RESUMEN
BACKGROUND: Immobilization of the cervical spine is a standard procedure in emergency medicine mostly achieved via a cervical collar. In the emergency room other forms of immobilization are utilized as cervical collars have certain drawbacks. The present study aimed to provide preliminary data on the efficiency of immobilization in the emergency room by analyzing the residual spinal motion of the patient's head on different kinds of head rests. METHODS: In the present study biomechanical motion data of the cervical spine of a test subject were analyzed. The test subject was placed in a supine position on a mobile stretcher (Stryker M1 Roll-In System, Kalamazoo, MI, USA) wearing a cervical collar (Perfit ACE, Ballerup, Denmark). Three different head rests were tested: standard pillow, concave pillow and cavity pillow. The test subject carried out a predetermined motion protocol: right side inclination, left side inclination, flexion and extension. The residual spinal motion was recorded with wireless motion trackers (inertial measurement unit, Xsens Technologies, Enschede, The Netherlands). The first measurement was performed without a cervical collar or positioning on the pillows to measure the physiological baseline motion. Subsequently, three measurements were taken with the cervical collar applied and the pillows in place. From these measurements, a motion score was calculated that can represent the motion of the cervical spine. RESULTS: When the test subject's head was positioned on a standard pillow the physiological motion score was reduced from 69 to 40. When the test subject's head was placed on concave pillow the motion score was further reduced from 69 to 35. When the test subject's head was placed on cavity pillow the motion score was reduced from 69 to 59. The observed differences in the overall motion score of the cervical spine are mainly due to reduced flexion and extension rather than rotation or lateral inclination. CONCLUSION: The motion score of the cervical spine using motion sensors can provide important information for future analyses. The results of the present study suggest that trauma patients can be immobilized in the early trauma phase with a cervical collar and a head rest. The application of a cervical collar and the positioning on the concave pillow may achieve a good immobilization of the cervical spine in trauma patients in the early trauma phase.
