Neck

The muscles that move and support the head — a surprisingly heavy load balanced on a slender spine. They turn, tilt and nod the head and, critically, hold it stacked over the shoulders.

This muscle in 3D

Drag to rotate · scroll to zoom — see the shape, origin and insertion of the neck. 3D model via Sketchfab (CC-BY).

Anatomy

Muscles: Sternocleidomastoid, scalenes, deep neck flexors, upper cervical extensors

Origin: Sternum & clavicle (SCM), cervical vertebrae (scalenes, deep flexors/extensors).

Insertion: Mastoid process of the skull (SCM), ribs (scalenes), skull base and cervical vertebrae.

Actions:

• Head/neck flexion, extension, rotation and side-bending
• Deep neck flexors: stabilise and hold the head over the shoulders
• Assist breathing (scalenes elevate the ribs)

How the muscle works

The larger SCM and scalenes produce big movements and can dominate when the deep stabilisers are weak; the deep neck flexors do the quiet postural job of keeping the head balanced, reducing strain.

Fibre-type bias: Deep stabilisers are strongly postural (type I); superficial movers are more mixed.

Functional role: Positioning the head and eyes, and protecting the cervical spine in posture and impact.

Common problems

• 'Tech neck' / forward-head posture and tension headaches
• Whiplash
• Deep-flexor weakness with overactive superficial muscles

Training & stretching

Chin tucks (deep neck flexors), controlled neck range-of-motion, isometric holds.

Gentle side-bend (ear to shoulder) and upper-trap/levator stretches.

Fix or train this

• Neck & Shoulder Pain
• Build Muscle (Plateau)