What parts of muscles will you lose when running?
If you jog, you can lose excess body fat as long as you stick to it every day. Actually, posture is not the key. You just jog, don't run hard, it will only hurt your leg. I suggest you leg press in the middle of running, which should be more helpful to correct valgus of calf muscles. Running is a good way to lose weight, which makes muscles more elastic and has no cost.