It could be many things. Form and/or ligament strength is probably your best bet, though. Muscles can gain in strength faster than connective tissues, thus causing an imbalance. The popping noise could just be a ligament snapping over bone if it's not strong enough to support the load you're lifting. Of course, that could also apply to poor form. We can always take a look at your form in about 3.5 weeks when you arrive in Little Rock.
