Eighty-five percent of all adults will experience low-back pain during their lifetime. Limitations and dysfunctions of the hip joint result in a transfer of responsibility to the lumbar spine, which is not designed to work the way the hips do. We will take a look at the functional interdependency of the hips and the lumbar spine, and delve into the unique mechanical properties of the iliopsoas muscle and it’s affect on upper-body and lower-body motion.