• Hoon Choi, Vicky Varghese, Jamie Baisden, Diane W Braza, Anjishnu Banerjee, and Narayan Yoganandan.
• Center for NeuroTrauma Research, Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
• Mil Med. 2021 Jan 25; 186 (Suppl 1): 632-638.

IntroductionAddition of head-supported mass imparts greater demand on the human neck to maintain functionality. The same head-supported mass induces greater demand on the female spine than the male spine because female necks are comparatively slender. Prevalence of neck pain is greater in military than civilian population because of the head-borne mass (among other factors). The goal of this study is to determine quantifiable parameters related to muscle geometry using female human volunteers and upright magnetic resonance imaging.Materials And MethodsYoung healthy subjects were consented. Demographics and head-neck anthropometry were recorded. For all the 7 subjects, the T1- and T2-weighted magnetic resonance imaging in the neutral sitting position was obtained immediately following donning and after 4 hours of continuous wear of standard issued military helmet, while seated in the same posture for 4 hours. Cross-sectional areas of sternocleidomastoid and multifidus muscles from C2-C7, overall and segmental Cobb angles (C2-T1), and centroid and radius of each muscle were calculated. Data were compared with determine differences with the continuous helmet wear.ResultsThere were level specific changes in morphological parameters for each of the muscles. Significant difference (P < 0.05) in cross-sectional areas was noted at C2-3 level for sternocleidomastoid and at C3-4 and C5-6 levels for multifidus. For centroid angles, significant difference (P < 0.05) was observed at C2-3 and C5-6 levels for sternocleidomastoid and at C3-4 level for multifidus. There was no significant difference (P > 0.05) in muscle centroid radii between the pre- and posttest conditions.ConclusionsAlterations in muscle geometries were muscle specific and level specific: sternocleidomastoid was significant at the upper level, whereas multifidus was significant at the mid-lower cervical spine segments. The insignificant difference in the Cobb angles was attributed to length of time of continuous helmet wear attributed and sample size. Helmet wear can lead to morphometric alterations in cervical flexor/extensor musculature in females.Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2021. This work is written by (a) US Government employee(s) and is in the public domain in the US.

20 keywords...

hide…