Overview
Uraken - literally means opposite or reverse hand. Like a backhand, it can be delivered with a strong wrist, or with a fast, whipping motion. Although often dismissed as a weak technique, I know of a person who broke someone's sternum with a backfist. The technique is most commonly delivered to the head, butr if the oppoirtunity and your body posittion permitted, it could easily be delivered to the groin or torso.
Striking targets
Temples, side of the jaw, side of the neck, bridge of the nose, sternum, groin, quadricep, bicep
Any pressure points
Used in these katas
Saifa, Seiunchin, Sepai, Kanku Dai
Technique
Bring the tips of your fingers tightly together. Ensure that the thumb is at the same level as the other finger tips as this will add additional tension to your forearm. Bend the wrist as far forwards as it will go.
When striking or blocking, snapping rapidly from a straight wrist to a bent one, is a way of achieving additional power from the technique.
Strengths
A backfist is a very fast technique that can be delivered on the way past an opponent, enabling it to be used in ways that a straight punch cannot. Because of the way that it is delivered, it enables you to attack targets from the sides without repositioning your body.
Weaknesses
The backfist depends very much upon its angle of intersection with the target, and will be unsuitable in many situations. Because it doesn't have your weight behind it, it has no ability to stop a charging opponent, or to push an opponent backwards.