br br Dr. Guevara br 678-223-3900 br br If you sit at a desk job for 8 hours a day and don't take br many breaks, you may be causing harm to your lower back. br One of the muscles which is affected by chronic sitting is br the Illiopsoas muscle or Psoas for short. br br The Psoas muscle attaches to the lumbar vertebrae and the br femur (thigh bone) and its main function is hip flexion. When br you are seated, your hip is flexed (your thighs are in a horizontal br position), which means the psoas is in a contracted state. br Over time, a contracted psoas muscle becomes tight and it can br cause the low back curve to increase causing lower back pain. br br For more informative health videos like this one, please visit us br and Like us on Facebook.