Trapezius

Musculus trapezius

// Structure & location

Both trapezius muscles together form a large diamond on the upper back, hence the name (trapezoid). It is divided into upper, middle and lower parts. The upper fibres run diagonally from the neck to the shoulder, the middle ones horizontally to the shoulder blade, the lower ones diagonally up to the spine of the scapula.

// Function

The upper part lifts the shoulder blades (shrugging) and tilts the head to the side. The middle part pulls them together (retraction), the lower part pulls them down. Upper and lower parts together rotate the shoulder blade upwards so you can raise your arm overhead.

// For training & sport

• Shrugs and heavy carries (farmer's walk) train the upper part.
• Rows and face pulls challenge the middle part.
• Y-raises on an incline bench target the lower part.

// Good to know

Neck tension often sits in the upper trapezius. In deadlifts the whole muscle works isometrically to keep the shoulders stable.

// Sources

• LehrbuchOpenStax – Anatomy and Physiology, 11.5 Muscles of the Pectoral Girdle and Upper Limbs ↗cite

// More from the atlas: Muscles