A Chiropractor uses two types of molds when trying to get a mold of a patient’s foot for their foot orthotics – plaster cast or foam box. We discuss the pros and cons of both, and tell you which of the two types of molds is the better choice.

Plaster Cast

Plaster casting is one of the most common and popular casting techniques used by Chiropractors when designing foot orthotics for their patients. It’s particularly useful for sports orthotics, as this requires a higher degree of precision.

Plaster casts are non-weight bearing casts and are molded as the patient lies face down on a bed. It is possible to have a perfect alignment using a plaster cast. Plaster casts can also be molded with the patient standing on a leg with the other leg rested on a chair, with an angle of 90 degrees between the knee and the ankle. This ensures great accuracy in the casting.

Plaster casts are recommended for patients with flexible foot types, as weight bearing casts may prove to be error prone in such cases. Plaster casts are very effective at making sure that the final cast is a perfect image of a patient’s foot.

While plaster casts cannot go wrong with the accuracy of the casting, and it’s possible to get the foot orthotics designed to perfection with them, they are time consuming, and require a lot of patience from a patient. If the patients are elderly, lack control over their body and may not be able to stay still for long, the perhaps plaster casting may not be the best option for their foot orthotics casting.

Foam Box

A foam box is a weight bearing cast, which involves the chiropractor pushing the patient’s foot into the foam, which creates an impression onto the foam. Patients are advised not to push their feet and to allow the chiropractor to do all the work.

The chiropractor makes sure that the alignment of the foot is perfect, even as he controls the patient’s movements. The foot is then removed and the cast is checked for the alignment and the positioning.

Since a foam box is a weight bearing cast, chiropractors are more comfortable with using this method while designing the foot orthotics of restless patients, such as children or the elderly, who lack control over their bodies and find it hard to stay still for long. This is also the preferred molding technique for people with disabilities or for those who are injured or suffering from diabetes or arthritis.

Foam casting method is safe, easy and does not require any effort from the patient. However, it suffers in comparison to the Plaster Cast molding technique when it comes to capturing the precision of the foot alignment and positioning.


We believe that Plaster cast is better than a foam box for the casting of foot orthotics because of a couple of reasons. Foam box does not allow the chiropractor to compare the cast with the shape of the foot, in exactly the position that it was molded in.

Also, it’s difficult to ensure that the patient has not applied even the slightest force during foam box molding, and when the Chiropractor fails at this, the result is a high arched cast – which is most likely to be inaccurate. This means that the Chiropractor has to be extra careful while using a foam box for the casting.

In comparison, a Chiropractor has more control while using a Plaster Cast, and the accuracy of the foot alignment and positioning is also likely to be perfect. That’s why we prefer Plaster Cast to Foam Box for the foot orthotics casting.