How common
Can you do this?
These are answers from visitors, not a study.
How it works
The platysma is a broad, thin sheet of muscle that lies just under the skin of the neck. It starts on the upper chest and shoulders, runs up over the collarbones and the front of the neck, and attaches to the jaw and the lower face1. It is a muscle of facial expression, and the facial nerve controls it2.
When it contracts, it pulls the corners of the mouth down and lifts the skin of the chest and neck. It fires during expressions of fear, disgust, and strain. Because it is so thin and so close to the surface, a hard contraction makes its fibres stand out as vertical cords running from the jaw to the collarbone.
People often call these cords neck tendons. They are not. They are the muscle bands themselves. The thick rope that runs from behind the ear to the breastbone is a different muscle, the sternocleidomastoid, and it stands out when you turn your head.
Most people can make the platysma fire as part of a grimace. Making it fire on its own, with a calm face, is uncommon. Bodybuilders train it because it makes the neck look defined in a pose.
Try it
- Stand in front of a mirror with your neck bare.
- Pull the corners of your mouth down and out as hard as you can, as if making a disgusted face.
- Watch your neck. Vertical cords should appear from the jaw to the collarbone.
- Relax your face. Now try to tense the neck alone, without the grimace. Keep your mouth still.
- Practise for a minute a day. Isolated control usually takes a few weeks.