Smartphone Use and Hand Function in Young Adults

April 18, 2026 updated by: ESRA PEHLIVAN, Saglik Bilimleri Universitesi

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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 Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
84

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Healthy Universitty Student

Description

Inclusion Criteria:

  • Healthy adults
  • Aged between 18 and 35 years
  • Voluntary participation in the study

Exclusion Criteria:

  • 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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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.
Other: Assessment Protocol
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
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.
Other: Assessment Protocol
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

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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).
Single assessment at baseline
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).
Single assessment at baseline
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.
Single assessment at baseline
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.
Single assessment at baseline

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Smartphone Screen Time
Time Frame: Single assessment at baseline
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.
Single assessment at baseline
Smartphone Addiction Scale-Short Form
Time Frame: Single assessment at baseline
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.
Single assessment at baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Saglik Bilimleri Universitesi

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 13, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 13, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 20, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 22, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 18, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Smartphone&Proprioception1

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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