Lesson 7: Scapular Muscles

The scapula (shoulder blade) is the base for the humerus (upper limb); specifically, scapular movement ensures the glenoid fossa (shoulder socket) is aligned with the humeral head, optimizing upper limb stability during all movement.

The muscles that move the scapula (shoulder blade) and shoulder girdle (scapulothoracic joint, acromioclavicular joint, and sternoclavicular joint) include the pectoralis minor, rhomboids, serratus anterior, trapezius, and levator scapulae. Scapula muscle strength is responsible for stability of the scapula, which lacks bony attachment to the rib cage. Further, these muscles are responsible for scapular motion. For example, the upper trapezius, lower trapezius, and serratus anterior contribute to upward rotation when the shoulder abducts during the shoulder press exercise. The middle trapezius and rhomboids contribute to scapular retraction when the shoulder extends during a cable row. And, the serratus anterior is the prime mover of scapular protraction and an important scapular stabilizer.

These muscles also play a role in maintaining optimal posture (preventing scapular dyskinesis), the alignment and stability of the cervical spine and thoracic spine, and the position of shoulder anatomy to maintain optimal arthrokinematics.

Sports medicine professionals (personal trainers, fitness instructors, physical therapists, massage therapists, chiropractors, occupational therapists, athletic trainers, etc.) must be aware of the muscles of the scapula for detailed analysis of human movement, and the development of sophisticated exercise programs and therapeutic (rehabilitation) interventions. Further, this course is essential knowledge for future courses discussing shoulder anatomy (e.g. muscles originating on the lateral border of the scapula and crossing the shoulder), the elbow and humerus muscles (e.g. triceps brachii), and the spine and back muscles (e.g. latissimus dorsi). More advanced courses include discussions about injury and pain (e.g. muscle weakness, scapular dyskinesis, shoulder pain), palpation (e.g. using the inferior angle to palpate underneath the scapula), and sports performance (optimizing muscle activity for optimal scapular movement and upper limb muscle strength).

For more advanced anatomy check out our integrated functional anatomy courses:

• Pectoralis Minor
• Rhomboids
• Serratus Anterior
• Trapezius
• Levator Scapulae

Caption: The scapulothoracic muscles on the posterior side of the body