Measurement of segmental lumbar spine flexion and extension using ultrasound imaging.
METHODS
Clinical measurement, technical note.


OBJECTIVE
To describe a technique to measure interspinous process distance using ultrasound (US) imaging, to assess the reliability of the technique, and to compare the US imaging measurements to magnetic resonance imaging (MRI) measurements in 3 different positions of the lumbar spine.


BACKGROUND
Segmental spinal motion has been assessed using various imaging techniques, as well as surgically inserted pins. However, some imaging techniques are costly (MRI) and some require ionizing radiation (radiographs and fluoroscopy), and surgical procedures have limited use because of the invasive nature of the technique. Therefore, it is important to have an easily accessible and inexpensive technique for measuring lumbar segmental motion to more fully understand spine motion in vivo, to evaluate the changes that occur with various interventions, and to be able to accurately relate the changes in symptoms to changes in motion of individual vertebral segments.


METHODS
Six asymptomatic subjects participated. The distance between spinous processes at each lumbar segment (L1-2, L2-3, L3-4, L4-5) was measured digitally using MRI and US imaging. The interspinous distance was measured with subjects supine and the lumbar spine in 3 different positions (resting, lumbar flexion, and lumbar extension) for both MRI and US imaging. The differences in distance from neutral to extension, neutral to flexion, and extension to flexion were calculated.


RESULTS
The measurement methods had excellent reliability for US imaging (intraclass correlation coefficient [ICC3,3] = 0.94; 95% confidence interval: 0.85, 0.97) and MRI (ICC3,3 = 0.98; 95% confidence interval: 0.95, 0.99). The distance measured was similar between US imaging and MRI (P>.05), except at L3-4 flexion-extension (P = .003). On average, the MRI measurements were 1.3 mm greater than the US imaging measurements.


CONCLUSIONS
This study describes a new method for the measurement of lumbar spine segmental flexion and extension motion using US imaging. The US method may offer an alternative to other imaging techniques to monitor clinical outcomes because of its ease of use and the consistency of measurements compared to MRI.
Division of Physical Therapy, Ohio University, Athens, OH 45701, USA. chleboun@ohio.edu
Gary S
GS
Chleboun
Matthew J
MJ
Amway
Jesse G
JG
Hill
Kara J
KJ
Root
Hugh C
HC
Murray
Alexander V
AV
Sergeev
D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D016683:Supine Position / Q000502:physiology; D014463:Ultrasonography; D055815:Young Adult