The anterior superior iliac spine, which develops from an anterior apophysis of the iliac crest, is the site of origin of the sartorius muscle and part of the tensor fasciae latae.bstract. Avulsion fractures of the anterior superior iliac spine are rare. This injury is usually seen in adolescents, as an avulsion fracture of the apophyses, a result of sudden vigorous contraction or repetitive contraction of the sartorius and tensor fasciae latae muscles.