Spine
-
Comparative Study
Cineradiographic motion analysis of normal lumbar spine during forward and backward flexion.
Motion characteristics of the lumbar spine in the sagittal plane were investigated in vivo using cineradiography. ⋯ During forward flexion of the lumbar spine, initial motion started from upper segments to the lower segments with phase lags. During backward flexion, initial motion started from the lower segments to the upper segments. Motion profiles of the vertebral corners during forward flexion were similar to those during backward flexion at L3/L4 and L4/L5. The motion profiles at L5/S1 were different between both flexions.
-
Comparative Study
Segmental stability and compressive strength of posterior lumbar interbody fusion implants.
Human cadaveric study on initial segmental stability and compressive strength of posterior lumbar interbody fusion implants. ⋯ The biomechanical data did not suggest any implant construct to behave superiorly either as a stand-alone or with supplemental posterior fixation. The PLIF Allograph Spacer is biomechanically equivalent to titanium cages but is devoid of the deficiencies associated with other cage technologies. Therefore, the PLIF Allograft Spacer is a valid alternative to conventional cages.
-
A longitudinal cohort study of patients with acute, work-related low back pain undergoing physical therapy treatment. ⋯ Because the nonorganic tests are purported to serve as screening tests, cut-off values were selected that minimized false-negative results. Even with optimal cut-off values, none of the nonorganic tests served as effective screening tools. Other screening tools may prove more effective for the early identification of patients at increased risk for delay in returning to work after an episode of acute low back pain.
-
Decrease in trunk muscular response to perturbation with preactivation of lumbar spinal musculature.
An experimental study of healthy subjects' trunk muscle responses to force perturbations at differing angles and steady state efforts. ⋯ Findings are consistent with the hypothesis that the spine can be stabilized by the stiffness of activated muscles, obviating the need for active muscle responses to perturbations.