MANUAL PHYSIOLOGY PRACTICAL - Repository:The Medical ...

FM/UOJ
Measurement of the body surface area
The surface area has been found to correlate well with many physiological parameters
such as cardiac output and metabolic rate. In common practice these parameters are expressed
as per unit surface area.
Method:
Direct measurement of surface area is very difficult and time consuming and hence
not suitable for routine measurement. This can be determined indirectly from a nomogram
using height and weight.
Exercise:
Determine the surface area.
Measurement of Body Fat.
Fat is found in the body in two main forms: structural fat and stored fat. Structural fat
is relatively small amount and is in proportion to the mass of the tissues. Stored fat is found
in adipose tissue which is seen in specific areas. The amount of stored fat differs among
individuals.
The best method to measure the body fat accurately is to analyze the body chemically.
Since this method is not possible in live animals, indirect methods are employed.
Measurements based on body density, body water, or body potassium are laborious and
usually applied for measurements on small number of subjects for research purposes. An easy
method which is accurate enough for routine measurement is to predict the fat content from
skin-fold thickness.
Instrument:
Harpenden skin-fold calipers.
Method:
The subject sits on a stool comfortably. At the sites of measurement, skin-fold is
pinched up firmly between the thumb and forefinger and pulled away slightly from the
underlying tissue before applying the calipers. The calipers are applied so that the foot plate
is vertical to the surface. The calipers exert constant pressure at varying opening of the jaws.
The width of the opening is read off a scale incorporated in the apparatus. The reading is
taken when the needle in the scale stabilizes soon after the application. All measurements are
taken on the right side of the body. At least four measurements are made in each standard site
and the mean is calculated.
The standard sites for measurements are:
Biceps: Over the mid-point of the muscle belly with the arm resting supinated on the
subject’s thigh.
Triceps: Over the mid-point of the muscle belly, mid-way between the olecranon and
the tip of the acromian with the upper arm hanging vertically.
Subscapular: Just below the tip of the inferior angle of the scapula, the arm hanging
vertically, at an angle of about 45° to the vertical.
Suprailiac: Just above the iliac crest in the mid-axillary line.
Introductory
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