I think I understand what you mean. I'm still wondering whether it might be related to underactivity in the finger and excessive arm pressure though. If the finger is notably performing the activity of trying to straighten itself out (towards a near vertical position) would pressing on the arch still cause the knuckle to drop down, in all circumstances? Or could the action of straightening back (from a stable point of contact at the fingertip) keep it elevated? I'm just wondering whether the ligaments are necessarily a key element in balance- or whether they're just a useful safety net?
Yeah. I think you are looking at how, without proper instruction a pianist may do injury to a finger: "related to underactivity in the finger and excessive arm pressure..."
If too much pressure is applied, somethings gotta give. Either the ligaments, the volar plate or all three. But it'll take a lot of force to cause this to happen.
I think you can tell if it's a ligament problem, by, if you get the hand in the arch, with proper skeletal alignment, and put slight to mild downward pressure on the joint, it collapses, then that's a ligament problem.
If the ligaments are doing their job, you should be able to push on the arch at the knuckle (joint) and it will hold. I don't think the ligaments are a safety measure but are designed to hold the skeletal alignment in place. (I'll send you some pictures. 1 shows oval-8 brace worn by someone playing piano.)
bob
I think you can tell if it's a ligament problem, by, if you get the hand in the arch, with proper skeletal alignment, and put slight to mild downward pressure on the joint, it collapses, then that's a ligament problem.
So there's definitely no way of using the straightening action to stop this? I find this interesting, as I'm wondering about how much is down to ligaments and how much is down to muscular activity- within any hand. I'm trying to figure out how much certain movements are based on reaching the limits of a joint's motion and being unable to go further, and how much is down to using muscular actions to balance in the middle of the range of motion.
I have one student who struggled a lot with stopping the joint of the fingertip from collapsing. Perhaps not the same issue- although it doubles back a good deal more than horizontal. I was worried at first that the straightening action would simply be unworkable for her. However, we managed to find a way of balancing involving it (even though the joint had been going too far in the very same direction of movement). When she started totally curled up (with the nail resting against a depressed key) and very slowly and lightly straightened out, it was possible to balance into a more lightly curved position- without suddenly slipping past that point and into collapse. I think it revealed that the reason for collapse was simply too much arm pressure acting through it.
In the end, I don't think the ligaments were actually coming into it- as the finger was never being pushed towards its limit of motion. It was only when the balance of muscular actions slipped, that her finger was able to double beyond the straighter position that tighter ligaments would have stopped it in. I'm just wondering whether there are similar issues in the knuckle itself- or whether every "normal" hand depends on ligament issues? Do we actually need to rely on the points where regular joints cannot go any further? While I suspect that it's possible without doing so, I cannot tell for definite how much dependent I might be. Do ligaments also play a significant role in what happens within the mid-ranges of movement though?
It's good that you found the equilibrium point with your student.
Did you check to see what happened if you went with just a little more force of pushing down? Did it still remain in the arch, or would it suddenly give and collapse?
Your student may have a conditions called "mallet" finger, where the PIP will with enough force, collapse, but the distal joint does not raise up.
With my finger, when I did as you found, got to the equilibrium point by uncurling it, everything was fine with that amount of force, but once past that applied force, it would immediately collapse. so there must be a point at where the laxity of the ligament is not coming into play--it is strong enough to hold the knuckle up, but past that point, regardless of skeletal alignment it will give way. It's like pulling taffy--it's strong and hard to stretch and then there's the place where once reached it's too far and just keeps on stretching.
The question I faced was how much force did it take before the arch, after finding the point where the curve held, would no longer work. For me it was obvious, it took very little force--either applied by my arm/shoulder weight or just pushing on the joint with the other hand.
I especially noticed it when playing consecutive 5ths or 8vas. If there were a lot of them up & down the piano, after a while, my pinky would lock with the PIP down and the DIP, up. That didn't feel very good.
And of course I could no longer play.
this condition is great for flexibility, being a gymnast, contortionist, but not very good for strength, unless like a gymnast you wrap tape around everything to make up for going past the point where the ligament fails.
bob
quick add:
I don't think we have to worry about a "normal" joint collapse because of not knowing proper alignment. Teach the person where things work for them and know the limits. If the joint is working, ligaments holding, even for mild motion, nothing will go wrong. But if over stressed that will result in an injury. and the joint will collapse, & have to be rehabilitated. Of course if you put a bowling ball on the knuckle it will probably collapse it, unless the muscles are able to withstand the force & the ligaments hold everything together.
It's when you have the student where it takes very little force to collapse the knuckle, that you realize it is not "normal" and the issue will have to be addressed differently, recognizing this is the way the person's body is and it is not a result of incorrect or no training of proper alignment.
bob t
Ah, that makes sense.
With my finger, when I did as you found, got to the equilibrium point by uncurling it, everything was fine with that amount of force, but once past that applied force, it would immediately collapse. so there must be a point at where the laxity of the ligament is not coming into play--it is strong enough to hold the knuckle up, but past that point, regardless of skeletal alignment it will give way.
Is that necessarily the limits of what is possible due to ligaments though- or is it misjudging the balancing activity of muscles,in a situations where the joints are subjected to unnecessary arm pressures? I've been practising stopping between notes and "testing" the quality of the extending action in my fifth a lot recently- by moving the arm around at different angles and slightly pressing in. When I was doing it just now, at one point the joint at the fingertip suddenly popped out and gave way. I'm not sure whether the ligaments are necessarily involved most of the time- as I don't usually let the joints double back to their full range of motion, even when testing with a little pressure. Perhaps they still help- but I don't feel dependent on my full range of motion. I'm pretty confident that it's primarily muscular action that determines the position and balance. I rarely press from the arm in a way that send joints towards the limits of the the ligaments.
I especially noticed it when playing consecutive 5ths or 8vas. If there were a lot of them up & down the piano, after a while, my pinky would lock with the PIP down and the DIP, up. That didn't feel very good.
And of course I could no longer play.
Actually, I have a related issue myself- but only with the fifth and I can't get into that position in thin air. A more pronounced condition probably causes vastly more problems, but I find that extending the finger out through every key prevents any bad effects. I couldn't start in a notably curled up position with my 5th and hope to press the arm through it without major collapse. However, it's fine as long as the finger extends out through the key. If I try to brace the finger for arm pressure (instead of move it) the middle joint abruptly collapses 100% back, every time.
I'm certainly not going to suggest that anyone with excessively loose ligaments ought to be able to do exactly the same as everyone else, but I do wonder if there are ways to minimise the collapses, with the right approach to movement.
