Flexion Pain and Instability
Lumbar spinal flexion, or forward bending of the spinal column, is the most important motion of the lumbar spine. It has the largest range of motion1,2 and is the most-exercised during activities of daily living.3,4 The LimiFlex is the first spinal instrumentation system developed specifically to restore healthy kinematics in lumbar flexion.
Bible et al. "Normal functional range of motion of the lumbar spine during 15 activities of daily living."
J Spinal Disord Tech. 2010, 23(2): 106-112.
Biomechanically, flexion increases loads in the anterior column of the spine, which can be associated with exacerbation of disc pain and degeneration.5 Furthermore, flexion instability is coupled with translational instability.
When a segment of the lumbar spine is in flexion, less of the facet’s articular surface is engaged, decreasing the resistance of the segment to shear forces. In addition, the portion of the facet that is engaged in flexion is less coronally oriented and therefore less capable of resisting segmental shear loads.6,7
Facets limit sagittal translation
The facet joints are less engaged in flexion, and the parts of
the facets that are engaged provide less resistance to shear
Clinically, pain and instability on flexion affect over 400,000 patients worldwide annually.
Flexion has long been associated with clinical issues, including the following (click on link to see the corresponding sagittal plane image):
- instability in flexion associated with degenerative spondylolisthesis
- post-operative instability in flexion associated with surgical decompression
- adjacent segment disease manifesting in flexion
- pain on forward bending associated with degenerative disc disease
The LimiFlex Spinal Stabilization System addresses flexion instability associated with these pathologies.