The serratus posterior superior muscle is a broad, flat muscle located in the posterior (back) region of the chest. It originates at the spinous processes of the upper three or four thoracic vertebrae, and inserts into the superior (upper) borders of the second to fifth ribs. The serratus posterior superior muscle is one of the muscles that make up the chest wall, and is located just above the serratus posterior inferior muscle.

The main function of the serratus posterior superior muscle is to elevate (raise) the ribs, and assist in inspiration (breathing in). This movement is essential for activities such as breathing, and helps to provide stability and support for the rib cage. The serratus posterior superior muscle also helps to stabilize the ribs, and assist in rotation of the rib cage.

In everyday life, the serratus posterior superior muscle is used in many activities that involve elevation of the ribs, such as breathing and coughing. It is also used in activities that require stability and support for the rib cage, such as lifting a heavy object or bending over to pick something up.

To strengthen the serratus posterior superior muscle, exercises that involve elevation of the ribs, such as rib cage compressions and deep breathing, can be effective.