The Trapezius Muscle

Many bodybuilders tend to neglect trapezius development, because small traps will give an illusion of greater shoulder width. Judges at important contests always look for thickness which only the traps can impart to the upper back. Relatively heavy trapezius musculature is essential for an impressive, muscular pose.

MUSCLE SHAPE AND LOCATION

The trapezius is named for its trapezoidal shape (diamond-shaped muscle). The trapezius muscle is a flat, triangular muscle that covers the upper back and part of the neck and shoulders, but it’s actually part of the thorax. In other words, the trapezius is a large upper back muscle on both sides of the spine between the shoulder joint and the neck.

MUSCLE SIZE

The traps are actually larger than the abdominals. If more men understood this, they might put a lot more work into trap training. A muscular trapezius is a great way to tell a weight lifter from somebody who does not lift. An evenly and well developed trapezius muscles can highlight and excellently finish off a physique and prevent shoulder and neck problems.

TRAPEZIUS MUSCLE ORIGIN

The muscle spans from the base of the skull all the way down the back to the 12th thoracic vertebrae. The muscle inserts on the shoulder girdle at the distal portion of the clavicle, the acromion, and the spine of the scapula.

MUSCLE  INSERTION

1. Upper trapezius – Lateral one third of the clavicle & acromion process of the scapula
2. Middle trapezius – Medial margin of acromion & superior lip of spine of scapula
3. Lower trapezius – Tubercle at apex of spine of scapula

TRAPEZIUS FUNCTIONAL REGIONS

Three Areas of the Trapezius Muscle

Anatomically, the trapezius is a single muscle.  Functionally, it is often treated regionally. The significance of this division lies in the variety of functions performed by this muscle.

1. Superior region (upper fibers) – Upper fibers of the trapezius originate at the base of the skull and attach to the clavicle. This region of the trapezius controls movement of the neck and shrugging of the shoulders
2. Intermediate region (middle fibers) – The middle fibers allow the scapula to move back toward the spine as well as upward and to the sides.
3. Inferior region (lower fibers) – Lower trapezius fibers function in the adduction and depression of the scapula, movements that are also associated with the latissimus dorsi.

FUNCTIONS OF THE TRAPEZIUS MUSCLE

• Keeping the neck and head in position
• Moving the shoulder blade in toward the spine
• Moving the shoulder blade up and down
• Rotating the shoulder blade so that the topmost part of the upper arm faces up
• Bringing the head and neck in a backward direction
• To rotate and side bend the neck
• To assist in breathing