Latissimus Dorsi Activation During Shoulder Extension Exercises

NCT07297758 | Recruiting

• 1 other identifier: Shoulder-EX-EMG
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

This observational, cross-sectional laboratory study at Hacettepe University will examine surface EMG activation of the latissimus dorsi during resisted, dynamic shoulder extension performed at three shoulder flexion angles (30°,60°, 90°, 120°). The primary objective is to quantify latissimus dorsi activation and to determine how elevation angle influences activation; secondary analyses compare synergists.

Conditions

Muscle Activation

Keywords

Shoulder; Latissimus Dorsi; Exercise

Outcome Measures

Primary Outcomes (1)

• Electromyography

  Muscle activation will be assessed with an 8-channel surface EMG system (TeleMyo DTS, Noraxon). Following SENIAM, bipolar Ag/AgCl electrodes (2 cm inter-electrode distance) will be placed over medial and lateral latissimus dorsi, teres major, infraspinatus, posterior deltoid, and triceps brachii, secured with double-sided tape. Before exercise, MVICs will be obtained on the dominant arm by the same assessor (3 × 5 s with 30 s between trials and 2 min between muscles) using standardized, literature-based positions with verbal encouragement.The exercise protocol will consist of elastic-band resisted shoulder extension performed for three repetitions (3 s concentric-3 s isometric-3 s eccentric) with 5 s between repetitions and 2 min rest between conditions, while EMG from all target muscles is recorded and timing is controlled by a metronome.

  Baseline (Day 1)

Secondary Outcomes (1)

• Activity Level

  Baseline (Day 1)

Study Arms (1)

Healthy Active Adults

Ages 18-40; Tegner ≥5; no GH restriction; no shoulder/cervical/lumbar complaints in last 6 months; no systemic/neurologic disease; BMI ≤25 kg/m².

Behavioral: Exercise

Interventions

Exercise BEHAVIORAL

Standing with the shoulder in \~30° abduction and external rotation and the elbow extended, participants elevate the arm to three preset flexion angles (30°,60°, 90°, 120°; measured by goniometer) and then perform shoulder extension past the trunk against color-coded elastic bands. Bands are anchored overhead and pulled diagonally downward; the band angle is adjusted to match each shoulder-flexion condition. Tempo is metronome-paced: 3 s concentric, 3 s isometric (at peak), 3 s eccentric. Resistance is individualized using the OMNI Perceived Exertion Scale and titrated until 6-8/10 is reached prior to data capture. Each condition is recorded for 3 repetitions with \~5 s between reps; \~2 min rest is provided between conditions. A brief familiarization (\~3 min per condition) is given, and the order of MVICs and exercise conditions is randomized.

Healthy Active Adults

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Healthy, physically active adults aged 18-40 years, recruited from a university cohort and local community, for a single-visit laboratory EMG study at Hacettepe University. Eligibility requires Tegner ≥5, full glenohumeral range of motion, no shoulder/cervical/lumbar complaints in the past 6 months, and no systemic or neurological disease; individuals with BMI \>25 kg/m² are excluded

You may qualify if:

• Age between 18 and 40,
• No restriction of the glenohumeral joint,
• No complaints related to the shoulder, cervical, or lumbar region in the last 6 months,
• No systemic or neurological disease,
• Agreeing to participate in the study,
• A Tegner Activity Score of 5 or higher,

You may not qualify if:

• A body mass index greater than 25 kg/m2

Sponsors & Collaborators

• Hacettepe University: lead

Study Sites (1)

Hacettepe University

Ankara, Samandag, 06100, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Motor Activity

Interventions

Exercise

Condition Hierarchy (Ancestors)

Behavior

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Officials

• Irem Duzgun, PhD, Professor

  Hacettepe University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Irem Duzgun, Professor, PhD

CONTACT

312-305 15 76; iremduzgun@hacettepe.edu.tr

Kubra Caylan Gurses, MSc

CONTACT

312 305 25 25-186; kubracaylan@hacettepe.edu.tr

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor, Department of Physiotherapy and Rehabilitation

Study Record Dates

• First Submitted: December 9, 2025
• First Posted: December 22, 2025
• Study Start: October 14, 2025
• Primary Completion: March 1, 2026
• Study Completion: March 1, 2026
• Last Updated: December 29, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)