The last few days have been a lot of fun. My wife, Jeanna, and I got to visit with her family for Father’s Day. To their surprise they were somewhat unexpectedly tricked into helping us move out of our apartment! We also made some time for ice cream and hanging out by the harbor in downtown Baltimore. We even got to spend time with our beautiful little nephews. Always fun seeing how much joy they get out of the little things in life that I often take for granted. Over the past few days I have been getting more proactive with videos. I can’t wait to start offering some more visual content that helps you better understand how to care for yourself!
Today I want to discuss your supposed carpal tunnel diagnosis. The goal of this post is to help you determine the validity of that diagnosis. Something I commonly see with a suspicious carpal tunnel diagnosis is the reproduction of “carpal tunnel” like symptoms with touching or pressing on the infraspinatus muscle (one of your four rotator cuff muscles). In our last post we discussed the role trigger points can play in pain, numbness and/or tingling in other regions of the body.
What is Carpal Tunnel Syndrome?
Carpal tunnel syndrome is the entrapment of the Median nerve at the wrist. The symptoms of carpal tunnel syndrome often appear as:
- Painful tingling in the hand during the night.
- Swelling, weakness or clumsiness of the hand.
- Sensory deficits in the Median innervated region of the hand (thumb, the index finger, the middle finger and the lateral half of the ring finger). Numbness, tingling and/or pain may also spread into the arm or shoulder.
- Weakness and atrophy at the base of the thumb are commonly seen over time.
How Do you accurately diagnose carpal tunnel syndrome?
To confidently diagnose carpal tunnel syndrome your physician needs to find:
- Positive Nerve Conduction Velocity
- A nerve conduction study (NCS), also called a nerve conduction velocity (NCV) test--is a measurement of the speed of conduction of an electrical impulse through a nerve. NCS can determine nerve damage and destruction. During the test, the nerve is stimulated, usually with surface electrode patches attached to the skin (Hopkinsmedicine.org).
- Positive EMG Findings
- Also called a myogram, an electromyography (EMG) measures muscle response or electrical activity in response to a nerve's stimulation of the muscle. During the test, one or more small needles (also called electrodes) are inserted through the skin into the muscle (Hopkinsmedicine.org).
Based on these findings, your suspect carpal tunnel syndrome will be classified as either:
So if it is not carpal tunnel syndrome, what else could it be?
Glad you asked! As we discussed earlier, trigger points in the infraspinatus muscle can reproduce pain, numbness and/or tingling in the same region as carpal tunnel.
So now we need to ask ourselves, is this a true carpal tunnel or are these sensations generated from the infraspinatus muscle? If we compare the location of symptoms found with infraspinatus trigger points and carpal tunnel it is hard to say.
Muscle atrophy (wasting) at the palm, hand weakness and clumsiness would having me leaning more toward a CTS diagnosis. However, as we mentioned earlier, we would need a nerve conduction study and/or EMG study to confidently make a CTS diagnosis.
Infraspinatus Referral vs. Carpal Tunnel
How can I tell if the Infraspinatus muscle is at fault?
Simple. Press your finger into the infraspinatus muscle looking for tenderness. You can offer the job to a friend or family member that has been waiting for years to make you cry like a baby. My recommendation would be a medical provider that is familiar with myofascial pain. Using a ball or thera-cane over the infraspinatus could also get the job done. Tenderness at the infraspinatus alone is not necessarily enough. You are looking for a region that reproduces your symptoms at the hand, wrist and/or forearm.
Interesting fact: In 1938, Kellgren actually found that injecting saline in this muscle produced the same symptoms. We have been aware of the role that the infraspinatus can play in referred pain at the hand, wrist and arm for almost 80 years!
Can I have both carpal tunnel syndrome and referred symptoms from the infraspinatus?
Great question! (I realize I am complimenting myself here… sad, I know). The answer is… ABSOLUTELY. However, it is more common to find trigger points in the infraspinatus in people without carpal tunnel syndrome.
- 50% of people without carpal tunnel syndrome, that had symptoms at the hand and wrist, had infraspinatus trigger points.
- 26% of people with carpal tunnel syndrome, that had symptoms at the hand and wrist, had infraspinatus trigger points.
- Trigger points of the infraspinatus were more common in people with MILD carpal tunnel syndrome compared to SEVERE carpal tunnel syndrome.
What is the takeaway from this information?
Your symptoms could easily be a combination of carpal tunnel syndrome and infraspinatus trigger point(s). In that case, do what you can to treat the infraspinatus in hopes of reducing your symptoms. It is not uncommon to find positive nerve conduction velocity testing in people that report no symptoms (obviously this is found in research. Normal people don’t get nerve conduction testing done for fun on their day off). If you have a legitimate carpal tunnel syndrome it should be treated as one by your medical team.
Self-Assess: After performing you should always look for some type of change to determine effectiveness.
- Reduced tenderness at the infraspinatus
- Improved range of motion
- Less symptoms (monitor over the course of the day and week)
Go forth and conquer! Use the information provided today to determine if the infraspinatus is the culprit in your hand, wrist and/or arm symptoms. By pressing on the infraspinatus muscle you can quickly identify whether or not this recreates your symptoms. If so, WONDERFUL! We continue to do our best to help you avoid hefty medical bills, and be in control of your own body.
Have you or someone else been diagnosed with carpal tunnel syndrome? If so, what has your experience been like? Please comment with any questions about today’s topic!
Dr. Michael Infantino, DPT
Kellgren JH. Observation on referred pain arising from muscle. Clin Sci 1938;3: 175.
Simons DG. Referred phenomena of myofascial trigger points. In: Vecchiet L, Albe- Fessard D, Lindblom U, editors. New trends in referred pain and hyperalgesia. Amsterdam: Elsevier Science; 1993. p. 341–57 [chapter 28].
Qerama E, Kasch H, Fuglsang-Frederiksen A. Occurrence of myofascial pain in patients with possible carpal tunnel syndrome - a single-blinded study. Eur J Pain. 2009;13(6):588-591