A similar thread was posted in "Muscle Gain" not too long ago, but I'd like to open this topic again if I could as I'm pretty sure the increased flexibility answer doesn't apply to me. I've noticed a similar phenomenon, but it's not at all near my knee. It is sharp pain in the lower right abdominal/groin area. I have the flexibility indicated in Scott's video on maximizing your squat (from the original thread's suggestions) and in most cases much more flexibility than shown in the video. I can achieve a deeper squat and a more vertical torso (I do a lot of Oly Lifting). The pain only seems to come when i hit 80% of my 1RM or above and only if I do more than 2 reps at these weights (and only when I am driving up out of the squat). A single squat at above 80% is generally ok. Note the pain is there regardless of whether it's a front or back squat. Since it's a problem that manifests after more than one rep and only above 80%, I was wondering if it's somehow related to fatigue. However, my form is not breaking down in any major noticeable way. Perhaps it's a shift in what musculature is bearing the load/working as I get fatigued (Note wearing a lifting belt doesn't seem to help)? Thoughts?