A COMPARATIVE ELECTROMYOGRAPHICAL INVESTIGATION OF TRICEPS BRACHII AND PECTORALIS MAJOR DURING FOUR DIFFERENT FREEHAND EXERCISES

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Correspondence: Amritashish Bagchi, Research Scholar, Lakshmibai National
Institute of Physical Education, Gwalior (M.P), INDIA, Tell: +917415318615,
Email: amritashishbagchi23@gmail.com
A COMPARATIVE ELECTROMYOGRAPHICAL INVESTIGATION OF
TRICEPS BRACHII AND PECTORALIS MAJOR DURING FOUR
DIFFERENT FREEHAND EXERCISES
Amritashish Bagchi
Lakshmibai National Institute of Physical Education, Gwalior, INDIA.
Email: amritashishbagchi23@gmail.com
How to cite this article: Bagchi, A. (June, 2015). A comparative
electromyographical investigation of triceps brachii and pectoralis major during
four different freehand exercises. Journal of Physical Education Research,
Volume 2, Issue II, 20-27.
Received: April 02, 2015 Accepted: June 09, 2015
ABSTRACT
This study aimed to investigate the effects of different freehand exercises on the
electromyographic (EMG) activity of Triceps Brachii (TB) and Pectoralis Major (PM)
muscles. Ten healthy men (21.25 ± 2.09 years) performed 1 repetition of four different
freehand exercises. The maximum voluntary contraction (MVC) was recorded with the
help of biograph infinity software (EMG). Surface ElectroMyoGraphy (SEMG) was
used for measuring muscle electrical activity that occurs during muscle contraction.
The four different freehand exercises were vertical dips (VD), wider grip vertical dips
(WGVD), back dips (BD) and diamond push-ups (DPU). The results of the study shows
that in case of the muscles activation in Triceps Brachii, except diamond push-ups
(DPU) all the other exercises reveals significant differences with the vertical dips (VD),
suggesting that Vertical dips is more effective inactivating the primary mover (Triceps
Brachii) as compare to wider grip vertical dips (WGVD) and back dips (BD). When it
comes to Pectoralis Major Muscle activationwider grip vertical dips (WGVD) was
foundto be more effective, as all the other exercises reveals significant differences with
the wider grip vertical dips (WGVD).
Keywords: Electromyography, muscle activation, freehand exercises, triceps brachii,
pectoralis major.
1. INTRODUCTION
The identification of each movement’s peculiarities and its suitability to the
training objectives is a task which demands the interaction of many fields of
knowledge. A number of exercises can be adopted for the development of a given
Journal of Physical Education Research, Volume 2, Issue II, June 2015, pp.20-27
ISSN: Print-2394 4048, Online-2394 4056

Bagchi, A. (June, 2015). A comparative electromyographical investigation of triceps brachii and
pectoralis major during four different freehand exercises. Journal of Physical Education Research,
Volume 2, Issue II, 20-27.
JOPER® www.joper.org JOPER 21
muscular group; however, an exercise is usually more indicated for each specific
situation. The use of machines or free weights may also interfere in the muscular
recruitment, once free weight exercises require the control of the implement in
three dimensions, which can generate greater activation of the stabilizer muscles
(Ferreira, Büll, & Vitti, 2003a; Ferreira, Büll, & Vitti, 2003b; Rocha, Gentil,
Oliveira, & Carmo, 2006). Muscle activity is one of the major factors associated
with human body movements during sports, exercise, and survival in different
daily life tasks (Ronald, Snarr, & Esco, 2013; Ali, Sundaraj, Ahmad, Ahamed,
Islam, & Sundaraj 2014). The cause for evolution of different physiological
responses is about the different shapes and densities of different muscles. In this
very respect, the electromyographic measurements gain great importance (Türker,
& Sözen, 2013). Electromyography used in many sports techniques nowadays.
Electromyography (EMG) utilizes either surface electrodes that are placed over
the muscle or finewire/needle electrodes placed into the muscle (Türker, & Sözen,
2013). In general, surface electromyography (sEMG) is used to measure the
activity of superficial muscles and is an essential tool in biomechanical and
biomedical assessments. Surface ElectroMyoGraphy (SEMG) is a non-invasive
technique for measuring muscle electrical activity that occurs during muscle
contraction and relaxation cycles. As the subject then moves the joint and
contracts the muscles, the EMG unit detects the action potentials of the muscles
and provides an electronic readout of the contraction intensity and duration. EMG
is the most accurate way of detecting the presence and extent of muscle activity
(Sousa, Bérzin, Silva, & Negrão-Filho, 2000; Floyd, 2012; Tibold, & Fuglevand,
2015). Triceps brachii is a muscle without whom biceps never looks better.
Imagine a well-developed biceps muscles with triceps that never been worked out
(Nazário-de-Rezende, Sousa, Haddad, de Oliveira, Medeiros, de Agostini, &
Marocolo, 2012). Similarly, when we perform bench press pectoralis activates as
the primary muscles with triceps brachii and anterior deltoid acting as secondary
muscles. The role of these primary and secondary muscles can also be switch over
depending upon the hand spacing while performing the bench press (Rodrigues,
Büll, Dias, & Gonçalves, 2003).
The purpose of the study was to determine the effectiveness by comparing
the four different freehand exercises with the EMG responses of the selected
muscle groups (i.e. Triceps Brachii and Pectoralis Major).
2. METHODS AND MATERIALS
2.1 Subjects
Ten healthy volunteers (age = 21.25 ± 2.09 years, height = 1.71 ± .038 m, weight
=69.65 ± 2.92 kg) from Lakshimibai National Institute of Physical Education

