Entrapment of middle cluneal nerves as an unknown cause of low back pain

Figure 2 Schematic illustration of typical running courses and entrapment of superior and middle cluneal nerves. Multiple branches of the superior cluneal nerve may be entrapped where they pierce the thoracolumbar fascia over the iliac crest. Middle cluneal nerve may be entrapped where this nerve pass under or through the long posterior sacroiliac ligament.