5.1.1 The head-neck segment

The head and neck are represented by two subsegments joined at the C1 vertebra. The neck subsegment extends from the C7/T1 region to C1, while the head subsegment extends from C1 to the vertex. For biomechanical calculations, they are considered together as a single functional head-neck segment.

The head-neck assembly has three degrees of freedom: flexion and extension, left and right lateral flexion, and left and right rotation. When any of these angles is changed, Ergoniza Intelligent distributes the total rotation equally between the neck and head subsegments.