Parkinson 0, me 1   I win this round, Parkie !

I'm teaching myself to play the English Concertina (sorry, neighbours !) and was finding it difficult because the shaking of my hands kept making the notes warble as my fingers slipped.
This made me mad, so experimented with different positions and discovered that I could brace my arms and prevent most of the shaking by sitting with my feet up on a chair and legs well apart, then holding the  concertina in my hands between my legs and pressing my forearms against the insides of my knees.

I look weird this way, but it works and may be useful for other things.  So, Parkie you bastard that's one round you lost.