There is nothing that is parallel in human body. If we’ll look at the forearm, we’ll see it becomes wider from the elbow, and becomes more narrow by the wrist. Hand continues these principal, from wrist it becomes wider, and becomes more narrow by the tips of the fingers. It can be compared with a tree. The branches of the tree are wide at the trunk, and the more we go the more narrow they become.
Asymmetry vs symmetry
When creating a character you must not put it in a static pose, where positions of its hands and legs are duplicating each other, like in the mirror. When setting a character, you should rely it on its leg, to feel the weight of the character. Same with the position of the hands. If both hands are placed at the waistband, then they must not reflect each other.