Smartphone AddictionNCT07540546
Smartphone Use and Hand Function in Young Adults
An observational study of Smartphone Addiction, run by Saglik Bilimleri Universitesi at 1 site in Turkey (Türkiye).
Trial summary
This observational cross-sectional study aims to investigate the relationship between daily smartphone usage duration and hand function parameters in young adults. Specifically, the study will examine the association between smartphone screen time and dominant hand grip strength, thumb strength, and wrist and thumb… Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Smartphone Addiction
- What is being tested?
- Assessment Protocol
- How many people
- 84 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 May 2026to 1 May 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Healthy Universitty Student
Who may be able to join
- Healthy adults
- Aged between 18 and 35 years
- Voluntary participation in the study
Who cannot join
- History of hand or wrist surgery
- Fracture or serious injury in the hand/thumb within the last 6 months
- Neurological disorders
- Rheumatologic diseases
- Cognitive impairment preventing understanding of instructions
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site
Saglik Bilimleri Universitesi
Istanbul, Uskudar, 34668
Esra Pehlivan, fztesrakambur@yahoo.com
About this study
Official title: The Relationship Between Daily Smartphone Use Duration and Dominant Hand Grip Strength, Thumb Strength, Wrist and Thumb Proprioception in Young Adults
This observational cross-sectional study aims to investigate the relationship between daily smartphone usage duration and hand function parameters in young adults. Specifically, the study will examine the association between smartphone screen time and dominant hand grip strength, thumb strength, and wrist and thumb proprioception. Healthy individuals aged 18-35 years will be included. All participants will undergo a single-session assessment including measurement of smartphone usage duration, hand grip strength, pinch strength, and joint position sense of the wrist and thumb. The findings are expected to provide insight into the potential effects of prolonged smartphone use on hand function and proprioceptive performance in young adults.
Read the detailed description
The widespread use of smartphones in daily life has increased significantly, particularly among young adults. While these devices provide convenience and accessibility, excessive smartphone use has been associated with various musculoskeletal and functional impairments, particularly in the upper extremity. Repetitive thumb movements, sustained grip positions, and prolonged device use may negatively affect muscle strength, joint proprioception, and overall hand function. Previous studies have reported that excessive smartphone use may lead to decreased grip strength, altered thumb mechanics, and impaired proprioception. However, there is limited research directly examining the relationship between objectively measured smartphone usage duration and detailed hand function parameters. This study is designed as a cross-sectional, observational, and analytical investigation. Healthy individuals aged 18-35 years will be recruited. Participants with a history of upper extremity injury, neurological disease, or musculoskeletal disorders affecting the hand and wrist will be excluded. All participants will be evaluated in a single session. Demographic data and clinical history will be recorded. Smartphone usage duration will be obtained from built-in device tracking systems (Screen Time for iOS and Digital Wellbeing for Android) based on the last 7 days of use.
- Conditions
- Smartphone Addiction
- Being tested
- Assessment Protocol
- Medical subject headings
- Internet Addiction Disorder
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Assessment ProtocolOther
All participants will undergo a standardized assessment protocol including measurement of smartphone addiction level, daily smartphone screen time from the past 7 days, dominant hand grip strength, thumb pinch strength, wrist proprioception, and thumb proprioception in a single session
| Study group | Role | What they receive |
|---|---|---|
| Observational Group: Smartphone-Addicted Participants | Participants classified as having smartphone addiction according to the Smartphone Addiction Scale-Short Form will undergo a single-session assessment including daily smartphone screen time, dominant hand grip strength, thumb pinch strength, wrist joint position sense, and thumb joint position sense. Receives: Other: Assessment Protocol | |
| Observational Group: Non-Addicted Participants | Participants classified as not having smartphone addiction according to the Smartphone Addiction Scale-Short Form will undergo the same single-session assessment including daily smartphone screen time, dominant hand grip strength, thumb pinch strength, wrist joint position sense, and thumb joint position sense. Receives: Other: Assessment Protocol |
What is being measured
The primary outcome is the main question the study is designed to answer.
