Hi,
I'm wondering if you could consider adding an exercise to your database.
I have bad knees and I do it to help strengthen the muscles around my knees.
It's called Toe Raises (it's different to calf raises)
I am included a YouTube video so you can see how it works.
https://m.youtube.com/watch?v=VzIcGAgBiaM&pp=ygUPV2FsbCB0b2UgcmFpc2Vz
Thank you,
Nicola Tibby