Dynamic lumbar curvature measurement in acute and chronic low back pain sufferers

(1) To determine the reliability of a novel fiber-optic method to dynamically measure lumbar curvature in low back pain (LBP) sufferers, and (2) to investigate the dynamic lumbar curvature in acute and chronic LBP sufferers.

Cross-sectional study.

Physiotherapy clinic.

Acute (n=20) and chronic (n=20) LBP sufferers recruited from general practitioner and therapist referrals.

Not applicable.

A fiber-optic device was used to measure curvature through time during flexion, lifting, and extension movements. Repeated-measures reliability for curvature-time curves was tested using coefficients of multiple correlation (CMCs) and root mean square error, and for peak curvature values intraclass correlation coefficients (ICCs) and mean absolute errors were used. Acute and chronic LBP groups were compared using peak curvatures and sequencing of curvature change.

The fiber-optic method was shown to be highly reliable in measuring both whole lumbar and lower lumbar curvature with CMC values >.81 and ICC values >.99. Chronic LBP sufferers displayed greater peak curvatures during flexion and lifting for the whole lumbar spine and lifting for the lower lumbar spine. The sequencing behavior demonstrated that the quartile of movement associated with the greatest curvature change was the second for flexion and lifting and first and second for extension across both groups. No significant differences in sequencing were demonstrated between the 2 groups.

This method is reliable for dynamic lumbar curvature measurement in back pain sufferers and is a viable option for clinicians. Acute LBP sufferers display less kyphosis during flexion and lifting. Sequencing of curvature change is similar across the 2 groups.