[Correlation of the (rotation) traction force with the pressure in the nucleus pulposus in multiple segments of the cervical vertebra].

Objective: To study the correlation between cervical (rotation) traction force and the pressure in the cervical nucleus pulposus based on an examination of multiple segments of the cervical vertebra.

Methods: The data obtained from our observation were processed by the exponential model, and the changes in the pressure reduction (P) in the cervical nucleus pulposus were analyzed.

Results: When stretching followed by rotation was imposed on the cervical vertebra, an increase of P was first observed due to the stretching before a reduction in P caused by the rotation. The P of C(3-4) segments was constantly greater than that of C(5-6) segments, while the changes in P of C(4-5) followed different patterns.

Conclusion: Changes of P in each segment of the cervical vertebra are similar in response to the load force, and there is no correlation of monotonic increase or decrease between the changes of P and the location of the cervical vertebra.