Iliacus Muscle Syndrome can cause weakness in the quadriceps muscle, and changes in sensation to the medial thigh, leg, and foot. Compression of the femoral nerve by the Iliacus Muscle causes this entrapment syndrome. The femoral nerve passes between the iliacus and psoas muscle, and then enters the leg with the combined iliospoas tendon under the inguinal ligament. This narrow area is a site of entrapment. The femoral nerve innervates the upper leg and mostly controls muscle strength, entrapment of the femoral nerve can lead to muscle weakness in these muscles.
Surgical procedures within the pelvis are the most common cause of femoral nerve compression. The surgeries may require stretching this area to obtain better access to the pelvic organs, inadvertently compressing the nerve.
Muscle spasms of the iliacus and psoas muscle are also common causes of constriction of the femoral nerve. The iliacus and psoas muscle become tight and in spasm with prolonged sitting or immobilization. This eventually leads to the muscle entrapping the nerve.
Additional signs of muscle weakness include difficulty standing from a seated position or extending their knee. The quadriceps muscle may decrease in size. Stretching the hip into extension increases the pain. Flexing the hip forward may relieve the pain. In advanced cases the patellar reflex may diminish or disappear.
Conservative treatment involves strengthening the muscle weakness and increasing muscular stability. When Iliacus Muscle Syndrome is caused by spasm of the iliacus and psoas muscle, treatment is aimed at decreasing the muscle spasms. Stretching and decreasing the muscle tension through massage therapy is also beneficial. Iliacus Muscle Syndrome which is not caused by surgery responds very well to conservative treatment.