ANATOMY IN ACTION SERIES: Thoracic Outlet Syndrome
Educational articles designed to help CA's understand the underlying anatomy and physiology of conditions presenting to the chiropractic office.
Laurie Mueller
TOS Compressive Syndrome
There are several 'tunnels' or 'compartments' in the body through which important structures, like nerves, blood vessels, or tendons travel. When a narrowing of these tunnels occurs, via a misalignment of bones or spasm of associated muscles, it can lead to the compression of those vital structures that travel through the area. We see this happen in conditions like 'Carpal Tunnel Syndrome' (which we will discuss in a future article), or 'Piriformis Syndrome' which we have discussed in a previous article.
Thoracic Outlet Syndrome, or TOS, is a fairly common compressive syndrome that can be addressed very effectively in the chiropractic office. Let's learn a little more about this condition through a review of the associated structures that create the tunnel.
Associated Structures
Bony Structures that border the Thoracic Outlet include:
• Clavicle
• Scapula
• 1st Rib
You can see from the diagram how the nerves in yellow run in-between the clavicle and the 1st rib on the anterior of the body and the scapula on the posterior. There are several associated joints that could subluxate near this area and narrow that tunnel: Acromio-clavicular joint (acromion process of scapula and the clavicle), sternoclavicular (superior lateral sternum and clavicle), 1st rib misalignment or rib cartilage laxity, and/or any scapular misalignment.
It is also important to recognize the cervical spine as the source of the involved nerves. Whenever a patient has an upper extremity issue the DC must evaluate the cervical spine, the Thoracic Outlet, and the structures of the arm and hand to determine cause.
Muscular Structures that border the Thoracic Outlet include:
# The Anterior Scalenes
# The Middle Scalenes
# Pectoralis Minor
In this diagram we see the muscles and where they attach. We also see how close the nerves lie to the bordering structures. In the case of muscle spasm the nerves could certainly be affected.
The Contents of the Thoracic Outlet include:
# The Brachial Plexus
# Subclavian Artery
# Subclavian Vein
As already mentioned, tunnels exist in the body to provide a passageway for vital structures like nerves and blood vessels. The above-named structures are important because they are the primary nerve and blood supply to the upper extremity. Thus pressure on them could cause a variety of symptoms including but not limited to: numbness, tingling, weakness, and of course pain. The Brachial Plexus (brachial=arm, plexus=web) is of particular note here because these nerves exit the spine in the mid to lower cervical region and form a network/web of nerves that travel on to supply all of our nervous function for the arm and hand.
What Causes Compression?
There are a variety of potential causes of compression that must be analyzed for TOS. These include: muscle spasm, clavicle or 1st rib misalignment, deformity or elongated transverse process (part of the cervical or upper thoracic vertebrae), or trauma to the ribs such as could occur via whiplash.
As already mentioned, more rare causes of pain, such as tumor, must also be on the doctor's differential list as they evaluate the patient.
What is the Most Common Cause of TOS?
Muscle spasm is the most common: As with any muscle, spasm in the scalenes or pectoralis minor can be caused by one or more of a variety of mechanisms. These may include sprain/strain injuries such as from whiplash, sports, or personal injury/slip and fall. Spasms could also stem from a subluxation of the joints, or bone, to which the muscles attach.
The DC may also analyze the patient's nutrition. An imbalance of calcium/magnesium is often involved in muscular dysfunction. Particularly a magnesium deficiency.
Management of TOS
There are several conditions that can cause pain and/ or weakness in the arm. Before a diagnosis of TOS can be made, the DC must first rule out the possibility of a herniated disc or other underlying lesion that could be causing the symptoms via pressure to the brachial plexus or blood vessels. This will be accomplished through physical examination, orthopedic and neurological testing, and diagnostic imaging tools.
Of course the DC must also rule out more uncommon causes like a tumor which would indicate the need for referral to a surgeon or specialist.
Keep in mind that it is always great news for a parient to hearthatthey have TOS vs. a disc herniation ortumor!
When the DC creates a care plan for a patient with TOS they will address the issues of misaligned bones through
chiropractic adjustments, and they will work to alleviate the muscle spasm. Those doctors that work with nutrition may also recommend a calcium/magnesium supplement. Those minerals tend to be key nutritional deficiencies associated with muscular symptoms. Some DC's may also recommend an herbal supplement like St. John's Wort which can help promote muscle relaxation.
From the perspective of physiotherapy, the DC may recommend ultrasound or electric muscle stimulation on the overlying tissue.
Manual massage and stretch of the muscle, if affected, is very effective and can be accomplished by the doctor or by a massage therapist.
Education Fosters Understanding
An understanding of anatomy helps all health-office employees better communicate with patients and provide care more safely. Online training programs in particular make high quality training affordable and convenient and can be taken any rime of day. At www.CCCAonline.com learners can engage in a streamlined 24-hour training program that meets or exceeds FCLB guidelines in every area of study and fulfill the training requirement needed for the national examination!
DC's will often pay fortheir employees to train. Full price for this training is an affordable $339 for the entire 24-hour program. www.CCCAonline.com also has special discount program available for you ilf you are receiving this article through The American Chiropractor Magazine, you can still enjoy a discount. Use AMCHIRO as your discount code. When this code is entered during the registration process it will automatically provide a $15 discount off the regular price of the program. This is the program that gives back to the profession.
Learners can expect text, images/schematics, dynamic video lectures, and robust customized experiential interactivities in a thorough 19-module program. Plus an extensive note-packet of nearly 200 pages is included and can be downloaded, printed, and studied off line. Learners work at their own pace and can conveniently take programming around work hours to avoid disruption in the office. Questions? Visit our website or send us an email at [email protected]
Laurie Mueller, D.C. served in private practice in San Diego, California. She was the post-graduate director at Palmer College from 2000-2010; served as the ACC Post Graduate subcommittee chair for 6 years; peer reviewed for the Research Agenda Conference, and wrote the informal role determination study that aided in the development of FCLB’s guidelines for chiropractic assistants. Dr. Mueller currently works as a private eLearning consultant with a focus on healthcare topics and functional medicine through her company, Impact Writing Solutions and subsidiary www.CCCAonline.com. She is a clinician, an educator and an expert in online educational pedagogy.
