[Functional analysis of the cervical spine in healthy persons].

Radiograms were taken of subjects with no symptoms of cervical spine problems; the cervical spine was evaluated in the spontaneous posture and at maximal flexion and extension. The position and movement of the vertebra, intervertebral height and gliding were calculated. The results showed that (1) lordosis in women occurred less pronounced than in men, and that there was an increase with age; (2) C 2-3 was the least flexible segment and motility increased in the caudal direction; mobility decreased with age and the segments of the lower cervical spine with the highest mobility decreased the most; (3) all posterior and ventral intervertebral heights showed a decrease with age at C 5-6 and C 6-7; (4) vertebral gliding decreased with age.