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Skinfold (SKF) measurement is arguably the most ubiquitous method of estimating percent body fat (%BF) because of cost, ease, and feasibility. However, it is unknown how accurately novice exercise science students measure SKF thickness. Thus, the purpose of this study was to determine the validity with which exercise science students in an Exercise Physiology course measured skinfold thickness and estimated percent body fat (%BF) when compared to a skilled technician. Twenty-three novice undergraduate students were afforded both verbal measurement instruction and visual measurement demonstration and, subsequently, assessed SKF thicknesses of a male and female testee. %BF was calculated using measurements obtained by the skilled technician and students. Comparisons were made between measurements taken by the skilled technician and students using error, absolute error, and one sample t-tests. For the female testee, average error ranged from -0.5 mm to -4.8 mm for the 7-sites, 1.7±15.4 mm for the sum of 7-sites, and -3.7±2.6% for %BF. The average absolute error ranged from 1.2 mm to 4.9 mm for the 7-sites, 23.3±12.7 mm for the sum of 7-sites, and 3.9±2.2% for %BF. For the male testee, average error ranged from 0.0 mm to 0.9 mm for the 7-sites, 2.9±8.5 mm for the sum of 7-sites, and 0.5±1.4% for %BF. The average absolute error ranged from 0.6 mm to 1.1 mm for the 7-sites, 4.8±7.5 mm for the sum of 7-sites, and 0.8±1.2% for BF%. The one sample t-tests revealed no significant differences in the sum of 7-sites and %BF for the male model (p>0.05), but significant differences were found for the female model (p<0.05). From a practical perspective, when novice exercise science students were provided both verbal and visual instructions of SKF measurement technique, students were able to accurately assess %BF of a male testee as compared to the skilled technician. With respect to the female testee, however, students underestimated the sum of the 7 SKF sites by ~ 20 mm when compared to the skilled technician. Additional tutelage and practice may be necessary when teaching SKF measurement of females and/or individuals with higher %BF to novice undergraduate exercise science students.
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Original Research
The Validity Of 7-Site Skinfold Measurements Taken By Exercise
Science Students
TIAGO V. BARREIRA†
1
, MATTHEW S. RENFROW‡
2
, WAYLAND TSEH‡
3
, and
MINSOO KANG‡
4
1
Pennington Biomedical Research Center, Baton Rouge, LA, USA;
2
Taylor
University, Upland, IN, USA;
3
University of North Carolina Wilmington,
Wilmington, NC, USA;
4
Middle Tennessee State University, Murfreesboro, TN,
USA
†Denotes graduate student author, ‡Denotes professional author
ABSTRACT
International Journal of Exercise Science 6(1) : 20-28, 2013. Skinfold (SKF)
measurement is arguably the most ubiquitous method of estimating percent body fat (%BF)
because of cost, ease, and feasibility. However, it is unknown how accurately novice exercise
science students measure SKF thickness. Thus, the purpose of this study was to determine the
validity with which exercise science students in an Exercise Physiology course measured skinfold
thickness and estimated percent body fat (%BF) when compared to a skilled technician. Twenty-
three novice undergraduate students were afforded both verbal measurement instruction and
visual measurement demonstration and, subsequently, assessed SKF thicknesses of a male and
female testee. %BF was calculated using measurements obtained by the skilled technician and
students. Comparisons were made between measurements taken by the skilled technician and
students using error, absolute error, and one sample t-tests. For the female testee, average error
ranged from -0.5 mm to -4.8 mm for the 7-sites, 1.7±15.4 mm for the sum of 7-sites, and -3.7±2.6%
for %BF. The average absolute error ranged from 1.2 mm to 4.9 mm for the 7-sites, 23.3±12.7 mm
for the sum of 7-sites, and 3.9±2.2% for %BF. For the male testee, average error ranged from 0.0
mm to 0.9 mm for the 7-sites, 2.9±8.5 mm for the sum of 7-sites, and 0.5±1.4% for %BF. The
average absolute error ranged from 0.6 mm to 1.1 mm for the 7-sites, 4.8±7.5 mm for the sum of 7-
sites, and 0.8±1.2% for BF%. The one sample t-tests revealed no significant differences in the sum
of 7-sites and %BF for the male model (p>0.05), but significant differences were found for the
female model (p<0.05). From a practical perspective, when novice exercise science students were
provided both verbal and visual instructions of SKF measurement technique, students were able
to accurately assess %BF of a male testee as compared to the skilled technician. With respect to
the female testee, however, students underestimated the sum of the 7 SKF sites by ~ 20 mm when
compared to the skilled technician. Additional tutelage and practice may be necessary when
teaching SKF measurement of females and/or individuals with higher %BF to novice
undergraduate exercise science students.
KEY WORDS: Body composition, novice, validity, accuracy
INTRODUCTION
Body composition (BC) is an important
component of health-related physical
fitness. High levels of body fat (BF),
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International Journal of Exercise Science http://www.intjexersci.com
21
specifically abdominal fat, can significantly
increase risk for cardiovascular disease.
