It Is Not Isomorphic
The neck also called the cervical spine, consists of 7 bones called vertebrae C1, C2, C3, C4, C5, C6, C7. These segments each bear at least 3 joints. The range of motion of the vertebral column is not isomorphic, that is, the segments do not contribute to total spinal function in the same manner, to the same extent, nor do they do it in the same way regularly during a movement.
The total degrees of movement of the neck is not the arithmetic sum of the segmental ranges of motion. Intervertebral angles are significantly different at identical head orientations during flexion and extension. Range of motion can be as much as 10 or 30 degrees less than the total aggregate sum of possible segmental action. Measuring the extent of movement of an athlete’s neck when he or she flexes then extends may be different then extends and then flexes. This may vary day to day and each day this may be considerably different.
Cervical spinal action does not negate teaching specific posture, correct seat heights and training form. This information only gives the coach and athlete understanding and an acceptance of what may or may not be occurring during a repetition. Consistency, effort and overload will Get an athlete Strong.