Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Compressive Follower Load Influences Cervical Spine Kinematics and Kinetics During Simulated Head- First Impact in an in Vitro Model J Biomech Eng. 2013;135(11): doi: / X-positions (i.e., anteroposterior axis positions) of the anterior-most markers at each vertebral level plotted with respect to time: (a) specimens exhibiting hyperextension and hyperextension injuries have marker positions that trace parabolic loci through time, as shown for specimen H1177 (FL group), (b) specimen H1062 (NFL group) exhibited C1-C2 subluxation and the loci of markers on C1 and C2 convey the posterior to anterior transition of C2 relative to C1 (subluxation), and (c) specimen H1116 exhibited hyperextension and a fracture dislocation at C3/4, which is indicated by a relatively large difference in the translated distance between C3 and C4 relative to other levels Figure Legend:

Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Compressive Follower Load Influences Cervical Spine Kinematics and Kinetics During Simulated Head- First Impact in an in Vitro Model J Biomech Eng. 2013;135(11): doi: / Positions of photo-reflective markers fixed to the vertebral bodies and the superior-most vertices of the specimen mount-cup for increasing chronological time for (a)–(c) specimen H1177 (FL group), and (d)–(f) H1062 (NFL group). The time of 0 ms, nominally, just prior to head impact. Solid lines span the inter-marker space of the anterior-most markers at each vertebral level and the space between the superior-most surface of the mount-cup. Figure Legend:

Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Compressive Follower Load Influences Cervical Spine Kinematics and Kinetics During Simulated Head- First Impact in an in Vitro Model J Biomech Eng. 2013;135(11): doi: / Typical kinetic results: compressive Z-head force (dotted line); compressive Z-neck force at mount-cup/six axis load cell interface (solid line); and the neck moment about the Z-axis of the six axis load cell (dashed line). Note that the Z-axis of the load cell is parallel to the Z-axis in Fig. 1 but originates at approximately the volumetric center of the load cell. Results shown are for specimen H1091 (FL group). Figure Legend:

Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Compressive Follower Load Influences Cervical Spine Kinematics and Kinetics During Simulated Head- First Impact in an in Vitro Model J Biomech Eng. 2013;135(11): doi: / Photograph of osteo-ligamentous cervical spine and surrogate head complex showing follower load and compression springs. The lordotic posture shown was typical of all specimens. Figure Legend:

Date of download: 9/19/2016 Copyright © ASME. All rights reserved. From: Compressive Follower Load Influences Cervical Spine Kinematics and Kinetics During Simulated Head- First Impact in an in Vitro Model J Biomech Eng. 2013;135(11): doi: / (a) Schematic of the vertical drop-tower used to simulate axial head-first impact. The carriage translates along the Z-axis and is constrained in the X- and Y-axes by linear stanchions/bearings. The direction of translation is the Z-direction and impact occurs between the surrogate head and impact platen. The approximate location of the head center of mass is shown as a solid filled circle. (b) Schematic of the cervical spine and surrogate head complex showing mount-cup center to head-mount center distance (D c-c ) and head inclination. Figure Legend: