58 yr F 40lbs overweight typically very strong since previously weight trained in my 30s, i walk over terrain that is steep to flat everyday 3x plus up to two miles each outing. Started having some night time calf tightness. I would stretch and hold stretches still the cramping/ px subsided (last two weeks). Decided to wear a flat flexible shoe so calf could be stretched more fully one evening. Caused no discomfort but later had after laying down for bed had worse cramps. Next morning I put on my regular trail shoes and went down my stairs (2 full flights) and walked about two blocks and had a sudden severe pain in my lower shin. I thought maybe it was a clot or something as it seemed like it wanted to travel. So I just stood there for a minute, took a deep breath, and turned around to head back home. I didn't even take a step and I felt like it had freed itself and shot into my calf. I have kept a strong muscle oitment and wrap (cotton, sern wrap, ace bandage). Today (fourth day) bruising now appearing at shin and interior calf.