Smartphone AddictionNCT06843863
The Effects of Smartphone Addiction on Pinch Strength, Muscle Stiffness, and Hand/Wrist Function in Young Adults
An observational study of Smartphone Addiction, run by Istanbul Gelisim University at 1 site in Turkey (Türkiye).
Trial summary
Smartphones have become an indispensable part of daily life, and their increasing use has raised concerns about various health effects, including musculoskeletal symptoms. Repetitive movements of the thumb and hand muscles can lead to issues such as tendinosis, myofascial pain syndrome, and a decrease in pinch… Read more about this study
- Who is it for?
- Ages 18 to 25 yearsHealthy volunteers can take part
- Conditions the study is for
- Smartphone Addiction
- How many people
- 134 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 15 Dec 2024to 5 Jan 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 25 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: University student from Istanbul Kent University and Istanbul Gelisim University.
Who may be able to join
- Willing to participate in the study
- Have been using a smartphone for more than one year
- Aged between 18 and 25 years
- Send 25 or more text messages or emails per day
- Spend more than 2 hours browsing the internet and/or play games for more than one hour a day
Who cannot join
- Having radiating/radicular pain in the upper extremity
- Having neck pain
- Congenital deformities in the upper extremity and neck
- A history of diagnosed neurological, rheumatic, musculoskeletal, or cardiovascular diseases
- Having previously undergone surgery on the neck and/or upper extremity
- Having been diagnosed with De Quervain's disease or tendinopathy in the hand/hand wrist muscles before
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Istanbul Kent University
Istanbul, Kağıthane, 34320
About this study
Official title: The Effects of Smartphone Addiction on Pinch Strength, Muscle Stiffness, and Hand and Wrist Function in Young Adults: A Cross-Sectional Study
Smartphones have become an indispensable part of daily life, and their increasing use has raised concerns about various health effects, including musculoskeletal symptoms. Repetitive movements of the thumb and hand muscles can lead to issues such as tendinosis, myofascial pain syndrome, and a decrease in pinch strength. Studies have shown that musculoskeletal symptoms related to smartphone use are common among young adults and university students. Additionally, an increase in device size may place greater strain on the wrist and finger muscles. Repetitive movements can cause stiffness changes in the thumb muscles, and the relationship between these changes and pinch strength is considered an important research topic. In this study, we aimed to investigate the effects of smartphone addiction on pinch strength, muscle stiffness, hand/wrist pain, and function in young adults.
Read the detailed description
This study was designed as a cross-sectional study. Volunteers eligible to participate were first screened based on the results of the Smartphone Addiction Scale-Short Version (SAS-SV), and they were divided into two groups as Smartphone Addiction and Non-Smartphone Addiction, with a cutoff score of 31 for males and 33 for females. Subsequently, the determination of dominant hand was performed. All assessments were conducted on the participants' dominant extremity. The assessments were carried out in the following order: Patient-Rated Wrist/Hand Evaluation Questionnaire (PRWHE), the Finkelstein test, muscle stiffness measurement, and finally, pinch strength assessment, as it was considered to potentially cause fatigue. All assessments were conducted by expert physiotherapists within a total duration of 30 minutes, and participants were not followed up afterward, nor recieved any intervention.
- Conditions
- Smartphone Addiction
- Being tested
- No intervention.
- Keywords
- Smartphone, Behavior, Addictive, Muscle stiffness, Musculoskeletal Pain
- Medical subject headings
- Internet Addiction Disorder, Behavior, Musculoskeletal Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No intervention.Other
Participants allocated to the groups were assessed only once. No intervention was applied, and they were not followed up.
| Study group | Role | What they receive |
|---|---|---|
| Smartphone Addiction Group | Individuals classified as having smartphone addiction based on the Smartphone Addiction Scale-Short Version (SAS-SV). Participants in this group scored 31 or higher for males and 33 or higher for females on the SAS-SV, indicating problematic smartphone use that meets the threshold for addiction. Receives: Other: No intervention. | |
| Non-Smartphone Addiction Group | Individuals who are not classified as having smartphone addiction based on the Smartphone Addiction Scale-Short Version (SAS-SV). Participants in this group scored below 31 for males and below 33 for females on the SAS-SV, indicating that their smartphone use does not meet the threshold for addiction. Receives: Other: No intervention. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Muscle Stiffness
Muscle stiffness (Abductor Pollicis Brevis, Abductor Pollicis Longus and Extensor Pollicis Brevis) was measured using the MyotonPRO (Myoton SA, Tallinn, Estonia) device. A brief mechanical impulse was applied to the muscle and then quickly released. Stiffness (N/m) is a parameter related to the capacity to withstand an external force. The reliability of the device has been proven in healthy individuals. The measurement site was marked on the skin with a pen. In all applications, the MyotonPRO probe was placed perpendicular to the skin, and in multi-scan mode, three measurements were recorded with 10 pulses at 1-second intervals. The average of the three measurements was used for analysis.
