The trapezius was a muscle that extended from the occipital bone to the lower thoracic vertebrae and to the spine of the scapula.
In 2374, The Doctor told Kathryn Janeway that her trapezius was "as hard as a rock" while massaging her in her quarters. (VOY: "Scientific Method")
In 2377, The Doctor experienced a spasm of the trapezius while his program was stored in Seven of Nine's body. (VOY: "Body and Soul")