There are many dimensions to hatha yoga. One fundamental aspect of it is to knead the body. Life is kneading you in so many ways. You can either enjoy it or suffer it. You can either mature and blossom, or get crushed by the process. This is the choice you have.
Hatha yoga is a kind of kneading – not just of the muscle but of every aspect of who you are. What you refer to as karma (means action or the imprint of action which remains within us) is embedded in every cell of the body and in every aspect of your energy. This becomes apparent when, in the same process or activity, the energies of different individuals behave differently, depending on the type of memory their energy system carries. Kneading means trying to make your system so malleable that it has no power to influence you. You are taking charge of your life through the body.
Hatha yoga can be an ultimate path, because body, mind, energies and being are not separate entities. You can approach the same thing from different ends.
One meaning of the word hatha is being adamant. No matter if your body, mind, emotions or your family like it or not, you get up in the morning and do your hatha yoga.
Hatha yoga is not just about bending and twisting the body. Essentially, it is about consciously working towards eliminating all that is compulsive in us – compulsions that we have carried on over millions of years of evolution. What distinguishes human beings and animals, or, in other words, the essence of being human is the possibility to move from compulsiveness to consciousness. Only if you transcend your compulsiveness completely, are you a full-fledged human. Otherwise, you are not a human being, you are a human becoming.