Possible causes of leg and feet pain

Hi all,
I have a question I am hoping someone might be able to shed some light on. I am having leg and feet pain when ever any pressure is put on them. I can stand and sit fine, I can sit indian style fine, but if my children step on me or sit on my legs (calf area mainly)the pain is quick and intense. When playing on the floor with them (my 3yo and 18 mo) they can step on my arms, back, etc and it does not hurt, a little uncomfortable, but if they step on my legs or feet, or crawl on them I cannot believe the sharp quick pain, even just accidently stepping on my feet. What could be causing this? any and all ideas would be appreciated. Thank you
Anna Tweet