Injuries

It's been an accident-prone couple of days in the gym. Tuesday night was a yoga class and biceps / back. Which was fine, until just before I left, when I stumbled into an open footlocker door, which ripped into my tensed calf muscle, sideways. It still hurts, though thankfully, last night it proved no handicap to doing calf presses (new PB, 79kg).
Yoga does seem to leave me feeling relaxed, yet interfere with my balance. I guess they must hit stabiliser muscles in a way that I'm not - yet - used to, so after a decent class they're ready to give up.

Last night was triceps / chest. It started badly - I dropped a 18kg dumbbell while warming up for the bench press, and decided to ditch the exercise rather than risk damaging my shoulder. Must space arm workouts farther apart.
I realised I was probably too knackered for a serious workout, so decided it might be a good idea to experiment - with skullcrushers.
There are two versions of this exercise I've seen - one with a barbell; and one where you dangle a dumbbell vertically over your head, cupping the top plate under your hands, with your thumbs and forefingers circling the grip. The latter is more common, presumably because you can tweak the weight in smaller increments than if you're using a bar, and also because you don't have to worry so much about balance.
It does, however, have a certain disadvantage - namely that it's far too easy to misjudge the movement and smack yourself in the face with the lower plate. Won't be doing that again (hopefully).