Concentric vs Eccentric Full Can Exercise in Partial Rotator Cuff Tears (FULLCAN-PRCT)

Comparison of the Effects of Concentric and Eccentric Full Can Exercises on Supraspinatus Muscle Architecture in Individuals With Partial Rotator Cuff Tears

This study aims to compare the effects of concentric and eccentric full can exercises on supraspinatus muscle architecture in individuals with partial rotator cuff tears.

Rotator cuff tears are a common cause of shoulder pain and functional limitation. The supraspinatus muscle plays a key role in shoulder movement and stability, and its structure may be affected in individuals with partial tears.

Exercise-based rehabilitation is widely used in the conservative management of these conditions. The full can exercise is commonly prescribed to selectively activate the supraspinatus muscle. However, the effects of different contraction types, specifically concentric and eccentric exercises, on muscle structure and clinical outcomes are not fully understood.

In this study, participants will be randomly assigned to either a concentric or eccentric full can exercise group. Both groups will receive a standard physiotherapy program, including therapeutic ultrasound and transcutaneous electrical nerve stimulation (TENS), in addition to the assigned exercise protocol.

The intervention will last for 6 weeks, with sessions performed three times per week. Outcomes will be assessed before and after the intervention.

The primary outcome is the change in supraspinatus muscle pennation angle measured by ultrasound imaging. Secondary outcomes include muscle architecture parameters, pain intensity, range of motion, muscle strength, functional status, and kinesiophobia.

The findings of this study may help improve exercise selection in the rehabilitation of individuals with rotator cuff tears.

Study Overview

• Status: Not yet recruiting
• Conditions: Rotator Cuff Injuries; Shoulder Pain Syndrome; Partial Rotator Cuff Tears
• Intervention / Treatment: Other: Concentric Full Can Exercise; Other: Standard Physiotherapy Program; Other: Eccentric Full Can Exercise

Detailed Description

Study Design and Setting This study is designed as a prospective, randomized, assessor-blinded, parallel-group clinical trial. The study will be conducted at Firat University Faculty of Health Sciences, Department of Physiotherapy and Rehabilitation, and Fethi Sekin City Hospital, Department of Physical Medicine and Rehabilitation.

Participants A total of 60 individuals aged between 18 and 65 years with a diagnosis of partial supraspinatus tendon tear confirmed by ultrasound or magnetic resonance imaging will be included. Participants will be randomly allocated into two groups (n=30 per group).

Randomization and Blinding Participants will be assigned to groups using a computer-generated randomization sequence. Allocation will be concealed using sealed, opaque envelopes. Outcome assessments will be performed by a blinded assessor.

Interventions

Both groups will receive a standard physiotherapy program including:

Therapeutic ultrasound Transcutaneous electrical nerve stimulation (TENS) Standard shoulder rehabilitation exercises

The only difference between groups will be the contraction type of the full can exercise:

Concentric Group: Emphasis on the lifting phase (approximately 2 seconds), with minimal eccentric loading Eccentric Group: Emphasis on the lowering phase (approximately 4 seconds), with minimal concentric loading

All interventions will be applied 3 times per week for 6 weeks (total of 18 sessions).

Outcome Measures

Primary Outcome:

Supraspinatus muscle pennation angle measured by B-mode ultrasonography

Secondary Outcomes:

Muscle architecture parameters (fiber length, physiological cross-sectional area) Pain intensity (Visual Analog Scale) Range of motion (goniometric assessment) Muscle strength (hand-held dynamometry) Functional status (DASH, SPADI) Kinesiophobia (Tampa Scale of Kinesiophobia)

Assessments will be performed at baseline (T0) and at the end of the 6-week intervention (T1).

Sample Size and Statistical Analysis Sample size calculation was based on the primary outcome (pennation angle change), assuming an effect size of 0.70, alpha of 0.05, and power of 80%. A minimum of 26 participants per group was required; therefore, 30 participants per group will be recruited to account for potential dropouts.

Data will be analyzed using appropriate statistical methods including mixed-design ANOVA for group and time comparisons. Non-parametric tests will be used if assumptions are not met. Intention-to-treat analysis will be applied.

Ethical Considerations The study will be conducted in accordance with ethical principles for human research. Informed consent will be obtained from all participants prior to inclusion.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Muharrem Gökhan Beydağı, PhD; Phone Number: +905323581105; Email: mgbeydagi@firat.edu.tr

Study Locations

• Turkey (Türkiye)
  • MErkez
    • Elâzığ, MErkez, Turkey (Türkiye), 23200
      • Firat University
      • Contact: Muharrem Gökhan Beydağı, PhD; Phone Number: 05323581105; Email: mgbeydagi@firat.edu.tr
      • Contact: Muhammet Şahin Elbastı, MD
      • Principal Investigator: Muhammet Şahin Elbastı, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Aged between 18 and 65 years
• Diagnosed with partial supraspinatus tendon tear confirmed by ultrasound or magnetic resonance imaging
• Shoulder pain lasting at least 3 months
• Pain intensity ≥3 on the Visual Analog Scale (VAS)
• Willing to participate and provide informed consent

Exclusion Criteria:

• Full-thickness rotator cuff tear
• History of shoulder surgery
• Shoulder instability
• Neurological disorders
• Rheumatological diseases
• Corticosteroid injection within the last 3 months
• Inability to adhere to the exercise program

