All About the C7-T1 Spinal Segment (Cervicothoracic Junction)

The C7-T1 spinal motion segment connects the base of the neck (C7) with the top of the upper back (T1).

This transition zone is known as the cervicothoracic junction (CTJ).

• Cervico – stands for “cervical spine” (your neck), which provides rotation for you to turn your head, and flexibility to move in all directions.
• Thoracic – is the upper part of the spine, which attaches to the rib cage is highly stable.

The C7-T1 spinal segment is the link from the highly mobile cervical spine to the more rigid thoracic spine, which makes it uniquely susceptible to degeneration and injury.

C7-T1 Location

The C7-T1 segment is located at the base of the neck, roughly level with the top of the shoulders.

You can identify the location of C7 by running your fingers down the back of your neck. The most prominent bony bump felt at the base of the neck is the spinous process of the C7 vertebra, also called the vertebra prominens.  

C7 is the term used for the 7th vertebra in the Cervical Spine (neck).

Directly below it sits the T1 vertebra, the top level of the thoracic spine.  This level is the attachment point for the first rib and is structurally stable.

C7-T1 Level: Anatomy and Function

The C7-T1 level consists of two vertebrae, a shock-absorbing disc, and a complex network of nerves and ligaments. Together, they facilitate movement while protecting the spinal cord.

Vertebrae and Joints

• C7 and T1 Vertebrae: The C7 is a cervical vertebra, and the T1 is similar but also has "costal facets" where it hinges with the first rib.
• Facet Joints: These small, synovial joints connect the back of the vertebrae. They are lined with cartilage to allow for smooth gliding during neck rotation and bending.
• Costovertebral Joints: Unique to the T1 level, the costovertebral joints connect the spine to the first rib, providing structural stability to the chest cavity.

Watch Cervical Spine Anatomy Video

Intervertebral Disc

A cervical disc sits between C7 and T1 to provide cushioning.

It is composed of a tough outer layer (annulus fibrosus) and a soft, gel-like interior (nucleus pulposus). The C7-T1 disc is thinner than those in the mid-neck but is essential for absorbing the downward weight of the head.

The C8 Spinal Nerve

The C7-T1 level is where the C8 spinal nerve exits the spinal cord.

• Pathway: Even though there are only seven cervical vertebrae, there are eight cervical nerves, spinal nerve C1 through C8. At the C7-T1 level, the C8 nerve exits through the intervertebral foramen, a bony opening between the upper and lower vertebra.
• Function: The C8 nerve provides motor control to the muscles that help you grip objects and flex your fingers. It also provides sensation to the skin along the bottom of the forearm and the pinky side of the hand.

C7-T1 Symptoms

When the C7-T1 segment is compromised by injury or degeneration, symptoms can range from localized discomfort to neurological deficits.

• Radicular Pain: If the C8 nerve root is compressed or irritated, pain may radiate from the neck down the inside of the arm and into the ring and pinky fingers.
• Localized Pain: A dull, deep ache centered at the base of the neck or between the shoulder blades, often exacerbated by looking down for long periods.
• Myelopathy: If the spinal canal is narrowed at the C7-T1 level (cervical spinal stenosis), the spinal cord may be compressed. This can result in balance issues, coordination problems in the hands, and/or heaviness in the legs, and in severe cases of spinal cord compression loss of bowel and/or bladder control may occur.
• Referred Pain: Muscle trigger points in the trapezius or rhomboids can cause pain that feels like it is coming from the C7-T1 joint, even if the spine itself is healthy.

Horner’s Syndrome: In rare cases, severe injury at this level can affect the sympathetic nerves, leading to a drooping eyelid or constricted pupil on one side of the face.