Head Position and Football Equipment Influence Cervical Spinal-Cord Space During Immobilization

OBJECTIVE: To assess the effect of head position and football equipment (ie, helmet and shoulder pads) on cervical spinal cord space in individuals lying supine on a spine board. DESIGN AND SETTING: The independent variables were head position (0-cm, 2-cm, and 4-cm occiput elevation with no helmet and shoulder pads and with helmet and shoulder pads) and cervical spine level (C3, C4, C5, C6, and C7). The 3 dependent variables were sagittal space available for the cord (SAC) (mm), sagittal spinal-cord diameter (mm), and cervical-thoracic angle ( degrees ), determined via magnetic resonance imaging. SUBJECTS: Twelve men (age = 24.3 +/- 2.1 years; height = 181.1 +/- 5.7 cm; weight = 93.9 +/- 3.6 kg). MEASUREMENTS: Sagittal space available for the cord was determined by subtracting the sagittal spinal-cord diameter from the corresponding sagittal spinal-canal diameter. The spinal-canal diameter was measured as the shortest distance from the vertebral body to the spinolaminar line at each of the spinal levels. Each measurement was taken 3 times, and the 3 measurements were averaged. RESULTS: Sagittal space available for the cord was significantly greater (P <.01) for 0-cm (mean = 5.50 mm) than for 2-cm (mean = 4.86 mm) and 4-cm (mean = 5.07 mm) occiput elevation. SAC was also significantly greater (P <.01) for the equipment condition (mean = 5.34 mm) than for the 2-cm and 4-cm elevation levels. No significant difference (P =.093) in SAC existed between 0-cm elevation and the equipment condition. CONCLUSIONS: The helmet and shoulder pads should be left on during spine-board immobilization of the injured football player. Similarly, during spine-board immobilization of an individual without football helmet and shoulder pads, the head should be maintained at 0 cm of occiput elevation. Sagittal spinal-cord space is optimized in both of these conditions.