Accession Number:

ADA616740

Title:

Effect of Load Carriage on Lumbar Spine Kinematics

Descriptive Note:

Journal article

Corporate Author:

NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA

Personal Author(s):

• Rodriquez-Soto, Ana E.
• Jaworski, Rebecca
• Jensen, Andrew
• Niederberger, Brenda
• Hargens, Alan R.
• Frank, Lawrence R.
• Kelly, Karen R.
• Ward, Samuel R.

Report Date:

2013-01-01

Pagination or Media Count:

11.0

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 p0.0001 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.

Descriptors:

• *BACKPACKS
• *KINEMATICS
• *LOADS(FORCES)
• *SPINAL COLUMN
• ACTIVE DUTY
• BASE LINES
• BODY ARMOR
• COMPRESSION
• HEIGHT
• MARINE CORPS PERSONNEL
• MEASUREMENT
• RECOVERY
• REPRINTS
• STRATEGY
• VARIABLES
• VERTEBRATES
• WALKING

Subject Categories:

• Anatomy and Physiology
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE