Trapezius Muscle Activation During Bilateral Scapular Retraction and Shoulder External Rotation Under Kinetic Chain and Unstable Surface Conditions

NCT07000773 | Completed

• 1 other identifier: Gazi-BSR-SER
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to investigate the effects of performing the Bilateral Scapular Retraction with Shoulder External Rotation (BSR-SER) exercise under kinetic chain involvement and unstable surface conditions on trapezius muscle activation. Surface electromyography (EMG) will be used to assess the activity levels of the upper, middle, and lower trapezius muscles. The goal is to determine whether integrating kinetic chain elements and instability can optimize muscle activation patterns in healthy individuals during a commonly used scapular rehabilitation exercise.

Conditions

Healthy Volunteers

Keywords

scapular muscle activation; Electromyography; Kinetic Chain; Scapular Retraction; Trapezius; Unstable Surface

Outcome Measures

Primary Outcomes (4)

• Upper Trapezius Muscle Activation

  Surface electromyography (EMG) will measure the muscle activation level of the upper trapezius during the stationary phase of the BSR-SER exercise under various conditions. The activation will be normalized as a percentage of maximal voluntary isometric contraction (%MVIC).

  Day 1 (during the exercise session)

• Middle Trapezius Muscle Activation

  Surface EMG will measure the muscle activation level of the middle trapezius muscle during the stationary phase of the BSR-SER exercise under different surface and lower limb position conditions. Activation levels will be expressed as %MVIC.

  Day 1 (during the exercise session)

• Lower Trapezius Muscle Activation

  Surface EMG will measure the muscle activation of the lower trapezius during the stationary phase of the BSR-SER exercise. Muscle activity will be normalized to %MVIC.

  Day 1 (during the exercise session)

• Muscle Activation Ratios

  Ratios of muscle activation between the upper, middle, and lower trapezius muscles will be calculated to assess balance of muscle recruitment during exercise.

  Day 1 (during the exercise session)

Study Arms (6)

Standing on Stable Surface

EXPERIMENTAL

Participants perform the bilateral scapular retraction with shoulder external rotation (BSR-SER) exercise in a standing position on a stable surface using resistance bands.

Behavioral: Bilateral Scapular Retraction with Shoulder External Rotation (BSR-SER) Exercise

Standing on Unstable Surface

EXPERIMENTAL

Participants perform the BSR-SER exercise in a standing position on an unstable surface (BOSU®) using resistance bands.

Behavioral: Bilateral Scapular Retraction with Shoulder External Rotation (BSR-SER) Exercise

Lunge Position on Stable Surface

EXPERIMENTAL

Participants perform the BSR-SER exercise in a lunge position on a stable surface using resistance bands. Knee and trunk angles are standardized.

Behavioral: Bilateral Scapular Retraction with Shoulder External Rotation (BSR-SER) Exercise

Lunge Position on Unstable Surface

EXPERIMENTAL

Participants perform the BSR-SER exercise in a lunge position on an unstable surface (BOSU®) using resistance bands. Knee and trunk angles are standardized.

Behavioral: Bilateral Scapular Retraction with Shoulder External Rotation (BSR-SER) Exercise

Squat Position on Stable Surface

EXPERIMENTAL

Participants perform the BSR-SER exercise in a squat position on a stable surface using resistance bands. Knee and trunk angles are standardized.

Behavioral: Bilateral Scapular Retraction with Shoulder External Rotation (BSR-SER) Exercise

Squat Position on Unstable Surface

EXPERIMENTAL

Participants perform the BSR-SER exercise in a squat position on an unstable surface (BOSU®) using resistance bands. Knee and trunk angles are standardized.

Behavioral: Bilateral Scapular Retraction with Shoulder External Rotation (BSR-SER) Exercise

Interventions

Bilateral Scapular Retraction with Shoulder External Rotation (BSR-SER) Exercise BEHAVIORAL

Participants perform the Bilateral Scapular Retraction with Shoulder External Rotation (BSR-SER) exercise using a resistance band. The exercise is conducted under various conditions including stable and unstable surfaces (using BOSU® balance trainer) and in three different lower limb positions: standing, lunge, and squat. Each condition is randomized, and participants complete all conditions in a crossover design. The intervention aims to evaluate trapezius muscle activation patterns during these exercises using surface electromyography (EMG).

