Article reviewed and approved by Dr. Ibtissama Boukas, physician specializing in family medicine
Run your fingers down your spine. You will feel bony prominences along the midline. Each “bump” or “lump” felt refers to a spinous process.
What is the spinous process and what does it do? This article explains the anatomy and several important details related to this structure of the spine.
Definition and anatomy
The spinous process is a bony protrusion on the posterior (back) part of each vertebra. The spinous process protrudes where the laminae meet at the posterior arch of a vertebra.
Each spinous process provides an attachment point for the muscles and ligaments of the spine. Most of the muscles attached to it act as spinal extensors. Certain muscles, on the other hand, also act by allowing the rotation of the vertebrae to which they attach.
The size, shape, and direction of each spinous process varies greatly from one region of the spine to another. Thus, these bony prominences are different at the cervical level compared to the dorsal level, which is also different at the lumbar level.
Interesting fact: The spinous processes are not perfectly straight along the spine. Indeed, it is possible for a spinous process to deviate slightly to the left or right of the midline.
This can be a source of confusion, because some will associate this phenomenon with a vertebral fracture or even a displaced vertebra. It is not so.
Pathologies related to the spinous process
A cervical sprain (with stress in hyperextension of the neck) can cause spinous process fracture. This type of fracture usually occurs in the upper part of the spine. It mainly concerns the 6th and 7th cervical vertebrae (called C6 and C7) and the first dorsal vertebra (called D1).
These fractures can also occur following a violent contraction of the trapezius or rhomboid muscle. This is most often an avulsion fracture.
Fractures at this level are usually minor, and have a good long-term healing prognosis with no sequelae. They are typically treated with immobilization for 4 to 6 weeks with a cervical collar.
Otherwise, Baastrup disease is a so-called interspinous contact arthropathy. It is defined by the presence of a joint between the spinous processes. This joint forms in an abnormal way.
To know everything about Baastrup's disease, see the following article.
Evaluation
A healthcare professional (such as a physiotherapist, physiotherapist or osteopath) regularly assesses the mobility and sensitivity of the spinous process in their clinical examination of the cervical spine, dorsal and lumbar.
For example, he will palpate the spinous process of each vertebra looking for pain, hypomobility (lack of movement meaning joint stiffness), or hypermobility (excess movement indicating potential instability).
Depending on his findings, he will adjust his treatment plan and apply mobilization techniques. For example, very gentle mobilizations will desensitize the region and reduce pain in the spinous process concerned. Or, more aggressive mobilizations will increase the mobility of a stiff vertebral segment.
Medical imaging also makes it possible to observe the integrity of the spinous processes, and to exclude damage such as a fracture (X-ray or CT scan), ligament detachment or muscle damage (MRI).