title: Lumbar spine postures in Marines during simulated operational positions.
abstract: Low back pain has a 70% higher prevalence in members of the armed forces than in the general population, possibly due to the loads and positions soldiers experience during training and combat. Although the influence of heavy load carriage on standing lumbar spine posture in this population is known, postures in other operationally relevant positions are unknown. Therefore, the purpose of this study was to characterize the effect of simulated military operational positions under relevant loading conditions on global and local lumbar spine postures in active duty male US Marines. Secondary objectives were to evaluate if intervertebral disc degeneration and low back pain affect lumbar spine postures. Magnetic resonance images were acquired on an upright scanner in the following operational positions: Natural standing with no external load, standing with body armor (11.3 kg), sitting with body armor, and prone on elbows with body armor. Custom software was used to measure global lumbar spine posture: Lumbosacral flexion, sacral slope, lordosis, local measures of intervertebral angles, and intervertebral distances. Sitting resulted in decreased lumbar lordosis at all levels of the spine except L1-L2. When subjects were prone on elbows, a significant increase in local lordosis was observed only at L5-S1 compared with all other positions. Marines with disc degeneration (77%) or history of low back pain (72%) had decreased lumbar range of motion and less lumbar extension than healthy Marines. These results indicate that a male Marine's pathology undergoes a stereotypic set of postural changes during functional tasks, which may impair performance. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2145-2153, 2017.
authors.affiliation: Department of Bioengineering, University of California San Diego, La Jolla, California.
authors.forename: David B
authors.initials: DB
authors.lastname: Berry
authors.affiliation: Department of Bioengineering, University of California San Diego, La Jolla, California.
authors.forename: Ana E
authors.initials: AE
authors.lastname: Rodríguez-Soto
authors.affiliation: Department of Radiology, University of California San Diego, La Jolla, California.
authors.forename: Jeannie
authors.initials: J
authors.lastname: Su
authors.affiliation: Doctor of Physical Therapy Program, San Diego State University, San Diego, California.
authors.forename: Sara P
authors.initials: SP
authors.lastname: Gombatto
authors.affiliation: Department of Radiology, University of California San Diego, La Jolla, California.
authors.forename: Bahar
authors.initials: B
authors.lastname: Shahidi
authors.affiliation: Warfighter Performance Department, Naval Health Research Center, San Diego, California.
authors.forename: Laura
authors.initials: L
authors.lastname: Palombo
authors.affiliation: Department of Radiology, University of California San Diego, La Jolla, California.
authors.forename: Christine
authors.initials: C
authors.lastname: Chung
authors.affiliation: Warfighter Performance Department, Naval Health Research Center, San Diego, California.
authors.forename: Andrew
authors.initials: A
authors.lastname: Jensen
authors.affiliation: Warfighter Performance Department, Naval Health Research Center, San Diego, California.|Department of Exercise and Nutritional Sciences, San Diego State University, San Diego, California.
authors.forename: Karen R
authors.initials: KR
authors.lastname: Kelly
authors.affiliation: Department of Bioengineering, University of California San Diego, La Jolla, California.|Department of Radiology, University of California San Diego, La Jolla, California.|Department of Orthopaedic Surgery, University of California San Diego, La Jolla, California.
authors.forename: Samuel R
authors.initials: SR
authors.lastname: Ward
mesh_terms: D000328:Adult; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000503:physiopathology; D017116:Low Back Pain / Q000209:etiology* / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000502:physiology*; D008297:Male; D008889:Military Personnel; D016273:Occupational Exposure / Q000009:adverse effects*; D011187:Posture / Q000502:physiology*; D055815:Young Adult
keywords: intervertebral disc; low back pain; lumbar spine posture; upright MRI