The mid-upper arm circumference (sometimes abbreviated as MUAC) is the circumference of the upper arm half way between the olecranon process of the ulna and the acromion process of the scapula. It is measured with a non-stretchable tape measure, and is expressed in centimeters. The mid-upper arm circumference is a recognized and important anthropometric measure in children and in pregnant women to assess their nutritional status. This class represents an Observation Clinical Statement wherein the Arm Circumference has been Evaluated, which can be used in a variety of other models as if it were a datatype.