Bagchi, A. (June, 2015). A comparative electromyographical investigation of triceps brachii and
pectoralis major during four different freehand exercises. Journal of Physical Education Research,
Volume 2, Issue II, 20-27.
JOPER® www.joper.org JOPER 22
(Gwalior, M.P) were included in the study as subjects. Purposive sampling
technique was used for the selection of those subjects. They were all experts in
weight training, with a minimum of 1 year of practice with the selected exercises.
Each participant provided informed consent prior to participation in any testing
procedures. As part of the selection criteria, the participants were expected to
perform 10 or more proper repetitions of each exercise.
2.2 Experimental Approach to the Problem
To compare the EMG response between different freehand techniques, subjects
performed 1 repetition of 4 freehand techniques of the exercise, with surface
electrodes positioned over the 2 muscle bellies (Triceps Brachii and Pectoralis
Major). A familiarization session was carried out 1 week before testing. During
this session, the set up for all the freehand exercises and the participant’s
technique for performing those exercises were designed. The four different
freehand exercises were vertical dips (VD), wider grip vertical dips (WGVD),
back dips (BD) and diamond push-ups (DPU). Surface Electro Myo Graphy
(SEMG) is a non-invasive technique for measuring muscle electrical activity that
occurs during muscle contraction and relaxation cycles. The SEMG signal
generated by the muscle fibers is captured by the electrodes, then amplified and
filtered by the sensor before being converted to a digital signal by the encoder. It
is then sent to the computer to be processed, displayed and recorded by the Infiniti
software. The MyoScan-Pro sensor’s active range is from 20 to 500 Hz. It can
record SEMG signals of up to 1600 microvolts (μV), RMS. A/D Converter
(Encoder; ProComp Infiniti) has 2 channels (C and D) sampling at 256 samples
per second.
2.3 Data Collection
The participants performed 1 repetition of eight exercises one by one. Sufficient
recovery time was provided to the participants after completing each exercise. As
mentioned earlier that the exercise were of freehand in nature, body weight was
used for the dips and diamond push-ups.
On the testing day, maximum muscle activation was recorded with the
help of Biograph infinity version 5.0 (Electromyography Software). After shaving
and applying the abrasive cream to the electrodes, the EMG electrodes were
placed parallel to the muscle fiber on two locations (i.e. channel C for Triceps
Brachii and channel D for Pectoralis Major). Raw EMG signals were recorded
using a 15 foot optic fiber wire that is directly connected to A/C encoder. A 20
mega pixels extended video camera was synchronized with the EMG software
(Biograph infinity version 5.0), to find out the maximum voluntary contractions