The seven-site skinfold (SKF) measurement
technique is arguably the most common
method of BF estimation. This method is
attractive because of its low relative cost
when compared to reference methods such
as hydrodensitometry, air displacement
plethysmography, and dual-energy X-ray
absorptiometry (8). SKF measurement is
quick and less invasive compared to
aforementioned reference methods which
require minimal clothing, complete
exhalation, and/or exposure to X-ray
photon. Moreover, as a field measure, SKF
technique is feasible, reliable, and valid
(14).
Although BF is commonly quantified in
health- and performance-based research,
measurement issues related to BF
assessment have been investigated for
decades (3). The validity of SKF
measurements can be affected by numerous
variables. Measurement technique,
technician experience, hydration, sex, age,
and ethnicity are significant factors when
measuring BC as demonstrated by the
numerous population-specific equations
used to calculate body density and BF (11).
Consequently, measurement technique can
be improved to reduce error. The National
Strength and Conditioning Association
(NSCA) and the American College of Sports
Medicine (ACSM) have set specific
guidelines for the SKF testing procedures
including specific locations of
measurement, number of times each site
should be measured, the acceptable margin
of error between measurements, etc. (1, 2)
Heyward and Wagner (8) suggested that
SKF technicians be meticulous in marking
anatomical landmarks, take a minimum of
two measurements, practice on over 50
clients, and be trained and mentored by
skilled technicians to improve
measurement skills.
Hume and Marfell-Jones (10) investigated
the importance of adherence to protocols by
examining the differences in SKF
measurement with a small change in the
SKF site measurement location. Using the
International Standards for Anthropometric
Assessment (12), two International Society
for the Advancement of Kinanthropometry
(ISAK)-accredited testers measured the
eight defined ISAK sites. Along with each
ISAK-defined site, eight peripheral sites 1
cm away from the defined sites were also
measured (all sites, then, assumed a 3x3
grid with the ISAK-defined site located
centrally in the grid). The results indicated
that 70% of the peripheral site
measurements were statistically different
from the ISAK-defined site measurements
and 39% were considered “non-trivial”
(Effect Sizes > .2). Hume and Marfell-Jones
(7) noted that these results reinforced the
importance of strict adherence to a proper
measurement protocol.
Previous research on SKF measurement has
uncovered many factors of reliability and
validity for this method of BF measurement
(7, 10, 11, 15, 16). However, as validation is
a continual process (18), other validity
issues may still be elucidated. Accurate
SKF measurement technique has been
investigated in testers who were well-
trained (10, 15), but the validity of SKF
measurements taken by novices is
uncertain. Because SKF measurement is
relatively inexpensive and less invasive
than other BF estimation methods (8, 15), it
is commonly taught in universities to
undergraduate students in kinesiology,
VALIDITY OF 7-SITE SKINFOLD MEASUREMENTS
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22
physical education, athletic training, and
Exercise Science courses. This skill of
quantifying %BF via SKF measurement
then is commonly used in fields such as
personal training and strength and
conditioning to monitor changes in BC. As
with most human measurements, proper
SKF measurement technique is a skill not
quickly or easily acquired. A clearer
understanding of the validity of novice SKF
measurements would allow for proper
feedback pertaining to the skill-
acquirement process of this measurement
technique for professors, practitioners, and
students. Therefore, the purpose of this
study was to determine the validity with
which exercise science students in an
Exercise Physiology course measured SKF
thickness and estimated %BF when
compared to a skilled technician.
METHODS
Participants
Participants were Exercise Science majors
(N = 23) enrolled in an undergraduate
exercise physiology laboratory class at a
university in the southeast United States.
They were considered novice SKF
technicians as they possessed little to no
knowledge of assessing BC via SKF
technique.
The conducted study met
ethical standards (5) and all volunteers
signed an informed consent form, approved
by the University’s Institutional Review
Board for human subject use, prior to
participation. Two participants, one female
(age = 21 years) and one male (age = 23
years), were asked to serve as testees for the
SKF measurements. Both study testees
attended all three laboratory sessions to be
measured by the novice exercise science
students.
Protocol
A skilled technician (i.e., Ph.D., ACSM and
NSCA certified) with over 20 years of
experience measuring and teaching SKF
procedures measured the SKFs of the male
and female testees for the investigation.
Once the SKF data were recorded for the
testees, the novice exercise science students
came into the laboratory to learn the SKF
measurement technique. The skilled
technician then spent the next 45 minutes
describing the location of the seven sites
verbally as well as visually locating the
seven sites on both skeleton and human
models in accordance with the guidelines
set forth by ACSM (1). Once the locations
of the SKF were explained, the skilled
technician then demonstrated the technique
to obtain a proper SKF pinch while stating:
"Firmly but gently, pinch the skin and
subcutaneous fat between the thumb, forefinger,
and middle finger. Open the skinfold caliper
and measure the skinfold approximately 1 cm
below your fingers and approximately 1 cm deep
into the skinfold. Do not release the skinfold
while taking the measurement. Once you have
obtained the skinfold measurement, release the
caliper from the skinfold. Take a minimum of 2
measurements at each site. If the measures do
not agree within 1 millimeter, subsequent
assessments should be taken until all values are
within 1 millimeter."
