Current understanding of the biomechanics of cervical spine injuries in head first impact is based on decades of epidemiology, mathematical models and on ex vivo experimental studies. Recent mathematical modeling suggests that muscle activation and muscle forces are relevant to injury risk in head first impact. It is also known that muscle forces are central to the overall stability of the cervical spine. Despite this knowledge, the vast majority of ex vivo head first impact models do not incorporate musculature. We hypothesize that the simulation of the stabilizing mechanisms of musculature during head first osteoligamentous cervical spine experiments will have considerable influence on the resulting kinematics and injury mechanisms. We simulated head first impact using cadaveric cervical spines with surrogate heads (n=12). Six spines were instrumented with a follower load to simulate in vivo compressive muscle forces, while six were not. The principal finding was that mechanical coupling between the head and the base of the cervical spine (T1) was increased in specimens with follower load. Increased coupling was indicated by reduced time between head impact and peak neck reaction force (and spine buckling) and reduced vertebral rotations, during buckling, in specimens with follower load. These preliminary results suggest that simulating follower load that may be similar to in vivo muscle forces results in significantly different buckling behaviour, and therefore potentially different injury mechanics occur in vivo than in many biomechanical tests where musculature is not simulated.