Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Original article    73 
ABSTRACT 
This study aimed to compare the effects of handgrip and 
range of motion (ROM) variations on muscle activity in 
different deltoid exercises. 14 resistance-trained men 
volunteered for 1RM and EMG testing with a load 
corresponding to 80% of 1RM. The subjects performed 
three different handgrips during Dumbbell Front Raise 
(DFR), two different ROM variations for Dumbbell 
Lateral Raise (DLR), and two different handgrips during 
Dumbbell Rear Delt Raise (DRDR). Electromyogram 
(EMG) activity was measured in the anterior, medial, and 
posterior heads of deltoids. For the DFR exercise, the 
highest mean EMG activity was greater for the anterior 
deltoid, and the highest activity was observed in pronate 
grip (PG) con (51.57%). For the anterior deltoid EMG 
activity was significantly greater in PG con (51.57%) 
compared with hammer grip (HG) con (43.36%) (p˂0.05). 
HG ecc activity (40.36%) was significantly greater than 
PG ecc (36.4%) in posterior deltoid (p˂0.05).  For the DLR 
exercise, the highest activity was observed in medial 
deltoid, and for limited ROM (LTR) (20.74%). LTR con 
activity (19.37%) was significantly greater than full ROM 
con (FLR) (16.88%) in the anterior head (p˂0.05). For the 
DRDR exercise, the mean activity was greater in medial 
deltoid, and HG con showed the highest activity (24.47%).  
The mean electromyography activity for the posterior 
deltoid was significantly greater in standard grip (STD) 
ecc compared with HG ecc (17.3%) (p˂0.05). In 
conclusion, for the heads of the deltoid muscle, the use of 
the different handgrip and ROM variations may increase 
neuromuscular activity. 
Keywords: Resistance training, EMG, shoulder muscles, 
exercise variations 
1Sakarya University of Applied Sciences, Faculty of 
Sport Sciences, Sakarya, Turkey 
2Yalova University, Faculty of Sport Sciences, Yalova, 
Turkey 
 
 
 
IZVLEČEK 
Namen te študije je bil primerjati učinke različnih 
prijemov uteži in obsega gibanja (ROM) na mišično 
aktivnost deltoidnih mišic pri različnih vajah. V raziskavi 
je 14 treniranih moških opravilo testiranje 1RM in EMG z 
obremenitvijo, ki je ustrezala 80 % 1RM. Preiskovanci so 
izvajali dvig uteži iz priročenja do predročenja (DLR; 
fleksija ramena) s tremi različnimi prijemi, stranski dvig 
uteži (DLR; abdukcija ramena) z dvema različicama 
obsega gibanja in stranski dvig uteži v predklonu (DRDR; 
abdukcija ramena v predklonu) s dvema različnima 
prijemoma uteži. Aktivnost sprednje, medialne in zadnje 
glave deltoidov je bila izmerjena s 
pomočjo elektromiograma (EMG). Pri vaji DFR je bila 
največja povprečna aktivnost mišic izmerjena v sprednjem 
delu deltoida z nadprijemom v koncentrični fazi (51.57%) 
in kaže na to, da obstajajo statistično značilne razlike 
(p<0.05) v primerjavi z nevtralnim prijemom v 
koncentrični fazi (43.36%). Statistično pomembne razlike 
(p<0.05)  pa obstajajo tudi pri aktivnosti mišic v zadnji 
glavi deltoida pri nevtralnem prijemu v ekscentrični fazi 
(40.36%) in nadprijemom v ekscentrični fazi  (36.4 %). Pri 
vaji DLR je bila največja aktivnost opažena v medialnem 
deltoidu pri omejenem gibanju (LTR) (20.74 %). 
Aktivnost pri vaji LTR v koncentrični fazi (19.37 %) je 
bila pri sprednji glavi deltoida bistveno večja kot pri vaji 
popolnega obsega gibanja (FLR) (16.88 %) (p˂0.05). Pri 
vaji DRDR je bila povprečna aktivnost večja v medialnem 
deltoidu z nevtralnim prijemom v koncentrični fazi (24.47 
%). Povprečna EMG aktivnost zadnjega dela deltoida je 
bila statistično pomembno večja (p˂0.05) pri nadprijemu 
v ekscentrični fazi  (23.07%) v primerjavi z nevtralnim 
prijemom v ekscentrični fazi. Zaključimo lahko, da se 
živčno-mišična aktivnost glav deltoidne mišice poveča z 
uporabo različnih prijemov uteži in obsega gibanja.  
Ključne besede: vaje za moč, EMG, mišice ramenskega 
sklepa, prijem, obseg gibanja 
Corresponding author*: Barbaros Demirtaş,  
Sakarya University of Applied Sciences, Faculty of Sport 
Sciences, Sakarya, Turkey 
E-mail: barbarosdemirtas@subu.edu.tr 
https://doi.org/10.52165/kinsi.29.1.73-87 
Barbaros Demirtaş 1,* 
Onur Çakır 1 
Onat Çetin 2 
Murat Çilli 1 
 
