[Reaction of the cerebral vertebrae in imagined changes in the shape of the cervical spine].

Postural reaction of the cervical vertebrae on imagined, but actually not performed changes in the shape of the cervical spine in the sagittal plane are described. The percentage of reacting vertebrae is relatively high. The findings seem to indicate, that 1.) the described phenomena belong to the constant features of the spinal dynamics, 2.) that there, probably, exist residual traces of preceding activities and 3. that these changes are due to the activation of the polymetameric system of the intrasegmental muscles.