacuum (see video). Excess material is trimmed away to create the AFO. To allow the patient to walk in the AFO, an articulation point is introduced to the device at the ankle. The AFO is first constructed in one piece. The device is then cut at the ankle, and each piece is rounded over at the plane of articulation to allow for a natural range of motion. It is important to keep the trim gap between the footplate and ankle sections of the orthotic close to ensure the AFO and joints work optimally. The most expensive component of the articulated AFO is the flexure joint. The purpose of the flexure joint is to allow the AFO to move with the foot as the patient walks, while helping to maintain medial-lateral stability. Two of these flexure joints are necessary per AFO, as seen in the figures. In Africa, off-the-shelf flexure joints are often prohibitively expensive. I was told of two low-cost alternatives employed in areas of high need: 1\. Two links from a bicycle chain has been used with great success. The top link is attached to the ankle section of the AFO, while the bottom link is attached to the footplate. The joint between the two links provides the articulation. 2\. A figure-8 shape can be cut from the side wall of a tire, mimicking the shape and function of the flexure joint. It should be noted that the off-the-shelf version is often reinforced in the form of an embedded steel wire, or other. e-NABLE Call to Action I have seen first-hand the need for low-cost orthotic devices during my time in Tanzania and Rwanda. While these devices should be employed by professionals on the ground, e-NABLE volunteers have the potential to do good for the world by working together to create a repository of 3D printable orthotics. There is a world of potential in the area of designing training and assistive devices for people with arthritis or other ailments of the hands and fingers. If we expand our focus to include these additional devices, we can reach more people in an impactful way.