THE EFFECTS OF HANDGRIP AND RANGE OF 
MOTION VARIATIONS ON MUSCLE ACTIVITY 
IN DIFFERENT DELTOID EXERCISES  
UČINKI RAZLIČNIH PRIJEMOV UTEŽI IN 
OBSEGA GIBANJA NA MIŠIČNO AKTIVNOST 
DELTOIDNIH MIŠIC PRI RAZLIČNIH VAJAH 
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    74 
INTRODUCTION 
Resistance exercises are used by recreational or competitive athletes to increase muscle strength 
and hypertrophy (Vigotsky et al., 2018). Planning and development of a resistance training 
program are based on the creation of combinations of basic training variables such as the 
number of repetitions and sets performed, the external loads lifted, and the selection and order 
of exercises (Fleck & Kraemer, 2014). The exercise selection and the variations of these 
exercises has great importance in reaching the goals of the planned training program (Lusk et 
al., 2010).  
Recently, there has been increasing interest in the effect of technical variations in exercises for 
the development of upper body muscle groups on muscle activity pattern (Cogley et al., 2005). 
Shoulder muscles, one of the upper body muscle groups, is a penne muscle that surrounds the 
shoulder joint with three muscle parts assigned to move the humerus relative to the scapula and 
is considered the primary motor muscle in many upper body strength training exercises (Botton 
et al., 2013; Franke et al., 2015; Smith, 1996). In most sports and daily life activities, the 
muscles surrounding the shoulders are involved in a series of multi-plane movements and 
various exercises are performed to strengthen these muscles (Escamilla et al., 2009). The 
glenohumeral joint is a complex joint and allows six main movements of the shoulder to take 
place (flexion, extension, adduction, abduction, internal rotation, and external rotation). The 
deltoid muscle of the shoulder consists of three heads as anterior, medial, and posterior 
(Escamilla et al., 2009; Hik & Ackland, 2019; Sweeney, 2014). The anterior head of the 
shoulder attaches to the collarbone and raises the arm forward. The medial head attaches to the 
acromion process of the scapula and lifts the arm outward and laterally. Its posterior head 
attaches to the scapula and moves the arm backward (Sweeney, 2014).  
Since the shoulder is such a complex joint, it becomes difficult to choose the best exercise for 
shoulder muscle development. For this reason, it has been strongly recommended to use 
different mechanical stress methods and different exercise types for the development of all 
muscle groups of the shoulder (Campos et al., 2020). One way to determine the level of muscle 
activation associated with these different methods and exercises is to use electromyography 
(EMG) (Jakobsen et al., 2012). When the previous studies that investigated the activity level in 
the shoulder muscles using EMG are examined, Campos et al. (2020) found that the shoulder 
press exercise activates the anterior and lateral shoulder muscle groups more than the bench 
press and dumbbell fly exercises, but the lateral raise exercise shows higher muscle activity in 
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    75 
the lateral and posterior shoulder muscle groups than the shoulder press. Botton et al. (2013) 
reported that for the medial part of the shoulder, cable or dumbbell lateral lifting exercise 
provides higher muscle activity than shoulder press exercise. Coratella et al. (2020) observed 
that in variations of the lateral raise exercise, when the humerus is rotated outward, the anterior 
shoulder activity increases, when it is rotated inwards, the posterior shoulder activity increases, 
and when the humerus tends to rotate inward, the upper trapezius shows more activity. 
Saeterbakken and Fimland (2013) compared 4 shoulder press exercises in their study. This 
study showed that combining 2 unbalanced strategies in shoulder presses (standing + 
dumbbells) increased shoulder muscle activation. Franke et al. (2015) examined the activity 
level of the seated row, incline lat pulldown, and reverse peck deck fly exercises in the shoulder 
muscles and found that seated row was effective in working the medial part of the shoulder and 
reverse peck deck fly was effective in working the medial and back parts of the shoulder. Dickie 
et al. (2017) compared the muscle activity level of different variations in the pull-up exercise 
and found that the pronation grip variation activates the medial trapezius muscle more than the 
neutral grip. Also, they did not observe any difference between supination grip and neutral grip. 
At the same time, it is seen that training experience can positively affect the stimulation of the 
targeted muscles in such studies. Compared to other athletes, bodybuilders have a unique 
sensitivity to focus on metabolic stimuli and muscle stimulation (Hackett et al., 2013; Maeo et 
al., 2013). 
The effects of different grip and ROM variations on muscle activation in the deltoid muscle 
have not been fully observed in the current literature. We believe that it is valuable to determine 
effects of hand grip and ROM variations on muscle activation of deltoid muscle heads for 
improving muscle strength and hypertrophy in many sports branches and reducing the risk of 
injury. This study aimed to compare the dumbbell front raise (DFR), dumbbell lateral raise 
(DLR), and dumbbell rear delt raise exercises (DRDR) muscle activity with different handgrip 
and ROM variations in males with a resistance training background. The current research can 
help trainers, physiotherapists, and athletes to choose and apply the most appropriate exercise 
for performance improvement and hypertrophic adaptation. 
 
