CALIPER
Prepared by- Dr Meena Khot
Second year PG Scholar
Kriya Sharir Department
Guided byDr. Vaidehi raole
Dr. Sunil nikhate
Dr. Neha gadgil
Dr. Mariya husain
Dr. Narendra yadgnik
Introduction
A caliper or a pair of caliper is a measurement
tool that is used to measure the distance
between two opposite sides of an object. Caliper
usage is very wide, from medicine , science,
mechanical engineering, woodworking
metalworking to forestry.
Types of caliperThere are a few types of a calipers.
• Vernier caliper
• Harpenden caliper
• Inside caliper
• Outside caliper
• Divider caliper
• Digital caliper
• Oddleg caliper
• Micrometer caliper
Vernier caliper
Principle – To measure length or diameter of an object
accurately up to .0001 mm.
Parts of vernier caliper- vernier caliper consist of
1. Right angled steel plate graduated in millimeters and
marked centimeters.
2. Small vernier scale which slides along the main scale.
3. Jaws to hold object.
4. The vernier scale consist of ‘n’ division on one side of
vernier zero . These ‘n’ division are exactly equivalent
to n-1 division on main scale.
Zero error
When both jaws completely touch each other and ‘0’ of
main scale match with the ‘0’ of the vernier scale. Then
it is said to be ‘ Zero error’
Use of vernier caliper in clinical practiceVernier caliper is used to measure individual finger unit
which is useful for deciding marma areas on the body
and to assess the longevity of the person .
To measure the diameter of finger, the middle phalanx of
middle finger is to be held in the jaws of vernier and
measurement is taken by noticing which division of
vernier scale concedes with the division of main scale.
HERPENDEN CALLIPER
Herpenden caliiper
• The Herpenden skin fold calliper is a precision
instrument designed to be measure skin fold
thickness from which estimates of body fat can be
derived .
• It was designed in 1995
• The harpenden skin fold caliper has been used
worldwide and it the most prestigious caliper
available.
FEATURES
Dial graduation -0.20 mm
Measuring range-0-80 mm
Measuring pressure-10gms/mm(constant over range)
Accuracy- 99.0%
repeatability-0.20 mm
Includes handbook and carrying case
PRINCIPLETo measure skin fold thickness ,then predict body density.
Then the body density is converted to a percent fat using an
approprite population – specific conversion formula.
PROCEDURE
SITES
SITE FOR MALE SUBJECTS
• SITE 1- BICEPS The anterior surface of the biceps midway
between the anterior auxiliary fold and the antecubital fossa.
• SITE 2 TRICEPS A Vertical fold on the posterior midline of
the upper arm, over the triceps muscle, halfway between the
acromion process (bony process on top of the shoulder) and
olecranon process (bony process on elbow). The elbow should
be extended and the arm relaxed.
• SITE 3 -SUBSCAPULAR The fold is taken on the diagonal
line coming from the vertebral border to between 1 and 2 cm
from the inferior angle of the scapulae. (A diagonal fold about 1
to 2 cm below the point of the shoulder blade and 1 - 2 cm
toward the arm.)
• SITE 4- SUPRAILIAC A diagonal fold above the crest of the
ileum at the spot where an imaginary line would come down
from the anterior auxiliary line just above the hip bone and 2 - 3
cm forward.
SITE SYSTEM FOR FEMALE SUBJECTS
• SITE 1
• TRICEPS A Vertical fold on the posterior midline of the upper
arm, over the triceps muscle, halfway between the acromion
process (bony process on the top of the shoulder) and olecranon
process (bony process on elbow). The elbows should be extended
and the arm relaxed.
• SITE 2
• SUPRAILIAC A diagonal fold above the crest of the ilium at the
spot where an imaginary line would come down from the anterior
auxiliary line just above the hip bone and 2 - 3 cm forward).
• SITE 3
• THIGH A vertical fold on the anterior aspect of the thigh,
midway between the hip and knee joints (on the front of the thigh
halfway between the hip joint, where the leg bends when the knee
is lifted, and the middle of the knee cap). The leg should be
straight and relaxed
PROCEDURE
Taking the Skinfold Measurements
1- All measurements should be taken on the right side of the
body with the person standing.
2- Locate the anatomical sites.
3- Grasp a double thickness of skin firmly with the thumb and
one forefinger, pulling the fold slightly away from the
muscular tissue.
4.- The caliper is held perpendicular to the fold. With your
thumb on the serrated portion of the caliper, slide the
caliper open.
5- Place the caliper approximately 1 cm (¼ inch) below the
finger hold. Slowly allow the caliper to close around the
fold. Release the thumb so that full tension is exerted on the
skinfold.
6- Take the reading to the nearest ½ mm. For 1 to 2 seconds
after the thumb has been released.
7- Release the trigger of the calipers so the entire force
of the jaws is on the Skin fold. Do not release the
fingers of the left hand while taking the readings.
8- The dial should be read to the nearest 0.50 mm, 1 to 2
seconds after the grip has been fully released
9- Reopen the caliper to remove and carefully close the
caliper. Do not allow the spring to snap the caliper
closed.
10- Each site is measured three (3) times. The readings
should be taken without delay to avoid excessive
compression of the skin fold. Releasing and refolding
the skin fold is required between readings. The average
of the two (2) closest readings is recorded.
INSTRUCTION
• Measurement should be taken on healthy undamaged,
non infected, dry skin.
• Don’t use caliper on broken/ infected skin.
• Instruct the test person to keep muscles relaxed during the
test.
• Caliper should have constant pressure. Because changes
in pressure can lead the fat to be compress.
• Caliper should not be placed too close or too away from
the body.
• Experience is necessary to grasp the same size skin fold
in the same location.
TUNING FORK
PrincipleTo set tuning fork in vibrations and to place tuning fork
near ear canal and then on mastoid bone and to examine
hearing capacity of a person by comparing air
conduction and bone conduction.
PARTS• It is ‘U’ shaped metallic instrument.
• two parallel limbs.
• One handle- it is lowest part of tuning fork.
• Tuning fork must have frequency of 512
cycles/second.
Use
• It is used to tune musical instrument. E.g rhodes piano.
• In clock and watch-tiny tuning fork. It usually vibrate at
frequency 32,768Hz.
• Medical and scientific use-tuning fork usually C512, are
used by medical practitioners to asses a patients hearing
by Weber’s test, and Rinne’s test respectively.
• C128 are used to examine peripheral nervous system,
bone fracture test, sonopuncture and polarity therapy.
• Radar gun calibration- it is used for measuring the speed
of cars or balls in sports usually calibrated with tuning
fork.