Talk to Diabetologist on Heel Pain When Walking In Diabetic Patient

Aoa .My mother has a diabetic II patient .She use medicines for diabetes on regular basis for about 2 years. Now the problem is when she wakeup in the morning and going from bed the heel of foot starts severe pain for a while and then the pain spontaneously goes away .If she sat on chair for a while then she can't walk due to pain of heel .Did Xray of heel but nothing found in xray