Upper Arm

Do you know that Doctors Without Borders volunteers use an arm bands to
measure the circumference of a child's arm to determine the level of
malnourishment. Doctors use data to save lives in refugee camps around
world. This and other valuable health and social information can be found on
the Doctors Without Borders teacher and student resource page.

http://www.doctorswithoutborders.co.nz/education/activities/braceletoflife/i
ndex.html