AnthropometryCHAPTER 1

Anthropometry is the measurement of certain parameters of the human body. It is used not only to assess nutritional status, but to study the growth and development in young children and adults. Growth is a measure of physical maturation, signifies an increase in size of the body and its various organs. Thus, it can be measured in terms of centimeters and kilograms. Growth and development are the most distinctive attributes of children, which distinguish them from adults. The anatomical characteristics and functional maturity of organs at different ages affect the incidence and manifestations of diseases in children; childhood disorders can profoundly and adversely affect the growth and development of children. Protein-energy malnutrition (PEM) is the core health problem in children, which makes them vulnerable to develop a variety of infectious diseases perpetuating a vicious cycle of disease and debility. The main aim is to assess the physical parameters and to identify the deviation in growth and development.

Measurement of weight is the most reliable criterion of assessment of health and nutritional status of children. The weight may be recorded on a beam type weighing scale [Detecto scale (Fig. 1.1) with an accuracy of ± 20 g]. Electronic weighing scales for infants (± 1–5 g) and children (± 10 g) are preferred for their accuracy and convenience.

The bathroom type of scale is very unreliable for children and should not be used. In field conditions, Salter spring machine is quite satisfactory because it is convenient to carry. The machine is hung from a hook or held by an attendant and baby is placed on the sling attached to the bottom hook. The weighing machines should always be cleaned with soap and water.

The three types of weighing machines used commonly are:

Up to 2 years of age, recumbent length is measured with the help of an infantometer, while in older children standing height can be measured by stadiometer.

Infantometer is used to measure the length of infants. It is used for evaluating the growth of low-birth weight (LBW) babies. It is a horizontal board with a fixed head and moving foot end (Fig. 1.6).

Stadiometer is used to measure the height accurately. It is a simple device, which has a fixed wooden or aluminum height scale along with a sliding head platform (Fig. 1.7). The common practice of fixing a height chart on a wall and placing a ruler or a pencil over the head of the child, whose height has to be measured, is inaccurate. It is error prone and has often up to 5 cm difference when measured by different individuals.

Crown-heel length is recorded on infantometer. The infant is placed supine on the infantometer and keep the vertex snugly touching the fixed vertical plank. The legs are fully extended by pressing over the knees and feet are kept vertical at 90°. The movable pedal plank of infantometer is snugly opposed against the soles and length is read. It is also useful to record the length of the baby from crown to rump (gluteal region or ischial tuberosity).

The child should stand with bare feet on a flat floor against a wall with feet parallel and with heels, buttocks, shoulders and occiput touching the wall. The head should be held erect, so that the child looks directly forward with the Frankfurt plane (the line joining floor of external auditory meatus to the lower margin of orbit) and the biauricular plane being horizontal.

The occipitofrontal head circumference (Fig. 1.8) should be measured with a non-stretchable fiberglass tape. The tape should encircle over the most prominent part of occipital and supraorbital frontal areas. Normal head circumference at birth is 35 cm. If the head growth exceeds 1 cm in 2 weeks during the first 3 months, hydrocephalus should be suspected.

The chest circumference is measured by passing the tape around the chest at the level of nipples.

The reading is recorded midway between inspiration and expiration in recumbent position. Do not press the measuring tape on the chest wall; it would compress the soft tissue underneath. The chest circumference (Fig. 1.9) is about 3 cm less than head circumference at birth. The head and chest circumference are almost equal by the age of 1 year.

To measure mid-arm circumference (MAC), place the tape firmly, but without compressing the tissue around the midpoint between the acromion and the olecranon. If the MAC (Fig. 1.10) is less than 12.5 cm, it is suggestive of severe malnutrition, while MAC between 12.5 and 13.5 cm is indicative of moderate malnutrition.

Thickness of subcutaneous fat is measured with Harpenden caliper over the triceps or subscapular region. Hold a fold of skin between thumb and index finger and measure the fat thickness. Normally it is 10 mm or more among healthy children between 1 to 6 years of age.

If it is less than 6 mm, it is indicative of moderate-to-severe degree of malnutrition.

Lower segment is measured from symphysis pubis to heel, whereas upper segment is derived by deducting lower segment from the height (length). At birth the ratio is 1.7:1. With greater increase in length of the legs compared to the trunk, by the age of 10 to 12 years, the ratio becomes approximately 1:1.

Span is the distance between the tips of middle finger when the arms are outstretched. It is equal to height at 10 year. In earlier year, it is 1 to 2 cm less than the height/length.