Effect of Load Carriage on Lumbar Spine Kinematics

Abstract

Superior and inferior lumbar levels showed different kinematic behaviors under heavy load carrying conditions. These findings suggest a postural, lumbar flexion strategy aimed at centralizing a heavy posterior load over the base of support.

The effect of training on lumbar spine posture and intervertebral disc degeneration in active-duty Marines

“…Each image data set was analyzed as previously described (Rodriguez-Soto et al 2013). Briefly, a set of markers was manually placed at the corners of each vertebra (L1-S1) and posterior elements to model vertebral position and orientation.…”

“…To date, one study by Aharony et al measured the impact of Israeli Navy Special Forces training on lumbar spine (LS) pathology through physical examination and radiological evaluation; however, no overuse changes or new injuries in the LS were noted (Aharony et al 2008). In a previous study, whole LS and lumbar level-dependent postural changes were measured in activeduty Marines while posteriorly carrying a load of 50.8 kg (Rodriguez-Soto et al 2013). …”

“…However, the Marines who were evaluated in this study had already been in operation for 8-48 months and were conditioned to carry heavy loads while marching. Importantly, Marines participating in both studies (Aharony et al and Rodriguez-Soto et al) had measureable, pre-existing structural changes in muscles, vertebrae, and intervertebral discs (IVDs) that may have affected load-carrying posture (Rodriguez-Soto et al 2013, Aharony et al 2008). …”

An Endplate-Based Joint Coordinate System for Measuring Kinematics in Normal and Abnormally-Shaped Lumbar Vertebrae

“…Sagittal T1-weighted images (TR: 427 ms, TE: 17 ms, NEX: 1) were obtained with a matrix size of 256 × 256, field of view of 35 cm, thickness of 3 mm, and scan time of 2:30. 6 Markers were placed on the corners of each vertebra on each sagittal magnetic resonance image ( Figure 1C) using OsiriX (Geneva, Switzerland). 14 A second set of markers was placed on each pedicle at the same distance from the posterior vertebral body in axially-reformatted images ( Figure 1D).…”

“…1,2 High-resolution studies have quantified the kinematics of the lumbar spine in vitro, however the effect of active muscles and passive soft tissue tension are difficult to replicate, 3 which makes their correlation to the in vivo condition questionable. In vivo vertebral posture changes have been measured using computerized tomography (CT), 4 biplanar radiography, 5 magnetic resonance imaging (MRI), 6,7 and combinations of multiple imaging modalities. 8 The development of upright MRI machines has allowed for the study of in vivo postural changes in the bony elements and soft tissues of the spine in relevant and functional positions.…”