This is another of the less versatile techniques in the exercise I mostly think of this as a strike - but still, it can be interpreted as several different kinds of striking ideas:
- a simple backfist strike
- an uppercut
- a hammer fist
- I've even seen folks call it a rising block-backfist-uppercut combo.
- a forearm smash...
Additionally, whichever strike you think this is, it can approach the opponent from several different directions - downward or upward into an eye socket...downward as a forearm or hammer onto a collarbone... upward into the chin... sideward into a temple or xygomatic arch...