Did backhandspring twisted arm and felt elbow pop, sharp pains a lot, behind elbow...?

Elbow pain: Are you able to fully bend & straighten elbow joint? Can you turn hand palm down & back? May have dislocated elbow or broken radius/ulna/humerus or merely strained ligaments. Best to have joint examined & x-rayed (emergencyroom) so appropriate treatment can be given. Motrin/aleve/etc (if you can take them) may take edge off pain. Ice for swelling. Sling or splint for support until seen by doc.

Get it checked: You need to have this looked at. Could be a "sprain" of your elbow ligaments, but also could be a torn ligament or even a fracture. Recommend seeing an orthopaedic physician familiar with elbow injuries.

Get an evaluation: More than likely you suffered from a hyperextension injury to the elbow and may have even subluxated it. I would highly recommend an evaluation by a specialist who will perform a general elbow exam and obtain appropriate x-rays and/or MRI to rule out any ligament or bony damage. Elbow instability can become a disabling chronic problem if not diagnosed and treated early.

See a physician: You should not have sharp pain in your elbow. You should see an orthopedists or a sports medicine specialist for further investigation.