A NEW APPROACH TO ANALYSING CERVICAL SPINAL MOTION

Abstract

INTRODUCTION Several investigations on the problem of cervical spine motion describe the difficulties of measuring the movement exactly. Those models have to deal with the difficulties to fixate something at the human head and to track the range of motion in degrees concerning the three directions of movement, flexiodextension, lateral bending and rotation. The only objective method of measuring cervical spine movement and CO/C 1 or C 1lC2 displacements is the functional computer tomogram as described by Dvorak et. al. (1989). The aim of our survey has been to differ between the "normal" and pathologic cervical spine (after whip leash injuries, disc diseases or spondylarthrosis in sport) concerning with the range of movement and angular velocity. l b o Groups of 15 probants have been tested by a new computer-controlled setup. By using a three-dimensional motion-analysis-system special rigid-body software has been developed to calculate the cervical spine motion in all three coordinate directions (Truesdell & Noll, 1965). The first time it is possible to get results about the movement and their time-derivations. These angles and the angular velocities were traced for 15 normal individuals and 15 persons suffering with cervical spine problems. The setup for the tested patients was not more then a small frame like sunglasses which gives us an exact information about the movement in space. This information gives accurate data to calculate the amount of motion concerning the patients personal orientation in space and can be additionally used to compute the coupled motions to the probants reference coordinate system. We found significant differences in the range of motion between normal individuals as reference group and patients with cervical spine problems in all defined directions. CONCLUSIONS One conclusion, was that there were possibilities to measure those differences in cervical spine motion by the presented biomechanical measurement-setup very easily. The setup furthermore is capable of getting exact results about rang of motion, coupled motion end their time-derivations very fast and without any x-ray exposition for the patient. This possibilities and the good results are very important to judge problems after "whip lash injuries" and other cervical spine diseases in sport. REFERENCES Dvorak, A. et. al. (1989): Functional evaluation of the spinal cord by magnetic imaging in patients with rheumatoid arthritis and instability of upper cervical spine, Spine 14 (10); 1057- 1064. Truesdell, C.; W. No11 (1965): The nonlinear field theories of mechanics - Kinematics, in: Handbuch der Physik, von: S. Fliigge, Springer, New York.