  
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    76 
METHODS 
Participants 
14 healthy men (mean ± SD age: 23.6 ± 0.90 years, body weight = 77.8 ± 6.43 kg, height = 176 
± 0.07) participated in the study. Gpower 3.9.1 software was used to determine the number of 
subjects to be included in the study. The total number necessary for the expectation of a high 
effect size (f = 0.25) to be found statistically significant was determined as 14 (α = 0.05; 1-β = 
0.80). Participants were well trained athletes with at least 5 years of resistance training history. 
All athletes were accustomed to the shoulder exercises included in the study and used these 
exercises consistently in their training programs. In addition, the athletes stated that they do 
split resistance training 4-5 times a week. All athletes were informed about the measurement 
procedures and possible risks, and a written consent form was signed before the measurement. 
Participants were selected from athletes who had not experienced any upper extremity muscle 
or joint injury and cardiovascular disease in the last 1 year, and who did not use any prohibited 
substance. Before the study, ethical approval was obtained from the ethics committee of 
Sakarya University of Applied Sciences (100/7428) and it was applied in accordance with the 
Declaration of Helsinki (1975) for studies with human subjects. 
Experimental design 
Repeated measures design was used to examine the effects of grip variations in shoulder 
exercises on 1RM strength and neuromuscular activity. On the first day, trial training was 
carried out in order to adapt to the different variations. On the second day, 1RM strength 
measurements were taken in three different DFR variations of the athletes and after 30 minutes 
of passive recovery, the athletes performed three different DFR variations in random order, at 
80% intensity, and 5 repetitions. Finally, on the third day, 1RM strength measurements were 
taken in two different DLR and DRDR variations of the athletes and after 30 minutes of passive 
recovery, the athletes performed two different variations of DLR and DRDR in random order, 
at 80% intensity and 5 repetitions. A minimum of 72 hours of rest was given between all 
sessions and the athletes were instructed not to do any other resistance training until the end of 
the measurements. Participants were instructed to continue their normal diet and routine 
training preparations throughout the study period. Athletes came to the measurement area at a 
time as close as possible to their routine training hours.  
  
