Muscle Minute TUESDAY – Carpal Tunnel Syndrome and the Median Nerve

Diagram of human arm nerves and arteries

The median nerve is one of five terminal ends of the brachial plexus, unique as it originates from the lateral and medial cords of the brachial plexus AND is the only nerve to pass through the carpal tunnel at the wrist. Though carpal tunnel syndrome affects only 1%-5% of the population (mostly women), if you’ve ever had your hand go numb, it can become a significant problem. Let’s take a closer look at the potential median nerve compression points:

Enters the arm in the axilla, inferior to teres major
Passes between biceps brachii and brachialis
Passes between the two heads of pronator teres
Passes between the finger flexors (FDS/FDP)
Passes through the carpal tunnel

Just like any other nerve, it must be able to glide like dental floss. Here are some methods to floss or glide the median nerve:

Person demonstrating shoulder stretch exercise on chair.

Successful treatment of the median nerve must include evaluation of each of the potential compression sites. Here is a quick checklist to get you started:

Compression Site	Evaluation	Treatment
Teres major	Palpate for trigger point in “posterior armpit”	Deep trigger point massage
Biceps brachii and brachialis	Palpate for trigger points in mid muscle belly Check flexibility with shoulder extension/elbow extension and forearm pronation	Deep trigger point massage
Pronator teres	Palpate for trigger points Check flexibility with forearm supination	Counterstrain with passive elbow flexion to 90˚ and forearm pronation (hold for 90 seconds)
FDS/FDP	Palpate for trigger points	Try this cool 11-minute yoga routine
Carpal tunnel	Tinel’s test Phalen’s test	Improve flexibility of finger flexors (see above)

Why does this matter?

The median nerve traverses several potential compression sites before it enters the carpal tunnel. Biomechanically, these muscles are usually tightened with a “slouching” posture, therefore, movement to pull you into a more upright posture will counteract shortening of the muscles that potentially compress the median nerve. It seems like a lot, but evaluation of these sites takes only a couple of minutes and it will be well worth the effort.

Because nobody has time to be in pain.

Until next time…