“…While these ligaments are largely responsible for the stability of the pelvic ring, they are also attachment points for multiple inferior trunk and proximal lower limb muscles, such as the gluteus maximus, the erector spinae, and the biceps femoris (Aldabe, Ribeiro, Milosavljevic, & Bussey, 2012). Because of its anatomical structure, the SIJ mainly experiences rotation along its horizontal axis, where nutation is the posterior rotation of the ilium with respect to the sacrum and counternutation is the opposing motion (Al-Khayer & Grevitt, 2007).…”