Anthropometry
Anthropometry provides the data used in the indirect appraisal of
body composition. Girths and skin folds can be entered into a number of
equations to estimate the body density, total body fat and the overlying
subcutaneous fat. Moreover, trunk and limb girths provide estimates of
relative muscle mass.
Assessment and monitoring of growth:
Growth in stature and weight are frequently used as markers of health,
nutritional status and developmental progress. Both absolute and
proportional changes in specific body measures may influence strength,
movement mechanics and physiological parameters in addition to the effects
of training or detraining.
The anthropometrical techniques of proportionality assessment can be
applied to the identification of the common physical characteristics of the
athletes within any given sport. Within the collection of sufficient data,
anthropometrical prototypes for a certain sport can be created. Such
prototypes assist in talent identification, training protocol and equipment
design.
Advantage of anthropometrical measurement:
- It is non- invasive.
- It is relatively easy to carry out with a modest amount of training.
- It is possible to become skilled at acquiring reliable measures.
- Most techniques utilize inexpensive equipment that is generally portable.
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Growth characteristics related to anthropometry:
Growth is a major, highly variable aspect of infancy, childhood and
adolescence. Somatic growth is more than the regular increase of tissue mass
in that it includes dramatic alterations in size and proportion. The physique
changes that accompany growth may affect the skill, exercise tolerance and
injury potential of an individual overtone. These changes can have a
profound influence on the mechanics of movement and the physiological
capacities of the growing organism. One must consider the individual’s
potentials and variations.
Heights and weights are available on specific tables of:
- Height for age.
- Weight for age.
- Weight for height.
Measuring stature:
The recommended method for measuring the stature is to position the
subject barefoot on a level directly against a vertical wall or door. The
subject stands erect with heels and toes together and the arms hanging by the
sides. The measurement is taken as “the maximum distance from the floor to
the vertex of the head”, which is from the floor to the highest point on the
skull.
To measure the stretch stature, gentle upward traction is applied from
this position. Hair clips and ribbons must be removed before the stature is
measured. A pencil mark is made on the level of the headboard. The subject
then stands away from the wall and the vertical distance from the floor to the
pencil mark is measured by a measuring tape.
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Measuring sitting height:
“It is the distance from vertex to the surface on which the erect
subject is seated”. There is no consensus as to whether the feet should hang
freely or be supported. However, in either instance thighs should rest on a
horizontal position, with knees flexed over the edge of the sitting surface.
The subject is directed to sit up straight. Care must be taken to ensure that
the subject does not reposition or push upwards with hands or legs.
Measurement is taken from posterior of the patient. “The sub-ischial height
(the length of the lower limbs) is derived by subtracting sitting height from
stature height”.
Measuring limb lengths:
Length of limb segments can be measured either directly between two
skeletal landmarks or as vertical distance between a constant flat surface (as
the floor) and a skeletal landmark. This latter is preferred as projected
lengths, which through subtraction gives a number of derived segment
lengths (e.g. trochanteric height minus total tibial height gives an estimate of
the length of the femur or thigh; although not accurate).
The use of tape measurement is the most valid tool for measuring limb
length (long measurement). Upper limb length discrepancy affects the
cosmetic appearance, while lower limb length discrepancy affects both
cosmetic appearance and function. Inequality of lower limb length will:
* Affect gait pattern (function).
* Create degenerative changes in weight bearing joints.
* Cause deformities, which may be non-structural at first, then become
structural. Unilateral shortening of lower limb leads to pelvic tilt, scoliosis,
dropping of shoulder and tilting of head.
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Tape measurement is also used for round measurement or the contour
of the:
- Muscle to detect atrophy or hypertrophy.
- Joint to determine swelling.
- Chest to determine its mobility.
1) Long measurements:
a. Upper limb length:
* Whole upper limb length:
Measurement is taken from most superior lateral point of acromion
process (acromial landmark) to the lower and lateral border of styloid
process of radius (radial landmark). The arm is positioned in the anatomical
position, relaxed at the side of the subject.
* Segmental measurement:
- Upper arm length: With arm flexed at 90º, so that ulnar surface of forearm
and hand are horizontal and palms facing medially with fingers extended,
measurement is taken from acromial landmark to the posterior surface of
olecranon process of ulna.
- Forearm length: It is the distance from the head of radius (upper radial
landmark) to the most distal point of the styloid process of radius (or
styloin).
- Hand length: With hand extended and the palm rested in the direction of
the longitudinal axis of forearm, measurement is taken from styloid process
at base of thumb to the tip of middle finger.
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b. Lower limb length:
* Whole lower limb length:
To determine true leg length, first place the patient's legs in precisely
comparable positions and measure the distance from the anterior superior
iliac spines (ASIS) to the medial malleoli of the ankles (from one fixed bony
point to another). Begin measurement at the slight concavity just below the
anterior superior iliac spine, as the tape measure may slide if pressed directly
onto the spine. If there is tilting of pelvis. Measurement will be taken from
the umbilicus to the medial or lateral malleolus. If there is shifted umbilicus,
measurement is then taken from xyphoid process to the medial or lateral
malleolus. Apparent shortening (due to pelvic tilt) should be differentiated
from true shortening (bony).
* Segmental measurement:
If during inspection, one of the patient's legs appears shorter than the
other, the following procedures will assist in determining whether the
discrepancy is true or only apparent.
