Related Experiment Video
Updated: Apr 7, 2026
Precision Measurements and Parametric Models of Vertebral Endplates
Published on: September 17, 2019
Cervical intradiscal pressure responses to end-range supine postures: a cadaveric investigation
Marc T Crawford1, Jean-Michel Brismée2, Marc-Olivier St-Pierre3
1University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, 76107, USA. marc.crawford@unthealth.edu.
Background:
Cadaveric studies suggest neck postures may affect cervical intradiscal pressure (CIDP) and potentially contribute to intervertebral disc (IVD) pathologies. Despite neck flexion and protraction posture prevalence and potential impact on cervical IVD health, no studies have investigated CIDP during end-range protraction and retraction. This study investigated (1) CIDP differences between cervical traction, six sagittal plane cervical end-ranges, and neutral posture; (2) CIDP and segmental cervical range of motion (ROM) correlation; and (3) CIDP measurement reliability.
Methods:
Seven cadaveric specimens, mean age 80.6±7.2 years, had cervical segmental ROM assessed by lateral radiographs and CIDP responses measured by fiberoptic pressure sensors in C4-5, C5-6, and C6-7 IVDs for supine end-range chin to neck, chin to sternum, protraction-flexion, occiput to neck, occiput to thorax, retraction-extension, and neutral traction.
Results:
Friedman tests revealed greater CIDP in (1) chin to sternum as compared to traction at C4-5, C5-6 and C6-7 (p < .02); (2) chin to sternum as compared to retraction-extension at C5-6 and C6-7 (p = .027); and (3) chin to sternum as compared to protraction-flexion at C5-6 (p = .042). End-range postures demonstrated moderate effect sizes on CIDP at C4-5 (ES = 0.31), C5-6 (ES = 0.46), and C6-7 (ES = 0.36) using Kendall's W. Strong correlations between cervical segmental ROM and CIDP were identified at C4-5 chin to neck, rS=0.79, p = .04; C5-6 occiput to thorax, rS=0.79, p = .04; and C6-7 protraction-flexion, rS=0.82, p = .02. Reliability was good to excellent for CIDP and segmental ROM measurements (ICC > 0.92, 95%CI 0.86-0.98).
Conclusions:
Consistent chin to sternum increases and traction decreases in CIDP occurred at all cervical IVD levels. The CIDP tended to increase during flexion end-ranges at all IVD levels, while extension, protraction, and retraction tended to decrease at C5-6, C6-7 and increase at C4-5. Large positive or negative CIDP variations with even larger standard deviations were observed within and between cervical IVD segments during various postures.
