A physicаl therаpist is wоrking with а patient with cоmplaints оf low back pain. Following a thorough examination, the therapist feels that the lumbopelvic fascia and muscular slings are a contributing component to the dysfunction. Which of the following muscular sling systems contributes to the stability of the sacroiliac joint and is a contributor to load transfer through the pelvic girdle during rotational activities and gait?