Effects of Electrical Muscle Stimulation Exercise on Lower, Upper Extremity and Core Strength in Sedentary Women
Phase: NA
Conditions: Sedentary Lifestyle, Muscle Stimulation
Sponsor: Ondokuz Mayıs University

Official Title: The Effects of Electrical Muscle Stimulation Exercise on Upper, Lower 
Extremity and Core Strength in Sedentary Women 
NCT Number: Pending 
Date: October 7, 2025 
Prepared by:  Dr. Ali Kerim Yılmaz  
           Esra Korkmaz Salkılıç 
Institution: 19 Mayıs University 

The Effect of Electrical Muscle Stimulation Exercise on Lower, Upper Extremity, and 
Core Strength in Sedentary Women 
 
Participants 
Our study was conducted with 27 sedentary women between the ages of 19-24. The 
optimal number of subjects to participate in the study was determined using the GPower 3.1.3 
program. The results indicated that a total of 16 subjects would be an appropriate sample size 
for the study (effect size r: 0.87, lower and upper critical p: 0.53, true power: 0.92). Before the 
study, the subjects were informed in detail and included in the study by obtaining an "Informed 
Consent Form". 
 
 
         Figure 1. Flowchart 
Study Design 
This study was designed as a 2-arm parallel-group randomized controlled trial comparing 

the effects of submaximal EMS exercises. The study was approved by the Ondokuz Mayıs 
University Clinical Research Ethics Committee (approval number: 021/482) and was conducted 
as per the ethical principles stated in the Declaration of Helsinki. The inclusion criteria of the 
participants were determined as being between the ages of 19-24, being female, and 
volunteering. Exclusion criteria were those who had cardiovascular, neurological, or orthopedic 
disorders, were pregnant or were planning to become pregnant. Subjects made a total of 10 
visits, including the familiarization session for the study.  During the first visit, participants 
were informed about test protocols. Anthropometric measurements were then taken and trial 
measurements were made. In the pre-, mid (week 4), and post (week 8) test periods, all 
participants performed 3 visits at 24-hour intervals for a total of 9 visits according to the test 
protocols they selected from the practice cards specified for each period, and mid and post-tests 
were arranged so that they did not coincide with training days. Practice cards were as follows: 
1- modified push-up (MPU),Handgrip strength (HS), single hop for distance (SH), Biering 
Sorensen (Bie-sor), 2- Bent arm hanging (BAH), triple hop for distance (TH), crossover triple 
hop for distance (CH), v-sit flexor (V-sit) and 3- deep squat (DS), medial side triple hop for 
distance (MSTH),  sit-up. After completion of the pre-tests, participants were randomized into 
one of two exercise groups using computer-validated software (www.random.org) and divided 
into EMS (n=15) and Control (CON) (n=16) groups. Participants who did not participate in 
regular exercises and tests in both groups were excluded from the study and the study was 
completed with 12 participants for the EMS group and 15 participants for the CON group. All 
measurements and exercises were done at the same time of the day (12:00-16:00). The 
participants performed warm-up exercises before the tests. Both groups were asked not to make 
any changes in their usual physical activity behavior. Also, all participants were instructed to 
maintain their normal dietary intake before and during the study. The endpoint of the study was 
determined as the participant withdrawing consent to participate in the study, the experts 
deciding that it was not appropriate for the participant to continue in the study, and non-
compliance with the study protocol. 
 
Electro Muscle Stimulation (EMS) Implementation: Participants were instructed that the 
clothing they would wear during training should be cotton and of a length that would cover 
their major muscle groups. Then, before the EMS vest was put on, water was sprayed on the 
main muscle groups where the apparatus that will transmit the current inside it corresponds. 
After the vest was put on, cable connections were made to the device.Participants were 
subjected to EMS currents in cardio mode (continuously alternating low-frequency currents 

ranging from 1 to 1000 Hz) in a 9 s current/2 s rest pattern for 20 minutes. The muscles 
stimulated with EMS were: gluteus maximus, quadriceps and hamstrings of the lower 
extremity, biceps brachii, triceps brachii, pectoralis major and teres major of the upper 
extremity, and rectus abdominis and latissimus dorsi of the trunk. The content and scope of the 
exercise to be performed were designed as intermittent, low intensity/low intensity to affect the 
lower, upper, and core strengths. 
 
