LOW CERVICAL THORACIC ORTHOSES
Low CTOs are similar to high CTOs except that they extend down to encompass more of the thorax. This provides a firmer base to stabilize the cervical spine and allows increased control of lower C-spine and upper T-spine vertebrae. Commonly used low CTOs include the sternal-occipital-mandibular immobilizer (SOMI) (Seattle Systems, Seattle, WA), Yale, and Aspen two-post and four-post. The Aspen two- and four-post collars consist of two padded rigid breast and back plates connected to a high thoracic Aspen CTO by either two or four rigid posts ( Fig. 27-12A-C ). The SOMI brace has a similar thoracicback and breast plate connected to an occipital plate by two rigid bars ( Fig. 27-13A, B ). In addition the SOMI brace has a chin rest that can be removed for mastication when eating. The Yale CTO brace is a two-piece rigid foam and plastic clamshell low CTO that is similar to the Philadelphia collar but encompasses the entire thorax. It is held in place with a strap around the neck and the lower chest.