I've always sat like that too. It can cause blood vessels to become visible near the skin in the area where your upper calf rests against the other knee, probably from sitting long periods of time with the circulation restricted in that one spot. I've also lost 2 full inches in height in the last 14.5 months, as documented by my doctor (from 5'11 to 5'9). I take a calcium supplement every day and I don't think my bones have shrunk any, but they have definitely shifted positions. My normal gait is quite different than it used to be, and I've also noticed my legs and feet turn slightly inward now when I walk.