Bagchi, A. (June, 2015). A comparative electromyographical investigation of triceps brachii and
pectoralis major during four different freehand exercises. Journal of Physical Education Research,
Volume 2, Issue II, 20-27.
JOPER® www.joper.org JOPER 23
(MVCs) of the selected muscles at the time of performing the exercises.
Myoscan-pro sensor with triode electrode was used.
2.4 Statistics Analysis
The descriptive statistics (mean, standard deviation, skewness, kurtosis etc.) and
Shapiro-Wilk’s test was used for testing the assumption of normality and to know
the nature of data. All data are presented as mean with standard deviations. A
repeated measure analysis of variance (ANOVA) was used to detect the mean
differences between each four different freehand exercises. For this purpose
Statistical Package for Social Science (SPSS) version 20.0 was used. The level of
significance was set at 0.05.
3. RESULTS
Table 1: Descriptive statistics and test of normality
As a guideline, a skewness value more than twice its standard error indicates a
departure from symmetry. Since none of the variables skewness is greater than
twice its standard error, hence all the variables are symmetrically distributed.
Similarly, the value of kurtosis for the data to be normal of any of the variable is
not more than twice its standard error of kurtosis hence none of the kurtosis
values are significant. In other words the distribution of all the variables is meso-
kurtic.
Vertical dips
Wider grip
vertical dips
Back dips
Diamond push
ups
T.B
P.M
T.B
P.M
T.B
P.M
T.B
P.M
Mean
1053.6
654.5
845.8
937.0
721.5
434.9
829.0
618.6
Std. Error of
Mean
61.25
39.35
60.96
83.36
33.63
44.62
53.25
48.08
Std. Deviation
193.7
124.4
192.77
263.6
106.37
141.1
168.4
152.0
Skewness
0.59
-0.20
1.17
1.32
-0.51
0.11
0.40
1.34
Std. Error of
Skewness
0.68
0.68
0.68
0.68
0.68
0.68
0.68
0.68
Kurtosis
0.86
-0.52
2.12
1.64
.40
-1.65
-.37
2.14
Std. Error of
Kurtosis
1.33
1.33
1.33
1.33
1.33
1.33
1.33
1.33
Shapiro – Wilk
(p-vaule)
0.92
0.59
0.22
0.14
0.67
0.37
0.83
0.15

Bagchi, A. (June, 2015). A comparative electromyographical investigation of triceps brachii and
pectoralis major during four different freehand exercises. Journal of Physical Education Research,
Volume 2, Issue II, 20-27.
JOPER® www.joper.org JOPER 24
Further for testing the normality Shapiro-Wilks test was used. It compares
the scores in the sample to a normally distributed set of scores with the same
mean and standard deviation. If the test is non-significant (p>.05) it tells that the
distribution of the sample is not significantly different from a normal distribution
(i.e. it is probably normal) and vice-versa. Here from table 1 we can see that none
of the variables p value is less than .05, hence the data is normally distributed.
Figure 1: Mean value of muscles activation (triceps brachii and pectoralis
major) in four different freehand exercises
Figure 1 shows that in vertical dips the muscles activation of Triceps Brachii is
more than the other three freehand exercises. And in case of back dips the EMG
response of Triceps Brachii muscle is lower than the other three freehand
exercises. Similarly, the Pectoralis major muscle shows higher muscle activation
in wider grip vertical dips and lower muscle activation in case of back dips.
Table 2: Mauchly’s test of Sphericity and corrections
To test the equality of variances of the differences between the treatment levels,
Mauchly’s Test of Sphericity was used. Repeated measures ANOVAs (within-
0
200
400
600
800
1000
1200
VERTICAL
DIPS
WIDER GRIP
VERTICAL
DIPS
BACK DIPS
DIAMOND
PUSH UPS
TRICEPS
BRACHII
PECTORALI
S MAJOR
Within
Subjects
Effect
Mauchly’s W
Approx.
Chi-
Square
Df
Sig.
Epsilon
Greenhouse-
Geisser
Huynh-
Feldt
Lower-
bound
Triceps
Brachii
0.31
8.98
5
0.11
0.56
0.68
0.33
Pectoralis
Major
0.51
5.06
5
0.41
0.72
0.96
0.33

