Why'd you link those elements to those specific body parts? There's a number of different attributions out there, but the one I'm most familiar with is the one out of Franz Bardon's IIH where fire is the head, air is the chest, water is the guts/stomach and earth takes the legs and limbs in general.
Well it was mainly due to my own possibly misguided posturing.
Theres five elements but only four in the zodiac. The missing element is the element of metal which can represent creative mutations. Five is the number that represents the "creative mind"
It only made sense to me that the five elements are reflective of the five extremities of man himself. The fifth element was the head, and the other four elements were the other extremities.
To explain a little futher lemme post what rudhyar said about the symbol scorpio 15:
"CHILDREN PLAYING AROUND FIVE MOUNDS OF SAND.
KEYNOTE: Early steps in the development of a mind seeking to be attuned to the higher level of human evolution.
This is a particularly cryptic symbol. It may be deciphered if one realizes that Man's essential destiny is to develop as a five-fold being, a "Pentagram" or five-pointed star. Number 5 symbolizes mind in its most creative and penetrating aspect, while number 4 refers to the life processes operating at present within the earth's biosphere. Our Western civilization has realized only the lower level of this vibration 5; i.e. mind contaminated by compulsive instincts and emotional involvement. Some individuals, however, are born with a special potential for development of the higher, creative mind, and in social circumstances favoring this development. In most cases, they are still "playing around" with their unusual capacity. They are in the kindergarten stage of this higher mind development.
In this final stage of the forty-fifth sequence of five symbols the transcendent possibilities of mental evolution, which require interpersonal communion in consciousness, are evoked. The free spirit of true scientific inquiry is only a foreshadowing of such a type of mind, which demands dedication to mankind as a whole. What is seen here is FUTURE-ORIENTED GROWTH."
He talked a lot about the cross and the star in his book.