Above is a picture of the palm side of the hand. The four thick white lines are your flexors (their other end is by the elbow). Between them in red (and attached to them) are the lumbricales - you can just make out their numbers 2nd, 3rd, 4th, the one on the far right marked 1st lumbricale is the one that connects to the index finger. They are a major element of the intrinsic muscle group of the hand. Their job is to do two things 1) straighten (extend) the nail and middle joints and 2) bend (flex) the knuckle joint. I was told by a hand transplant surgeon that they do job 1 whilst you bend your finger to make the movement smooth. If you could contract them on their own they would bend the finger at the knuckle and make your last two joints stick up (extend) - maybe excellent for flat finger technique! Obviously if they were to get too strong they would pull on the tendon and deform your hand.

This you do want to know - about 22% of people have their lumbricales starting further down by the carpal tunnel. It could be the cause of carpal tunnel syndrome. Timins ME. Muscular anatomic variants of the wrist and hand: findings on MR imaging. AJR 1999;172 : 1397-1401

Alan Fraser says that the lumbricals are responsible for movement of cupping the palm. Imagine taking a ping pong ball and trying to squeeze it into your palm so it doesn't drop, without the fingers curling around. Do you have evidence to confirm or deny this? I can certainly feel that same action in playing.

I think before I took Fraser's word for it I might consult a well respected text on the subject like Muscles Testing and Function (2005):

You mean the opponens digiti minimi and the flexor digiti minimi muscles - there, I've done some of your homework for you.

also the Palmaris Longus origin - medial epicondyle of humerus - interesting.

Okay, fair enough. I'll basically take your word for it, although I recall that you said that trumpeters use the lumbricals. Specifically, what means that can they do so, while you deny that pianists can?

Anyway, you said on a previous thread that you agreed with this:

"However, all that really matters about an approach is whether you can play difficult pieces with ease and comfort. Anything that does not contribute to that is purely academic."

What matters in this case is not the anatomical details, but what leads to healthy and efficient movement. If the lumbricals are not the biggest power source, it's of interest to hear that. However, it really doesn't trouble me with regard to any practical issues- especially if the difference cannot be perceived, as you say. Even if knuckle actions are more based on tendons, I'm still more than happy to believe the widely held ideas both that actions within the last two joints are more conducive to tendonitis and that such actions are an inefficient means of applying power. Actions from the knuckle better involve the arms mass, whereas scratching actions are inherently more dependent upon a "held" arm and divorced finger actions. I certainly do not believe that it is right to encourage anybody who has suffered tedonitis to scratch keys from those joints, rather than activate from the knuckle.

this information is very handy.

thanks kbk

No need to do take my word for it - here's Tubiana:


Now that's the first page (google won't give the second). The last column is Tension fraction (%) (got missed off). Lumbricals don't do too bad at Mean resting fiber length when you consider in Mass and Tension fraction they're at the bottom of the next page. They range from 0.1 to 0.2!

Well, great, a load of abstracted numbers. Even if they are not the power source, is it not significant that action via the knuckles is at least aided by something? That's without even going into the mechanical issues of why isolating the last two joints is not terribly productive. As I say, it's interesting to be aware of what you say, but I'm not seeing any practical consequences or implications about technique from this. If I'm using strong and healthy action from the knuckles, what generates that is of solely academic interest- unless it informs me of something specifically that would benefit the movement. If there is some specific hidden practical issue that you feel is raised by this, could you clarify what that is?

Also, could you answer my question that you omitted within the (...)?

"I'll basically take your word for it, although I recall that you said that trumpeters use the lumbricals. Specifically, what means that can they do so, while you deny that pianists can?"

If you read the OP you'll know that the lumbricals help flex the proximal joints and extend the other two - fine for trumpeters and real flat fingering pianists (real flat fingering being playing on the proximal phalange).

I think the answer is a bit obvious - the valves are not in contact with the fingertip. From kbk's description, the lumbricals just don't work the same way at the nail joint as they do at the knuckle joint. They're not comprehensively responsible for the cupping of the hand and fingers, just the part of the cup at the bridge of the hand.

"If you read the OP you'll know that the lumbricals help flex the proximal joints and extend the other two - fine for trumpeters and real flat fingering pianists (real flat fingering being playing on the proximal phalange)."

I'm sorry but that reveals nothing to me as to why you feel this is possible for trumpeters but not for pianists. I use such actions extremely often, especially with my fifth finger.

Aren't flat finger pianists pianists?

