Both the forward flexion of the lumbar spine when you bend over to put on your socks and the sneeze (similar to a valsalva's maneuover) suggest a disc problem which could refer pain to the areas you described. The most common area is the lower 2 discs, however, if you are getting pain radiating around to the front of you I would be suspect that there could be something else going on higher up possibly L1/2 levels. Have you had any testicular pain or bowel/bladder disturbances?