Bagchi, A. (June, 2015). A comparative electromyographical investigation of triceps brachii and
pectoralis major during four different freehand exercises. Journal of Physical Education Research,
Volume 2, Issue II, 20-27.
JOPER® www.joper.org JOPER 25
subject factors) are particularly susceptible to the violation of the assumption of
sphericity, as violation causes the test to become too liberal (i.e., an increase in
the Type I error rate). Therefore, determining whether sphericity has been
violated is very vital. Mauchly’s Test of Sphericity tests the null hypothesis that
the variances of the differences are equal. Thus, if Mauchly’s Test of Sphericity is
statistically significant (p<0.05), we can reject the null hypothesis and accept the
alternative hypothesis that the variances of the differences are not equal (i.e.,
sphericity has been violated). The results of Table 2 show that the assumption of
sphericity has not been violated as mauchly’s test was not significant.
Table 3: A summary of the within group repeated measure analysis of
variance in the four different exercises with regards to muscles activation in
pectoralis major and triceps brachii
Muscles
Groups
Type III Sum
of Squares
df
Mean
Square
F
Sig.
Triceps
Brachii
Sphericity
Assumed
578013.47
3
192671.15
11.89
.000
Sphericity
Assumed
437525.77
27
16204.65
Pectoralis
Major
Sphericity
Assumed
1291369.70
3
430456.56
19.50
.000
Sphericity
Assumed
596005.30
27
22074.27
In the above table, for both the cases p-value is less than 0.05. Hence the F-ratio
for Triceps Brachii and Pectoralis Major is significant at 5% level. In this case the
null hypothesis is rejected; therefore at least one of the means will be different.
4. DISCUSSION
The repeated measure ANOVA table shows that statistical differences was
observed when comparing the muscle activation or the EMG responses of Triceps
Brachii and Pectoralis Major muscles with the 4 different freehand exercises. It
means the EMG responses of the TB and PM muscles in various selected
freehand exercises were not similar. Since ANOVA does not tell us where the
difference lies; Bonferroni’s post hoc test was used to get the clear picture. The
result of Bonferroni’s post hoc test shows that, in case of the muscles activation in
Triceps Brachii, except diamond push-ups (DPU) all the other exercises reveals
significant differences with the vertical dips (VD).This difference is may be due
to the nature of exercise as the back dips and diamond push – ups are closed chain

Bagchi, A. (June, 2015). A comparative electromyographical investigation of triceps brachii and
pectoralis major during four different freehand exercises. Journal of Physical Education Research,
Volume 2, Issue II, 20-27.
JOPER® www.joper.org JOPER 26
exercises whereas vertical dips and wider grip vertical dips are open chain
exercises. In back dips and diamond push-ups the body weight is distributed to
four points and in case of vertical dips and wider grip vertical dips the whole body
weight is only on two points that increases the load. When it comes to pectoralis
major muscle activation all the exercises reveals significant differences with the
wider grip vertical dips (WGVD). With respect to variation in hand spacing, it has
been noted that a wider grip requires more activity in pectoralis major muscles
while a narrow grip activates the triceps brachii (Barnett, Kippers, & Turner,
1995). Vertical dips (VD) also show significant differences with back dips (BD).
Again it may due to the nature of exercise as the wider grip vertical dips and
vertical dips are almost similar except the width of the bar.
5. CONCLUSIONS
This study compared the muscle activity of triceps brachii and pectoralis major
between four different freehand exercises. Vertical dips (VD) produced the
maximum voluntary contraction and maximum muscles activation in triceps
brachiias compared to other three exercises. Except diamond push-ups (DPU) all
the other exercises reveals significant differences with the vertical dips (VD),
suggesting that Vertical dips is more effective in activating the primary mover
(Triceps Brachii) as compare to wider grip vertical dips (WGVD) and back dips
(BD) Similarly, wider grip vertical dips (WGVD) produced a greater level of
muscle activity in pectoralis majoras compared to other three exercises. Here
significant differences were found suggesting that by increasing the width in
vertical dips the muscles activation in pectoralis major get enhanced and it acts as
a primary mover while performing the wider grip vertical dips.
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Bagchi, A. (June, 2015). A comparative electromyographical investigation of triceps brachii and
pectoralis major during four different freehand exercises. Journal of Physical Education Research,
Volume 2, Issue II, 20-27.
JOPER® www.joper.org JOPER 27
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