Active range of motion of the head and cervical spine: a three-dimensional investigation in healthy young adults.

PURPOSE: To define reference values for head-cervical range of motion (ROM) in healthy young adults, to assess the effect of sex, and to quantify the separate contribution of other body districts.

METHODS: Thirty women and 30 men performed maximal head and cervical spine flexion-extension, lateral bending, and axial rotation. Movements were detected using a digital optoelectronic instrument. Maximum head-cervical spine and thoracic motions were separated.

RESULTS: Flexion and extension were performed mainly in the sagittal plane. The movement was larger in women (136 degrees) than in men (130 degrees). During flexion, both sexes moved the head-neck and the thorax in the same direction. During extension, men moved only the head-cervical spine, while women moved the two analyzed districts in the opposite directions. Lateral bending was nearly symmetric, associated with head-cervical rotation and extension, and larger in women (91 degrees) than in men (77 degrees). Adjunctive thoracic motion was limited in the sagittal and frontal planes, but larger in the horizontal plane (opposite motions of about 20 degrees). Head-neck rotation was symmetric, and associated with concomitant movements in both the sagittal and frontal planes. It was larger in women (162 degrees) than in men (155 degrees), and performed with limited adjunctive thoracic motions.

CONCLUSIONS: The present values can be used as a first group of normative data for head-cervical ROM in young men and women.