Ok Bullethead.... everyone has to find their own happy position but I am trying to suggest that you might eventually find it more comfortable with a deeper inserted thumb. From reading your other post I see that you have been playing less than a month whereas I have been at it for 44 years. Your hand shape appears to be not that different to my own but what you are playing is a very truncated version of the EC keyboard.When you move onto a full sized keyboard your views may change.
I've never felt the need to modify the EC holding equipment, perhaps I just started young enough or naive enough that I thought the instrument was 'correct' as recieved. Forty years later when I began to play Duet concertinas I did a fair bit of experimenting with handrail positions but still play EC's sans modification.
Good luck with your playing,
I bow to your vast experience. I'll never live long enough to match your current total, let alone what you continue to accumulate . I'm not out to change the concertina world here. What works for me in my particular situation probably won't work for everybody because we're all different.and, as you say, the Jackie only has 30 buttons. If I ever get more buttons, that will also be a different situation and that will require its own solution, which is a problem for another day.
As to modifying concertinas in general, I wouldn't do that with an antique. These are "living museum" pieces to be treated with reverence and awe to preserve their historical (not to mention resale) value. But I see anything newly made as fair game. Nobody cares about cheap entry-level things and my mod to my Jackie made no irreversible change to the instrument anyway. I can always put the rest back in its stock position. At worst, the paint on the end will get marks from where the rest is now. So that leaves new mid-range and top-end boxes, the prices of which are not insignificant. The way I see it, if I'm going to spend that kind of money, it had damn well better be a perfect fit for my hand, like a tailored pair of gloves. Without a total custom rearrangement of the guts to move buttons around, which would be ridiculously expensive, the only option is to move and/or redesign the straps and rests. I'd definitely do that if I ever buy such a box. And the result would have about zero resale value because it wouldn't fit anybody else, but I wouldn't plan on selling it anyway It would be strictly for my own use and enjoyment.
Now, as to why I feel the urge to speak my opinion unashamedly here, despite not having played concertinas enough to count...
I have a degree in industrial engineering, a fair part of which involves the ergonomics of highly repetitive finger movements. I've also been typing for over 40 years and learned on a manual typewriter. So far, I find both of these experiences highly applicable to the EC. And if the ergonomics of the hand wasn't an issue with playing concertinas, this forum wouldn't have a whole topic devoted to it. So while I don't have any noticeable concertina experience, I do have a lot of experience with hand ergonomics so can perhaps offer a fresh perspective and some general guidelines for those unfamiliar with this field.
(EDIT: rephrased the 1st sentence of the next paragraph to make it clear I'm only talking about ECs)
So for the EC (I no nothing of Anglos), from the general guideline perspective, the main threat is repetitive motion injury (RMI), which can take a number of forms because the hand and wrist have so many moving parts. Carpal tunnel syndrome (CTS) is one of the most familiar but there are many others. A lesser threat is muscle fatigue, which shortens the amount of time you can go without a break. But while some of this will naturally occur in beginners (at least if they don't type much) until they develop the muscles used in concertina play, it can also be a sign that your ergonomics are wrong, which means they're a warning of impending RMI.
Therefore, the goal is to position the hand and use its parts in such ways as to avoid anything that might trigger RMI or cause muscle fatigue. This means keeping the wrist as straight as possible at all times, with the fingers arched and the wrist some distance off the surface of the box, as with a manual typewriter. With a manual typewriter, this posture evolved specifically to satisfy the 3 needs of speed and duration of work while avoiding RMI. This need for a straight wrist means that bellows must be moved by the elbows and shoulders as much as possible, although the push-pull notes of an Anglo might require more wrist involvement in certain passages (I've never played one so don't know).
The entire hand must be relaxed to avoid fatigue and to allow the fingers to be as nimble as possible. The hand must be positioned so that the fingers can reach all their buttons with as little movement of the wrist or hand as a whole.as possible, which both reduces fatigue and RMI risk, and also gives higher finger speed. This hand position, which will vary with the proportions of the user's hands and fingers, determines where the thumb straps pinky rests must be. And these attachment points must be designed and positioned so that the thumb and pinky sit on them naturally, without need of muscle tensing (to avoid fatigue and keep the fingers nimble), yet firmly enough to work the bellows by action of the elbows and shoulders without putting strain on the wrist.
If you can arrange all this, then you should be able to play the concertina at high speed for long periods of time without either fatigue or risk of RMI. This outcome seems to me a worthy goal. I found that, with my own set of hands, my Jackie violated nearly all of the above guidelines. Therefore, I applied my knowledge and experience of hand ergonomics and typing to move the rests. Now all the above guidelines are satisfied and I'm reaping the benefits.
I can't say that the above applies at all to Anglos or anything else but an EC, nor do I think that my own solution to my own problems will be of any use to others. However, I can at least point out the basic principles of hand ergonomics and let others apply them to suit themselves, or not. That's all I was trying to do.
Edited by Bullethead, 26 October 2015 - 11:40 AM.