Quantification of continuous in vivo flexion-extension kinematics and intervertebral strains

Tina M. Nagel, Jared L. Zitnay, Victor H. Barocas, David J. Nuckley

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


Purpose: Healthy subjects performed lumbar flexion and were assessed by video fluoroscopy to measure the in vivo kinematics of the lower lumbar motion segments. Methods: Fifteen healthy subjects (8 male, 7 female, 28 ± 10 years) performed lumbar flexion and extension back to neutral while their vertebrae were imaged. The sagittal plane vertebral margins of L3-S1 were identified. Lumbar angle, segmental margin strains, axial displacements, anterior-posterior (A-P) translations, and segmental rotations over the course of flexion were measured. Results: L4-L5 had the largest posterior margin Green strain (65 %). Each segment displayed more axial displacement than A-P translation. Peak vertebral angulation occurred at approximately 75 % of peak flexion during the extension phase. Conclusion: L4-L5 exhibited the largest anterior and posterior margin strains (29 and 65 %, respectively). Strains in the disc during in vivo lumbar flexion are due to both angular rotation and linear translation.

Original languageEnglish (US)
Pages (from-to)754-761
Number of pages8
JournalEuropean Spine Journal
Issue number4
StatePublished - Apr 2014


  • Biomechanics
  • Intervertebral disc
  • Lumbar spine
  • Motion segment
  • Spine kinematics


Dive into the research topics of 'Quantification of continuous in vivo flexion-extension kinematics and intervertebral strains'. Together they form a unique fingerprint.

Cite this