How to reliably hurt dwarves without killing them?

I've been trying to hurt dwarves, for my healthcare dwarf to practice on, by building a retracting bridge, stationing a squad there, and then retracting the bridge.

If the fall is just 1z, i.e. the bridge is on the level right above the ground, the dwarves just get stunned and not damaged. If the fall is 2z, they die every time.

How can I reliably hurt dwarves without killing them?

Solution 1:

You could try to use a danger room to injure them. It consist of a spike trap triggered by a lever, where your... test subject will stand and be injured.

The last time I did one, I used an actual wooden menacing pike instead of a training spear as the advice in the article, and I noticed that it tends to give your dwarf a nice wound after just a single lever pull.

Solution 2:

Give another dwarf a bad weapon, like a silver sword or an Adamantine hammer, and let him whack away at the trainee. This has the additional benefit of training the attacking dwarf as well. If that's not enough damage to actually hurt the victim, give the trainer weapons made of increasingly better material. See the Dwar Fortress Wiki article on Metal and Weapon quality