There is more musculature available for movement of the head and neck than degrees of freedom. This means the number of muscles that generate the required force for a given motion are far greater than needed to perform the movement. This is extremely important as we can sustain neck trauma, damage tissue and still function in our day to day lives - in many cases while still recovering at a high level.
The issue or problem in training is that the large powerful muscles are often substituting when we are trying to rehabilitate smaller deeper musculature that has been stressed. Having a system of training to ensure when exercising the head and neck that all muscles can be targeted is important.
The longus colli group: longus colli, longus capitis, rectus capitis and longus cervicis are the deep neck flexors. These muscles are loaded with proprioceptors and are important in postural control, position sense balance and neck stability. The mandible is the lower jaw bone and when elevated by closing the mouth it triggers a contraction of the cervical flexors. This contraction occurs because the fascia covering the masticatory muscles that move the jaw has continuity with the fascia of the cervical muscles - they are a part of the same functional unit. Fascia is connective tissue, beneath the skin that attaches, stabilizes, encloses and separates muscles. Clenching or opening the mouth via this connective tissue leads to significant differences in the cervical muscles.
During deep cervical flexor training, the concurrent contraction of the masticatory muscles at a submaximal intensity selectively increases the thickness of the longus colli without contraction of the sternocleidomastoid.
Tip for Targeting the Deep Cervical Flexors:
Use a Mouth Guard - You can also Set your Jaw as if There was One
Set the Pendulum 4 or 5 Way Neck Pad on Hole #11
Face the Machine for Deep Cervical Flexion while Lightly Bite down on the Mouthpiece
Do Neck Flexion but Pull with the Jaw on the Face Pad not Push with Forehead and Face
Remain Lightly Biting Down on the Mouthpiece for Each Rep
*Because you are Targeting Deep Neck Flexors it is Unnecessary to Do Multiple Sets or Work to Momentary Muscular Failure
Ease into Any New Movement to Avoid Muscular Soreness
Training the Deep Cervical Neck Flexors