There is a discussion on Height of Anglo hand/Palm rest going on at c.net:

http://www.concertina.net/forums/index.php?showtopic=10752

Since there was a reference to my "communication" in PICA vol.6 p 62
I would like to make some comments:

Generally speaking the traditional handle with Anglos (and Duets too as being he same) suffers from these 'defects': a) it is not ideally located b) it is not high enough c) the height is equal, while it should be higher at the little finger side d) it should be wider to offer some stability e) the strap is too lean and floppy f) static work by the thumb is needed for stabilization while a thumb strap for instance would offer passive stabilization. A possible 'correction' of these disadvantages is shown in the photo in PICA when practised on a Duet and presented in a wider meaning in this article:

http://www.concertina.net/goran_ergonom.html

Questions and objections are welcome...!