Upon completion of instruction, the
students exited the laboratory and waited
in a hallway. Only two students were then
allowed back into the laboratory to employ
what they had learned via locating,
measuring, and recording the SKF on the
male and female testees using a Lange
Skinfold Caliper (model 68092). Once all
VALIDITY OF 7-SITE SKINFOLD MEASUREMENTS
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23
data had been collected, students exited the
laboratory and two more students entered
the laboratory. This process was repeated
until all students completed the process of
locating, measuring, and recording the SKF
measurements on the testees. The above
procedures were conducted three times as
there were three separate laboratory
sessions associated with the Exercise
Physiology lecture course.
Statistical Analysis
Data analyses were performed using SPSS
(version 19.0) and Microsoft Excel 2007.
Data were analyzed separately for the male
and females testees. Descriptive statistics
were computed for all variables. First, the
number of SKF measurements taken by the
exercise science student at each site was
computed. Error and absolute error were
calculated between the SKF measurements
taken by the skilled technician and the
exercise science students. Percent BF was
computed using the skilled technician’s and
students’ measurements, and error and
absolute error were calculated between
those variables. One sample t-tests were
used to compare the mean SKF thickness
measured by the exercise science students
and the skilled technician at each site for
both testees. The Mauchly’s sphericity test
was conducted prior to further data
analysis. Repeated measures ANOVAs
were performed to assess mean difference
in absolute error among different sites for
the female and male testees’ measurements
and post hoc analyses were conducted
when appropriate. The alpha level was set
at 0.05 for ANOVAs testing and was
adjusted using bonferoni transformation for
the one sample t-tests and was set at 0.003.
RESULTS
The average number of measurements
taken by the students for each SKF site can
be found on Table 1. The students took
between two to six measurements for the
female testeee and two to four
measurements for the male testee. SKFs for
each site, sum of SKFs, %BF measured by
the skilled technician and the average SKF
for each site, sum of SKFs, and %BF
measured by the students are found in
Table 2. Sum of SKFs, and %BF measured
by the skilled technician were 95 mm,
17.8%, and 37 mm, 3.8%, for the female and
male testees, respectively. The average sum
of SKFs and %BF measured by the students
were 73±15 mm, 14.2±2.6%, and 40±8 mm,
4.2±1.3%, for the female and male testees,
respectively. For the female participant, the
average error ranged from -0.5 mm to -4.8
mm and the average absolute error ranged
from 1.2 mm to 4.9 mm for the seven sites
(see Table 3). For the male participant, the
average error ranged from 0.0 mm to 0.9
mm and the average absolute error ranged
from 0.5 mm to 1.1 mm for the seven sites
(see Table 3).
Table 1. Number of measurements taken by
students.
Site Female Male
Chest 2.3 ± 0.6 2.1 ± 0.3
Axilla 2.3 ± 0.5 2.0 ± 0.2
Triceps 2.5 ± 0.6 2.1 ± 0.3
Subscapular 2.2 ± 0.4 2.0 ± 0.2
Abdominal 2.4 ± 0.7 2.1 ± 0.3
Suprailium 2.5 ± 0.8 2.1 ± 0.3
Thigh 2.4 ± 0.5 2.2 ± 0.5
Note. Data presented as mean ± standard deviation;
two is the minimum number of measurements
possible.
The results from the one-sample t-tests
comparing the measurements assessed by
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24
the students to those attained by the skilled
technician revealed that for the female
testee, the subscapula was the only
measurement that was not significantly
different from the skilled technician (t(22)=
-1.78; p = 0.09), all other measure were
significantly different (p < 0.001). In
contrast, for the male testee, the SKF
measurement taken by the students at the
suprailium was the only measurement
significantly different from the skilled
technician (t(22) = 3.40; p = 0.003), all other
measures were not significantly different (p
> 0.05).
The results for the Mauchly’s sphericity test
for the female testee indicated that the data
violated the assumption of sphericity (X2(2)
= 50.2, p < 0.001), so the F value was
corrected using the Greenhouse-Geisser
estimate. The repeated measure ANOVA
showed a significant difference in absolute
error among SKF sites, F(3.35,73.58) = 12.78,
p < 0.001. Follow up analyses of simple
effects revealed that the subscapula site had
lower absolute error compared to all other
sites (p < 0.01), and that the suprailium and
thigh had higher absolute error than all
other sites (p < 0.01) other than the
abdominal site (p > 0.05).
The results for the Mauchly’s sphericity test
for the male testee indicated that the data
violated the assumption of sphericity (X2(2)
= 69.5, p < 0.001), so the F value was
corrected using the Greenhouse-Geisser
estimate. The repeated measure ANOVA
showed no significant difference in absolute
error among SKF sites, F(2.6,57.2) = 1.28, p =
0.29.
DISCUSSION
BC is an important component of health-
related physical fitness as an undesirable
BC increases the risk for cardiovascular
disease (1). Therefore, the proper
measurement of BC, or more specifically
%BF, is essential for proper health
assessment and risk stratification. To our
knowledge, no research has been
Table 2. SKF measurements (in mm) and %BF for the male and female testees.
