J Manipulative Physiol Ther. 1998 Jul-Aug; 21(6): 383-7.

Natural variation of cervical range of motion: a one-way repeated-measures design.

Christensen HW, Nilsson N.

Nordic Institute of Chiropractic and Clinical Biomechanics, Odense, Denmark.

OBJECTIVE: To describe the natural variation of the active and passive cervical range of motion (ROM) in asymptomatic subjects over a 3-wk period. STUDY DESIGN: One-way repeated measures of active and passive cervical ROM. SETTING: Institute of Medical Biology (Center of Biomechanics) at Odense University, Denmark. PARTICIPANTS: Forty asymptomatic students from the University of Odense. Male/female ratio, 20:20; mean age, 23.9 yr (range, 20-30 yr). INTERVENTION: Measurements of the active and passive cervical ROM were taken using the electrogoniometer CA-6000 Spine Motion Analyzer. Each subject was measured six times during a 3-wk period. The measurements were performed at the same time of the day. The device gives the maximum end ROM for the motion plane examined. RESULTS: The natural variation in active and passive ROM was found to be in the order of chi +/- 20 degrees for flexion/extension, chi +/- 12 degrees for lateral flexion and chi +/- 14 degrees for rotation. CONCLUSION: In asymptomatic subjects, the individual natural variation is quite large for active and passive cervical flexion/extension, lateral flexion and rotation. When measuring individual patients, one should allow for a natural variation of 12-20 degrees.