Orthotics is the branch of medicine that produces devices intended to correct alignment problems in the body. The human body is a fairly amazing piece of biological machinery, consisting of 206 bones that act as the framework for hundreds of muscles, tendons and ligaments, and like any piece of high-performance equipment it needs to be properly aligned to work efficiently. Unfortunately many medical conditions - and even problems with posture - can affect that, so orthotics are a valuable aid in getting things back to normal.

The devices produced by orthotics are usually known as orthoses, although - confusingly - those designed for the feet are generally also called orthotics. They can be produced for many parts of the body. For example back braces are a form of orthosis and are often used to treat conditions like scoliosis. Knee and ankle braces are also orthoses, and athletes often use them when recovering from an injury.

Orthoses have many purposes. They can apply pressure to straighten misaligned bones, as with braces for scoliosis. Joint orthoses can be used to limit unnatural movement within the joint, either to prevent further injury or to give extra support to the joint. They can also be useful in managing conditions like arthitis.

An orthosis can take many forms. Many of those used for joints can be as simple as a tube of elastic bandage or, now, neoprene rubber. On the other hand rigid appliances can be made from metal or a range of harder plastics.

When it comes to fitting orthotics there are two options; off the shelf or custom. Obviously a neoprene knee brace is perfectly suited to being bought off the shelf; the material will shape itself into the correct form for the user. More elaborate braces often have a range of adjustment, so that one size or a range of standard sizes can be adjusted to give a perfect fit.

When it comes to foot orthotics the situation can be trickier. These are mostly made of materials like foam rubber, so it's difficult or impossible to make them adjustable. Obviously they can be made in standard shoe sizes, but even shoes of the same size can be very different shapes - compare the shape of a fashionable shoe and a hiking boot, for example - and this makes it difficult to get a good fit unless the orthotics are cut to fit inside the specific shoe.

Off the shelf orthotics also don't match the exact shape of the user's foot. Everyone's feet are different and, in the case of orthotics, the areas that need support are different too. A standard orthotic insole designed to support the arch of the foot might be applying this support slightly too far forwards or back to be really effective. In fact it could even make the problem worse!

The problem is that custom orthotics have always been an expensive item. Because they need to be shaped precisely to the user's foot it's been necessary to visit a specialist, often several times, to be measured and have the orthotics fitted. The process often involves plaster casts or repeated detailed measurements of the foot, which all adds up in time and money.

Technology can solve many problems, though, even for orthotic insoles, and now it's been done. A new patented process takes two recent developments and combines them to make custom orthotics easily available online. These technologies are image recognition and 3D printing.

By taking three photos of each foot from different angles, a detailed computer model of the foot can be built up using an image recognition package. This model is then recreated in ABS plastic by a 3D printer, after fine-tuning its shape to improve its effectiveness as an orthotic. The resulting plastic feet are used as a template to vacuum-form perfectly shaped custom orthotics which are guaranteed to be a perfect fit and give the best possible support. As a result of this process they're also as affordable as high-end off the shelf insoles.