Flexibility of the spine: normative values of goniometric and tape measurements.

A sample of 508 male and female white-collar and blue-collar employees aged 35 to 54 years were examined clinically to determine the reliability of spinal flexibility measurements using inclinometers and a tape measure, and to determine the normal values of cervical sagittal movements, lateral flexion, lumbar flexion and extension, trunk rotation and sidebending. Spinal flexibility decreased with advancing age, particularly among the blue-collar workers. Male predominance was observed in lumbar flexion and rotation and female predominance in cervical flexion-extension-movement. Spinal flexibility was negatively related to the experience of disabling pain. The strongest connections were between cervical flexion-extension-movement and neck pain, and between trunk sidebending and low back pain during the preceding year. The interobserver reliabilities were found to be generally good for all these measurements, and trunk sidebending showed the highest reliability coefficients. The intraobserver reproducibility (checked at a one-year interval) was acceptable only for cervical flexion-extension movement, cervical sidebending and trunk sidebending.