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Chronic Forward Head Posture is associated with headaches, neck pain, and disability, though few studies have investigated the effects it has on the suboccipital triangle. The objective of this study was to quantitatively assess whether the biomechanical changes in the suboccipital triangle help explain the clinical manifestations of Forward Head Posture. Specifically, this study aimed to identify whether the Greater Occipital Nerve or C2 nerve root may be compressed in Forward Head Posture. Three-dimensional, specimen-specific computer models were rendered from thirteen cadaveric cervical spine specimens. The spines transitioned from neutral to Forward head posture while motion data was collected. This data was synced with the computer models to make precise measurements. In Forward Head Posture, occiput-C1, C1-C2, and occiput-C2 segments extended by 10.7 ± 4.6 deg, 4.6 ± 4.3 deg, and 15.3 ± 2.3 deg, respectively. The Rectus Capitis Posterior Major and Minor and Obliquus Capitis Superior muscles shortened by 20.0 ± 4.6%, 15.0 ± 7.6%, and 6.6 ± 3.3%, respectively. The Obliquus Capitis muscle inferior length did not change. The suboccipital triangle area decreased by 18.7 ± 6.4%, but the protective gaps surrounding the C2 nerve root and the Greater Occipital Nerve did not reveal clinically significant impingement. The C2 nerve root gap decreased by 1.0 ± 1.3 mm and the Greater Occipital Nerve gap by 0.2 ± 0.18 mm. These results demonstrate that the C2 nerve root and the Greater Occipital Nerve are protected by the bony landscape of the cervical spine. However, there is likely persistent contraction of the rectus muscles in Forward Head Posture, which suggests a secondary tension-type etiology of the associated headache., (Copyright © 2019. Published by Elsevier Ltd.)

Much controversy exists regarding the mechanism of burst fracture (BF) induction and the proper techniques to treat such fractures. As such, there is a great need for validated preclinical models in which to study these injuries. In this study, an electronic search of the PubMed database (MEDLINE) was performed and the results were filtered to obtain only studies with a biomechanical focus. Forty five biomechanical studies were obtained, from which four distinct methods of injury induction were identified. Twenty one (46.7%) involved clinically relevant techniques for treating BF, involving anterior, posterior, circumferential, or a combination of approaches. Fifteen (71.4%) of the treatment studies used unstable spine specimens that do not fit the classical characteristics of BF. Given the consistent use of BF models that do not adhere to classical definitions, the clinical value of ex vivo induction is uncertain., (Copyright © 2014 Elsevier Ltd. All rights reserved.)