These include the positioning of the pelvis, the front hip flexors (known as the iliopsoas), the abdominals, and gently stretching and contracting the muscles of the lower back.    From Wordnik.com.  [Sara Avant Stover: Unplug and Recharge: Loving Your Lower Back, Part I (VIDEO)] Reference

It runs ventrally and backward, at first between the psoas major and minor, then crosses the deep face of the tendon of the latter and descends under cover of the sartorious over the terminal part of the iliopsoas.    From Wordnik.com.  [Lameness of the Horse Veterinary Practitioners' Series, No. 1] Reference

The major new muscles used are the hip flexors, or iliopsoas.    From Wordnik.com.  [PezCyclingNews.com] Reference

If it does, the problem could be that your iliopsoas muscles are too tight.    From Wordnik.com.  [WN.com - Articles related to Sonia showcases Haryana's progress] Reference

The main function of this muscular network is to maintain body posture via the abdominal, paraspinal and iliopsoas muscles.    From Wordnik.com. Reference