The trapezius muscle has a broad, triangular shape that spans from the occipital bone at the base of the skull, along the cervical and thoracic spine, to the spine of the scapula and the clavicle. The orientation of its muscle fibres varies by region—upper, middle, and lower—which creates distinct tension lines based on their direction and function. The upper fibres run downward and laterally from the skull and upper cervical spine to the lateral third of the clavicle. These fibres produce tensi