Quantitative measurement of cervical range of motion in patients with torticollis treated with botulinum A toxin.

Improvement in cervical range of motion in patients with spasmodic torticollis by botulinum A toxin injection is difficult to objectively measure. Recently, a three-dimensional cervical range of motion system (EMROM) that measures primary as well as secondary cervical angles has been developed. This system uses an electromagnetic tracking system for data collection and a personal computer for analysis and graphic display of the data. We have tested the EMROM system and, from our results, believe that it can be used clinically to objectively and accurately measure cervical range of motion in patients who have spasmodic torticollis and who receive botulinum toxin injections.