??? You just introduced the term "flat fingered pianists". Why are you asking me that question rather than yourself? In any case, I use a variety of different movements in different situations- very frequently including that which describe. Sorry, but I cannot follow your point about why the lumbricals are supposed to be impossible, or where any practical consequences might come via thinking about this when moving.

And from what Timins above says those 1 in 5 people whose lumbricales originate in the carpal tunnel should be careful about cupping their hands. There's probably evidence for that 'abnormality' in the heart line.

No, I introduced the term flat finger pianists. The OP mentions 'flat finger technique'.

So, you're telling me that I probably don't really use them and that nobody can really tell whether they do or not. But now you're saying that some people should be careful not use a movement that DOES use them? Where is the consistency in that?

Thankyou for correcting my inadvertent correction to your grammar upon quoting you. Can we return to the point now?

You'll need to point out where I say that.

Okay, I see from your other post that you were saying it's "unlikely" that they are the source for jazzwee, rather than that it's impossible. Apologies for misattribution. However, if you say it's difficult to distinguish the between different types of action from the knuckle, I'm still wondering where the practical consequences come into this? Why not just get with making a healthy pull from the knuckle? If we need to bear these things in mind for a specific reason, what is that reason and how does it inform better movement? Where does thinking about this translate into consequences?

One aspect that comes out of Timins' paper is that for those 1 in 5 willfully contracting all the lumbricals constantly whilst playing to form a 'strong' hand could well have a serious deleterious affect. These 1 in 5 have lumbricals that start within the carpal tunnel.

Okay, fair enough. I wouldn't have been seeking to do so for any reason in the first place, although that does add to many other reasons not to.

So let's explore this further. I'm glad to be the experiment here.

I had hand surgery for trigger finger. Now understand that those big giant tendons are not affected by the surgery other than for making sure they move freely through the tendon sheath.

But my grip, post op, was weak for a year. The incision was 1 inch long under my 3rd finger. If in fact all the power comes from the tendons, then my grip should have been unaffected.

A grip shape is essential for playing technique. Although they may have not incised any muscles on the inside, I betcha that they used spreaders of some sort to open up that 1 inch incision so they reach the tendon sheath easily. So they would have stretched the intrinsics in the area and caused some short term damage there.

Isn't this perfect for isolating the issue of the role of intrinsics?

My way of measuring this was that I play this "grip" game with my boys. I see who can grip hardest. Post surgery, my grip was perhaps 10% of normal. At 6 months it was 50%. Now my grip is MUCH stronger than before the surgery.

What changed here? It can't be the arm muscles. My LH grip hasn't changed much (again a bilateral test).

Here's Tubiana again:
So no jazzwee, I have no answer for you. My only assumption is that pain, though you were unaware of it, was holding you back.

But it does reveal that not everything is understood here.

Another side note. As technique has developed by hands remain in it's natural curved position more even after impact. Initially it collapsed more. So when key impact occurs, there's no real effort expended on a finger drop.

I'm sure every advanced pianist here must feel that. It doesn't require a lot of "force" to take and retain this shape. So there are aspects here that are affected by some intrinsic muscle development.

kbk, no there was absolutely no pain. It was a feeling of weakness. I suppose another explanation is nerve damage too so I'm not discounting what you're saying completely here.

That your hand stays in position does not reflect any intrinsic work. The flexor/extensor relationship holds the shape. How long could you play for before getting fatigued after your op?

Interesting. So what explains the firmness in one's hand shape after playing piano a long time?

No fatigue post op that's different from any other day. But I didn't have the power to play stretched chords on the RH. Essentially, anything that required a grip was difficult. Single finger action was fine.

You state that as fact but I doubt very much if there is any basis for doing so. Based on the descriptions of the lumbricals' action it strikes me as common sense that when they are more developed, the knuckles are substantially less likely to collapse. Just the slightest involvement would play a role in resisting collapse and development of such muscles might help to resist collapse on a purely passive basis. What reason do you have to casually state that that they are uninvolved, in such a matter of fact way?

Have any of your sources specifically studied pianists? Very few other activities are comparable in terms of how often such actions might be used. i don't think you can write something off based on an average hand.

Wow. This is kind of asinine. I really don't think piano playing is as freakishly complicated and scientific as you're all making it out to be. Jeez. If you teach 5 year old beginners and you're trying to develop good habits from them from a young age, are you really going to try with all these different things? Music is art, not science, and the mechanics behind it aren't THAT complex........

Maybe it's just me? I never think of such extreme implications. Anyway, carry on.

It's not just you.