See i. (muscle).
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il·io·cos·ta·lis -käs-'tā-ləs n the lateral division of the sacrospinalis muscle that helps to keep the trunk erect and consists of three parts:
a) ILIOCOSTALIS CERVICIS
b) ILIOCOSTALIS LUMBORUM
c) ILIOCOSTALIS THORACIS
Medical dictionary. 2011.