Female Male
S
it
e
t
ud
ent
s
k
illed
t
ec
hnic
ian
S
t
ud
ent
s
S
k
illed
t
ec
hnic
ian
Chest 5.0 ± 2.0* 8.0 4.0 ± 1.0 4.0
Axilla 7.6 ± 1.9* 10.0 5.2 ± 0.9 5.0
Triceps 14.2 ± 3.1* 17.0 5.4 ± 1.6 5.0
Subscapular 9.5 ± 1.5 10.0 7.5 ± 1.2 7.0
Abdominal 10.7 ± 3.5* 15.0 6.6 ± 2.3 6.0
Suprailium 12.2 ± 4.0* 16.0 5.9 ± 1.2* 5.0
Thigh 14.2 ± 2.8* 19.0 5.3 ± 1.3 5.0
T
o
t
al
73.3 ±
15.4
*
95.0
39.9
±
8.5
37.0
%BF
14.2 ±
2.6
*
17.8
4.2 ±
1.3
3.8
Note. * = significant different from skilled technician measure (p < 0.003)
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25
conducted on the validity of SKF at specific
sites and BF measurements taken by
novices who are learning the technique for
the first time. Therefore, the purpose of this
study was to determine how accurately
undergraduate Exercise Science majors in
an Exercise Physiology course measured
SKF thickness and estimated %BF when
compared to a skilled technician.
Measuring the SKFs of the female testee
was the most difficult for students between
the two testees which evidenced by the
higher number of measurements needed for
the female testee. With the exception of the
subscapula, the novice students had
significantly lower measurements than the
skilled technician at all sites for the female
testee. The suprailium, abdominal, and
thigh sites had a significantly greater
margin of error than most other sites.
Students were able to measure SKFs of a
lean male accurately when compared to the
skilled technician. The one sample t-tests
revealed only one SKF site (suprailium)
where the students had a slightly yet
significantly higher average measurement
compared to the skilled technician. The
students were also accurate when
compared to the skilled technician
regarding sum of SKFs and %BF estimation.
The dependence of measurement accuracy
on sex of the testee may have been due to
various factors. Clarys, Provyn, and
Marfell-Jones (4) noted that the
homogeneity of skin thickness is an
underlying assumption of the SKF
technique. Skin thickness at various sites
has not been extensively investigated, but
the sparse findings indicate that thickness is
not necessarily inconsequential. Skin
thickness could increase the difficulty of
measurement at different sites and could
contribute to the difference in error found
between males and females due to the
difference in thickness between sexes (13).
In addition, the accuracy could have been
influenced by the difference in %BF
between the testees.
Table 3. Average and absolute average error between the skilled technician measurement and t
he
students’ measurements.
Fe
m
ale
M
ale
Site Avg Error Abs Avg Error Avg Error Abs Avg Error
Ches
t
-
3.0 ±
2.0
3.2 ±
1.6
0.0 ±
1.0
0.7 ±
0.8
A
x
illa
-
2.4 ±
1.9
2.7 ±
1.4
0.2 ±
0.9
0.5 ±
0.8
T
ric
ep
s
-
2.8 ±
3.1
3.2 ±
2.7
0.4 ±
1.6
0.8 ±
1.4
S
ub
s
c
ap
ular
-
0.5 ±
1.5
1.2 ±
1.0
0.5 ±
1.2
0.7 ±
1.0
A
b
d
o
m
inal
-
4.3 ±
3.5
4.9 ±
2.5
0.6 ±
2.3
1.1 ±
2.1
S
up
railium
-
3.8 ±
4.0
4.2 ±
3.6
0.9 ±
1.2
0.9 ±
1.2
T
hig
h
-
4.8 ±
2.8
4.8 ±
2.6
0.3 ±
1.3
0.6 ±
1.2
Total -21.7 ± 15.4 23.3 ± 12.7 2.9 ± 8.5 4.8 ± 7.5
%BF -3.4 ± 2.6 3.9 ± 2.2 0.5 ± 1.3 0.8 ± 1.2
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26
Because participants in the current study
were measuring the same testees and the
accuracy of measurements were compared
against those of a skilled technician, we
assumed that the contribution of skin
thickness to measurement error was
controlled (i.e., each measurement was
taken on the same testees). However, skin
thickness may also contribute to SKF
compressibility (6). Himes, Roche, and
Siervogel (9) examined SKF compressibility
of 65 youth (33 males, 32 females) ages 8 to
19 years old. Although not statistically
significant, the trend at most of the seven
sites was for females to have less
compressible SKFs than males. Hattori and
Okamoto (6) examined SKF compressibility
across 16 sites in 96 Japanese university
students. Their findings were in partial
agreement with the previous findings
Himes et al. (17) and Martin et al. (14) in
that limb sites tended to be less
compressible in females than in males, yet
the opposite was found in the trunk sites.
Due to the compressibility of the skin,
participants that measure the testees after
multiple measures could have a
measurement bias between sexes and
different sites could be affected in diverse
manners.
The sex-dependent nature of measurement
error found in the current study also may
have been affected by the difference in SKF
thickness. Pollock, Jackson, and Graves
(18) studied the effects of sex, SKF site
location, and SKF thickness on
measurement error. Participants were 24
males (ages 34 ± 10 years old) and 44
females (ages 31 ± 5 years old). After two
testers on two separate days measured the
axilla, chest, abdomen, thigh, subscapular,
triceps, and suprailiac of the participants,
Pollock et al. (18) found no sex difference.
Participants were then tricotimized by the
sum of SKFs with the three groups
averaging 69 mm, 101 mm, and 180 mm.
Measurement error was significantly higher
in the group with the highest sum of SKFs.