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    77 
Maximal Strength Assessment 
Before 1RM strength tests the athletes performed a standard 10-minute warm-up protocol on 
the bicycle ergometer. Immediately after, they performed dynamic mobility exercises for the 
shoulder muscles. While performing 1RM strength measurements, 1 retest protocol 
recommended by the American College of Sports Medicine (ACSM) was applied. First, 2 
warm-up sets of light to moderate were applied. After the first set was performed 5-10 
repetitions, 1 minute rest was given. The second set was performed 2-5 repetitions and 2 
minutes of rest were given. With the third set, 1 repetition attempt was started and 2-4 minutes 
of rest was given. In the following sets, 5-10% load increase was continued with each successful 
lift and a rest period of 2-4 minutes was given. When an unsuccessful lift occurred, the load 
was reduced by 2.5-5% and the lift was performed again (ACSM 2013). 
Exercise Protocol 
In general, for strength and hypertrophy gain, resistance training is performed at 80% intensity 
of 1RM. This percentage of intensity corresponds to a load of 8 to 12 RM. In order to avoid the 
confusing effects of fatigue and postural sway on neuromuscular activation the exercises were 
performed as five repetitions. Each exercise was applied for 2 seconds for the concentric phase, 
2 seconds for the eccentric phase and 0.5 seconds for the isometric phase. A metronome was 
used to facilitate the implementation of the targeted protocol and a camera was used to provide 
feedback for each exercise technique. All exercises were performed standing up, and a square 
rope was used approximately 1 cm from the skin and 3 cm above the iliac crest to prevent 
postural sway while performing the exercises. The position was adjusted with the feet shoulder-
width apart and the knees extended. Movement forms were kept under control by 3 researchers 
and feedback was given. In the study, firstly, random measurements were taken in the hammer 
grip (HG), supinate grip (SG) and pronate grip (PG) grip variations of the DFR exercise (Fig. 
1). The DFR HG (Fig. 1a) was performed as follows: From a neutral starting position, the 
athlete, holding the weight upright, raises one arm to 90 degrees of shoulder flexion and returns 
to the neutral position on the same route. The DFR SG (Fig. 1b) and DFR PG (Fig. 1c) grips 
also start from a neutral starting position and lift the weight until the athlete reaches 90 degrees 
of shoulder flexion. At the same time, the SG rotates the arm outward, while in the PG, it rotates 
the arm inward. In all variations, the position is maintained with the elbows slightly bent 
throughout the range of motion. In the DLR exercise, measurements were taken in full ROM 
(FLR) and limited ROM (LTR) variations (Fig. 2). In the DLR FLR variation (Fig. 2a), the 
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    78 
athletes performed the exercise with their hips against the wall, in a position of 30 degrees trunk 
flexion, and lifting the weights from the anterior aspect of the pelvic bone to 90º shoulder 
abduction. 
In the DLR LTR (Fig. 2b) variation, the athletes applied by leaning against the wall in the 
anatomical position and lifting the weights from the lateral side of the pelvic bone until 90º 
shoulder abduction. Finally, measurements were taken in the STD and HG variations of the 
DRDR exercise (Fig. 3). In the DRDR STD (Fig. 3a) variation, the athletes performed the 
exercise with the trunk in 90 degrees flexion position and internal rotation of the arm. In the 
DRDR HG (Fig. 3b) variation, the athletes only performed the exercise without any rotation of 
the arm. In both variations, the elbows are kept in a slightly bent position throughout the range 
of motion. 
Figure 1. Handgrip variations for Dumbbell Front Raise. a) Hammer grip (HG) b) Pronate grip 
(PG) c) Supinate grip (SG). 
 
  
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    79 
Figure 2. ROM variation for Dumbbell Lateral Rise. a) Limited ROM (LTD) b) Full ROM 
(FLR). 
 
 
Figure 3. Handgrip variations for Dumbbell Rear Delt Raise. a) Hammer grip (HG) b) Standart 
grip (STD). 
 
 
 
 
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    80 
EMG Recording 
The skin of the athletes was cleaned using cotton and skin cleansing alcohol. Then, electrodes 
were placed on the anterior deltoid (AD), medial deltoid (MD) , posterior deltoid (PD) and 
flexor carpi radialis muscles (FCR) of each participant according to the SENIAM 
recommendations (Hermens et al., 1999). The IMU data of the FCR muscle and the surface 
EMG data of the AD, MD, PD muscles were recorded using the Trigno wireless biofeedback 
system with the EMG plot software at 1000Hz sampling frequency. The recorded data was 
analyzed with EMGwork analysis software. Filtering was applied according to SENIAM 
recommendations to remove noise from the data. The filtered signal (mV) root mean square 
(RMS) was calculated using a moving window (window length 11sample, window overlap 
3sample). Concentric and eccentric phases of five repetitions were determined by using the 
angular position data obtained from the IMU sensor. The first repetition was not included to 
avoid possible mistakes when starting the exercises (Saeterbakken & Fimland, 2012). The RMS 
of filtered sEMG data of each muscle was normalized for 1RM maximal activation and MVC% 
values were calculated. The mean and maximum MCV% values of four repetitions were 
calculated. 
Statistical analysis 
Means of the data are presented. The normality of the data was examined using the Shapiro–
Wilk test. It was determined that the data did not showed normal distribution. To compare the 
differences in 1-RM strength and neuromuscular activity of DFR exercise variations, Friedman 
test, one of the nonparametric tests, was used. The Wilcoxon test was used to compare 
variations of DLR and DRDR exercises. In this exploratory study, the level of significance of 
each comparison was set to p <0.05. The entire analysis was conducted using the software SPSS 
(Version 22.0). 
 
