The trapezius is a triangular muscle that connects the occiput, cervical vertebrae, and thoracic vertebrae to the shoulder girdle through the ribs, manubrium, and sternum. It has three sections: upper, middle and lower. They all have different fiber direction and function.
In general, the trapezius retracts the scapula. It acts to suspend and stabilize the shoulder girdle for use of the upper extremity. It also retracts and stabilizes the scapula so that extrinsic chest muscles can expand the rib cage during labored breathing and for labored breathing.
The upper trapezius connects the occiput and upper cervical vertebrae to the clavicle through the lower cervical vertebrae, first rib, and manubrium.
Origin -the medial third of the superior nuchal ridge and ligamentum nuchae from C1-C5
Insertion – posterior edge of the lateral clavicle
Function – draws the lateral clavicle medially toward the spine, rotating the scapula upward or laterally flexing the cervical vertebrae
The middle trapezius connects the lower cervical and upper thoracic vertebrae to the scapula through the upper ribs, sternum, manubrium, and clavicle.
Origin – the spinous processes and superior ligaments of the vertebrae C6-T3
Insertion – acromion and spine of the scapula
Function – adduction and retraction of the scapula
The lower trapezius connects the lower thoracic vertebrae to the scapula through the ribs, sternum, manubrium, and clavicle.
Origin – the spinous processes and superior ligaments of T4-T12
Insertion – the root of the scapula
Function – stabilize the scapula during movement of the upper extremity; may adduct or upwardly rotate the scapula
Tony Preston has a practice in Atlanta, Georgia where he sees clients.
He has written and taught about anatomy, trigger points and cranial therapies since the mid-90s.