Levator scapulae

What it is

A strap running from the upper neck vertebrae down to the top inner corner of the scapula, lying partly under trapezius. Its name is its function: the lifter of the shoulder blade.

Its fibres twist on their way down, so the ones attaching highest on the neck end up lowest on the scapula. Anatomically this is a minor curiosity; it is included because it explains why descriptions of its line of pull vary.

What it does

Elevates the scapula, and rotates it so the socket faces downward. With the shoulder blade fixed, it side-bends the neck towards the same side.

It works with the upper trapezius for elevation, and against serratus anterior and the trapezius force couple for rotation.

What loads it

Shrugging and carrying loads at the side. It is also under continuous low-level load whenever anything heavy hangs from the shoulder — a bag on one side, for instance.

What is commonly got wrong about it

That the ache at the top of the shoulder blade is this muscle being "knotted". The point where it attaches is a very common site of complaint, and the palpable band people find there is frequently described as a knot or a trigger point. The trigger point model — discrete taut bands that refer pain in predictable maps — has substantial problems: the examination has poor agreement between examiners, and the proposed underlying physiology is not established. Something is felt there. What it is remains genuinely uncertain.

That stretching it resolves neck tension. Neck pain has many sources, several of which are not muscular, and persistent neck pain deserves an assessment.

That it is a neck muscle or a shoulder muscle. It attaches to both and acts on both, depending on which end is fixed.