Together with her friend Leila Stuart, Donna Farhi, a seasoned and much-sought-after yoga practitioner and teacher, discloses the secret of the psoas, one of the most unknown and yet important muscles of our body. Forget about six-packs and pecs and learn how to feel this muscle, which plays a crucial role in the right balance of the pelvis and the spine over the feet, a healthy breathing pattern and a good heart condition.