Hi!
These are the 4 exercises I give for ankle sprains / weak ankles:
Roxy is right, walking on tip-toes is good for strengthening ankles, just make sure you kep your weight over your big toes, and don’t let your ankles roll outwards.
Do you have a strap on weight? If so, put it on your foot, lay on your bed on your side, with the lump on your ankle (your lat malleolus) facing up to the ceiling. Now, without moving your leg, try to turn your foot so the sole of your foot is pointing to the ceiling, and hold this for 10 seconds. I usually repeat this at least 10 times, three a day.
Walking barefoot on soft sand is an amazing exercise to strengthen ankles and foot arches.
Standing up, try to lift the outside borders of your feet off the ground.
Hope these help. If you do them every day you should show an improvement within 6 weeks.
x