Measured: Baseline
Pinch Strength
Lateral and palmar pinch strength were measured in kilograms using a Jamar hydraulic pinch gauge (ICC: 0.94-0.99). The measurements were performed in the standard position recommended by the American Society of Hand Therapists: seated, with the shoulder in adduction and neutral, elbow in 90 degrees of flexion, forearm in mid-rotation and supported, and wrist in neutral. Three consecutive measurements, each lasting five seconds, were taken, with one-minute rest intervals between each measurement to prevent muscle fatigue. The average of the three trials was used for analysis.
Measured: Baseline
Secondary outcomes (4)
Smartphone Addiction Scale-Short Version (SAS-SV)
The SAS-SV is a 10-item scale developed by Kwon and colleagues to measure the risk of smartphone addiction in adolescents. It is evaluated using a six-point Likert scale. The scale items are scored from 1 to 6. The scale scores range from 10 to 60, with higher scores indicating an increased risk of addiction. The scale is unidimensional and does not have subscales. In the Korean sample, the cutoff score is 31 for males and 33 for females.
Measured: Baseline
Patient-Rated Wrist/Hand Evaluation Questionnaire (PRWHE)
This form consists of two subscales: a pain subscale with five items, a specific function subscale with six items, and a daily function subscale with four items. Each item is scored on a scale from 0 to 10. In this scale, pain and function problems are weighted equally, and the total score is measured out of 100 points.
Measured: Baseline
Finkelstein Test
The Finkelstein test, one of the most commonly preferred clinical examination tests for diagnosing De Quervain's disease, was used. Participants were asked to make a fist with their thumb inside, and the researcher passively deviated the fist ulnarly. The presence of tenderness and pain at the radial styloid indicated a positive test.
Measured: Baseline
Smartphone Surface Area
The dimensions of the smartphones used by the participants were measured by the researchers. Using a measuring tape, the width and length of the smartphone were recorded in centimeters. The value used for statistical analysis was determined as the surface area of the smartphone (width × length).
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Feb 2025
- Study start15 Dec 2024
- Primary completion5 Jan 2026
- Study completion5 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Smartphone AddictionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 134 participants (actual)
Sponsor and investigators
- Lead sponsor
- Istanbul Gelisim University
- Sponsor type
- University, hospital or other
- Collaborators
- Istanbul University - Cerrahpasa, Istanbul Kent University
- Responsible party
- Principal investigator, Aysem Ecem Ozdemir, Istanbul Gelisim University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06843863
- Sponsor's protocol ID
- IUC002
- Status last verified
- Jul 2026
- First submitted
- 18 Feb 2025
- Last updated
- 28 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Smartphone Addiction on Pinch Strength, Muscle Stiffness, and Hand and Wrist Function in Young Adults: A Cross-Sectional Study
- ClinicalTrials.gov ID
- NCT06843863
- Acronym / sponsor ID
- IUC002
- Conditions
- Smartphone Addiction
- Keywords
- Smartphone, Behavior, Addictive, Muscle stiffness, Musculoskeletal Pain
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 134 participants (actual)
- Lead sponsor
- Istanbul Gelisim UniversityUniversity, hospital or other
- Collaborators
- Istanbul University - Cerrahpasa, Istanbul Kent University
- Study start
- 15 Dec 2024 (actual)
- Primary completion
- 5 Jan 2026 (actual)
- Study completion
- 5 Jan 2026 (actual)
- First posted
- 25 Feb 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Smartphones have become an indispensable part of daily life, and their increasing use has raised concerns about various health effects, including musculoskeletal symptoms. Repetitive movements of the thumb and hand muscles can lead to issues such as tendinosis, myofascial pain syndrome, and a decrease in pinch strength. Studies have shown that musculoskeletal symptoms related to smartphone use are common among young adults and university students. Additionally, an increase in device size may place greater strain on the wrist and finger muscles. Repetitive movements can cause stiffness changes in the thumb muscles, and the relationship between these changes and pinch strength is considered an important research topic. In this study, we aimed to investigate the effects of smartphone addiction on pinch strength, muscle stiffness, hand/wrist pain, and function in young adults.
