If I lift a leg in Bridge, it's all hammies. What's the cue to activate the glutes??? (Also, unrelated but important - press the back of your head into the mat to maintain the cervical curve.)
I haven't figured out how to completely take the wrist out of side plank, but you are activating your whole hand, yes? Doing it on the elbow feels just kind of ... strange, to me. Unlike prone plank, which is actually tougher on the core when I do it on my elbows.
Advanced class: prone plank bird-dog, then take the lifted arm and leg to 90° with the spine without tilting hips or shoulders. 
I assumed the OP meant side plank on knees by "half side plank." Note that you can do T-pushups into a half side plank by leaving the top leg extended but bending the supporting bottom knee.
Last edited by OakLeaf; 07-04-2011 at 05:12 PM.
Speed comes from what you put behind you. - Judi Ketteler