Measurement error ranged from 1.0 – 1.5
mm with SKFs under 15 mm thick, 1.5 2.5
mm with SKFs from 16 30 mm thick, and
3.0 3.5 mm with SKFs over 30 mm thick.
Pollock et al. (17) concluded that error in
the measurement of SKFs was more a
function of SKF thickness than a fuction of
site location or sex. In the current study, a
lean male and lean female with relatively
low sums of SKFs (37 mm and 95 mm for
the male and female, respectively, as
measured by a skilled technician) were
used and testees, consequently, would have
not been placed in a group where Pollock et
al. found the significantly higher
measurement error. However, Pollock et al.
(18) identified their technicians as
“trained”. Therefore, it is reasonable to
suspect that the measurement of thicker
SKFs of the female testee, although not
challenging for a trained technician, was
more difficult for the students to measure
and consequently resulted in greater
measurement error.
The current study was carefully designed
but is not without limitations. Student
measurements were compared to those
taken by only one skilled technician and,
although our technician is highly-
experienced, a degree of measurement error
is always possible. The testees were both
normal weight and lean, which may allow
for less measurement error of the SKFs (17),
although as expected the female testee had
higher %BF than the male testee. More
specifically, the female testee was a current
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27
member of the university’s tennis team and
the male testee was a former, competitive
wrestler. Further research is needed on the
accuracy of novices related to the
measurement of heavier population with
thicker SKFs, especially given the obesity
epidemic in many developed countries.
Also, the participants from each lab session
took measurements on the same testees in a
small time interval. This could make
placement of the measurement more
obvious and the fat may have been
compressed at the later measurements.
The measurements taken by students were
consistently lower for the female and
yielded %BF estimations about 4% lower
than the skilled technician’s estimation
while the students’ measurements for the
male were comparable to the skilled
technician. Proper undergraduate
education and experience with SKF
measurement appears to produce students
who can accurately measure SKFs,
however, additional attention is necessary
when teaching measurements individuals
with larger SKFs with specific emphasis on
the suprailium, abdominal, and thigh sites.
The goal of Exercise Science programs in
higher education institutions worldwide is
to produce professionals who are capable of
supporting and expanding the field of
exercise science. One such way is through
the proper measurement of particular
pertinent variables such as SKF thickness.
The current study revealed that properly
educated undergraduate students can
accurately measure the SKFs of a lean
young man and reasonably accurately
measure the SKFs of a lean young woman.
However, students were less accurate
measuring thicker SKFs. Professionals in
fields where SKFs are commonly measured
(e.g., personal training, strength and
conditioning) should be cognizant that
interns and young professionals may not
have the skills necessary to accurately
measure those with thicker SKFs.
Mentoring young professionals and giving
them sufficient practice in SKF
measurement would help them improve
skill and yield more accurate results.
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... While the three-site measurement BodyMetrix™ technique is used to determine body composition, the seven-site measurement technique with the BodyMetrix™ is utilized more often, as it is thought to be a better representation of overall body composition (1). Barreira (2013) discovered that the seven-site skinfold method with calipers is the most common method of body composition assessment (2). It is that a seven-site analysis provides a more accurate representation of overall body composition compared to the three-site because it incorporates subcutaneous adipose tissue values from more locations than the three-site estimation (1). ...
... While the three-site measurement BodyMetrix™ technique is used to determine body composition, the seven-site measurement technique with the BodyMetrix™ is utilized more often, as it is thought to be a better representation of overall body composition (1). Barreira (2013) discovered that the seven-site skinfold method with calipers is the most common method of body composition assessment (2). It is that a seven-site analysis provides a more accurate representation of overall body composition compared to the three-site because it incorporates subcutaneous adipose tissue values from more locations than the three-site estimation (1). ...
... The BodyMetrix™ (IntelaMetrix, Inc., Livermore, CA) ultrasound wand was calibrated on the day when testing was conducted, to ensure optimal accuracy of the BodyMetrix™ . Participants were asked to follow the same pre-testing guidelines, including no lotion or sweat on the skin prior to testing (2). The athletes arrived at the exercise physiology laboratory to meet with the researchers, where they were informed of all risks and benefits from participating in the study and signed an informed consent document. ...
Article
Full-text available
One method to measure body composition that is gaining popularity is the BodyMetrix™, which uses A-mode ultrasound. A-mode ultrasound, when used with the BodyMetrix™, has been found to be a reliable and a cost-effective tool for measuring overall body fat percentage. Furthermore, the portability and short duration testing features of the BodyMetrix™, allows for testing of a large group of athletes inside or outside of a clinical setting. Despite these advantages, research regarding the BodyMetrix™ is limited and has primarily focused on the seven-site testing technique. However, the three-site technique allows for faster testing and a reduction of time needed to test an entire team or multiple sports teams. Thus, the purpose of this study was to compare the three-site and seven-site methods using the BodyMetrix™ to determine body fat percentage in female collegiate athletes. It was hypothesized that body fat percentage determined via the seven-site method would be different from those obtained by three-site measurement technique. Study participants included 40 National Collegiate Athletic Association (NCAA) Division-II female athletes from volleyball, soccer, and softball teams. The Jackson Pollock three-site (thigh, suprailiac, triceps) and seven-site (thigh, suprailiac, triceps, abdominal, subscapular, chest, and axilla) equations were used to determine body fat percentage values. The time required to perform the three-site and seven-site measurements were also recorded. A paired samples t-test was used to assess if there was a difference between the three-site and the seven-site body fat percentage measurements with the use of the BodyMetrix™ . The three-site method (23.21 ± 3.61) was significantly lower (p < 0.001) compared to the seven- site method (25.75 ± 4.39). On average, the three-site technique took 2 minutes and 13 seconds less than the seven-site technique.
