To determine if the cervical range of motion (CROM) device, an instrument designed to assess the range of motion in the cervical spine, may be suited for accurately quantifying the magnitude of a patient's abnormal head posture, limitation of ductions, or range of single binocular vision at distance fixation.
The CROM device was used to measure abnormal head postures in 10 subjects and limitations of ductions in 12 patients by 2 masked observers. In addition, it was used to test the diplopia field in 17 patients at one third of a meter and 6 m. These findings were compared with a standard diplopia field performed on a Goldmann perimeter.
For 10 subjects with abnormal head postures, the findings of the 2 observers had a mean±SD difference of 1.0°±0.7° (P=.15, paired t test). For the assessment of limitations of ductions, the findings of the 2 observers had a mean±SD difference of 1.1°±2.6° (P=.17, paired t test). For the 17 patients undergoing diplopia field testing, the results obtained on the Goldmann perimeter and with CROM device at the same test distance were essentially identical (mean±SD difference of 1.3°±0.95°; P=.88, paired t test); however, there was a significant difference between the results at one third of a meter and 6 m (mean±SD difference of 6.0°±1.1° for esotropic patients [P=.001]; mean±SD difference of 6.0°±2.6° for exotropic patients [P=.002]).
The CROM device seems to be suitable for testing abnormal head postures, limitations of ductions, and the range of single binocular vision.