Last night, unexpectedly there was a TV program (UK on BBC4) where they dissected a human arm and hand, so of course I had to watch it, and it certainly improved & confirmed my own understanding of the thumb muscles as I am always trying to show pupils the muscles and structure to encourage them to develop an open hand. But never knew there’s a saddle joint at the base of the thumb. Â Hadn’t realised that there are 2 finger tendons which reach to different tarsals and one splits around the other and peals off, interesting design. Fascinating to instrumentalists. Â Take care of your hands…. !!