Anatomy of the Back Muscles
Latissimus Dorsi, Trapezius Muscle, Rhomboids, and Teres Major

Here is an overview of the anatomy of the back muscles. This page focuses on the upper back and muscles that attach to the humerus (upper arm bone) and scapula (shoulder blade).

The main muscles in the superficial back are the latissimus dorsi (lats), trapezius (traps), rhomboids, and teres major.

Sometimes, the levator scapula is included in the superficial back because of it's role on the scapula, and sometimes the levator scapula is included as a neck muscle.

Latissimus Dorsi Muscle aka "The Lats"

The latissimus dorsi is the largest and widest of the back muscles. It starts on the pelvis, ribs, and vertebrae, and it attaches to the front of the upper arm bone (humerus).

It pulls the arm down, back, and inwards, and the lats work during exercises like pull ups and the seated row machine.

Learn more about the latissimus dorsi.

Teres Major Muscle aka "The Little Lat"

The Teres Major is sometimes called the "little lat" because it moves the shoulder in the same directions as the latissimus dorsi.

It starts off on the edge of the scapula and attaches on the humerus just next to the lats.

The teres major will work during all the same exercises that work the lats.

Learn more about the teres major.

Trapezius Muscles aka "The Traps"

The trapezius muscle, also known as the traps, is a kite shaped muscle that starts at the base of the skull and runs down the tips of the vertebrae. Although it is one muscle, the traps has three sections-- upper, middle, and lower.

The trapezius attaches to various points on the scapula (shoulder blade) and pulls the shoulder blade in different directions.

The traps work with the lats during back exercises, and they work with the deltoids during shoulder exercises. The traps will also stabilize the scapula during chest, bicep, and tricep exercises.

Learn more about the trapezius muscle.

Rhomboid Muscle aka Rhomboids

The rhomboids are located just underneath the trapezius muscle. There are 2 rhomboids. Rhomboid major is the larger, and rhomboid minor is the smaller muscle.

The rhomboids pull the shoulder blades back together, and they work with the trapezius and lats during most back exercises.

Learn more about the rhomboid muscle.

Conclusion: Anatomy of the Back Muscles

It is very important to work the muscles in your back just as often as the chest muscles or arm muscles so that there is balance in your upper body strength.

It is especially important to work the upper back muscles (rhomboids and traps) that stabilize the scapula. A strong upper back can help to increase overall upper body and arm strength as well as decrease the likelihood of shoulder injuries.

Remember to follow a balanced upper body workout routine.

Yours in health,
Dr. Charles PT/PT

Return to Anatomy of the Arm Muscles from Anatomy of the Back Muscles

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