Smartphone addiction: effects on thumb muscle mechanics and touch sensitivity

Investigation of the Effect of Smartphone Addiction on the Biomechanical Properties of Thumb Muscles and Thumb Sensory Sensitivity in University Students

Observational Saglik Bilimleri Universitesi · NCT07040267

This test will see if heavy smartphone use changes thumb muscle stiffness and touch sensitivity in university students aged 18–30.

Quick facts

Study typeObservational
Enrollment36 (estimated)
Ages18 Years to 30 Years
SexAll
SponsorSaglik Bilimleri Universitesi Academic / other
Locations1 site (Istanbul, Üsküdar)
Trial IDNCT07040267 on ClinicalTrials.gov

What this trial studies

This prospective, non-randomized, controlled observational study will compare 36 university students aged 18–30 categorized as smartphone-addicted or non-addicted using the SAS-SV. Weekly screen time and types of smartphone applications will be recorded to characterize exposure. Biomechanical properties of three thumb muscles (abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis) will be measured bilaterally with a MyotonPro™, and sensory function will be tested bilaterally using two-point discrimination with a Baseline Aesthesiometer. Group differences and correlations between screen time and muscular or sensory outcomes will be analyzed.

Who should consider this trial

Good fit: Ideal candidates are university students aged 18–30 who regularly use smartphones and have no systemic, neurological, or recent upper-limb surgical history.

Not a fit: Individuals with systemic neuromuscular disease, prior upper-limb surgery or trauma, significant subcutaneous fat over target muscles (>20 mm), or wounds at the measurement site are excluded and unlikely to benefit.

Why it matters

Potential benefit: If successful, results could suggest that reducing excessive smartphone use helps preserve thumb muscle function and touch sensitivity.

How similar studies have performed: Previous research has linked heavy smartphone use to thumb pain and functional changes, but applying MyotonPro biomechanical measures and structured two-point discrimination in this young-adult population is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Aged 18-30 years
* Currently enrolled university students
* Regular smartphone users

Exclusion Criteria:

* Presence of systemic, chronic, or neuromuscular disorders
* History of upper limb surgery or trauma
* Neurological or orthopedic conditions affecting upper extremities
* Subcutaneous fat over target muscles \>20 mm
* Presence of wounds or burns on the measurement area

Where this trial is running

Istanbul, Üsküdar

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Smartphone AddictionThumb Injury
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.