BASIC ANTHROPOMETRY BASIC ANTHROPOMETRY IN ADULTS AND CHILDREN IN ADULTS AND CHILDREN

Based on Dept of Physiology Protocol by Prof Edith FuetrePower-Point by Drs RM Abraham and Margie MatthewsClinical Skills NRMSM UKZNJuly 2011

Anthropometry: Anthropometry: IntroductionIntroduction A branch of anthropology that involves the quantitative

measurement of the human body.

It is the single most portable, universally applicable, inexpensive and non-invasive technique for assessing the size, proportions and composition of the human body.

Appropriate use and interpretation from infancy to old age is a valuable tool for guiding the health and nutritional status of individuals and populations.

Paediatricians have long used child growth as an important parameter to evaluate the health and well-being of children.

Anthropometric Anthropometric ParametersParametersBasic measurementsHeight (length)Weight (mass)Circumference eg

OFC (infant up to age 2years only)

Skin-fold thicknessDerived

measurements of body composition and interrelationships (e.g BMI, waist-hip ratio)

Some measurements used for nutritional assessment include:

HeightMassBMI Triceps skin-foldWaist, Hip and Mid-

arm circumference (MAC) and derived measurements/ ratios

Height/Stature Measurement Height/Stature Measurement TechniqueTechnique The subject must be barefoot,

wearing as little clothing as possible

The subject stands on a flat surface, at a right angle to the vertical board of the stadiometer

His/her weight is distributed evenly over both feet, with the head positioned in the Frankfurt Horizontal Plane (in this position, the most inferior point on the left orbital margin is at the same horizontal level as the left tragion – the line of vision is approximately horizontal )

The arms hang freely by the sides of the trunk, with palms facing the thighs

The subject places his/her heels together, with both heels touching the base of the vertical board

The medial borders of the feet are at an angle of about 60°

The scapulae and buttocks must also be in contact with the vertical board

The subject must inhale deeply and maintain a fully erect position without altering the load on the heels

The movable head board is brought onto the most superior point on the head with sufficient pressure to compress the hair

The measurement is taken to the nearest 1 mm

Height/Stature Height/Stature MeasurementMeasurement

Mass/Weight Measurement Mass/Weight Measurement TechniqueTechnique Subject must be barefoot

and wear as little clothing as possible.

Subject stands on the platform of the scale with his/her weight distributed evenly over both feet.

The arms hang by the sides of the trunk, with palms facing the thighs .

The subject is instructed to maintain a stable position while the measurement is taken.

The measurement is taken to the nearest 0.1 kg .

Body Mass IndexBody Mass Index

This ratio is expressed in Kg/m2 and provides a rough estimation of the body mass status of the individual in relation to his/her height.

BMI Ranges and Co-BMI Ranges and Co-morbidity Riskmorbidity Risk

  ANTHROPOMETRY  

QUANTIFYING OBESITY WITH BODY MASS INDEX (WEIGHT/HEIGHT²)

BMI (kg/m²) CLASSIFICATION* RISK OF OBESITY COMORBIDITY

     

18.5 - 24.9 Normal range Negligible     

25.0 - 29.9 Overweight Mildly increased     

>30 Obese       

30.0 - 34.9 Class I Moderate 35.0 - 39.9 Class II Severe

> 40.0 Class III Very severe     

* Classification of the World Health Organisation (WHO) and International

Obesity Task Force    

   

Waist-to-Hip Circumference Waist-to-Hip Circumference RatioRatioAn indicator of the

pattern of distribution of subcutaneous adipose tissue.

Distribution of fat is an important indicator of CHD (coronary heart disease)

More fat in the abdominal area - increases risk of CHD.

Men generally have a higher ratio than women

Women 0.85-1.7 (high risk)and <0.85 (Low risk)

Men 0.95-1.9 (high risk) and <0.95 (Low risk)

Waist-to-Hip Circumference Waist-to-Hip Circumference Ratio Measurement Ratio Measurement TechniqueTechnique Waist circumference A good quality non-

stretchable measuring tape should be used.

View the patient from the front.

Locate the narrowest point between ribs and iliac crests.

Ensure that the tape measure is at the same height around the waist.

Measure and state the measurement correctly to the nearest centimetre.

Waist-to-hip Waist-to-hip circumference ratiocircumference ratioHip circumference View the patient from

the front. Locate the greater

trochanter. Hip measurement is

taken at the widest lateral extension of the hips.

Ensure that the tape measure is horizontal.

Measure and state the measurement correctly to the nearest centimetre.

Calculate Waist/Hip Ratio to 2 decimal places.

Measures of body Measures of body compositioncompositionWeight loss, per se, does not provide

the nutritionist with an indication of type of tissue lost (i.e. weight loss due to loss of adipose tissue or loss of muscle tissue).

