Thank you everyone for your helpful advice and support. I have finally proven to the world what my problem has been for the last 23 months after 4 operations with some amount of success but still having some sort of problem which nobody could not work out.

You may see it for yourself
YouTube - Peroneal Tendon Subluxation

What a mission. Thanks again. A serious operation awaits me. I know far too much about ankle anatomy and conditions. I am a computer scientist, not a medical expert!

*wipes brow of sweat* What a story for my grandchildren.