The posterior muscles that move the cervical spine can be divided into four layers. Part of the fourth layer are two muscles, the semi-spinalis capitis and the splenius capitis that have an important role of moving the head and neck.
Maximum contraction of the semi-spinalis capitis and splenius occurs during extension with resistance against the head, while it is in the neutral position. In coaching we tend to want to start the neck extension movement with the neck flexed feeling that increasing the range of motion increases muscular development. In this instance it is not true. The neck has more neuromuscular activity when the motion starts at a neutral position against resistance. In actuality the same can be said about neuromuscular activity in free motion movements of neck extension without resistance.
When you are sitting and your head is resting, flexed, retruded, tilted or laterally bent the electrical activity is negligible or non existent in these fourth layer muscles. As a coach this means several things:
A head and neck injury requires inactivity and rest. If a neck muscle is injured the athlete will limit the movement of his or her head as the particular area affected is healing. The consequence is that the developed semi-spinalis and splenius capitis are also atrophying rapidly even if they are not traumatized. Thus, before the athlete returns to play their strength must return to normal, be assured, strength has been reduced.
When athletes are in an aggressive training program and take time off for needed rest, it is not uncommon for them to actually make strength gains or at least return to the same skill and strength level quickly. But with the neck, loss of neck circumference and strength, tends to be rather abrupt as lack of resistive exercise and limited movements means very little neuromuscular activity in the aforementioned select muscular groups.
Prioritize your neck training to Keep and Get Strong.
Pendulum 5 Way Neck