- True leg length discrepancy:
Unequal distances between these fixed points verify that one lower
extremity is shorter than the other. To determine in short order where the
discrepancy lies (whether in the tibia or in the femur), ask the patient to lie
supine, with his knees flexed to 90° and his feet flat on the table. If one knee
appears higher than the other, the tibia of that extremity is longer; while if
one knee projects furthers anteriorly than the other, the femur of that
extremity is longer. A true shortening may be due to poliomyelitis or a
fracture that crossed the epiphyseal plate during childhood.
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- Apparent leg length discrepancy:
Before testing for apparent leg length discrepancy, no true leg length
discrepancy should be confirmed (no true bony inequality). Apparent
shortening may arise from pelvic obliquity, hip adduction or flexion
deformity. During inspection, pelvic obliquity manifests itself as uneven
ASIS or PSIS while the patient is standing. While the patient is in supine
with his legs in the neutral position, measurement is taken from the
umbilicus (or xiphi-sternal juncture) to the medial malleolus (from a nonfixed point to a fixed bony point). Unequal distances signify an apparent leg
length discrepancy, if the true leg length measurements are equal.
If there is an unequal limb length, the physical therapist has to
determine where the difference is via measuring from the anterior superior
iliac spine to the greater trochanter of femur, then:
.. From the greater trochanter of femur to the lateral articulation of the knee
joint (shortening of femur).
.. From the lateral articulation of knee joint to the medial malleolus
(shortening of tibia).
* Quick test for measuring lower limb length:
From crook lying position, shortening or lengthening of femur can be
detected via determining the height of both knee joints. Placing the two
anterior superior iliac spines at the same level shows shortening or
lengthening of the femur or tibia:
- From the lateral view: A forward projection of knee denotes shortened
tibia and lengthened femur.
- From the anterior view: An upward projection of knee denotes shortened
femur and lengthened tibia.
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* Other tibial length measurements:
- From the prone lying position with the knees flexed to 90º, relative heights
are determined from the medial articulation of the knee joint to the most
distal border of the medial malleolus (legs must be perpendicular to the
plinth).
- The subject is seated with the tested leg resting on opposite knee, so that
the medial aspect of tibia faces upwards. With an anthropometer,
measurement is taken from medial articulation of the knee joint to the
medial malleolus.
* Foot length:
It is the distance between the most posterior part (center) of the heel to
the most anterior part of the longest toe (2nd toe).
2) Round (girth or circumference) measurement:
This length is looped around the part to be measured and held so that
the printed notches on the scale are next to each other (the stub end is pulled
superior to the easing end). As the tension applied to the tape varies, skin
surfaces should not be compressed or an observable space between the skin
and the tape left. Tapes with spring easing are not recommended.
Measurements should be recorded to the nearest 0.1 cm.
a. Head girth:
It is the maximum circumference of the head when the tape is located
immediately superior to the eyebrows and positioned at the back of the head,
so that the maximum parameter is measured.
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b. Neck girth:
The tape is located perpendicular to the long axis of the neck, slightly
superior to the larynx.
c. Upper limb girth:
* Mid-arm girth:
It is also known as arm circumference, upper arm circumference,
biceps circumference or relaxed arm girth. The tape is applied around the
mid-upper arm.
* Forearm girth:
This measurement is the maximal girth of the forearm. It is taken
around the upper third of forearm.
* Wrist girth:
It is the perimeter of the wrist taken distal to the styloid process of the
radius and ulna.
d. Trunk girth:
* Chest girth:
The chest should be bare and the subject stands in a natural erect
posture. Measurements are taken from under the axilla and around the chest,
passing by the xyphoid process:
- Just below the axillary fold.
- At the level of the nipple.
- At xyphoid process.
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* Waist girth:
It is measured at the narrowest part of the torso. The subject should be
standing comfortably erect with hands by the side, neither intentionally
contracting abdominal muscles nor breath-holding. The tape is placed
around torso, so that it is snug but not compressing the skin and the
underlying tissues. The measurements should be taken halfway between the
ribs (12th rib) and the iliac crest.
* Abdominal circumference:
This measurement is sometimes confused with the waist girth. It is the
perimeter distance around the torso at the level of the umbilicus.
* Gluteal girth:
It is also known as the buttocks or hip circumference. This is the
perimeter at the level of the greatest posterior protuberance of the gluteals.
The subject stands erect with minimal clothing, with the feet together and no
intentional contraction of the gluteal muscles. The tape is placed
compressing any overlying clothing but not the soft tissues.
e. Lower limb girth:
* Thigh girth:
It is the circumference of the thigh, which is measured when the
subject stands erect with the legs slightly parted and his weight distributed
equally on both feet. The tape is looped around the lower leg.
- Proximal or upper thigh girth: About 1 cm below the gluteal fold,
horizontal to the long axis of femur.
- Mid-thigh: It is the mid-distance between the inguinal crease and the
proximal border of patella.
- Distal thigh: From just proximal to femoral epicondyles.
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* Knee girth:
It is taken around the knee at the level of mid-patella (for joint
swelling) and 5 cm above the upper border of patella and 5 cm below the
level of patella (for muscle wasting).
* Calf girth:
It is the maximum circumference of the calf, when the subject is
positioned as for the thigh circumference. Measurements are taken around
the bulky area of the calf (two bellies of the gastrocnemius muscles).
* Ankle girth:
It is the minimum circumference of the lower leg, just proximal to the
malleoli.
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