Howard:"I am struggling to imagine how any system of straps can be firm enough to give the stability you are suggesting while at the same time allowing the hand to shift to reach awkward fingerings, but possibly yours does this".

RE:My object all the time has been finding a better compromise than what trad handles offer.For some styles of Anglo playing ( and for a player with not very small hands and possibly with say a 39 key MacCann)) it would be possible having a dead fixed hand. With larger keyboards that is impossible and the need to shift hand position within the handle is obvious.
Neither the Anglo/Duet type nor the English type of handle provides an optimal compromise, this is the basic point

H:" If I have to choose, I choose flexibility over stability, and stabilise the instrument on my knee (when sitting) or thigh (when standing)".

RE: I think this is what most players with some ambition to manage more than very simplified music do. The result still is that a)some music demanding stability more than flexibility will be excluded and b)playing standing will be desperate or excluded as well.Naturally the individual player may be quite happy with this situation and "no problems exist" but I see that as an unfortunate limitation of the musical potential of concertinas generally

H:"Nevertheless, apart from the stability question, where I accept the traditional design is not perfect, I still don't recognise that the other "defects" which you mention in your original post are actually problems:"

RE:Fine ! so I will try to comment without expanding too far here.You are not an ICA member? so you can read my articles (7 so far in later issues) in "Concertina World" where the views are presented further.

H: "a) it is not ideally located Why? What would be ideal?"

RE: Models do vary and some are better in this respect BUT with the common 6 1/2" sizes the handle is always (except on some cheap German 20 key models) 1)eccentric 2)offering no support for the wrist
1)may not be a big problem IF you consequently use a "fanning" way of bellowsing 2)is a general disadvantage (but sometimes eliminated with larger size)
In principle for mechanical reasons the handle should be located at the centre of gravity BUT if the trad eccentric instruments are played standing with a low position and elbow angle about 120 degrees the instrument balances in two dimensions which is acceptable
More:The hand bar of Anglo/Duet is located so that the support comes at the distal part of the palm. This MAY be fairly ok for SOME Anglo playing but generally supporting the wrist instead of the palm is preferrable, more below

H:"b) it is not high enough Why do you feel a higher rest brings an advantage?"

RE:Measures do vary a little but the original hand bar usually is 15mm high and this does not admit a relaxed hand position (= "natural grip position") vs the keyboard. To achieve that the wrist has to be 20-40mm above the endplate. This you find with large German Konzertinas for instance

H:"c) the height is equal, while it should be higher at the little finger side"

RE:If you rest your relaxed hand "flat" on a table you will find that the fingers do not point vertically to the surface. This means with the instrument that they can not flex and act perfectly in the same direction of travel as the buttons unless the hand position is compensated by lifting the little finger side 10-15mm

H:"Yet again, I don't see this. It might help to reach far buttons with the little finger, but there are other times when I want to angle my hand the other way, to raise the first finger to give that one more room to move".

RE: Hmm...The little finger is a nuisance in itself due to its handicap from shortness.It also has to come nearer to the keyboard rows to do its job better.Concerning your need to angle "the other way" this depends on individual habits. I can't speak for you there of course but I felt the same initially.After a short rehabituation period I found that I reached whatever I wished within the modified handle as well despite I have not very large hands but I would admit that a 64 key English or 65 key Crane for instance are not entirely comfortable in this respect

H:"d) it should be wider to offer some stability
Possibly, although I should have thought stability will mainly come from how firmly the straps hold the hand"

RE:A wider rest may offer support for the *wrist* like I said before.With the trad arrangement firm straps locks the mid part of the hand down and thus obstructs all finger movements. An essential object for an improved handle is to offer better stability while preserving the necessary flexibility and as far as I can see this can best be obtained by a combination of a suitable (higher) support for the wrist firstly (not for the palm) AND a steadier wrist strap (not the trad handstrap which obstructs flexibility)

H:"e) the strap is too lean and floppy Good quality straps aren't"

RE:Hmm...What I use is 1)2-2,5mm steady leather,50mm wide and anatomically cut in S or U shape, fixed so that it combined with the support forms a cuff for the wrist within which the hand can slide the 20-30mm necessary for reaching the whole keyboard while preserving the same degree of stability along the flexibility range

H:"f) static work by the thumb is needed for stabilization while a thumb strap for instance would offer passive stabilization.
As I said earlier, this is how I and many other players maintain stability while moving the hand, to control strap tension. It is an important playing skill, rather than a problem."

RE:Well, this is an issue where the ergonomist may get a bit agitated:-) Avoiding static effort is a main object for all sound and safe work! It can not be totally eliminated many times of course but all "solutions" must aim for reduction as far as possible.There is a very important *musical* side of it. Any unnecessary static load for the hand will impair precision movements by the fingers and that may be a disaster for musical performance.
I agree however that a good musical result may be achieved by "skill" but why getting there with a lot more strain and wasting a lot mroe time than necessary...?:-)

H:" However I have played anglo for more than 35 years without it ever occurring to me that the straps need redesigning. Ralphie presumably feels the same. Even with your professional interest, you admit that it took 15 years for you to decide there is a problem".

RE:What hurts me most today is that I did *know* spontaneously from the start that there were some fundamantal "defects" around but old players energetically told me to wait and see - practise will fix it.
15 lost years in retroperspective...The funny thing is that all collegues and nonconcetina friends said the same: Such pretty and handy instruments byt why these primitive handles??