Hand Grip Strength
Hand grip strength will be measured using a hydraulic hand dynamometer. The participant will be in a seated position with the elbow flexed at 90 degrees. Three measurements will be taken with a 10-second rest between each, and the average value will be recorded in kilograms (kg).
Measured: Single assessment at baseline
Thumb Pinch Strength
Thumb muscle strength will be measured using a pinchmeter. The participant will be seated with the elbow flexed at 90 degrees and the wrist in a neutral position. The average of three trials will be recorded in kilograms (kg).
Measured: Single assessment at baseline
Thumb Active Joint Position Sense (JPS)
Measured using a standard transparent plastic goniometer. The researcher will passively move the thumb to a 30-degree abduction target position. The participant will be asked to actively reproduce this angle. The absolute error between the target angle and the reproduced angle will be recorded in degrees.
Measured: Single assessment at baseline
Wrist Joint Position Sense (JPS)
Measured using a goniometer with the participant's eyes closed. The wrist will be passively moved to predetermined positions (30 degrees flexion, 30 degrees extension, 10 degrees radial deviation, and 15 degrees ulnar deviation). The participant will then actively reposition the wrist, and the absolute error will be calculated in degrees.
Measured: Single assessment at baseline
Secondary outcomes (2)
Smartphone Screen Time
Objective measurements of the participants' smartphone use over the last 7 days will be obtained. Data will be collected using built-in features such as "Screen Time" for iOS devices or "Digital Wellbeing" for Android devices.
Measured: Single assessment at baseline
Smartphone Addiction Scale-Short Form
The Smartphone Addiction Scale-Short Form (SAS-SF) was used to assess smartphone addiction. The scale comprises 10 items rated on a 6-point Likert scale (1 = strongly disagree to 6 = strongly agree), yielding a total score between 10 and 60. Higher scores reflect a higher risk or severity of smartphone addiction.
Measured: Single assessment at baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Apr 2026
- Study start1 May 2026 (estimated)
- Primary completion1 May 2027 (estimated)
- Study completion1 May 2027 (estimated)
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
- 84 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Saglik Bilimleri Universitesi
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, ESRA PEHLIVAN, Saglik Bilimleri Universitesi
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07540546
- Sponsor's protocol ID
- Smartphone&Proprioception1
- Status last verified
- Apr 2026
- First submitted
- 13 Apr 2026
- Last updated
- 22 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 22 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Relationship Between Daily Smartphone Use Duration and Dominant Hand Grip Strength, Thumb Strength, Wrist and Thumb Proprioception in Young Adults
- ClinicalTrials.gov ID
- NCT07540546
- Acronym / sponsor ID
- Smartphone&Proprioception1
- Conditions
- Smartphone Addiction
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 84 participants (estimated)
- Lead sponsor
- Saglik Bilimleri UniversitesiUniversity, hospital or other
- Study start
- 1 May 2026 (estimated)
- Primary completion
- 1 May 2027 (estimated)
- Study completion
- 1 May 2027 (estimated)
- First posted
- 20 Apr 2026 (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.
This observational cross-sectional study aims to investigate the relationship between daily smartphone usage duration and hand function parameters in young adults. Specifically, the study will examine the association between smartphone screen time and dominant hand grip strength, thumb strength, and wrist and thumb proprioception. Healthy individuals aged 18-35 years will be included. All participants will undergo a single-session assessment including measurement of smartphone usage duration, hand grip strength, pinch strength, and joint position sense of the wrist and thumb. The findings are expected to provide insight into the potential effects of prolonged smartphone use on hand function and proprioceptive performance in young adults.
