During early swing phase the iliopsoas aids in flexion of the hip. In running leaning back while running downhill will aggravate iliopsoas tendonitis, and it will be difficult to take a full stride and also difficult to run uphill. Occasionally this is correleated with lower back pain. There is also pain in this area when walking up and down stairs. Having the patient lie down, flex the knee to 10 - 20 degrees and then have the patient attempt to lift the leg against resistance.
Pain occurs with iliopsoas tendonitis.
The motion of hip flexion will also be weak and may cause pain even without resistance in severe cases. Tenderness may be present along the course of the tendon and at the insertion. Rest is usually recommended . A two to three week break from the sports and activities that cause pain can be very helpful. Relative rest, meaning less intense workouts, and fewer miles is also helpful, and should be used during your return to activity.