Median and Ulnar Nerve Function in Tattoo Artists

Occupational Hand-Arm Vibration Exposure and Its Effects on Median and Ulnar Nerve Function in Tattoo Artists: A Case-Control Study

This case-control study aims to investigate the effects of occupational hand-arm vibration exposure on median and ulnar nerve functions in tattoo artists. Chronic exposure to vibration generated by tattoo machines may lead to neurosensory impairment, reduced tactile sensitivity, and decreased hand strength. Objective assessments including nerve provocation tests, sensory threshold evaluation, two-point discrimination, vibration perception, grip and pinch strength measurements, and validated patient-reported outcome questionnaires will be used. Findings will be compared with age- and sex-matched healthy controls.

Study Overview

• Status: Recruiting
• Conditions: Cubital Tunnel Syndrome; Carpal Tunnel Syndrome (CTS); Peripheral Neuropathy Pain

Detailed Description

This observational cross-sectional case-control study evaluates neurosensory and motor function differences between professional tattoo artists exposed to long-term occupational vibration and healthy controls. Chronic exposure to hand-arm vibration (HAV) has been associated with peripheral neuropathy, entrapment neuropathies, and sensory receptor dysfunction.

Participants will undergo standardized assessment including:

Tinel, Phalen, reverse Phalen, and elbow flexion tests

Semmes-Weinstein monofilament testing

Two-point discrimination

Vibration perception testing (30 Hz and 256 Hz)

Grip and pinch strength measurements

Brief Michigan Hand Outcomes Questionnaire

Boston Carpal Tunnel Questionnaire

The study aims to determine whether occupational vibration exposure is associated with measurable alterations in median and ulnar nerve sensory and motor function.

• Study Type: Observational
• Enrollment (Estimated): 20

Contacts and Locations

• Study Contact: Name: Sedanur Güngör, MSc.; Phone Number: +905334480698; Email: sedagungor06@hotmail.com

Study Locations

• Turkey (Türkiye)
  • Ankara, Turkey (Türkiye)
    • Recruiting
    • Gazi University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Professional tattoo artists with at least one year of occupational exposure to vibration and age- and sex-matched healthy individuals.

Description

Inclusion Criteria:

• Age ≥ 18 years
• Professional tattoo artists with at least 1 year of occupational experience (case group)
• Healthy individuals without occupational vibration exposure (control group)
• Voluntary participation and provision of informed consent
• No upper extremity trauma or surgery within the last 6 months

Exclusion Criteria:

• Diagnosis of diabetes mellitus
• Diagnosis of peripheral neuropathy
• History of cervical radiculopathy or cervical disc herniation
• History of upper extremity surgery or injury
• Presence of rheumatologic or systemic inflammatory diseases
• Pregnancy
• Substance or alcohol abuse
• Engagement in a second occupation involving repetitive hand use or vibration exposure

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Tattoo Artists (Vibration-Exposed); Professional tattoo artists aged 18 years and older with at least one year of occupational exposure to hand-arm vibration generated by tattoo machines. Participants will undergo standardized sensory and motor assessments including nerve provocation tests, Semmes-Weinstein monofilament testing, two-point discrimination, vibration perception threshold, grip and pinch strength measurements, and validated hand function questionnaires.
Healthy Controls; Age- and sex-matched healthy individuals without occupational vibration exposure and without history of upper extremity trauma, neuropathy, or systemic disease affecting nerve function. Participants will undergo the same standardized sensory and motor assessments as the case group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Semmes-Weinstein Monofilament Threshold	Assessment of light touch sensory threshold using Semmes-Weinstein monofilaments applied to the index and little fingers.	Baseline (single assessment session)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Two-Point Discrimination	Minimum distance (mm) at which two points are perceived as separate on index and little fingers	Baseline (single assessment session)
Vibration Perception Duration	Duration (seconds) of vibration perception using tuning fork (30 Hz and 256 Hz)	Baseline (single assessment session)
Grip Strength	Maximal hand grip strength measured using a dynamometer (kg)	Baseline (single assessment session)
Pinch Strength	Lateral and tip pinch strength measured using a pinch gauge (kg)	Baseline (single assessment session)
Boston Carpal Tunnel Questionnaire Score	Symptom severity and functional status scores (1-5 scale)	Baseline (single assessment session)
Brief Michigan Hand Outcomes Questionnaire Score	Hand function score normalized to a 0-100 scale	Baseline (single assessment session)
Nerve Provocation Test Positivity	Presence of positive findings in Tinel, Phalen, reverse Phalen, and elbow flexion tests	Baseline (single assessment session)

Collaborators and Investigators

• Sponsor: Gazi University

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2026
• Primary Completion (Estimated): August 1, 2026
• Study Completion (Estimated): August 1, 2026

Study Registration Dates

• First Submitted: March 19, 2026
• First Submitted That Met QC Criteria: March 23, 2026
• First Posted (Actual): March 27, 2026

Study Record Updates

• Last Update Posted (Actual): March 27, 2026
• Last Update Submitted That Met QC Criteria: March 23, 2026
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Wounds and Injuries; Neuromuscular Diseases; Peripheral Nervous System Diseases; Median Neuropathy; Mononeuropathies; Nerve Compression Syndromes; Cumulative Trauma Disorders; Sprains and Strains; Ulnar Neuropathies; Ulnar Nerve Compression Syndromes; Carpal Tunnel Syndrome; Cubital Tunnel Syndrome
• Other Study ID Numbers: 2025-1981

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