Girths are circumference measures at standard anatomical sites around the body.
- aim: To measure the circumference of the chest, as a measure of the chest muscles and lung size.
- equipment required: flexible metal tape measure and pen suitable for marking the skin. If a plastic or cloth tape is used, it should be checked regularly against a metal tape as they may stretch over time.
- procedure: This measure is taken at the level of the middle of the sternum (breast-bone), with the tape passing under the arms. After the tape is in position, the arms should be relaxed by the side, and the measurement taken at the end of a normal expiration. When recording, you need to make sure the tape is not too tight or too loose, is lying flat on the skin, and is horizontal, particularly around the back.
- reliability: Factors that may affect reliability include changes to the testing personnel, constant and even tension on the tape, and correct landmarking (finding the correct anatomical site for measurement).
- advantages: low costs involved in the testing procedure.
- comments: Clothing over the site should be removed if possible to make sure measuring tape is positioned correctly and that the correct circumference is determined. Girth measurements combined with skinfold measurements can give a clearer picture of changes in tissue composition and distribution of muscle and fat. For this girth measurement, due to the location of the measure, care should be taken to maintain personal privacy of the subject, and sometimes it is appropriate to measure over clothing. If so, this should be recorded with the results.