A scoliosis brace

One of the biggest problems for children and teenagers treated with a brace is not wanting to wear it during the day at school and in social activities in the afternoon, which often leads to avoiding it altogether. So despite the parents’ financial investment, the treatment is not effective.

We decided to approach the subject from a slightly different angle, and these are the results. The HEXAGON form follows from what the brace is for: pressing on the spine at three points while rotating the vertebrae back towards where they should be.

The correction needed is slightly rotational, so on the upper left side the polygons lean towards the back, and on the lower right they lean towards the abdomen. Pressure at those two points produces a gentle rotation of the vertebrae. Tensioning the polygons is done with a rotary dial with two settings: released, where the brace sits against the body without pressing, and tensioned, where the polygons are drawn in and create pressure at those points.

The two sides of the brace are joined by straps. At the front there are two horizontal webbing straps closed with hook-and-loop and tension – so the wearer can put the brace on comfortably and even without any help, while the most sensitive part of the torso, the abdomen, is left open and under no pressure. At the back there are two webbing straps in an X, which stabilise and balance the brace and hold to the wearer’s spine thanks to their crossing form. Every hexagon in the system is attached to an orthopaedic foam pad.

The foam breathes, since a brace causes sweating from the heat it builds up where it is worn. It is also firm enough to take the change when the hexagons are switched between on and off. Another property of the foam is its elasticity, so it takes the shape of the body surface it sits against. Because the product is printed and made to fit the individual, the colour of the printed material and the type of straps can be chosen during the process itself.

There are two versions of the product: one more expensive and of higher quality, made from carbon fibre for its strength and light weight. The second version is cheaper and made by nylon printing. It meets the same strength standards as the carbon version, but weighs more.

In our proposal for the brace we solved the problems the teenagers themselves raised: quick to put on without help, straps positioned at the front, the weight of the brace, and reduced pressure on sensitive areas by clearing material away from the abdomen and the back.

The result is a three-dimensional correction for the spine.

The engineering logic behind the shape

A scoliosis brace fails when it is not worn. So the assumption that drove the development was that the product had to look like a piece of clothing rather than an orthopaedic device, and had to be ventilated enough to wear all day.

The hexagon structure is not decoration: each polygon leans in a different direction, so that pressure at the three points produces a gentle rotation of the vertebrae rather than straight pressure alone. The rotary dial allows two states – close-fitting without pressure, or tensioned and pressing – so the patient controls the dose through the day.

Why this is only possible in printing

A varying lattice structure with thousands of openings at different angles cannot be milled, cast or moulded. MJF printing builds that geometry with no supports and no added cost for complexity – complexity is free in additive manufacturing.

See 3D printing in medicine and product design and development.

A similar project of your own?

Send us a file or a description of the problem and you will get a recommendation on technology, material and timescale – talk to an engineer. See also product design and development and 3D printing production.