jwilzewske: fingers

Showing posts with label fingers. Show all posts

Saturday, May 22, 2010

Lumbricals, Some Getting Stronger, Others Discouragingly Staying the Same

G reat strength is necessary in the fingers, yes, but it comes with playing, if one plays rightly—that is, musically. From the moment one senses that the finger must ‘sing’, it becomes stronger. That is quite a different matter from playing exercises or etudes merely for the sake of strengthening, and saying ‘I must exercise my fingers and make them strong.’ Such playing as this latter sort does not help at all.”
— Vladimir Horowitz.

M y guitarist-pianist friend and colleague at work comes and visits with me this week, says that for more than a month he’s been doing exercises to strengthen the lumbrical muscles in his hands. The left hand has been responding, but the right hand—especially the ring finger and pinky—has been staying the same or, paradoxically, might even be getting weaker.

H e worries about focal dystonia. (Jason Solomon of Georgia Guitar Quartet has an excellent article about that here.) He worries about carpal tunnel syndrome (CTS). I am not a neurologist, but I know enough to know when to go and hire one. I ask my friend about whether he has any numbness or difference in sensation among the fingers on the right hand, or between the right and left...

T he fact that my friend is a professional software developer/engineer who spends 70+ hours at a laptop keyboard each week is something the neurologist will need to know, as part of the evaluation—in addition to the heavy hours on guitar and piano. In other words, if what my friend is experiencing is some type of repetitive stress injury (RSI), then characterizing the various types and intensities of repetitive motions will be clinically important.

T he state-of-the-art of hand biomechanics and hand problems of musicians have been a recurring interest for me for some years, so, in response my friend’s immediate situation, I go online and scan the current medical journal literature, to see what, if anything, is new in the last year or two. For his benefit and maybe for your own, I gather some relevant things together in the list of links below.

W here exactly is the ‘carpal tunnel’? The carpal tunnel is the narrow space anatomically between the small carpal bones of the wrist and the ligament called the flexor retinaculum. Here’s how you can find it: Put your left index finger in the center of your right palm, then move the finger about two inches down your palm toward your arm, stopping when your finger approaches the edge of the fleshy part of your hand. Your finger now lies directly over the carpal tunnel. The carpal tunnel is the U-shaped depression with carpal bones below and on either side. The flexor retinaculum ligament stretches over the top of the ‘U’ to make a tunnel-like space. The cross-section of the tunnel is only a centimeter or so, and nine flexor tendons (two to each finger and one to the thumb) have to pass through that little tunnel. The space is so narrow that some of the tendons are bundled on top of each other instead of going side-by-side the way they do outside the tunnel.

B esides tendons, the median nerve also goes through the carpal tunnel. By contrast, the ulnar nerve does not run in the carpal tunnel. The median nerve supplies most of the palm, the thumb, the index finger, the middle finger, and part of the ring finger. The first and second lumbricals (i.e. the two that are most ‘lateral’ on the radial side; index and middle fingers) are innervated by the median nerve. The third and fourth lumbricals (i.e. the most medial two; middle, ring, and little fingers) are innervated by the deep branch of the ulnar nerve. So if what’s going on is actually CTS, then you might expect weakness predominantly in lumbricals and/or interosseous muscles serving the thumb or index finger or middle finger or maybe the middle fingerward side of the ring finger. And you might think ‘ulnar neuropathy’ if the ring finger and/or pinky are predominantly affected.

B ut, gee, knowledge of the neuroanatomy of peripheral nerves in your arm and wrist and hand only gets you part of the way toward figuring out what is going on. In part, this is because of the interconnections elsewhere, including the motor cortex in your brain. Besides clinical evaluation, electrodiagnostic (EDX) tests are usually needed to confirm the diagnosis.

T he lumbrical and interosseous muscles are important in several motions—including flexing and plucking, increasing and diminishing the ‘spread’ of the fingers, and extending/raising the fingers. The lumbricals are used during an ‘upstroke’ when you are writing with a pen or pencil. These are the muscles that make the fingers separate and spread out or, alternately, converge and come together. The lumbrical muscles, with the help of the interosseous muscles, simultaneously flex the metacarpophalangeal (MCP) joints while extending both interphalangeal (IP) joints. In bats and other animals, these muscles are the ones that enable them to spread the wings and grab the air at one instant and flex and draw them in a few tens of milliseconds later and let the air go. If a bat acquired a repetitive stress injury of its lumbricals, on both sides or one side different from the other, it wouldn’t have long to live. Same thing for a seal: you can’t swim and catch fish if your lumbricals are faltering. Serious musicians—people whose livelihood or soul depends on playing—worry about this, as intently as a seal or bat.