Figure 2. EMS Device and Vest 
Table 1: Exercise Protocol 
Exercise 
Rest 
Rope skipping – 30 sec×2 
10 sec 
Overhead stand crunch – 30 sec×2 
10 sec  
Overhead side bends – 30 sec×2 
10 sec 
Squats 30 sec×2 
10 sec 
Sumo squats 30 sec×2 
10 sec 
Overhead lunge – 30 sec×2 
10 sec 
Side lunges - 30 sec×2 
10 sec 
Sit-up -30 sec×2 
10 sec 
Reverse shuttle -30 sec×2 
10 sec 
Single leg drop – 30 sec×2 
10 sec 
Flutter kicks – 30 sec×2 
10 sec 
V-sit – 30 sec×2 
10 sec 
Leg hold – 30 sec×2 
10 sec 
Reverse leg lift – 30 sec×2 
10 sec 
Heel touch – 30 sec×2 
10 sec 
Point single leg bridge drop – 20 sec×2 
10 sec 
Plank – 30 sn×2 
10 sec 
Procedures 
Modified Push Up Test (MPU) 
Participants were positioned face down on a mat with only their palms and toes touching 
the floor.  Then, the participants were instructed to start by bending only their elbows and 
lowering and raising their bodies so that the chest did not touch the floor. The participant 
repeated as many movements as possible for 30 s and the movement was recorded in units 
(Chen et al., 2018). 

Handgrip Strength Test (HS) 
The measurements were made using a hand dynamometer that can measure force between 
0-100 kilograms, and the dynamometer was adjusted according to the hand of the athlete to be 
measured before the measurement. The person to be measured was asked to squeeze with 
maximum force while standing, with arms hanging down so that the dynamometer did not touch 
the body. 3 measurements were made, with 1 minute of rest between measurements, and their 
averages were recorded (Melo et al., 2025). 
Bent Arm Hanging Test (BAH) 
This test was based on the measurement of the hanging time of the athletes with their 
arms in full flexion (elbow joint angle less than 75o). During the test, the athlete was verbally 
warned to remain in the position in question. The test was terminated when the participant's 
chin dropped below the bar level. The test result was recorded with a CASIO timer as the time 
the participant could hang under defined conditions (Clemons, 2014). 
Single Leg Hop Tests (SLHT) 
SLHTs were implemented on a single line by the parameters SH, TH, CH, and MSTH 
(Reid et al., 2007; Kivlan et al., 2013). For the line to be used in the test, a 0.3 m strip was 
determined as the starting point, and a 6 m long and 5 cm wide strip extending from the middle 
was placed vertically. Before starting the test, the test protocol was shown to the subjects 
verbally and practically. Each participant performed 1 trial forward from the baseline for each 
test and each limb. They then performed 3 trials for the actual test and the result was recorded 
in cm. A 30-second rest was given between trials. The best-recorded score was measured 
between the baseline and the subject's heel. No restrictions were made on arm swings. After the 
jump, care was taken to ensure that the subject was on the line in the limb that was tested in a 
controlled manner. The test was repeated if the subject lost balance landed on a limb different 
from the test limb, or made an additional jump after landing (Kehribar et al., 2022). 
Deep Squat Test (DS) 
In the deep squat test, individuals place their feet shoulder-width apart with their toes 
pointing straight ahead. On command, participants stand in the lowest squat position they can 
reach without lifting their heels off the floor. Although each individual has three attempts, if 
they complete the test on the first attempt, they do not need to repeat the test (Stanton et al., 
2021). 
V-Sit Flexor Test 
For the V-sit flexor endurance test, testing the endurance of the flexor muscles began with 
the person being placed in a sitting position and leaning on a jig with the back at an angle of 55 

degrees from the floor. Knees and hips were flexed 90 degrees, arms folded across the chest, 
and feet secured under the strap. To start, the jig was pulled back 10 cm (4 inches) and the 
person tried to hold it as long as possible without disturbing the posture of the body. Failure in 
the test was determined to occur when the subject's back was touched or when the subject was 
asked to stop (Chai et al., 2024). 
Sit- Up Test 
In the sit-up test, the participant lay on their back on a gymnastics mat and locked their 
hands behind their neck. The sole was fixed to the mat with the knees at a fixed angle (90°). An 
aid was used to stabilize the sole. The number of sit-ups the subject would perform for 30 
seconds was recorded (Kukic et al.,2022). 
Biering Sorensen Test (Bie-sor) 
For the Biering-Sorensen-back extensor test, the upper body was extended over the end 
of a stretcher and then the pelvis, knees, and hips were fixed. The test began after the hands 
were fixed crosswise on the chest. Failure in the test occurred when the upper trunk broke its 
horizontal position when it failed to maintain its position after a verbal warning, and when the 
participant requested to stop (Nuzzo & Mayer, 2013).