Kidney pain, kidney stones, kidney failure, and advanced kidney infections can cause radiating lower back pain, especially pain that affects the lowest ribs in the back and higher buttock area. Kidney issues can also cause pain in the groin area and difficulty urinating. Groin pain in women, especially pregnant women, is a special concern and the patient should be taken to the ER immediately. If you think a kidney issue is causing your back pain, get to an ER—because once a kidney issue is advanced enough to cause back pain, it is usually quite serious.
You can strain or tear one or more of your hip flexors when you make sudden movements such as changing directions while running or kicking. Sports and athletic activities where this is likely to occur include running, football, soccer, martial arts, dancing, and hockey. In everyday life, you can strain a hip flexor when you slip and fall, for example.