T he EDX testing for these conditions is steadily getting more sensitive and more precise. For example, Sheehan and coworkers (link below) studied people referred with suspected carpal tunnel syndrome (CTS) by measuring the ‘second lumbrical-interosseous distal motor latency difference’ (2LI-DML) as well as by other, more standard tests like ‘median-ulnar palmar velocity difference’. The referred cases included 74% who turned out to be CTS. Sheehan suggests that 2LI-DML, which is a more sensitive test than other nerve conduction velocity tests for detecting mild abnormalities, is useful as a screening test for latent CTS on the asymptomatic side.

M otor distal latency (MDL) differences between the median-thenar and ulnar-hypothenar (M-U) muscles and between the median-second lumbrical and ulnar-interossei muscles (2L-INT) have also recently been used to diagnose early or ‘mixed’ cases. After all, there is no law of Nature that says a person can’t have CTS and UNE or CTS and focal dystonia at the same time. In people in whom the conventional nerve conduction tests are so far ‘normal’ despite the symptoms they are having, the neurologist can measure both motor and sensory W-P conduction and in a large percentage of cases this can establish a diagnosis.

U lnar neuropathy at the elbow (UNE) is the second most common compressive neuropathy of the upper limb. Compared to ‘ulnar neuropathy at the elbow’ (UNE), ulnar neuropathy at the wrist (UNW) is rarer and more difficult to localize with routine electrodiagnostic (EDX) tests. In terms of expectation-setting, it is reasonable to anticipate that it may take some time (and multiple visits) to establish an accurate diagnosis and decide on the right treatment plan. In general, these are not things that can be sorted out in a single, quick office visit.

T he important thing—if you are having symptoms like the ones my guitarist friend is having—is to get yourself examined by a neurologist who is experienced in problems of performing artists and who has the equipment and training to perform the newer EDX tests that are available. You can search for practitioners who are diplomates of the American Board of Electrodiagnostic Medicine here. I regret that I don’t know what comparable search resources there may be for consultants having EDX professional certifications in other countries.

Wednesday, September 5, 2007

Mortensen: Artistic Expression and Absence of Tension

Lars Ulrik Mortensen, Fintan Damgaard photo

CMT: There is nearly as much beauty in watching Lars Ulrik Mortensen play as there is in hearing him play. The near total absence of tension in his hands and arms is impressive. Almost zero tension, even in extremely rapid and difficult passages.

DSM: He’s a phenomenally gifted artist, it’s true. I think also that careful videography and biomechanics analysis of his playing could be valuable for other performers and teachers. There’s a great deal to be gained by dissecting and understanding how he does what he does.

CMT: Beyond the ordinary pedagogical aspect, I believe too that videography and analysis of Mortensen’s technique might hold significant therapeutic value for harpsichordists who develop focal dystonia or other injuries. And not just harpsichordists—pianists as well!

W hat is the ideal in music? It is to create phrasing that arises organically from as many details as possible. The overall lines are the sum of the details; the detailed rhythm, intonation and rhythmic swing… The aim is to create the impression that the music materializes in the here and now—not because it says so in the notes, or because it is something that we are doing for our own pleasure. It is something we do to communicate, to involve the listener.”
— Lars Ulrik Mortensen, 2007

DSM: What do you think of the notion that if you can play keyboard instrument ‘A’ well, you can probably play keyboard instrument ‘B’ well? I tend to think this is refuted by the ‘A-B’ pair ‘piano-harpsichord’.

CMT: Yes, well, many harpsichordists may have hardly the musculature to depress the piano keys, or lack the stamina to do it through an entire program.

DSM: And pianists may inadvertently tend to man-handle harpsichord keys.

CMT: In other words, the ‘the muscle memory’ you’ve spent many years acquiring in pursuing mastery of your primary instrument can’t readily be unlearned. The neural and musculoskeletal pathways are ‘set’.

DSM: In similar fashion, you don’t see highly accomplished brass players switching between brass instruments. The embouchure for each is very different from the others, and switching to another one tends to cause injury or difficulties when returning to your primary instrument.

CMT: Is it the sheer hand strength required to play the piano that’s the issue? By contrast to piano, the harpsichord’s played with the fingers only—or mostly. The only role for anatomy that’s proximal to the proximal interphalangeal joint is to position the fingers over the keys. There’s very little force exerted from the hand, arm, shoulder, or back—nothing beyond what it takes to get the key down accurately.