Detailed description
This study was designed as a cross-sectional study. Volunteers eligible to participate were first screened based on the results of the Smartphone Addiction Scale-Short Version (SAS-SV), and they were divided into two groups as Smartphone Addiction and Non-Smartphone Addiction, with a cutoff score of 31 for males and 33 for females. Subsequently, the determination of dominant hand was performed. All assessments were conducted on the participants' dominant extremity. The assessments were carried out in the following order: Patient-Rated Wrist/Hand Evaluation Questionnaire (PRWHE), the Finkelstein test, muscle stiffness measurement, and finally, pinch strength assessment, as it was considered to potentially cause fatigue. All assessments were conducted by expert physiotherapists within a total duration of 30 minutes, and participants were not followed up afterward, nor recieved any intervention.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Smartphone Addiction Group | – | Other: No intervention.Individuals classified as having smartphone addiction based on the Smartphone Addiction Scale-Short Version (SAS-SV). Participants in this group scored 31 or higher for males and 33 or higher for females on the SAS-SV, indicating problematic smartphone use that meets the threshold for addiction. |
| Non-Smartphone Addiction Group | – | Other: No intervention.Individuals who are not classified as having smartphone addiction based on the Smartphone Addiction Scale-Short Version (SAS-SV). Participants in this group scored below 31 for males and below 33 for females on the SAS-SV, indicating that their smartphone use does not meet the threshold for addiction. |
Who may qualify
- Ages
- 18 to 25 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- University student from Istanbul Kent University and Istanbul Gelisim University.
Key inclusion criteria (5 listed)
- Willing to participate in the study
- Have been using a smartphone for more than one year
- Aged between 18 and 25 years
- Send 25 or more text messages or emails per day
- Spend more than 2 hours browsing the internet and/or play games for more than one hour a day
Key exclusion criteria (6 listed)
- Having radiating/radicular pain in the upper extremity
- Having neck pain
- Congenital deformities in the upper extremity and neck
- A history of diagnosed neurological, rheumatic, musculoskeletal, or cardiovascular diseases
- Having previously undergone surgery on the neck and/or upper extremity
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| No intervention.Participants allocated to the groups were assessed only once. No intervention was applied, and they were not followed up. | Other | Non-Smartphone Addiction Group, Smartphone Addiction Group |
Primary outcome
Muscle Stiffness
Time frame: Baseline
Muscle stiffness (Abductor Pollicis Brevis, Abductor Pollicis Longus and Extensor Pollicis Brevis) was measured using the MyotonPRO (Myoton SA, Tallinn, Estonia) device. A brief mechanical impulse was applied to the muscle and then quickly released. Stiffness (N/m) is a parameter related to the capacity to withstand an external force. The reliability of the device has been proven in healthy individuals. The measurement site was marked on the skin with a pen. In all applications, the MyotonPRO probe was placed perpendicular to the skin, and in multi-scan mode, three measurements were recorded with 10 pulses at 1-second intervals. The average of the three measurements was used for analysis.
Pinch Strength
Time frame: Baseline
Lateral and palmar pinch strength were measured in kilograms using a Jamar hydraulic pinch gauge (ICC: 0.94-0.99). The measurements were performed in the standard position recommended by the American Society of Hand Therapists: seated, with the shoulder in adduction and neutral, elbow in 90 degrees of flexion, forearm in mid-rotation and supported, and wrist in neutral. Three consecutive measurements, each lasting five seconds, were taken, with one-minute rest intervals between each measurement to prevent muscle fatigue. The average of the three trials was used for analysis.
4 secondary outcomes
Smartphone Addiction Scale-Short Version (SAS-SV)
Time frame: Baseline
Patient-Rated Wrist/Hand Evaluation Questionnaire (PRWHE)
Time frame: Baseline
Finkelstein Test
Time frame: Baseline
Smartphone Surface Area
Time frame: Baseline
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Jul 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Smartphone Addiction, run by Istanbul Gelisim University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Muscle Stiffness (time frame: Baseline). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Jul 2026.