What are some orthopedic/neurological tests I could do at home to differentiate between bulging disc, SI injury, and piriformis pain? My wife performed a straight leg test one day after onset of symptoms. It seemed to be negative (initially caused pain in low back but no pain down leg; felt like a very good stretch of the hamstrings) I can not bend forward or backward w/o pain. Side bending in each direction does not exacerbate symptoms, but it ain’t exactly comfortable either. Some minor, intermittent muscle spasm in left buttocks.