Cadaver assignments, subgroups, and experiments. In each cadaver, an intubation set consisted of two intubations, one with a Macintosh laryngoscope and another with an Airtraq laryngoscope in random order. All cadavers (n = 14) were included in Experiment 1: Primary Intubation Mechanics, wherein all intubations took place with an intact (stable) cervical spine. Thereafter, cadavers underwent additional studies in two subgroups: A (n = 10) and B (n = 4). Subgroup A underwent subsequent studies after an 18- to 24-h tissue recovery period. Two subgroup A cadavers could not undergo additional studies, leaving eight cadavers in subgroup A. Subgroup A cadavers underwent a second set of intubations with an intact cervical spine (set 2: intubations 3 and 4). After set 2 intubations, a type II odontoid fracture was created and a third set of intubations (set 3: intubations 5 and 6) were performed. In each subgroup B cadaver (n = 4), after set 1 intubations, a type II odontoid fracture was created, resulting in a 1-h tissue recovery period and, thereafter, cadavers underwent a second set of intubations (set 2: intubations 3 and 4). In Experiment 2: Effect of Repeated Intubations, data from subgroups A and B were pooled to compare intubation forces and cervical spine extension among intubation sets. In Experiment 3: Motion of an Injured C1-C2 Segment, data from subgroups A and B were pooled to compare C1-C2 motion between intact and injured states. *One subgroup A cadaver intubated only with Macintosh.