Anthropometry is concerned with the measurement of the human body and its different parts. In physical anthropology, accurate measurement of body dimensions is essential for studying human growth, development, biological variation, body proportions, sexual dimorphism, population differences and nutritional status. Among the most commonly used anthropometric instruments are the anthropometer, spreading calipers and sliding calipers. These instruments differ in their construction, range of measurement and the type of body dimension for which they are used. An anthropometer is a long, graduated measuring instrument used primarily for taking measurements of the vertical dimensions of the human body. It generally consists of a metal rod or series of rods that can be joined together, with a graduated scale and one or two movable branches. The instrument is usually capable of measuring large dimensions, such as standing height, sitting height and other vertical distances between anatomical landmarks. The anthropometer is designed to permit measurements while the subject is standing or sitting in a standardized anatomical position. The anthropometer may be regarded as a specialized anthropometric rod. It is generally divided into sections to make it convenient for transportation and storage. The graduated rod has a movable crosspiece or sliding arm that can be positioned at the required anatomical landmark. In taking standing height, for example, the subject stands erect on a level surface, with the body appropriately positioned according to the prescribed anthropometric technique. The movable headpiece of the anthropometer is brought into contact with the highest point of the head, usually the vertex, while the vertical rod remains aligned with the body. The reading on the scale provides the stature of the individual. Anthropometers are also used for measuring sitting height. In this case, the individual sits on a standardized seat or platform, and the distance from the sitting surface to the vertex is measured. Other measurements, such as acromial height, elbow height, iliac height and other vertical dimensions, may also be obtained with appropriate positioning. Such measurements are particularly useful in studying body proportions and growth patterns. In anthropological research, the anthropometer is valuable because it permits standardized measurements that can be compared between individuals, age groups, sexes and populations. Measurements obtained through an anthropometer are commonly expressed in millimetres or centimetres. Since small errors can influence anthropological comparisons, the instrument must be properly calibrated and held