Thank you for your kind words! I'm happy they're useful. Yes this is a simple pose, but to hold it for a long time needs some strenght.
You should be proud of your ability to be able to do this... I remember a time I once could do back hand springs until circumstances removed the use of my left arm from me. Live well and be safe.
And if I ever need it for more than just (unpublished) sketching practice, then I'll let you know.
Have a nice day!