... 1,2 For precise evaluation, several methods are available which give a reasonably accurate measure of body fat composition, the most commonly and widely used methods due to their ease and feasibility are skinfold caliper (SKF) method and bioelectrical impedance analysis (BIA) method. 3,4 Skinfold thickness is determined by pinching a fold of skin at the site and its thickness is measured using precision thickness calipers to represent the average thickness of the entire subcutaneous adipose tissue. Data from the sites of measurement will be used to analyzed by using specific formula to show the BF%. 5 While BIA is a portable non-invasive method that introduces a passage of low-level current into the body and measure the impedance to the flow. ...
... 11 The difference in the results maybe also be the result of the fact that females have less compressible SKF than males and compression of the fat layer during the use of calipers. 3,10 Almost half of the professors are obese and it makes the precise measurement of their skinfolds difficult because of the difficult handling of the thick skinfolds. As the skinfold calipers have upper measurement limit, the calipers may not enough to hold the thick skinfold in obese professors. ...
Article
Full-text available
Body fat composition reflected by body fat percentage (BF%) is one of the important components in disease risk evaluation. Among the methods available to measure BF%, skinfold calipers (SKF) and bioelectrical impedance analysis (BIA) are the most commonly used. The study was conducted to evaluate the difference in body fat composition measurement between SKF and BIA methods among professors. This study analyzed secondary data from the health evaluation of Universitas Padjadjaran (UNPAD) professors. This study involved 72 professors (50 male, 22 female) after fitted into the inclusion and exclusion criteria. BF% was measured among UNPAD professors using SKF and BIA. After obtaining agreement by Bland-Altman Plot, the data were analyzed by muliple paired-t test according to gender, physical activity level and body mass index (BMI) categories. The study showed no significant difference in BF% between SKF and BIA in overall population, between gender and physical activity level (p>0.05). For BMI, the only category that showed significant difference in BF% between the 2 methods was obese I group (p=0.001). In conclusion, there is no significant difference in BF% between SKF and BIA methods according to gender, physical activity levels and BMI categories except for obese I group.
... 1,2 For precise evaluation, several methods are available which give a reasonably accurate measure of body fat composition, the most commonly and widely used methods due to their ease and feasibility are skinfold caliper (SKF) method and bioelectrical impedance analysis (BIA) method. 3,4 Skinfold thickness is determined by pinching a fold of skin at the site and its thickness is measured using precision thickness calipers to represent the average thickness of the entire subcutaneous adipose tissue. Data from the sites of measurement will be used to analyzed by using specific formula to show the BF%. 5 While BIA is a portable non-invasive method that introduces a passage of low-level current into the body and measure the impedance to the flow. ...
... 11 The difference in the results maybe also be the result of the fact that females have less compressible SKF than males and compression of the fat layer during the use of calipers. 3,10 Almost half of the professors are obese and it makes the precise measurement of their skinfolds difficult because of the difficult handling of the thick skinfolds. As the skinfold calipers have upper measurement limit, the calipers may not enough to hold the thick skinfold in obese professors. ...
Article
Full-text available
Background: Body fat composition which is reflected by body fat percentage (BF%) is one of the important components in disease risk evaluation. Among the methods available to measure BF%, skinfold calipers (SKF) and bioelectrical impedance analysis (BIA) are the most common used. The study is conducted to observe the difference in body fat composition measurement between skinfold caliper and bioelectrical impedance analysis methods among Professors.Method: This study involved 72 UNPAD Professors (50 ♂, 22 ♀) after fitted into criterias. BF% was measured among UNPAD Professors using SKF and BIA. After obtaining agreement by Bland-Altman Plot, the data was analyzed by muliple paired-t test according to gender, physical activity level and BMI categories. Results: The study showed no significant difference in BF% between SKF and BIA in overall population, between gender and physical activity level (p>0.05). For BMI, the only category that showed significant difference in BF% between the 2 methods is obese I group (p=0.001, p>.05).Conclusions: There is no significant difference between SKF and BIA methods according to gender, physical activity levels and BMI categories except for obese I group.
... Unfortunately, SKF measurements are highly dependent on technician experience. Barreira et al. (2013) revealed a significant difference between the experienced technician's and educated exercise science students' SKF measurements for female subjects. Other studies have also reported low interrater reliability for this method (Kispert and Merrifield, 1987). ...
