The effect of a soft collar, used as normally recommended or reversed, on three planes of cervical range of motion

Clinicians recommend soft cervical collars to immobilize the cervical spine following trauma. They apply them either as intended by the manufacturer or reversed (collar rotated 180 degrees), purportedly to achieve limitation in a specific direction. This study investigated the effectiveness of soft cervical collars in limiting cervical range of motion when worn as recommended or reversed. All planes of cervical range of motion of 50 volunteer subjects without current or past cervical dysfunction were measured under three conditions (no collar, recommended use, and reversed) using the Orthopedic Systems Inc. Computerized Anatometry-6000 Spine Motion Analyzer. The instrument has been previously shown to produce measures with high reliability and to correlate strongly with known angular: measures. Within subjects analyses of variance indicated significant differences in all six ranges of motions among the three conditions. Post hoc paired t tests showed that wearing a collar either as recommended or reversed decreased motion compared with not wearing a collar, and that the position of the collar affected range of motion in three of the six motions. Differences in range can be attributed to location of the collar closure and initial head posture. Soft cervical collars can physically limit motion when worn either way.