Injury blog: Dorsal scapular nerve entrapment

Has one of your shoulders been feeling a bit off lately? Is the neck and mid-back region around the shoulder blade feeling stiff and heavy? If this sounds like you, then you may have a problem with a nerve known as the Dorsal Scapular Nerve (DSN). This is a previously under-diagnosed cause of neck, mid-back and shoulder pain and dysfunction. With advances in technology and the development of knowledge and skills of treating practitioners, it has become apparent that this problem is much more common than originally thought. A great excuse for a blog topic!

Relevant anatomy

The neck is made up of a stack of seven bones known as vertebrae. These are numbered C1-7, where ‘C’ stands for cervical (i.e. the neck region of the spine). The vertebrae are numbered from top (near the skull) to bottom (where the neck meets the back). Between the vertebrae are little holes where nerves run through on their way to provide electrical signals to our muscles and other body parts. Between the 4th and 5th vertebrae, the C5 nerve root lives. The DSN is a little off-shoot of the C5 nerve root which runs from the neck to the back of the shoulder and mid-back.

The DSN provides electrical stimulation to three muscles in the neck/shoulder region, all of which attach to the shoulder blade (or ‘scapula’) at one end, and the spine at the other. On its way to these muscles, the nerve pierces through another muscle in the neck (one of the three scalene muscles if you’re really interested!).

Muscle function

Two of the three muscles that the DSN supplies help to move the shoulder blade inwards from its resting position, towards the spine. These are the Rhomboid Major and Rhomboid Minor muscles. The other muscle, the Levator Scapulae, as its name suggests, helps to elevate or lift the shoulder blade. The proper functioning of these muscles is important for us to be able to move our shoulder through its full range of motion. Injury or entrapment of the nerve can lead to poor muscle function and subsequently, poor shoulder movement.

Signs and symptoms

As previously mentioned, the nerve pierces through one of the neck muscles on its way to innervating the other three muscles. This creates a potential point of entrapment of the nerve and this can lead to signs and symptoms commonly experienced with DSN injury. People with DSN injury may present to the clinic with any or all of the following signs and symptoms:

• Abnormal and/or reduced shoulder movement

• Pain around the lower neck, upper/mid back and shoulder region

• Winging of the shoulder blade (i.e. tilting of the blade away from the rib cage)

• Difficulty with drawing shoulders backwards and together

• Difficulty with raising the arm upwards to full range

• Altered resting position of the shoulder blade on the injured side. Due to poor functioning of the rhomboid muscles, the shoulder blade may sit away from the spine compared to the non-injured side.

• Weakness of the affected shoulder muscles

• Stiffness in the neck / spine

Who does it affect?

DSN injuries are common throughout the general population. People whose occupation puts their posture in a compromising position every day and leaves them open to issues around the neck joints and muscles are particularly susceptible to this issue. It has also been seen in people who lift weights and after car accidents.

Treatment

Great news! We can help you get over this issue. Once we’ve been through our assessment and are happy with our diagnosis, we can get to work on you. Yes, this is a problem which primarily affects muscles that drive shoulder movement, but the root of the problem is usually down to poor function of the joints and muscles around the lower neck and upper back. Don’t be surprised if we direct quite a bit of our treatment at the spine. We will provide tight neck muscles with a soothing massage. Stiff neck and back joints will be mobilised and may be manipulated (i.e. cracked) if we feel it is required.

As with most injuries, there is an exercise element to recovery. Poor movement patterns in the spine and shoulder have to be corrected and re-trained over a period of weeks to months. This is to ensure we get to the root cause of the problem and don’t just bandage over the top of it. Strength and stability exercises of the trunk and shoulder will be on your to-do list.

As previously mentioned, your occupation may be driving a lot of these issues. We may suggest changes to your work (i.e. a desk set-up assessment) and other aspects of your lifestyle to ensure you’re hitting this issue from all angles. That way we have more chance that the problem will be resolved permanently.

First and foremost, if you think you have a problem, please get in touch today on 5543 4254 so we can start your journey to recovery.

References 1. Snell, RS. 2012. Clinical Anatomy by Regions. 9th ed.Philadelphia: Lippincott, Williams & Wilkins 2. Muir, B. 2017. Dorsal scapular nerve neuropathy: a narrative review of the literature. The Journal of the Canadian Chiropractic Association. 61 (2). 128-144. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5596970/