RESULTS 
In the DFR exercise, three different grip variations were compared with the Friedman test, and 
the Wilcoxon test was applied to find the source of the difference. DLR and DRDR exercises 
were compared with the Wilcoxon test and the mean values are given in the figure. Muscle 
responses of anterior, medial and posterior head in concentric and eccentric phases in DFR, 
DLR, DRDR exercises are given in the figure below.  
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    81 
Figure 4. MVC% values of anterior, medial and posterior heads of deltoid in DFR exercise. 
 
a: Significant difference between Anterior Dfr Hg Con, Dfr Pg Con and b: Posterior Dfr Pg Ecc, Dfr Sg Ecc p<0.05.  
 
Muscle responses from each head of the deltoid muscle in the DFR exercise were compared for 
different grip variations. It was observed that the highest muscle activation occurred in the 
anterior head in the concentric phase with the PG (51.57%). When the anterior deltoid muscle 
responses compared related to the variations, it was observed that, difference between HG and 
PG con variations was statistically significant (HG con 43.36% PG con 51.57% p<0.05). 
However, no significant difference was observed between the HG, PG ecc (HG ecc 40.36%, 
PG ecc36.4%) and the SG variations (SG con 47.00%, SG ecc 41.51%, p>0.05). It was observed 
that the highest muscle activation in the medial deltoid occurred in the concentric phase with 
SG (29.63%). For medial deltoid, no significant difference was observed between the variations 
(HG con 21.11%, HG ecc 23.50%, PG Con 26.82%, PG ecc 24.19%, SG con 29.63%, SG ecc 
24.37%, p>0.05). It was observed that the highest muscle activation in the posterior deltoid 
occurred in the eccentric phase for PG (37.50%). The difference between SG and PG ecc 
variations was statistically significant (SG ecc 19.65%, Pg ecc 37.40%, p<0.05). No significant 
difference was observed between the PG, SG con (SG con 22.59%, PG con 29.43%) and the 
HG variations (HG con 26.59% HG ecc 31.14% p>0.05) (Fig. 4). 
 
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    82 
Figure 5. MVC% values of anterior, medial and posterior heads of deltoid in DLR exercise. 
 
a: Significant difference between Anterior Dlr Flr Con and Dlr Ltr Con p<0.05. 
Muscle responses from each deltoid heads in the DLR exercise were compared for different 
ROM variations. It was observed that the highest muscle activation occurred in the medial head 
in the concentric phase for the LTR (20.74%). When the anterior deltoid responses compared 
related to the variations, it was observed that, difference between FLR and LTR con variations 
was statistically significant (FLR con 16.88%, LTR con 19.37%, p<0.05). However, no 
significant difference was observed between the FLR and LTR ecc variations (FLR ecc 13.76%, 
LTR ecc 16.88%, p>0.05). It was observed that the highest muscle activation in the medial 
deltoid occurred in the concentric phase with LTR (20.74%).  
For medial deltoid, no significant difference was observed between the variations (FLR con 
20.60%, FLR ecc 18.99%, LTR con %20.74, LTR ecc 19.62%, p>0.05). It was observed that 
the highest muscle activation in the posterior deltoid occurred in the ecc phase with FLR 
(11.49%). However, no significant difference was observed between the FLR and LTR (FLR 
con 10.89% FLR ecc 11.49%, LTR con 10.41%, LTR ecc 9.20%) variations (Fig. 5). 
  
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    83 
Figure 6. MVC% values of the anterior, medial and posterior heads of the deltoid in DRDR 
exercise. 
 
a: Significant difference between Posterior Drdr Std Ecc and Drdr Hg Ecc p<0.05. 
 