DSM: The piano, on the other hand, takes considerable strength to play—a large proportion of the weight of the back, shoulder, arm, hand, and fingers is projected down into the keys. The forces are considerable.

CMT: But the big difference is how you get the key down, don’t you think? How you get the piano key down determines the attack—the rate at which the hammer rises to strike the string. How you release the piano key is somewhat less critical. You don’t find people afflicted with pianists’ cramp complaining about their release. The problem is primarily with the attack.

DSM: Moreover, a pianist never really touches the string directly. The hammer mechanism is a step removed. With the harpsichord, it’s the opposite—it’s ‘pedal to the metal’ all the time. As the harpsichord key does down, your finger communicates directly with the string through the plectrum—you feel the plectrum stretch the string, you feel the string as it’s released.

CMT: And there’s a very long decay until you release the harpsichord key. With harpsichord, your release is critical—you have to maintain finger independence even more rigorously than with piano. What’s remarkable with Mortensen’s playing is not only the absence of tension in his hands but also the amazing finger independence that he has. Watch his fourth and fifth digits and you’ll see what I mean...

DSM: So with piano, the action is mainly downward, using your whole upper body—essentially ‘into’ the keyboard. And, with harpsichord, the action is mainly upward, more or less ‘out’ of the keyboard—using your finger from the tip to the proximal interphalangeal joint.

CMT: Learning how to play a keyboard instrument is a long process of training neural pathways. I wonder if there’s any difference between keyboard instruments—between piano and harpsichord, say—with regard to susceptibility to focal dystonia or other injuries.

DSM: To date, there’s really no research literature addressing that. The rarity of the cases makes the systematic study of possible statistical associations of that kind very difficult. There are, though, some recent papers in the journal MPPA that touch on it, albeit in an anecdotal way.

CMT: I wonder, too, whether—since the finger action is so different between harpsichord technique and piano technique—switching instruments might be helpful for a player who has developed a disability that is specific to one keyboard instrument. Are harpsichord and piano sufficiently different, do you think, so that the injured central and peripheral neuroanatomy involved with focal dystonia affecting the performance on one instrument would be distinct from the neuroanatomy pertinent to performance on the other instrument?

DSM: Again, there’s no published research literature concerning that possibility. Interestingly, the percentage of left-handed professional musicians isn’t significantly different from the percentage of ‘south-paws’ in the overall population, except for keyboard musicians. The percentage of ‘lefties’ among piano, organ and harpsichord players is very low—primarily because of the right-dominant literature. For a left-handed musician to play piano is comparable to writing with her/his right hand—awkward, uncomfortable. Consequently, lefties tend to play non-keyboard instruments professionally. So my hunch would be that the neuroanatomical pathways that are relevant to harpsichord playing and piano playing overlap a great deal. It would be surprising that switching instruments would offer respite from something like dystonia, unless there were a different laterality-dominance.

CMT: There is the example of Leon Fleisher and the left-handed piano literature. And Reinhard Goebel gave up being Konzertmeister of Musica Antiqua Köln in 1990 at the age 38 because of focal dystonia. He obtained a left-handed instrument, re-learned the violin left-handed, and resumed playing from the second violin desk (second-chair not because of diminished ability, but more probably to prevent collisions with the bows of the other violins). The literature was, obviously, the same as before. But the pathways were sufficiently different so that the switch was successful.

C ould anything be more absolute than Bach’s faith in God? Well, the means that Bach employs to express his unswerving faith in God are revealed more by way of hints. If the word ‘God’ makes sense in the case of Bach; providence or meaning may be better words. His trust in authority does not give rise to the need to shout out some truth or other, but rather to suggest it. There is a very wide framework for interpretation in Bach, but he is much more challenging, because he is less blunt. He appeals much more to my temperament than the broad statements of the Romantics.”

— Lars Ulrik Mortensen, 2007

DSM: Mortensen is the artistic director of Concerto Copenhagen. He studied with Karen Englund and Jesper Bøje Christensen at The Royal Danish Academy of Music in Copenhagen and with Trevor Pinnock in London. From 1988 to 1990 he was a member of London Baroque, and from 1990 to 1993 he was a member of Collegium Musicum 90. He has recorded for Archiv Produktion, Harmonia Mundi, Kontrapunkt and DaCapo. His recording of Bach’s Goldberg Variations won him a Diapason d’Or. He directed the European Union Baroque Orchestra in 2003. He was professor of harpsichord and performance practice at the Hochschule für Musik und Theater in Munich from 1996 to 1999. This year he received the Léonie Sonning Music Prize, Denmark’s premier music award.