Shoulder blade anatomy is complex. The scapula has many different muscles tendons and other structures that are attached to it.
It’s pretty incredible that the shoulder blade (scapula) is essentially floating in space were it not for the connection to the clavicle and other musculature.
If you are looking for an article related to shoulder blade pain and how to improve that you’ll want to read the article I’ve linked to in this sentence.
If you are primarily interested in the anatomy, read on!
Oh and here’s a quick video I made to show how utterly complex the shoulder blade and middle back region actually is!
Shoulder Blade Anatomy: Muscles (and muscles between the shoulder blades)
There are 24 muscles (and potentially more that I missed) that are either connected to the scapula via inserting onto it or originating from it or that are between the shoulder blades. This is only part of the reason when people ask me “what muscle is it,” I can’t give a straight answer. Truth is, we have no idea due to the complexity.
The muscles are layered from layers 0 to 7. Layer zero is closest to the bone while layer seven is closest to the skin.
Longissimus Coli Muscle
This muscle at the deepest layer of muscles on layer 1 and sits between the shoulder blades, close to the spine.
Short Rotatores Muscle
This muscle is also at the deepest layer of muscles on layer one and assists with the rotation and stability of the spine. It connects one vertebra to the next.
Long Rotatores Muscle
Similar to the Short Rotatores, this muscle is also at the deepest layer of muscles on layer one and assists with the rotation and stability of the spine. It connects one vertebra to the next.
This muscle is a bit longer than the short rotatores hence the name.
Longissimus Capitis Muscle
This muscle is on the next layer of muscles and sits between the shoulder blades.
Semispinalis Colli Muscle
Sits between the shoulder blades
Transversospinal muscle
Sits between the shoulder blades.
Multifidus Muscle
Sits between the shoulder blades and basically over the top of the spine.
Longissimus Thoracis
Sits between the shoulder blades and is a larger, thicker muscle.
Infraspinatus Muscle
Sits on the posterior (back) aspect of the scapula (shoulder blade).
Supraspinatus muscle
Sits directly on top of the scapula in the supraspinous fossa (a part of the scapula that has an indentation).
Teres Minor Muscle
This muscle sits below the infraspinatus directly on the scapula.
Teres Major Muscle
This muscle sits below the teres minor and sits directly on the scapula.
Long Head of Triceps Brachii
This portion of the tricep attaches to the supraglenoid tubercle of the scapula.
Subscapularis Muscle
This part of the rotator cuff (one of four muscles) sits on the anterior surface (front) of the scapula and assists with internal rotation of the shoulder.
Iliocostalis Thoracis Muscle
Sits between the shoulder blade and is one of the longer spinal extensors in the spine.
Iliocostalis Lumborum Muscle
Also sits between the shoulder blade and is one of the longer spinal extensors in the spine.
Serratus Posterior Superior Muscle
Sits between the shoulder blades and attaches to the spine and medial aspect of the shoulder blade.
Levator Scapula Muscle
Attaches to the superior angle of the scapula.
Inferior Belly of Omohyoid Muscle
This muscle wraps around the neck and then attached on the superior border of the scapula.
Rhomboid Major Muscle
This muscle is on layer six of muscle and sits between the shoulder blades.
Rhomboid Minor Muscle
This muscle is on layer six of muscle and sits between the shoulder blades.
Middle Trapezius and Upper Trapezius Muscles
These muscles are on the most superficial layer of muscle, layer seven and sit between and slightly overlap the shoulder blades.
As you can see, there are an immense number of muscles that surround the scapula to help it do its job.
This is also why it’s very hard to diagnose a specific muscle (if not impossible).
In the next section, we’ll discuss different ligaments and connective tissue attaching to and around the shoulder blade.
Ligaments And Connective Tissue Near The Shoulder Blade
Intertransverse ligaments
This ligament connects each thoracic vertebrae via its transverse process.
Articular Zygapohpyseal Capsule
This ligament connects each facet joint together (there are four facet joints per vertebra).
Supraspinous Ligament
This ligament runs down the entire posterior aspect of the spine along the spinous processes.
Deep Fascia of Back
This fascia covers the middle and lower portion of the scapula as well the area between the shoulder blades. Fascia is a connective tissue that helps adhere various different structures together. All muscle is covered in fascia as well.
Superficial Investing Cervical Fascia
This fascia covers the top portion of the shoulder blade and connects up along the neck.
Nerve Near The Shoulder Blade
Suprascapular nerve
This nerve sits on the posterior surface of the shoulder blade both above and below the spine of the scapula.
Dorsal Scapular nerve
This nerve sits between the shoulder blades.
Subtrapezial Plexus
This nerve plexus (a collection of nerves) also sits between the shoulder blades.
Thoracic Spinal Nerve roots and their branches
The thoracic spinal nerve roots exit from the spinal cord and branch out into various different nerves with different autonomic and voluntary functions.
Key Takeaways
- There are 33 different structures that sit on or around the scapula.
- Due to the enormous complexity of the shoulder blade and the various structures surrounding it there is a low likelihood that we will ever be able to identify the one structure that is causing pain (maybe we will be able to do that in 100 years).