Measurements of skin-folds, mid-arm circumference and mid-arm muscle circumference therefore provide a more comprehensive picture of body composition/ changes.

Mid-arm circumference Mid-arm circumference (MAC)(MAC)

Locate the midpoint of the arm. Non-dominant arm elbow flexed at

90deg with palm facing upwards                  

Measurer stands behind the subject & locates the lateral tip of the acromion and the most distal point on the olecranon process               

Place a tape measure so that it passes between these 2 landmarks and mark the midpoint            

  Measure the midarm circumference The subject stands erect with arms

hanging freely at the sides and the palms facing the thighs

Place the tape measure perpendicular to the long axis of the arm at the marked midpoint & measure the circumference to the nearest mm. (e.g. 18.1 cm)                 

Provide the actual MAC in cm.

Skin-fold measurementsSkin-fold measurements Approximately half of the

total amount of fat tissue in the human body is located below the surface of the skin.

This makes it possible to predict total body fat from skin-fold thicknesses with a relative high degree of accuracy using a simple two-compartmental method.

This accuracy is confirmed by CT scan as well as ultrasonic and radiographic techniques used to measure subcut.fat.

In general, when measuring skin-fold thickness,

The assessor, using the forefinger and the thumb, grasps and lifts the subcut. tissue and skin from the underlying muscle.

Places the pincers of the skin-fold caliper, applying a constant pressure, 2cm below the fingers at a depth of 1cm.

Holds this position for 3-4seconds.

Takes three measurements for accuracy.

Provides the actual skin-fold thickness in mm.

Triceps skin-fold (TSF)Triceps skin-fold (TSF)A measure of subcutaneous fat

stores taken at the midpoint of the posterior aspect of the humerus.

Correlates closely with percentage of body fat and with total body fat.

Triceps skin-fold thickness varies between

6 -12mm in lean individuals and between

40 - 50mm in obese individuals.

Triceps skin-fold Triceps skin-fold measurement techniquemeasurement technique Subject should be standing with arms

hanging loosely at the sides. Assessor to be positioned behind the

subject. To locate the triceps skin-fold site,

locate the site previously marked for the midarm circumference measurement (MAC).

The triceps skin-fold site is on the posterior surface of the arm, midway between the shoulder and the elbow.

Using the forefinger and the thumb the assessor grasps and lifts the subcut. tissue and skin 2cm above TSF site.

Place the pincers of the skin-fold caliper at the TSF point at a depth of 1cm.

Hold this position for 3-4seconds. Take three measurements for accuracy. Provide the actual skin-fold thickness in

mm.

Mid-arm muscle Mid-arm muscle circumference (MAMC)circumference (MAMC)

TSF is preferably used in conjunction with subscapular, biceps and supra-iliac skin-fold measurements to determine actual percentage body fat from set equations or in conjunction with MAC to determine mid-arm muscle circumference.

MAMC provides an index of muscle mass.

MAMC (cm)= MAC (cm) - [3.14 x TSF (cm)]

Standard adult values(helps interpret the above

body compositional measurements)

Triceps skin-fold (mm)Male 12.5Female 16.5

Mid-arm circumference (cm)

Male 29.3Female 28.5

Mid-arm muscle circumf. (cm)

Male 25.3Female 23.2

Other skin-folds measuredOther skin-folds measuredBesides the most commonly used

triceps skin-fold, other commonly measured skin-folds include the following:

Biceps skin-foldSubscapular skin-foldSupra-iliac skin-fold

Biceps skin-fold Biceps skin-fold measurement techniquemeasurement technique

Locate the biceps skin-fold site: The assessor positioned in front of the

subject. Subject should be standing erect with

arms hanging loosely at their sides.           

To locate the biceps skin-fold site, locate the level previously marked for the mid-arm circumference measurement.                

The biceps skin-fold site is on the anterior surface of the arm, midway between the shoulder and elbow.                  

Measuring skin-fold thickness Using forefinger and thumb, grasp and

lift the subcutaneous tissue and skin 2cm above the midpoint .                

Place the pincers of the skin-fold caliper at the midpoint at a depth of 1cm.                  

Hold this position for 3 to 4 seconds.                

Take three measurements for accuracy (answer in mm).                  

Provide the actual skin-fold thickness in mm.                  

Subscapular skin-fold Subscapular skin-fold measurement techniquemeasurement technique

The assessor is positioned behind the subject.

The subscapular skin-fold site is located 1cm below the inferior angle of the scapula.

The assessor grasps and lifts the subcut. tissue and skin at a downward angle of approximately 45 towards the lateral aspect of the body.

