Measurement of segmental lumbar spine flexion and extension using ultrasound imaging.

Study Design: Clinical measurement, technical note.

Objectives: 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.