Background: Cranio-cervical flexion exercise (CCFE) is a representative exercise that activates the deep muscles of neck pain patients. However, there is a lack of studies that propose specific exercise methods to examine the more effective activity level of the deep cervical flexor.
Objective: The objective of this study is to propose a more effective exercise method through effect comparison based on an optimal degree of mouth-opening, a mouth-open versus mouth-closed position, eye gaze, and body position change during CCFE.
Methods: As a result of examining the optimal degree of mouth-opening during CCFE using a pressure biofeedback unit with 50 subjects conforming to a selection standard, sternocleidomastoid muscle activity was examined. An optimal degree of mouth-opening during CCFE was examined as well. In addition, muscle thickness and muscle activity were measured based on eye gaze. Then, the effect of the exercise based on body position was examined.
Results: The lowest sternocleidomastoid activity was presented at a mouth-opening of 20 mm. A significant difference was presented in sternocleidomastoid and longus colli muscle activity at a mouth-opening of (p< 0.05). The eye gaze of 45∘ below presented the lowest sternocleidomastoid activity.
Conclusions: The results suggest a new type of exercise method with the accompaniment of an optimal degree of mouth-opening of (20 mm), along with an eye gaze of 45∘ below, and an exercise method in the seated position without spatial restriction in order to increase the effect of CCFE, one of the conventional neck stabilization exercise methods.
Keywords: Cranio-cervical flexion exercise; eye gaze; longus colli; optimal mouth-open; sternocleidomastoid.