Place the pincers of the skin-fold caliper at a depth of 1cm.                  

Hold this position for 3 to 4 seconds.                

Take three measurements for accuracy (answer in mm).                  

Provide the actual skin-fold thickness in mm.

Supra-iliac skin-fold Supra-iliac skin-fold measurement techniquemeasurement technique

The assessor to be positioned in front of the subject.

The supra-iliac site is located 5cm above the anterior superior iliac spine.

The assessor grasps and lifts the subcut. tissue and skin at a downward angle of 45 towards the medial aspect of the body.

Place the pincers of the skin-fold caliper at a depth of 1cm.                  

Hold this position for 3 to 4 seconds.                

Take three measurements for accuracy (answer in mm).                  

Provide the actual skin-fold thickness in mm.        

Child AnthropometryChild AnthropometryBasic measurements in children include:

Weight Clothing to be removed. Baby weighed on clean calibrated

scale. The measurement is taken to at least

2 decimal places for accuracy in kg.

Height (Length) An infantometer is used. The baby is placed supine with head

against appropriate surface. The baby is held in a fully extended

position with the heels at a 90º position.

The measurement is taken to the nearest 0.1cm.

OFC (Occipitofrontal circumference) The OFC of the baby is measured to

the nearest 0.1cm with a firm tape measure placed appropriately.

Road-to-Health ChartRoad-to-Health ChartA simple, cheap, practical and

convenient method of monitoring child health.

Growth monitoring is the most useful tool available in child health as it assists with early identification of nutritional problems, disease, and developmental problems.

The most sensitive indicator of a child's growth is weight.

Growth chartGrowth chart

Graph records child's growth progress.

1)Vertical axis is the weight axis (represented in kgs both on the right and left margin of each year starting from 0)

2)Horizontal axis is the age axis-one space per month – goes up to 5 years

Standards and reference Standards and reference curves on the Road-to-curves on the Road-to-Health ChartHealth Chart If the weights of 100 healthy children according to age groups

are plotted on a graph, the average weight is represented by the 50th centile reference curve (bold curve on the graph)

The weights will be scattered around this 50th centile with more weights near to it rather than far above or below it.

To obtain a normal range of weights, an upper and lower reference curve is also plotted, referred to as the 97th and 3rd centile reference curves. This means that the weights of 3 healthy children will fall above the 97th centile and the weights of 3 healthy children will fall below the 3rd centile.

In statistics, a centile (or percentile) is the value of a variable below which a certain percent of observations fall. For example, the 50th percentile is the value (or score) below which 50 percent of the observations fall.

It is extremely important to plot the weight in a serial fashion in order to evaluate the growth trend. (term “failure to thrive”)

Note 60% of standard weight or 50th centile

Nutritional assessmentNutritional assessment Malnutrition may be acute/ chronic or a

combination, with the acute form manifesting with weight loss/ failure to gain weight, and the chronic form resulting in stunting (child is shorter than normal).

Normal Wasted Stunted

Weight/age % 100 70 70

Weight/height % 100 70 100

Height/age % 100 100 84

Nutritional assessmentNutritional assessment

Thus, the various anthropometric indices in children are used to measure the presence and severity of the various forms of malnutrition

1) Weight-for-height (decreased) indicates acute malnutrition (wasting)

2) Height-for-age (decreased) indicates chronic malnutrition (stunting)

3) Weight-for-age (decreased) in any protein-energy malnutrition (underweight)

Types of MalnutritionTypes of MalnutritionMalnutrition is a group of conditions in

children and adults generally related to poor quality or insufficient quantity of nutrient intake, absorption, or utilization

There are two major types of malnutrition:Protein-energy malnutrition - resulting

from deficiencies in any or all nutrientsMicronutrient deficiency diseases -

resulting from a deficiency of specific micronutrients (eg iron, specific vitamins)

Types of Protein-Energy Types of Protein-Energy Malnutrition (PEM) in InfantsMalnutrition (PEM) in Infants

Condition 60-80% of standard weight

< 60% of standard weight

No oedema Underweight Marasmus

Oedema Kwashiorkor Marasmic kwashiorkor

Standard refers to the 50th percentile or median

KwashiorkorKwashiorkor

- 60-80% of expected weight

- Sparse, depigmented hair

- Oedema- Skin rash- Distended abdomen and

enlarged liver- Diarrhoea

MarasmusMarasmus

- Weight<60% mean for age

- Wasted, wizened appearance

ReferencesReferencesBasic anthropometric

measurements in adults protocol (Dept of Physiology)

WHO: Global database on body mass index (Davidson 2006)

Illustrated Textbook of Paediatrics Lissauer and Clayden

SA Family Practice Manual Bob Mash and Julia Blitz-Lindeque