Latissimus Dorsi Activity During Different Exercises

NCT ID: NCT07297771

Last Updated: 2025-12-29

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 30 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2025-10-12
• Study Completion Date: 2026-02-25

Brief Summary

This single-visit, laboratory study will quantify latissimus dorsi activation during standardized band/body-weight exercises commonly used in rehabilitation (e.g., standing bent-over row, inferior glide, seated press-up, body-lifting). Healthy, physically active adults (18-40 y; Tegner ≥5) will perform three repetitions per exercise with metronome-paced phases (≈3 s concentric, 3 s isometric, 3 s eccentric), 5-s rest between repetitions and 2-min between exercises; load will be individualized to reach OMNI RPE 6-8. Surface EMG (TeleMyo DTS; Noraxon) will be recorded from the latissimus dorsi (medial and lateral) and selected synergists (teres major, infraspinatus, posterior deltoid, triceps); electrode placement will follow SENIAM recommendations. Signals will be band-pass filtered (20-500 Hz), rectified, RMS-smoothed with a 100-ms window, and normalized to %MVIC using standardized MVC tests; exercise/MVC order will be randomized to limit bias. The primary outcome is mean normalized EMG amplitude per exercise; secondary outcomes include peak amplitude and categorical activation levels (low ≤20% MVIC, moderate 21-40%, high 41-60%, very high >60%). The study involves minimal risk (possible mild skin irritation under electrodes and transient post-exercise fatigue).

Detailed Description

The latissimus dorsi (LD) originates from the spinous processes of the lower six thoracic vertebrae and the thoracolumbar fascia/iliac crest, and-together with the teres major-attaches to the medial lip of the intertubercular groove of the humerus. Functionally, LD contributes to shoulder adduction, internal rotation, and extension, linking the upper limb to the trunk. Alongside the rotator cuff, prevention of superior translation of the humeral head may be provided by the glenohumeral adductors (pectoralis major and LD) acting as humeral head depressors via a medio-inferior vector created by their tendon orientation. From an osteokinematic perspective, LD may protect against subacromial pain by facilitating inferior glide of the humeral head on the glenoid.

Selecting an appropriate strengthening exercise is critical to restore muscle performance and functional arm elevation in patients with shoulder injury or dysfunction. The literature emphasizes exercises targeting activation of the rotator cuff and scapulothoracic muscles that contribute to functional elevation. Surface electromyography (sEMG) is commonly used to guide exercise selection and progression by quantifying a muscle's contribution across different exercises, thereby enabling evidence-based advancement in strengthening programs.

However, much of the existing LD literature centers on lateral pull-down variations, with limited data for rehabilitation-relevant tasks such as low row, inferior glide, bent-over row (with trunk flexion), seated press-up, and body-lifting. Focusing on a single exercise limits clinical decision-making for shoulder rehabilitation (exercise selection and progression). Therefore, to support a scientific, evidence-based progression for LD strengthening in rehabilitation, this study was planned to obtain comprehensive sEMG data across multiple exercises.

Aim: To examine LD EMG activation levels during different exercises and determine between-exercise differences.

Conditions

Muscle Activation

Keywords

Latissimus Dorsi; Shoulder; Electromyography

Study Design

• Observational Model Type: OTHER
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

Healthy adults

Single-visit laboratory cohort. Physically active adults perform exercises; surface EMG is recorded from the latissimus dorsi

Exercise

Intervention Type: BEHAVIORAL

Participants will perform six standardized pulling tasks-inferior glide, low row, seated row, bent-over row, seated press-up, and body lifting-using a resistance band or body weight. Each exercise is done for 3 repetitions with \~5 s between reps and \~2 min between exercises. Resisted exercises follow a metronome-paced 3 s concentric / 3 s isometric / 3 s eccentric tempo; purely isometric tasks are held for 3 s. Load is individualized with the OMNI 0-10 scale and increased during up to 10 familiarization reps until perceived exertion reaches 6-8/10. Exercise order is randomized to minimize ordering effects.

Interventions

Exercise

Participants will perform six standardized pulling tasks-inferior glide, low row, seated row, bent-over row, seated press-up, and body lifting-using a resistance band or body weight. Each exercise is done for 3 repetitions with \~5 s between reps and \~2 min between exercises. Resisted exercises follow a metronome-paced 3 s concentric / 3 s isometric / 3 s eccentric tempo; purely isometric tasks are held for 3 s. Load is individualized with the OMNI 0-10 scale and increased during up to 10 familiarization reps until perceived exertion reaches 6-8/10. Exercise order is randomized to minimize ordering effects.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• Age 18-40 years
• No range-of-motion restriction at the glenohumeral joint
• No shoulder, cervical, or lumbar region complaints/injury within the past 6 months
• No systemic or neurological disease
• Competent to consent and provides written informed consent
• Tegner Activity Scale ≥ 5

Exclusion Criteria

• Body mass index (BMI) > 25 kg/m²

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Hacettepe University

OTHER

Sponsor Role: lead

Responsible Party

Irem Duzgun

Professor, Department of Physiotherapy and Rehabilitation

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Hacettepe University

Ankara, Altındag, Turkey (Türkiye)

Site Status: RECRUITING

Countries

Turkey (Türkiye)

Facility Contacts

Kubra Caylan Gurses, Research Assistant

Role: primary

Other Identifiers

LDORSI-EMG

Identifier Type: -

Identifier Source: org_study_id