Muscle Minute TUESDAY – Thoracic Outlet and the Brachial Plexus

Ever wake up with your arm numb or tingly? Maybe you fell asleep on one side or with your arm placed overhead. Chances are you experienced compression of the brachial plexus as it traversed through the thoracic outlet. The brachial plexus, a bundle of nerves, originates in your neck (C5-T1) and passes through a series of potential compression points on its way to innervate the muscles of your arm. Let’s take a closer look:

Between C5-T1
Between the anterior and middle scalene
Over the first rib
Under the clavicle
Behind pec minor

That is an anatomical obstacle course by which the brachial plexus and artery must traverse and diagnosis of this compression is often made by palpating the radial pulse during the following tests:

Adson’s testing
Hyperabduction (Wright’s) test

Successful treatment of thoracic outlet syndrome must include evaluation of each of the potential compression sites. Here is a quick checklist to help you get started:

Compression site	Evaluation	Treatment
C5-T1	Manual cervical traction Somatic dysfunction (vertebral rotation)	Cervical traction Muscle energy technique
Anterior/middle scalene	Palpate for trigger points just behind the clavicle	Counterstrain scalenes with cervical side bending
First rib	Assess with anterior/inferior/medial glide of first rib	Muscle energy technique
Clavicle	(see above) as an elevated first rib will compress the nerve bundle under the clavicle	Correct an elevated first rib with MET
Pec minor	Palpate for trigger point 1″ below the concavity of the clavicle	Counterstrain with passive scapular protraction. Activate lower trapezius

That’s a lot, but here is the point. All of the above are associated with an elevated and protracted shoulder. If you look in the mirror and one shoulder sits higher and more forward than the other, that is the arm with greater potential for brachial plexus compression.

Why does this matter?

Arm numbness from brachial plexus compression is fixable by making sure the path of the brachial plexus is clear. By correcting scapular position, many of the compression points will be addressed.

If you want to learn one quick fix now, watch this video and share it with someone you think it might help. Get that feeling back in your arm.

Because nobody has time to be in pain.

Until next time…