Detailed description
The widespread use of smartphones in daily life has increased significantly, particularly among young adults. While these devices provide convenience and accessibility, excessive smartphone use has been associated with various musculoskeletal and functional impairments, particularly in the upper extremity. Repetitive thumb movements, sustained grip positions, and prolonged device use may negatively affect muscle strength, joint proprioception, and overall hand function. Previous studies have reported that excessive smartphone use may lead to decreased grip strength, altered thumb mechanics, and impaired proprioception. However, there is limited research directly examining the relationship between objectively measured smartphone usage duration and detailed hand function parameters. This study is designed as a cross-sectional, observational, and analytical investigation. Healthy individuals aged 18-35 years will be recruited. Participants with a history of upper extremity injury, neurological disease, or musculoskeletal disorders affecting the hand and wrist will be excluded. All participants will be evaluated in a single session. Demographic data and clinical history will be recorded. Smartphone usage duration will be obtained from built-in device tracking systems (Screen Time for iOS and Digital Wellbeing for Android) based on the last 7 days of use.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Observational Group: Smartphone-Addicted Participants | – | Other: Assessment ProtocolParticipants classified as having smartphone addiction according to the Smartphone Addiction Scale-Short Form will undergo a single-session assessment including daily smartphone screen time, dominant hand grip strength, thumb pinch strength, wrist joint position sense, and thumb joint position sense. |
| Observational Group: Non-Addicted Participants | – | Other: Assessment ProtocolParticipants classified as not having smartphone addiction according to the Smartphone Addiction Scale-Short Form will undergo the same single-session assessment including daily smartphone screen time, dominant hand grip strength, thumb pinch strength, wrist joint position sense, and thumb joint position sense. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Healthy Universitty Student
Key inclusion criteria (3 listed)
- Healthy adults
- Aged between 18 and 35 years
- Voluntary participation in the study
Key exclusion criteria (5 listed)
- History of hand or wrist surgery
- Fracture or serious injury in the hand/thumb within the last 6 months
- Neurological disorders
- Rheumatologic diseases
- Cognitive impairment preventing understanding of instructions
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 |
|---|---|---|
| Assessment ProtocolAll participants will undergo a standardized assessment protocol including measurement of smartphone addiction level, daily smartphone screen time from the past 7 days, dominant hand grip strength, thumb pinch strength, wrist proprioception, and thumb proprioception in a single session | Other | Observational Group: Non-Addicted Participants, Observational Group: Smartphone-Addicted Participants |
Primary outcome
Hand Grip Strength
Time frame: Single assessment at baseline
Hand grip strength will be measured using a hydraulic hand dynamometer. The participant will be in a seated position with the elbow flexed at 90 degrees. Three measurements will be taken with a 10-second rest between each, and the average value will be recorded in kilograms (kg).
Thumb Pinch Strength
Time frame: Single assessment at baseline
Thumb muscle strength will be measured using a pinchmeter. The participant will be seated with the elbow flexed at 90 degrees and the wrist in a neutral position. The average of three trials will be recorded in kilograms (kg).
Thumb Active Joint Position Sense (JPS)
Time frame: Single assessment at baseline
Measured using a standard transparent plastic goniometer. The researcher will passively move the thumb to a 30-degree abduction target position. The participant will be asked to actively reproduce this angle. The absolute error between the target angle and the reproduced angle will be recorded in degrees.
Wrist Joint Position Sense (JPS)
Time frame: Single assessment at baseline
Measured using a goniometer with the participant's eyes closed. The wrist will be passively moved to predetermined positions (30 degrees flexion, 30 degrees extension, 10 degrees radial deviation, and 15 degrees ulnar deviation). The participant will then actively reposition the wrist, and the absolute error will be calculated in degrees.
2 secondary outcomes
Smartphone Screen Time
Time frame: Single assessment at baseline
Smartphone Addiction Scale-Short Form
Time frame: Single assessment at baseline
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Apr 2026.
- Individual participant dataSharing planned: Undecided
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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.
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 Saglik Bilimleri Universitesi 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 3 inclusion and 5 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: opening soon, as of the sponsor's last update on 22 Apr 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Esra Pehlivan (+90 0216 777 8 777, esra.pehlivan@sbu.edu.tr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Hand Grip Strength (time frame: Single assessment at baseline). The study lists 4 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 22 Apr 2026.