Before we discuss problems regarding hip flexors muscles, we should be aware about type of pain you may suffer in case of hip flexor problem. The discomfort and aching feeling can be felt in your upper groin region, an area at the end of your thighs, where it joins with pelvis. Hip flexors are strong muscles usually they can bear any pressure and shock but when a person specially athletes, sprint or kick by putting a lot of stress on the hip joint, that can sometimes lead to mild to severe (emergency case) hip flexor pain. Also there can be many reasons behind this, like disease, chronic pain, improper diet etc.