I have pain in the inner side of left foot.not constant almost around every 2/3 weeks i also get a burst of pain in my left foot which spreads ,that i am unable to walk until i rest it completely.xray and mri came normal with only a intraosseous cys?

It is not feasible to provide a meaningful opinion without additional history, physical examination and may be some tests. It would be prudent to see a doctor or a podiatrist. Wish you good health!

Your description is vague but it is possible you are describing tibialis posterior tendonitis. This muscle helps to support the arch on weight bearing. Wearing supportive shoes or an over the counter arch support helps see a podiatrist for a more accurate diagnosis and proper treatment.