Muscle responses from each deltoid heads in the DRDR exercise were compared different 
handgrip variations. It was observed that the highest muscle activation occurred in the medial 
head in the concentric phase with the HG (24.47%). It was observed that the highest muscle 
activation in the anterior deltoid occurred in the concentric phase with STD (24.10%). However, 
no significant difference was observed between the STD and HG (STD con 24.10%, STD ecc 
17.95%, HG con 22.95%, HG ecc 19.39%) variations (p>0.05). It was observed that the highest 
muscle activation in the medial deltoid occurred in the concentric phase with HG (24.47%). For 
medial deltoid, no significant difference was observed between the variations (STD con 
24.14%, STD ecc 21.55%, HG con %24.47, HG ecc 23.06%, p>0.05). When the posterior 
deltoid responses compared related to the variations, it was observed that, difference between 
STD and HG variations was statistically significant (STD con 17.27%, STD ecc 23.07, HG con 
15.72%, HG ecc 17.30%, p<0.05) (Fig. 6). 
 
  
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    84 
DISCUSSION 
In this study, the muscle activity levels of the deltoid muscle heads were measured for 3 
exercises (DFR, DLR, DRDR) at the different handgrip and ROM variations. For the DFR 
exercise, the level of anterior head activation was higher than the medial and posterior heads. 
The activation level of anterior and posterior heads was higher for PG at the concentric and 
eccentric phases. For DLR exercise, the highest muscle activation was observed at the medial 
deltoid but only the concentric phase anterior deltoid activity level differentiated for LTR. 
DRDR exercise activation was higher for the anterior and medial heads than the posterior 
deltoid during HG. STD demonstrated more muscle activity at the posterior deltoid eccentric 
phase of DRDR exercise than HG.  
To the authors’ knowledge, this is the first study to investigate differences in muscle activity of 
the deltoid heads during the concentric and eccentric phases of different exercises with different 
handgrip and ROM variations. Knowing the muscle activity levels of different exercises on the 
three heads of the deltoid muscle can assist in choosing the most appropriate exercise for 
strengthening and rehabilitation. The results of the present study showed that different deltoid 
exercises demonstrated different activation levels for each head of the deltoid muscle. This 
finding is consistent with the results of previous studies that reported each head of the deltoid 
is activated differently per specific exercise (Botton et al., 2013; Coratella et al., 2020; Raizada 
& Bagchi, 2017). In particular, Coratella et al. (2020) reported similar results with the present 
study. They found that the muscle activity in the anterior deltoid was greater during the frontal 
raises concentric phase, and the medial deltoid was more active during the lateral raises. These 
results can be explained by the primary functions of the deltoid heads in different movements. 
For example, in horizontal shoulder flexion movements, the anterior deltoid is defined as the 
main agonist head (Brum et al., 2008). Shoulder abduction is the primary function of the medial 
deltoid (Kronberg et al., 1990; Reinold et al., 2004). In addition, the posterior deltoid is 
considered the prime mover during horizontal shoulder extension (Knudson, 2007). 
 Another main finding of the present study is that dumbbell grip variations in deltoid exercises 
cause different degrees of muscle activation on deltoid heads. Past studies on different body 
parts and with different exercises have revealed that muscle activation is affected by grip 
variations (Pratt et al., 2020; Signorile et al., 2002). One of the limited numbers of studies on 
the shoulder muscle group supporting the results of our study reported that different hand 
positions cause differences in posterior deltoid activation in the horizontal abduction movement 
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    85 
exercise (reverse fly machine) (Schoenfeld et al., 2013). In the studies examining how grips 
and hand positions as a result of grips affect local muscle activation, it can be explained by 
length tension. For example, grips that require an internally rotated and horizontally addicted 
start position have the potential to stretch the posterior deltoid. Therefore, this situation may 
prevent the development of local strength in such exercises (Hung et al., 2010; Kolber & 
Hanney, 2010; Schoenfeld et al., 2013). It is thought that the grips versions of the exercises 
used in this study and performed in different planes affect muscle activation because they cause 
length tension in different parts of the deltoid. 
In our study, two different ROMs (Limited, Full) were used in the lateral raise exercise. No 
research has been found in the literature examining deltoid activation in the lateral raise exercise 
performed in different ROMs. The present results showed that only LTR caused higher 
activation in the concentric phase of anterior deltoid muscle activation. Contrary to our results, 
Paoli et al. (2010) stated that the wider the ROM in the military press exercise, which is an 
overhead exercise, the higher the activation in the deltoid sections. However, we do not find it 
appropriate to compare the results because the type of exercise used in this study and the 
exercise used in our study are biomechanically different. Especially due to the different starting 
positions and directions of the exercises, the muscle activation of the deltoid heads may also 
differ. Some limitations are present in this study and should be considered prior to exercise 
applications. In this study, the effects of grips and ROM variables only on the deltoid muscle 
were examined and exercises for this muscle area were selected. Participants were well-trained 
athletes with at least 5 years of resistance training history. Therefore, the variables selected in 
the study may show different muscle activations in inexperienced and recreational athletes. 
 
