Niddah 57 - Bloodstain on the Flesh
If a woman finds a bloodstain on her body, then if it is directly opposite her genitals, she is ritually impure. These areas would include her heel or the big toe, because they can either potentially come close to the genitals or be right across. However, if the stain is on an area of her flesh that is not directly opposite the genitals, she is ritually pure. If it is on her leg or her foot, then if it on the inside (facing the other leg), she is ritually impure, otherwise, she is pure.
If she finds it on her tunic, then if it is from the belt down - she is ritually impure, and from the belt up - she is pure. If it is on the sleeve, and that sleeve reaches opposite the genitals - she is ritually impure, if not, she is pure. If she is accustomed to take off her tunic and cover herself with it at night when sleeping, then no matter where the stain is found, she would be ritually impure, because the tunic moves around during the night (unless she tied it to her head).
Art: Jean Baptiste Greuze - Young Girl in a Lilac Tunic