Thank goodness for the thumb.
Its unique opposability allows us to grasp, hold, squeeze manipulate; its enormous strength gives power to our grip; and its unmatched sensitivity (matched by an colossal portion of the brain dedicated to its sensations) helps us feel the most minute differences in texture, size or pressure .
Thumbs are good at so many things that they are commonly overused, causing tissue and joint irritation, pain, and eventual damage. For example, the increasing use of small-device keyboards means that thumbs are more active than ever in awkward, repetitive movement patterns that are needed to type out texts, posts, and tweets.
Massage and manual therapists are vulnerable to thumb over-reliance. In our Advanced Myofascial Techniques seminars, we see practitioners in most every workshop suffering from the effects of thumb overuse; sometimes the symptoms are severe.
The structure of the thumb gives it special qualities, but predisposes it to unique vulnerabilities. The thumb’s joints are the most mobile of all the digits, allowing the thumb its distinctive opposability and adaptability.
As with the fingers, the articular ligaments provide some stability, but because of its highly mobile joints, the thumb gets most of its stability from coordinated active muscular tension. The muscles of the thumb are arrayed in all directions around it, much like guy-wires around a pole or mast.
Moreover, these muscles stay busy; given that so much of the thumb’s stability comes from the tension of these muscles, most thumb muscles are active during most thumb movements.1 It is no wonder our thumbs get tired.
The origins of the word “thumb” go back to the Old English word thūma, from the Indo-European word tum or “swelling” (which also gave us “tumor” and “thigh”). The swelling in the thumb’s case is thought to be its round shape, or the thumb’s rounded thenar eminence (the muscular portion of the palm at the base of the thumb).
The thenar eminence often takes the brunt of thumb overuse and repetitive strain. There are at least two reasons for this:
- Since the thenar eminence contains the primary muscles involved in finger-to-thumb gripping, activities or occupations that involve repeated or prolonged use of small instruments or fine tools (dentistry, electronic manufacturing, handwriting and so on) can be associated with thenar eminence overdevelopment, fatigue and pain.
- Since its three constituent muscles (abductor pollicis brevis, flexor pollicis brevis and opponens pollicis) are some of the thumb’s bulkiest, the thenar eminence also provides the lion’s share of palm-to-thumb grip strength. (For example, when using large tools such as hammers, shovels, or in manual therapy techniques involving sqeezing or kneading.)
Note the continuity of the thenar eminence muscles with the carpal tunnel’s flexor retinaculum at the wrist (dark orange)
The Carpal Tunnel Connection
Overuse of the thenar eminence is also intimately connected to neurovascular compression, inflammation, and the symptoms of carpal tunnel syndrome (such as hand, palm or wrist pain; numbness; and tingling).
Because all three of its muscles have direct connective tissue continuity with the carpal tunnel’s flexor retinaculum, repeated or heavy use of the thenar muscles can contribute to tension, strain or thickening of this carpal ligament, which could narrow the carpal tunnel space and compress its contents.
This thenar eminence/carpal tunnel connection works in both directions—the thenar muscles can contribute to tunnel compression, and tunnel compression can cause thenar pain. While the ulnar nerve, which does not pass through the carpal tunnel, innervated most palm muscles, the thenar eminence is typically innervated by the median nerve, which does pass through the carpal tunnel.
Thenar eminence/flexor pollicis brevis atrophy (arrows) as a result of untreated median nerve compression syndrome.
Compression and irritation of the median nerve is most often responsible for the pain of carpal tunnel syndrome. In fact, thenar eminence pain is one of the most common effects of median nerve compression and atrophy of these muscles is a possible long-term result of unresolved carpal tunnel neurovascular compression.
Direct myofascial manipulation of the thenar eminence has been observed to lessen carpal tunnel compression symptoms, but if you suspect that your client has muscle atrophy accompanied by thenar or wrist pain, referral to a rehabilitative specialist is clearly indicated.2
It is also important to remember that median nerve symptoms can be related to irritation anywhere along the median nerve’s length, from the cervical nerve roots, distally through the brachial plexus, or in the arm, elbow or forearm—not just in the wrist or hand.
Thenar Eminence Technique
Carpal tunnel symptoms are not the only reason why we would work the thenar eminence. Anyone who uses his or her hands will truly appreciate focused local work with the structures of the thumb’s base.
The Thenar Eminence Technique uses the knuckles of the practitioner’s soft fist. Note that a soft fist is open, which makes it more sensitive and adaptable than a hard, closed fist. In this position, hand stability is achieved by aligning the arm, carpal and metacarpal bones, rather than by contracting the muscles.
The thenar eminence technique. Slowly and patiently, work into the layers and structures of the thenar eminence.
This means that the wrist must be in a neutral or slightly flexed position. As with the thumb joints, avoid wrist hyperextension
With your non-working hand, cradle your client’s hand from below. This will provide you with extra sensitivity and control, as you can tune the position of your client’s hand to allow the soft fist to engage just the right layer.
Use your soft fist’s MPJ joints (the proximal metacarpal phalangeal joints at the base of the fingers, or the first knuckle) to feel into the hand’s layers. With the broad tool of the fist, you can anchor larger sheets of palmar fascia.
Once engaged, ask for slow, active client movement: “Let your hand open and close”; or “Open your thumb.” This will slide and differentiate the tissue layers under your pressure, and give clients control over the technique’s intensity.
Work from the center of the palm outwards, starting superficially with the palmar fascia and then working deeper, layer-by-layer, until you are deep within the thenar eminence.
Although there is some sliding involved, I suggest not using oil or lotion, as the friction will actually provide a therapeutic tension to the palmar and muscular fascias; it should not be uncomfortable if you work slowly enough.
As always, be sure your pressure is not too painful for your client. If he or she is gripping or contracting elsewhere in the body as a result of your pressure or speed, you are working against yourself. Slow down and let the layers melt away. Think about how much of the brain’s sensory cortex this little area occupies—so why rush it?
If your client’s thumb symptoms continue to be troublesome, a shift in your approach or in the client’s habits is indicated. Given that the thumbs are so active, you may find that clients with high-demand occupations or activities may need this kind of work on a regular basis in a maintenance and prevention capacity.
Thank You, Thumbs
Of course, the Thenar Eminence Technique is especially suited to bodyworker self-care; just lay your own hand down on the table at the end of your day and lean into your thenar eminence with the knuckles of your soft fist (or your elbow).
Slowly open and close your “client” hand, releasing any thumb tension and fatigue. This would be a great time to say a silent “thank you” for the wonder of thumbs—thank goodness we have them.
Excerpted from Til Luchau’s Advanced Myofascial Techniques, Volume 1: Shoulder, Pelvis, Leg and Foot, Chapter 12: The Thenar Eminence. Handspring Publishers, 2015.
Footnotes
- Austin, NM, (2005). “Chapter 9: The Wrist and Hand Complex.” Levangie PK, Norkin CC, eds. (2011) Joint Structure and Function: A Comprehensive Analysis (4th ed.). Philadelphia: F. A. Davis Company.
- Goodwin, S. (2003, December/January). Carpal Tunnel Syndrome and Repetitive Stress Injuries. Massage & Bodywork, 66-78.
About the Author
Til Luchau is the author of the Advanced Myofascial Techniques DVDs and books (Handspring Publishing, 2016), a Certified Advanced Rolfer and lead instructor in the Advanced-Trainings.com faculty, which offers online learning and in-person seminars throughout the United States and abroad.