CONCLUSION 
In conclusion, for the heads of the deltoid muscle, the use of the different grip and ROM 
variations may increase or decrease the neuromuscular activity. Especially HG for anterior 
deltoid in dumbbell front raise, LTR for anterior deltoid in lateral raise, and STD for posterior 
deltoid in dumbbell rear delt raise exercise are the grip and ROM variations that increase muscle 
activation.  The results of this research may be effective for competitive athletes rather than 
recreational athletes. Especially for experienced fitness and bodybuilding athletes, using hand 
grips and ROM that provide more muscle activation in the development of hypertrophy for 
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    86 
specific body regions can achieve their goals. It can also assist trainers who aim for optimum 
load and impact in their training in choosing the most appropriate hand grip and ROM.   
Declaration of Conflicting Interests 
The author(s) declared no potential conflicts of interest with respect to the research, authorship, 
and/or publication of this article. 
 
REFERENCES 
American College of Sports Medicine (Ed.). (2013). ACSM's health-related physical fitness assessment manual. 
Lippincott Williams & Wilkins. 
Botton, C. E., Wilhelm, E. N., Ughini, C. C., Pinto, R. S., & Lima, C. S. (2013). Electromyographical analysis of 
the deltoid between different strength training exercises. Medicina Sportiva, 17(2).  
Brum, D. P. C. d., Carvalho, M. M. d., Tucci, H. T., & Oliveira, A. S. d. (2008). Electromyographic assessment of 
scapular girdle and arm muscles during exercises with fixed boundary and axial load. Revista Brasileira de 
Medicina do Esporte, 14(5), 466-471.  
Campos, Y. A., Vianna, J. M., Guimarães, M. P., Oliveira, J. L., Hernández-Mosqueira, C., da Silva, S. F., & 
Marchetti, P. H. (2020). Different shoulder exercises affect the activation of deltoid portions in resistance-trained 
individuals. Journal of human kinetics, 75, 5.  
Cogley, R. M., Archambault, T. A., Fibeger, J. F., & Koverman, M. M. (2005). Comparison of muscle activation 
using various hand positions during the push-up exercise. Journal of Strength and Conditioning Research, 19(3), 
628.  
Coratella, G., Tornatore, G., Longo, S., Esposito, F., & Cè, E. (2020). An electromyographic analysis of lateral 
raise variations and frontal raise in competitive bodybuilders. International Journal of Environmental Research 
and Public Health, 17(17), 6015.  
Dickie, J. A., Faulkner, J. A., Barnes, M. J., & Lark, S. D. (2017). Electromyographic analysis of muscle activation 
during pull-up variations. Journal of Electromyography and Kinesiology, 32, 30-36.  
Escamilla, R. F., Yamashiro, K., Paulos, L., & Andrews, J. R. (2009). Shoulder muscle activity and function in 
common shoulder rehabilitation exercises. Sports Medicine, 39(8), 663-685.  
Fleck, S. J., & Kraemer, W. (2014). Designing resistance training programs, 4E. Human Kinetics.  
Franke, A., Botton, C. E., Rodrigues, R., Pinto, R., & Lima, C. (2015). Analysis of anterior, middle and posterior 
deltoid activation during single and multijoint exercises. J Sports Med Phys Fitness, 55, 714-721.  
Hackett, D. A., Johnson, N. A., & Chow, C.-M. (2013). Training practices and ergogenic aids used by male 
bodybuilders. The Journal of Strength & Conditioning Research, 27(6), 1609-1617.  
Hermens, H., Freriks, B., Merletti, R., Hägg, G., Stegman, D., Blok, J., Rau, G., & Disselhorst-Klug, C. (1999). 
SENIAM 8: european recommendations for surface electroMyoGraphy roessingh research and development bv. 
Enschede, The Netherlands.  
Hik, F., & Ackland, D. C. (2019). The moment arms of the muscles spanning the glenohumeral joint: a systematic 
review. Journal of anatomy, 234(1), 1-15.  
Hung, C.-J., Hsieh, C.-L., Yang, P.-L., & Lin, J.-J. (2010). Relationship between posterior shoulder muscle 
