In different parts of the world, different plants are used to make casts. In Mexico, several different plants such as tepeguaje (a tree of the bean family) and solda con solda (a huge, tree-climbing arum lily) are used to make casts. However, any plant will do if a syrup can be made from it that will dry hard and firm and will not irritate the skin. In India, traditional bone-setters make casts using a mixture of egg whites and herbs instead of a syrup made from plant juices. But the method is similar. Try out different plants in your area.
For a cast using tepeguaje: Put 1 kilogram of the bark into 5 liters of water and boil until only 2 liters are left. Strain and boil until a thick syrup is formed. Dip strips of flannel or clean sheet in the syrup and carefully use as follows.
Make sure the bones are in a good position.
Do not put the cast directly against the skin.
Wrap the arm or leg in a soft cloth.
Then follow with a layer of cotton or wild kapok.
Finally, put on the wet cloth strips so that they form a cast that is firm but not too tight.
Most doctors recommend that the cast cover the joint above and the joint below the break, to keep the broken bones from moving.
Leave the fingertips uncovered so that you can see if they keep a good color.
However, traditional bone-setters in China and Latin America use a short cast on a simple break of the arm saying that a little movement of the bone-ends speeds healing. Recent scientific studies have proven this to be true.
A temporary leg or arm splint can be made of cardboard, folded paper, or the thick curved stem of the dried banana leaf, or palm leaf.
CAUTION: Even if the cast is not very tight when you put it on, the broken limb may swell up later. If the person complains that the cast is too tight, or if his fingers or toes become cold, white, or blue, take the cast off and put on a new, looser one. Never put on a cast over a cut or a wound.