The Boston brace, similar to the DDB brace, is an active, underarm, custom-made brace. It is made of hard thermoplastic, cylindrically surrounding the body from the pelvis to below the armpits, with an opening in the middle of the back.

It consists of a pelvic section that fits perfectly to the pelvis without hindering hip flexion and comfortable sitting. This is followed by the thoracic-abdominal section, which reaches below the chest, to the sides below the armpits, and covers the back to the middle of the shoulder blades. Foam plastic pads are placed internally at the points where pressure is needed, and the entire structure is tied at the back with four horizontal straps.