NCIt definition : One of the four muscles comprising the rotator cuff that is triangular in shape and
extends from the infraspinatus fossa of the scapula to the greater tubercle of the
humerus. The infraspinatus muscle extends and rotates the arm laterally.;
Alternative definition : CDISC: A muscle of the rotator cuff, in general extending from the infraspinatus fossa
of the scapula to the greater tubercle of the humerus; primary function is to extend
and rotate the arm laterally.;