Proper fitting of the cervical orthosis.

This study evaluated the effect of fitting of the sternal occipital mandibular immobilization (SOMI) orthosis in restricting sagittal cervical spine motion. Cervical orthotic devices are usually fitted according to the subjective tolerance of the patient. Pressures were recorded after fitting in the usual manner by a certified orthotis and when fitted more loosely. Eight able-bodied adults were fitted in this manner and were then immobilized in a straight-backed chair while lateral cervical spine films were taken in neutral, flexion, and extension. Previously standardized methods were used to measure flexion-extension of the cervical spine. The resting pressures, when fitted in the usual manner, were approximately 105 mmHg at the chin and occiput. When pressure sensors were used to fit the brace loosely, the average pressure was approximately 25 mmHg. The data indicate that regardless of fit, there was no significant difference in the mobility of the entire cervical spine or at any intervertebral level. Recommendations for fitting of the SOMI are discussed.