Article
The purpose of this study was classified in two aspects: (1) evaluating seasonal changes in body composition of an elite male soccer team; (2) comparing body fat estimates of two different skinfold thickness equations (Jackson-Pollock (JP), Withers) to those of multifrequency bioimpedance (BIMP) among soccer players. Skinfold thickness (7-site) and BIMP measurements were done to 24 players from the same team at 5 different time points throughout the season of 2016-2017. Team displayed no seasonal changes in any of the body composition parameters (body weight, muscle mass, body fat, bone mass, body water, visceral fat rate) (P>0.05). According to Bland-Altman plot analysis for repeated measures, bias between BIMP and JP estimates was 2.88±2.94, whereas bias between BIMP and Withers estimates was 0.53±2.13 and limits of agreement ranged between -2.83 and 9.69 for JP and BIMP, and between -3.57 to 4.76 for Withers and BIMP. A poor correlation was observed between JP and BIMP (ρ c =0.29, 95% confidence interval (CI) [0.18-0.39]). Assessment between BIMP analysis and Withers formula returned a fair correlation (ρ c =0.49, 95% CI [0.34-0.61]). Finally, Withers and JP formulas’ estimates displayed only a moderate correlation (ρ c =0.66, 95% CI [0.60-0.72]). Either of the methods cannot be used interchangeably, therefore longitudinal tracking of body fat must be done with a single method and equation. When 7-site skinfold measurements are conducted, we suggest implementing Withers equation among elite male soccer players.
... It consisted of a sealed hydraulic system with adjustable hand spacing that registered hand grip force. [18][19][20][21][22][23][24][25] Most of the recent studies of grip strength measurement have reported the Jamar dynamometer to be the most reliable and accurate device for measurement of hand grip strength. [20][21][22][23][24] Body mass index is the overall anthropometric measure of health status of an individual. ...
... Of the 4 field assessments examined, percent body fat estimated using skinfolds thickness yielded the lowest percent error and was statistically equivalent with DXA. Skinfolds thickness requires some administer training, but is characterized as having low participant burden and is inexpensive [47,48]. Health-related fitness test batteries often use skinfolds thickness to assess body composition across a variety of populations [49]. ...
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The purpose of this study was to examine the agreement in percent body fat estimates among 7 laboratory and field assessments against dual-emission x-ray absorptiometry using equivalence testing. Participants were 437 college students (mean age=19.2±0.6 years). Dual-emission x-ray absorptiometry was used as the criterion with hydrostatic weighing, skinfold thickness, air displacement plethysmography, near infrared reactance, and three methods of bioelectrical impedance analysis examined as surrogate assessments. Relative agreement was examined using intraclass correlation coefficients. Group level agreement was examined using equivalence testing. Individual-level agreement was assessed using Mean Absolute Percent Error and Bland-Altman Plots. Single measure intraclass correlation coefficient scores ranged from 0.71-0.80. Hydrostatic weighing, skinfold thickness, air displacement plethysmography, and 4-electrode bioelectrical impedance analysis showed statistical equivalence with the criterion using a 10% Equivalence Interval with absolute mean differences ranging from 1.0%-4.9% body fat. Mean Absolute Percent Error ranged from 11.7% using skinfold thickness to 21.9% using Omron (hand-held) bioelectrical impedance analysis. Limits of Agreement were heteroscedastic across the range of mean scores compared to dual-emission x-ray absorptiometry, with greater mean differences observed at higher levels of percent body fat. Hydrostatic weighing, skinfold thickness, air displacement plethysmography, and 4-electrode bioelectrical impedance analysis showed strong evidence for statistical equivalence with dual-emission x-ray absorptiometry in a sample of college students.
Article
The purpose of this study was to compare the body fat per cent (BF%) assessed with a unique handheld electrical impedance myography (EIM) device, along with other popular methods, to dual-energy X-ray absorptiometry (DXA). Participants included 33 males (aged 24.3 ± 4.6 years) and 38 females (aged 25.3 ± 8.9 years) who completed 2 visits separated by 24–72 h. The assessments included DXA, bioelectrical impedance analysis (BIA), skinfold measures (SKF), and three separate EIM measurements. No significant differences in BF% (P > 0.05) were found between all EIM assessments when compared against DXA for both males and females for each visit. All methods showed no significant differences in BF% (P > 0.05) between days within themselves. Across both days, the standard error of the estimate (SEE) for the EIM measurements ranged from 2.66% to 3.15%, the SEE for BIA was 2.80 and 2.85, and for SKF was 2.90 and 2.82. The 95% limits of agreement ranged from ±5.34% to ±6.38% for EIM measurements and were highest for SKF (±7.42% and ±7.47%). The total error for both days was largest for SKF (5.20% and 5.35%) and lowest for the EIM measurements (2.48–3.24%). This investigation supports use of a handheld EIM device as an accurate and reliable method of estimating BF% compared to DXA in young, apparently healthy individuals with BF% in the range of 10–22% for males and 20–32% in females and suggests this EIM device be considered a viable alternative to other established field measurements in this population.
Article
Pediatric obesity is a major health concern that has an increased prevalence in children with special needs. In order to categorize a child’s weight, an assessment of body composition is needed. Obtaining an accurate body composition measurement in children with special needs has many challenges associated with it. This perplexing scenario limits the provider’s ability to screen, prevent and treat an abnormal weight status in this vulnerable population. This systematic review summarizes common methods of body composition measurements, their strengths and limitations and reviews the literature when measurements were used in children with cerebral palsy, spina bifida and spinal cord injury. Following PRISMA guidelines, 222 studies were identified. The application of the inclusion and exclusion criteria yielded a final sample of nine studies included in this review. Overall, articles reinforced the inconsistencies of body composition measurement and methodology when used with children with special needs. Concerns include small sample sizes, the need to validate prediction equations for this population, and the lack of controlled trials and reporting of measurement methodology. Healthcare providers need to be aware of the complexities associated with measuring body composition in children with special needs and advocate for further testing of these measurements. Additional studies addressing the reliability and validity of these measures are needed to facilitate appropriate health promotion in children.
