The following exercises for foot injury should be done in a pain free range and are just a general treatment without assessing what is the cause of your pain. Please seek advice from a professional.
Grab a tennis ball and place it under your bare foot around your arch and heel area. Push your weight down onto the ball and then slowly move your foot inwards and outwards (like windscreen wipers) so that your are massaging the underside of your feet. Move the ball up and down your foot and repeat as much as you feel you need. This can be done across the whole of the under side of you foot.
While seated cross one leg over the other so that you can get a good grip of your toes. Slowly pull them down so that you are bending your toes and feeling a stretch on the top of you foot/toes. Now engage your foot muscles so that your are trying to straighten your toes but resist the movement with your hand so there isn’t actually any movement but your muscles are working. Hold this for 5 seconds and then relax for 10 seconds. Now repeat this cycle for 4 or 5 times.
This a great one for improving ankle and foot mobility. This can be done standing or sitting so choose which one is more comfortable. Lift the foot a few inches off the floor and write the alphabet in the air with your big toe, beginning with uppercase letters. Make sure to exaggerate the downward strokes. Once you reach the end of the alphabet, write lowercase letters.
Repeat with the other foot.