Abstract
Study Purpose
A preliminary study to compare continuous sagittal plane lumbar inter-vertebral kinematics in 10 healthy volunteers in recumbent and weight bearing configurations using quantitative fluoroscopy.
Background
There are no direct in-vivo comparisons between continuous weight bearing and non-weight bearing inter-vertebral kinematics in the same healthy individuals. This information will advance our knowledge of spine mechanics and provide reference values for clinical studies.
Methods
Ten male healthy control volunteer subjects aged between 30 and 50 underwent a recumbent bending procedure during fluoroscopy. All participants repeated this in weight bearing. Trunk motion was controlled for range and velocity. Digital image sequences (DICOM) of these movements were captured at 15 fps and analysed using automated frame to frame image registration codes in MATLAB (Mathworks). Inter-vertebral motion characteristics, including inter-vertebral angular range of rotation and attainment rate (Laxity), were calculated.
Results
These results are the preliminary output of an ongoing study to create a reference database for normal spine kinematics. Comparisons of the motion patterns within and between participants will be demonstrated along with preliminary statistical analysis of range of motion and speed of attainment (laxity) of the angular range within the first 10° of trunk motion after the inter-vertebral motion starts. Laxity is proposed as a new in vivo proxy for the neutral zone where force is replaced by trunk motion near the neutral position.
Conclusion
These preliminary comparisons demonstrate the feasibility of establishing a reference database of lumbar spine kinematics to which patient populations can be compared, potentially allowing these to emerge as outcome measures.
No conflicts of interest
Sources of funding: PhD studentship: School of Design Engineering and Computing, Bournemouth University
This abstract has not been previously published in whole or substantial part nor has it been presented previously at a national meeting.