stiffness and rotation in patients with stiff shoulder. Journal of rehabilitation medicine, 42(3), 216-220.  
Kinesiologia Slovenica, 29, 1, 73-87 (2023), ISSN 1318-2269   Muscle Activation of Different Deltoid Exercises    87 
Jakobsen, M. D., Sundstrup, E., Andersen, C. H., Zebis, M. K., Mortensen, P., & Andersen, L. L. (2012). 
Evaluation of muscle activity during a standardized shoulder resistance training bout in novice individuals. The 
Journal of Strength & Conditioning Research, 26(9), 2515-2522.  
Knudson, D. V. (2007). Fundamentals of biomechanics (Vol. 183). Springer.  
Kolber, M. J., & Hanney, W. J. (2010). The reliability, minimal detectable change and construct validity of a 
clinical measurement for identifying posterior shoulder tightness. North American journal of sports physical 
therapy: NAJSPT, 5(4), 208.  
Kronberg, M., Németh, G., & Broström, L. (1990). Muscle activity and coordination in the normal shoulder. An 
electromyographic study. Clinical orthopaedics and related research(257), 76-85.  
Lusk, S. J., Hale, B. D., & Russell, D. M. (2010). Grip width and forearm orientation effects on muscle activity 
during the lat pull-down. The Journal of Strength & Conditioning Research, 24(7), 1895-1900.  
Maeo, S., Takahashi, T., Takai, Y., & Kanehisa, H. (2013). Trainability of muscular activity level during maximal 
voluntary co-contraction: comparison between bodybuilders and nonathletes. PloS one, 8(11), e79486.  
Paoli, A., Marcolin, G., & Petrone, N. (2010). Influence of different ranges of motion on selective recruitment of 
shoulder muscles in the sitting military press: an electromyographic study. The Journal of Strength & Conditioning 
Research, 24(6), 1578-1583.  
Pratt, J., Hoffman, A., Grainger, A., & Ditroilo, M. (2020). Forearm electromyographic activity during the deadlift 
exercise is affected by grip type and sex. Journal of Electromyography and Kinesiology, 53, 102428.  
Raizada, S., & Bagchi, A. (2017). Comparison among the EMG Activity of the Anterior Deltoid and Medial 
Deltoid During Two Variations of Dumbbell Shoulder Press Exercise. Indian Journal of Public Health Research 
& Development, 8(4).  
Reinold, M. M., Wilk, K. E., Fleisig, G. S., Zheng, N., Barrentine, S. W., Chmielewski, T., Cody, R. C., Jameson, 
G. G., & Andrews, J. R. (2004). Electromyographic analysis of the rotator cuff and deltoid musculature during 
common shoulder external rotation exercises. Journal of orthopaedic & sports physical therapy, 34(7), 385-394.  
Saeterbakken, A. H., & Fimland, M. S. (2012). Muscle activity of the core during bilateral, unilateral, seated and 
standing resistance exercise. European journal of applied physiology, 112(5), 1671-1678.  
Saeterbakken, A. H., & Fimland, M. S. (2013). Effects of body position and loading modality on muscle activity 
and strength in shoulder presses. The Journal of Strength & Conditioning Research, 27(7), 1824-1831.  
Schoenfeld, B., Sonmez, R. G. T., Kolber, M. J., Contreras, B., Harris, R., & Ozen, S. (2013). Effect of hand 
position on EMG activity of the posterior shoulder musculature during a horizontal abduction exercise. The Journal 
of Strength & Conditioning Research, 27(10), 2644-2649.  
Signorile, J. E., Zink, A. J., & Szwed, S. P. (2002). A comparative electromyographical investigation of muscle 
utilization patterns using various hand positions during the lat pull-down. The Journal of Strength & Conditioning 
Research, 16(4), 539-546.  
Smith, L. K. (1996). Brunnstrom's Clinical Kinesiology: Laura K Smith.  
Sweeney, S. P. (2014). Electromyographic analysis pf the deltoid muscle during various shoulder exercises  
Vigotsky, A. D., Halperin, I., Lehman, G. J., Trajano, G. S., & Vieira, T. M. (2018). Interpreting signal amplitudes 
in surface electromyography studies in sport and rehabilitation sciences. Frontiers in physiology, 8, 985.