There are these small muscles in our upper neck, especially right under the back of the skull, called the superior oblique, inferior oblique, and rectus capitis posterior (major and minor). These are known as the suboccipital muscle group.

They play an important role in head movement, posture, and fine motor control of the head and neck movement.

What’s so special about these muscles?

It’s been found to have these muscles have a high number of special sensors called muscle spindles. These spindles help our brain to understand where our head is in space, which is key for good posture and head coordination.

This is interesting because it suggests these small neck muscles play a more important role in balance and coordination than previously thought. Having so many sensors in such small muscles likely helps your body make very precise adjustments to keep your head stable and coordinate your eye movements when you move around.

This study looked at these muscles to understand how many spindles they had and how they were arranged.

The results were surprising.

These tiny muscles had an unusually high number of sensors, way more than we’d expect for such small muscles. One muscle had 190 sensors per gram, another had 242 per gram, and the third had 98 per gram.

This is almost as much as five times compared to any other in the spine musculature. This is very interesting that there are no tendon organ in these muscles, which may suggest these muscles are not a primary CONTRACTORS but STABILIZERS and SENSORY FEEDBACK as their primary functions.