Backhand is the stunningability for the Attack skill, unlocked at level 10 Attack. It is available for all melee combat and deals 20-100% ability damage. This ability shares its countdown timer with Kick, Impact, Shock, Binding Shot and Demoralise.
Backhand is identical to Kick, except that Kick will move small targets back a square as well. As such, there is no reason to use Backhand over Kick, unless one wants to avoid movement or does not have level 3 Strength.
The stun from backhand is not long enough to gain the effect from Slice or Punish, as the stun only lasts for 1.2 seconds and abilities may only be activated every 1.8 seconds.