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We assessed the importance of accurate site location for skinfold measurement in ten healthy males in a cross-sectional quantitative study. Nine measurements, in a 1-cm grid pattern, centred on each of eight ISAK-specified skinfold sites, were taken three times at each grid point by each of two ISAK Level 4 practitioners using Harpenden skinfold callipers. The presence of significant systematic discrepancy between reliability measures of different skinfold sites and grid points for each of the two testers was determined using P-values. Effect sizes were calculated to show the magnitude of effects. Skinfolds taken at the eight peripheral grid points were generally different from the skinfolds taken at a central ISAK grid point and there was an effect by direction away from the central ISAK point (anterior, posterior, superior or inferior). The subscapular skinfold had the least number of differences (three) and the abdominal had the most (eight). All other skinfold sites showed some variation with most care needed in marking the biceps and triceps skinfold sites. Adherence to identifying, marking, and measuring at the defined site is essential.
Article
The assessment of body composition has become an important method for determining a desirable body weight of adults and athletes. Hydrostatic weighing is a popular and valid method, but it is often not feasible for the clinical setting or for mass testing; thus, anthropometry has become the preferred method. This article reviews the scientific basis for generalized body composition prediction equations and provides methods for evaluating body composition. The authors recommend using a sum of three skinfolds (triceps, chest, and subscapula for men and triceps, abdomen, and suprailium for women) and give detailed instructions for securring accurate measurements of body fat.
Article
Variability in both skin thickness and skinfold compressibility affects the relationship between the skinfold caliper reading at a particular site on the body and the actual adipose thickness at that site, thus inducing error in the estimation of body fatness. To investigate this variability, skinfold thickness by caliper and incised depth of subcutaneous adipose tissue were measured at 13 skinfold sites in 6 male and 7 female unembalmed cadavers aged 55 to 94 years. All skin was then removed and its thickness measured at the exact sites of skinfold measurement. The regional patterns for skin thickness were similar in men and women, though women had significantly (P < .05) thinner skin than men at the biceps, chest, supraspinale, and abdominal sites. Mean (SD) skin thickness for each cadaver over all sites ranged from 0.76 mm (0.28 mm) to 1.47 mm (0.43 mm), with an overall mean for men of 1.22 mm (0.36 mm) and for women of 0.98 mm (0.36 mm). The thickness of a double layer of skin expressed as a percentage of skinfold thickness for all cadavers over all 13 sites ranged from 7.1% to 33.4%. Because of their leanness and thicker skin, the mean for men, 22.7% (10.1%), was significantly greater than that for women, 10.8% (6.2%) (P < .0001). Mean skinfold compressibility over all sites was 53.5% (16.4%) in men adn 51.9% (16.5%) in women (not significant). Such marked variability in skinfold compressibility and in the relative contribution of skin thickness to skinfold thickness suggests the need for caution in comparing estimates of fatness by skinfold caliper between different subjects. © 1992 Wiley-Liss, Inc.
Article
Compressibility of subcutaneous fat thickness when measured with skinfold calipers was investigated in 65 white American youths. Compression of skinfolds was determined relative to measurements of subcutaneous fat thickness from radiographs at each of seven sites. There is statistically significant heterogeneity among sites in skinfold compression, with skinfolds on the medial and lateral calf being the least compressible of those measured. There is little statistically significant sex difference in skinfold compression in the present sample and, within the range concerned, there were no significant correlations between skinfold compressibility and age. When compressibilities of the seven skinfolds were intercorrelated within individuals, statistically significant average correlations were obtained, indicating that individuals tend toward similar degrees of skinfold compressibility among sites. This communality of skinfold compression within individuals is such that, at least in male youth, there are significant differences among individuals in the average compressibility of the seven skinfolds.
Article
Sub-cutaneous fat thickness was measured at 12 sites on the body surface of 24 males and 26 females using magnetic resonance imaging (MRI), skinfold calipers, and A-mode ultrasound. The mean of the 12 fat thickness measurements and individual site thicknesses were compared between individuals using analysis of variance. In males, the mean thicknesses for ultrasound and calipers were similar (P greater than 0.05) but both were less than the MRI (P less than 0.001). MRI and ultrasound were similar in females but less than calipers (P less than 0.001). A good between-subject correlation was found between all three methods in the males but only the calipers and MRI were well correlated in females. Within-subject correlations are poor for all measures and in both sexes. Factor loadings for a varimax rotation of two principal components indicate that the fat is distributed in 1 of 2 patterns: either principally on the trunk or on the limbs. The principal component analysis and the result of canonical correlations obtained from the factor loadings confirm the findings of the analysis of variance, in that a general level of fatness is measurable by all three methods over a range of subjects. However, the pattern of fat thicknesses measured over a number of specific sites by one method of measurement is unlikely to be duplicated by either of the other two methods on the same individual.