... She's also very sensitive about it, and prone to abusive outbursts !
PRW the tendon of FHL runs from the inner side of the ankle, going under the foot to reach the big toe. It can get injured anywhere, but esp where it crosses the tendons that flex the lesser toes, right in the middle of the foot. But as it's getting better, it doesn't' matter anyway. Fingers crossed it stays good.
I thought it sounded like FHL too. Do you mean it hurts when you actively scrunch your big toe under, or when you do it passively, eg with your hand? Also, does it hurt when you stretch the tendon (by using your fingers to bend the toe"backwards")?
Meldy has a bit of a thing about Achilles tendons as hers are particularly old and decrepit.