Measurement of Upper Cervical Flexion and Extension with the 3-Space Fastrak Measurement System: A Repeatability Study

Abstract

Most external measurement devices do not allow ready differentiation of upper cervical flexion and extension from total cervical movement. This study investigated the "within" and "between-days" repeatability of measurement focused on upper cervical flexion and extension in three dimensions using the Fastrak, a 3-Space measurement system, on 21 subjects. To localize the measurement, one sensor of the Fastrak was centered over the subject's forehead and the other was held manually over the C2 spinous process. Three repetitions of upper cervical flexion (nod of the head) and extension (chin lift) were performed in each trial. Two trials were performed on the first day with the third trial one-week later. Results indicated high levels of repeatability for "within" and "between-days" measurements (ICC_2,1: 0.97 to 0.99). The mean ranges of upper cervical flexion and extension were 15.03° ± 2.80° and 23.32° ± 4.20° respectively, were accompanied by a small amount of lateral flexion and rotation, predominantly in a contralateral pattern. The method appears suitable for clinical evaluation of upper cervical motion.

Keywords:

• UPPER CERVICAL SPINE
• FLEXION
• EXTENSION
• MEASUREMENT
• RELIABILITY