Erector spinae muscles

Muscles that straighten and rotate the back

The erector spinae muscles are a group of muscles and tendons that run more or less vertically on each side of the vertebral column. They are primarily responsible for extending the spine and are crucial for maintaining posture and the curvature of the spine.

Anatomy

The erector spinae muscles are divided into three columns:

• Iliocostalis: The most lateral column, it is subdivided into iliocostalis lumborum, iliocostalis thoracis, and iliocostalis cervicis.
• Longissimus: The intermediate column, it is subdivided into longissimus thoracis, longissimus cervicis, and longissimus capitis.
• Spinalis: The most medial column, it is subdivided into spinalis thoracis, spinalis cervicis, and spinalis capitis.

Each of these columns is further divided into regional components based on their location along the spine.

Function

The primary function of the erector spinae muscles is to extend the vertebral column. They also play a role in lateral flexion and rotation of the spine. These muscles are essential for maintaining an upright posture and are active during activities such as lifting, bending, and twisting.

Innervation

The erector spinae muscles are innervated by the posterior branches of the spinal nerves. This innervation allows for the precise control of spinal movements and posture.

Blood Supply

The blood supply to the erector spinae muscles is primarily provided by the lateral sacral artery, with contributions from other segmental arteries along the spine.

Clinical Significance

The erector spinae muscles can be involved in various clinical conditions, such as back pain and muscle strain. Strengthening and stretching exercises targeting these muscles are often recommended for the prevention and management of back pain.

Also see

• Vertebral column
• Muscle
• Spinal cord
• Back pain
• Posture