1. Experimental Impact Injury to the Cervical Spine: Relating Motion of the Head and the Mechanism of Injury* by ROGER W. NIGHTINGALE, JAMES H. MCELHANEY, WILLIAM J. RICHARDSON, THOMAS M. BEST, and BARRY S. MYERS J Bone Joint Surg Am Volume 78(3):412-21 March 1, 1996 ©1996 by The Journal of Bone and Joint Surgery, Inc.

2. Diagram of the test apparatus, showing the accelerometer on the torso mass (A), the optical velocity sensor (B), the carriage and torso mass (C), the six-axis load-cell at the first thoracic level (D), the accelerometers on the head (E), and the impact surf... ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.

3. Graph of the magnitude of the resultant forces on the head and neck, with the time-interval between the onset of force to the head and injury to the cervical spine. ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.

4. A typical impact sequence. ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.

5. Time line showing the relative occurrences of injury to the neck and noticeable (more than 20- degree) motions of the head with respect to the duration of motion of the head and cervical spine. ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.

6. Four frames of video data (specimen E), obtained one millisecond apart, showing the initial serpentine deformation (at three milliseconds) followed by a rapid transition to buckling (at six milliseconds). ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.

7. Illustration of the initial posture of the cervical spine and the buckling deformation. ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.

8. Radiographs of specimens F (Fig. 7-A) and B (Fig. 7-B), showing the injuries that were produced, the most evident of which are the bilateral dislocated facets at the sixth and seventh cervical levels (Fig. 7-A) and a hangman's fracture (Fig. 7-B). ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.

9. Radiographs of specimens F (Fig. 7-A) and B (Fig. 7-B), showing the injuries that were produced, the most evident of which are the bilateral dislocated facets at the sixth and seventh cervical levels (Fig. 7-A) and a hangman's fracture (Fig. 7-B). ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.

10. Graph of the positions of the pins in the pars interarticularis in specimen D. Each point represents sequential spatial positions of the pins in the transverse processes of the third through seventh cervical vertebrae before the impact (t = 0) and at six, n... ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.

11. Illustration of a more complicated buckling, seen two to eight milliseconds after impact of the head. ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.

12. Illustrated example of the variation in local forces at different vertebral levels. ROGER W. NIGHTINGALE et al. J Bone Joint Surg Am 1996;78:412-21 ©1996 by The Journal of Bone and Joint Surgery, Inc.