Lunge Position on Stable Surface; Lunge Position on Unstable Surface; Squat Position on Stable Surface; Squat Position on Unstable Surface; Standing on Stable Surface; Standing on Unstable Surface

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age between 18 and 35 years
• Body Mass Index (BMI) less than 30 kg/m²

You may not qualify if:

• Engaging in more than 6 hours per week of overhead sports or upper extremity strength training
• History of surgery in the spine, lower extremities, or upper extremities
• Experiencing pain in these regions within the past 6 weeks
• Having a rheumatologic, systemic, or metabolic disease

Sponsors & Collaborators

• Recep Tayyip Erdogan University: lead
• Gazi University: collaborator

Study Sites (1)

Gazi University

Ankara, Çankaya, Turkey (Türkiye)

Location

Related Publications (8)

• Colado JC, Garcia-Masso X, Triplett NT, Calatayud J, Flandez J, Behm D, Rogers ME. Construct and concurrent validation of a new resistance intensity scale for exercise with thera-band(R) elastic bands. J Sports Sci Med. 2014 Dec 1;13(4):758-66. eCollection 2014 Dec.

  PMID: 25435767 BACKGROUND

• Ecemis ZB, Cobanoglu G, Oksuz BS, Kaya B, Guzel NA, Kafa B, Kafa N. Trapezius Muscle Electromyographic Activity in Lawn-Mower Exercise: Standing Versus Quadruped. J Sport Rehabil. 2024 Dec 10;34(4):436-442. doi: 10.1123/jsr.2023-0404. Print 2025 May 1.

  PMID: 39657698 BACKGROUND

• Hermens HJ, Freriks B, Disselhorst-Klug C, Rau G. Development of recommendations for SEMG sensors and sensor placement procedures. J Electromyogr Kinesiol. 2000 Oct;10(5):361-74. doi: 10.1016/s1050-6411(00)00027-4.

  PMID: 11018445 BACKGROUND

• Cobanoglu G, Guzel NA, Ecemis ZB, Demirkan MY. Investigation of muscle activation during kinetic chain based exercises in individuals with and without forward head posture. J Back Musculoskelet Rehabil. 2024;37(6):1537-1549. doi: 10.3233/BMR-230397.

  PMID: 38968043 BACKGROUND

• Kara D, Harput G, Duzgun I. Trapezius muscle activation levels and ratios during scapular retraction exercises: A comparative study between patients with subacromial impingement syndrome and healthy controls. Clin Biomech (Bristol). 2019 Jul;67:119-126. doi: 10.1016/j.clinbiomech.2019.05.020. Epub 2019 May 11.

  PMID: 31103961 BACKGROUND

• Melo ASC, Vilas-Boas JP, Cruz EB, Macedo RM, E Ferreira SB, Sousa AS. The influence of shoulder position during multi-joint exercises in the relative scapular muscles activity in symptomatic and asymptomatic conditions. J Back Musculoskelet Rehabil. 2023;36(4):883-893. doi: 10.3233/BMR-220056.

  PMID: 36776036 BACKGROUND

• Uysal O, Akoglu AS, Kara D, Sezik AC, Calik M, Duzgun I. Theraband Applications for Improved Upper Extremity Wall-Slide Exercises. J Athl Train. 2022 Aug 1;57(8):795-803. doi: 10.4085/1062-6050-0305.21.

  PMID: 36356616 BACKGROUND

• Mendez-Rebolledo G, Morales-Verdugo J, Orozco-Chavez I, Habechian FAP, Padilla EL, de la Rosa FJB. Optimal activation ratio of the scapular muscles in closed kinetic chain shoulder exercises: A systematic review. J Back Musculoskelet Rehabil. 2021;34(1):3-16. doi: 10.3233/BMR-191771.

  PMID: 32831190 BACKGROUND

MeSH Terms

Interventions

Exercise

Intervention Hierarchy (Ancestors)

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

Study Officials

• Gamze Cobanoglu Demirkan, PhD

  Gazi University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Research Assistant, PhD, Physiotherapist, Department of Physiotherapy and Rehabilitation

Model Details: This is a randomized crossover study where each participant performs the Bilateral Scapular Retraction with Shoulder External Rotation (BSR-SER) exercise under multiple conditions. The exercise is performed on both stable and unstable surfaces and in different lower extremity positions (standing, lunge, and squat). Each participant acts as their own control by completing all exercise conditions in a randomized order. Electromyographic (EMG) activity of the trapezius muscles is measured during each condition to assess muscle activation patterns.

Study Record Dates

• First Submitted: May 22, 2025
• First Posted: June 3, 2025
• Study Start: April 1, 2022
• Primary Completion: June 1, 2022
• Study Completion: January 1, 2024
• Last Updated: June 3, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)