I suggest you try split squats, possibly with back foot elevated.
This will force the hip flexors to lengthen under load, possibly resetting the gamma loop (an neurophysiological phenomenon that sets muscle tone).
Another way to overcome neurogenic tone is to do some active stretching.
I use both techniques, plus I stretch out (actively) before bed and sleep on my front for an hour (or thereabouts - when my arms go numb, I flip over) as this encourages true plastic deformation and lengthening of the muscle fascia.
You are awesome. Thanks, I will try this tomorrow. So should I stay clear of back and front squats? I know the leg press was pretty painful so I am defiitely going to avoid that. What about lunges?
And I agree with your response about the heavy decline crunches, I actually think doing heavy decline crunches a few weeks ago contributed greatly to my problem. Is there any "safe" ab-work, besides planks? What do you think about deads or rack deads?
Thanks for the kind words!
I find it odd that the leg press would cause you pain, since the hip flexors are never in an extended position during this exercise.
I know that my own leg press issues come from a fixated/malaligned sacroiliac joint. You may want to get this assessed by a competent professional.
The SIJ can refer pain anteriorly and/or posteriorly.
The fact that you think the weighted decline situps may have been the initiator to your injury, may point to SIJ involvment too, since the loads on the spine and SIJs during this exercise can be considerable.
Do any exercise that doesn't cause you pain. When my back plays up, lunges are about the only lower body exercise I can do without pain.