Correlating head kinematics and cervical cerebrospinal fluid pressure transients in simulated whiplash exposures.

The origin and mechanics of whiplash injury from motor vehicle collisions are poorly understood. Among the proposed injury mechanisms, the inertial loading of the head and neck during whiplash exposures is theorized to produce injurious cerebrospinal fluid pressure (CSFP) transients. To better understand the mechanics and modal behavior of CSFP transients during whiplash exposures, we quantified the time-frequency relationship between input head kinematics and cervical CSFP responses in an in vivo pig model. Wavelet coherence analysis was used to correlate seven head kinematic parameters (including temporal Neck Injury Criterion, NIC) with CSFP during simulated extension and flexion whiplash exposures. Overall, the first and last 50 ms of exposures, and frequency ranges between 30-65 Hz had larger coherences between head kinematics and CSFP, with higher coherences in extension exposures than flexion exposures. NIC did not universally outperform other head kinematic parameters as a correlate of CSFP. These findings highlight the complexity of the dynamics involved in generating CSFP transients in the cervical spine during whiplash exposures.