Final answer:
The three motions for full opening in the cervical spine are flexion, which is forward bending of the neck; extension, which is backward bending; and rotation, which allows for side-to-side turning of the head.
Step-by-step explanation:
When examining full opening motions in the cervical spine (c-spine), it is important to understand the three primary movements that facilitate this range of motion. The three motions for full opening in the c-spine are flexion, extension, and rotation.
Flexion and extension occur in the sagittal plane, where flexion involves anterior bending of the neck, bringing the chin towards the chest, and extension is the posterior bending, moving the head back. For the c-spine, lateral flexion, which goes either right or left, isn't a part of the full opening motions.
Rotation of the c-spine allows for the turning of the head from side to side, such as when shaking the head 'no.' This rotational movement is produced by the summation of small rotational movements available between adjacent vertebrae.