Spider Push-up
Start with locked elbows and protracted shoulders, bring knee up to elbow keeping foot off ground as you descend, return to traditional push-up position as you come up.
Cues:
Stay level and move leg to outside without twisting your body
Lift the leg all the way to the arm - beyond it if you have the flexibility to do so
Switch sides each rep, or complete all of one side first
Scale:
Allow foot to rest on ground as you descend
Rest knee on top of elbow as you descend
Errors:
Twisting body to help lift leg further
Abbreviating ROM