Effect of Load Carriage on Lumbar Spine Kinematics
Abstract
PURPOSE: To measure kinematic changes in the lumbar spines of Marines carrying heavy loads. We hypothesized that heavy loads would increase lumbar lordosis and disc compression. METHODS: Sagittal T2 MR images of the lumbar spine were acquired on a 0.6T vertical MRI scanner in 10 active duty Marines. Each was scanned without load (SW1), immediately after donning body armor and a backpack (SL2), after 45 min of standing with the load after walking for 45 min with load (SL4), and after 45 min of side-lying recovery (SW5). In order to characterize the kinematic behavior functional spinal units (L1-S1) and overall lumbar spine during each task a 3D geometric representation of the spine was generated processing of the images acquired using an upright MRI scanner. Repeated measurements ANOVAs and post hoc Sidak tests were identify significant differences between tasks (?? = 0.05). RESULTS: The position of the spine was significantly (p<0.0001) more horizontal relative to the external reference frame and load reduced during all tasks with load compared with those without load. Superior and inferior lumbar levels showed different kinematic be When carrying load, superior levels became more lordotic while inferior levels became more kyphotic. All kinematic variables return baseline levels after 45 min of side-lying recovery. CONCLUSIONS: Heavy load carrying induced lumbar spine flexion and only anterior disc and posterior intervertebral disc height were observed, contrary to our initial hypothesis. These findings suggest a postural, lumbar flexion strategy aimed at centralizing posterior load over the base of support.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2013
- Accession Number
- ADA616740
Entities
People
- Alan R. Hargens
- Ana E. Rodriquez-soto
- Andrew Jensen
- Brenda Niederberger
- Karen R. Kelly
- Lawrence R. Frank
- Rebecca Jaworski
- Samuel R Ward
Organizations
- Naval Health Research Center