An observational study in Smartphone Addiction, Masseter Muscle Hypertrophy and Masseter Muscle Spasm, sponsored by Bandırma Onyedi Eylül University. Completed at 1 site in Turkey. Open to participants aged 18 Years to 30 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-06-06.
Sponsored by Bandırma Onyedi Eylül University · Observational
The aim of this study was to determine the short- and long-term effects of smartphone use on the masseter muscle. In the short term, to investigate whether repetitive thumb movements during phone use will cause a spontaneous muscle activation and/or tenderness in the masseter muscle; in the long term, to investigate the relationship between strength change and tenderness of the tenar and masseter muscles depending on the intensity and duration of phone use.
A total of 120 healthy university students aged 18-30 years at Bandırma Onyedi Eylül University will be included in our study. Descriptive data form, Smartphone Addiction Scale - Short Form, Edinburg Hand Preference Inventory, pressure pain threshold, muscle activity, lateral grip strength, hand grip strength will be evaluated in the participant students.
166 studies on the registry are indexed under Internet Addiction Disorder; 47 are open to participants now.
This study's enrollment of 105 is below the median of 120 across 69 observational studies indexed under Internet Addiction Disorder.
Browse Internet Addiction Disorder studies →Bandırma Onyedi Eylül University is the lead sponsor of 70 studies on the registry; 19 are open to participants now.
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University students
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Smartphone Addiction Scale-Short Form
In our study, the Smartphone Addiction Scale-Short Form will be filled out to evaluate the intensity of smartphone use of students, and the daily duration of smartphone use will be recorded. This scale consists of 10 6-point Likert-type items used to measure the risk of smartphone addiction. Scores on the scale range from 10-60, with an increase in score indicating an increased risk for smartphone addiction. The cut-off score of the scale was determined as 31 for men and 33 for women in the Korean sample.
Time frame: 4 months
Edinburg Hand Preference Inventory
Edinburg Hand Preference Inventory will be used to determine the dominant hand in our study. This scale asks which hand is used while performing 10 activities such as "writing", "drawing", "brushing teeth", "holding a fork (while eating)". For each activity; left hand preference is -10 points, right hand preference is +10 points and both hand preference is 0 points. After hand preference for all activities, the highest score that individuals can get is +100 and the lowest score is -100. A "negative" score is in favor of "left-handedness" and a "positive" score is in favor of "right-handedness". According to this scoring, individuals with a score between "+40 and +100" are recorded as "right-handed", individuals with a score between "-30 and +30" as "two-handed", and individuals with a score between "-100 and -40" as "left-handed".
Time frame: 4 months
Pressure Pain Threshold Assessment
In our study, pressure pain threshold measurement of the dominant and non-dominant side masseter and tenar muscles before and after the activity will be evaluated with Baseline manual algometer (2.5 kg-11 lb).
Time frame: 4 months
Muscle Activation Measurement
In our study, a four-channel Neurotrac Myoplus Pro 4 EMG Biofeedback device will be used for superficial electromyographic (EMG) measurements of the masseter muscle. The results of electromyographic activity will be presented as both mean data (microvolts) and normalized mean data (%MVC- Maximum Voluntary Contraction). The mean, minimum and peak contraction values of the activation will be recorded, the variability of the activation produced will be evaluated with the Inter Quantile Range (IQR). The average muscle activations that will occur in the muscle will be used as %MVC.
Time frame: 4 months
Hand Grip Strength Assessment
Hand grip strength will be measured with 'Saehan Hydraulic Hand Dynamometer'. A total of three measurements will be made for each hand with a 15 s break between each measurement of the extremity and the average of the three measurements will be taken. Test results will be recorded in kilograms.
Time frame: 4 months
Finger Lateral Grip Strength Assessment
Hand grip strength will be measured with 'Saehan Hydraulic pinch gauge'. Three measurements will be made for each hand in total with a 30-second break between each measurement and the average of the three measurements will be recorded in kilograms.
Time frame: 4 months
This study is completed, as verified in May 2024. You cannot join it, but the record below documents what was studied.
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Bandırma Onyedi Eylül University