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Concentric Exercise Group; Participants will receive a standard physiotherapy program including ultrasound, TENS, and shoulder rehabilitation exercises, combined with concentric full can exercises. The concentric phase (lifting) will be emphasized, while the eccentric phase will be minimally loaded.	Other: Concentric Full Can Exercise; A strengthening exercise performed in the scapular plane with emphasis on the eccentric phase. The lowering phase is performed slowly in approximately 4 seconds against resistance, while the concentric phase is minimized. Exercises are performed 3 times per week for 6 weeks.; Other: Standard Physiotherapy Program; Includes therapeutic ultrasound, transcutaneous electrical nerve stimulation (TENS), and standard shoulder rehabilitation exercises applied to all participants.
Active Comparator: Eccentric Exercise Group; Participants will receive a standard physiotherapy program including ultrasound, TENS, and shoulder rehabilitation exercises, combined with eccentric full can exercises. The eccentric phase (lowering) will be emphasized, while the concentric phase will be minimally loaded.	Other: Standard Physiotherapy Program; Includes therapeutic ultrasound, transcutaneous electrical nerve stimulation (TENS), and standard shoulder rehabilitation exercises applied to all participants.; Other: Eccentric Full Can Exercise; A strengthening exercise performed in the scapular plane with emphasis on the eccentric phase. The lowering phase is performed slowly in approximately 4 seconds against resistance, while the concentric phase is minimized. Exercises are performed 3 times per week for 6 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Supraspinatus Muscle Pennation Angle	The pennation angle of the supraspinatus muscle will be measured using B-mode ultrasonography. Measurements will be obtained at baseline (T0) and after 6 weeks (T1). The change between time points will be analyzed. Supraspinatus Muscle Pennation Angle: Assessed by B-mode ultrasonography.; Pennation angle will be measured in degrees (°).; Higher values indicate greater muscle architectural adaptation.; Measured at baseline (T0) and after 6 weeks of intervention (T1).	Baseline and 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Supraspinatus Muscle Fiber Length	Measured using B-mode ultrasonography at baseline and after 6 weeks. Supraspinatus Fascicle Length: Measured using B-mode ultrasonography in millimeters (mm).; Greater fascicle length may indicate improved muscle architectural properties.; Assessed at baseline and 6 weeks.	Baseline and 6 weeks
Change in Physiological Cross-Sectional Area of Supraspinatus	Measured via ultrasound imaging at baseline and after 6 weeks. Physiological Cross-Sectional Area (PCSA): Measured using ultrasonography in cm².; Higher values indicate greater muscle size.; Assessed at baseline and 6 weeks.	Baseline and 6 weeks
Change in Pain Intensity (VAS)	Pain intensity will be assessed using the Visual Analog Scale (0-10 cm). Visual Analog Scale for Pain: Pain intensity will be assessed using the Visual Analog Scale (VAS).; The scale ranges from 0 to 10.; 0 indicates no pain and 10 indicates worst imaginable pain.; Higher scores indicate worse pain severity.; Assessed at baseline and 6 weeks.	Baseline and 6 weeks
Change in Shoulder Range of Motion	Measured using a goniometer for flexion, abduction, internal and external rotation. Shoulder Range of Motion: Active shoulder flexion, abduction, internal rotation, and external rotation will be measured using a universal goniometer in degrees (°).; Higher values indicate greater joint mobility.; Assessed at baseline and 6 weeks.	Baseline and 6 weeks
Change in Shoulder Muscle Strength	Measured using a hand-held dynamometer during isometric contraction. Shoulder Muscle Strength; Isometric muscle strength will be assessed using a handheld dynamometer.; Measurements will be recorded in kilograms or Newtons.; Higher values indicate greater muscle strength.; Assessed at baseline and 6 weeks.	Baseline and 6 weeks
Change in Functional Status (DASH Scores)	Functional status will be assessed using DASH questionnaires. Disabilities of the Arm, Shoulder and Hand (DASH) Score; Functional disability will be assessed using the DASH questionnaire.; Scores range from 0 to 100.; Higher scores indicate greater disability.; Assessed at baseline and 6 weeks.	Baseline and 6 weeks
Change in Functional Status (SPADI Scores)	Functional status will be assessed using SPADI questionnaires. Shoulder Pain and Disability Index (SPADI): Shoulder-related pain and disability will be assessed using SPADI.; Scores range from 0 to 100.; Higher scores indicate greater pain and disability.; Assessed at baseline and 6 weeks.	Baseline and 6 weeks
Change in Kinesiophobia (Tampa Scale)	Measured using the Tampa Scale of Kinesiophobia. Tampa Scale for Kinesiophobia: Fear of movement will be assessed using the Tampa Scale for Kinesiophobia.; Scores range from 17 to 68.; Higher scores indicate greater kinesiophobia.; Assessed at baseline and 6 weeks.	Baseline and 6 weeks

Collaborators and Investigators

• Sponsor: Firat University
• Collaborators: Elazıg Fethi Sekin Sehir Hastanesi

Study record dates

Study Major Dates

• Study Start (Estimated): May 20, 2026
• Primary Completion (Estimated): August 20, 2026
• Study Completion (Estimated): January 20, 2027

Study Registration Dates

• First Submitted: April 27, 2026
• First Submitted That Met QC Criteria: May 7, 2026
• First Posted (Actual): May 14, 2026

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 7, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Shoulder Rehabilitation; Muscle Architecture; Eccentric Exercise; Concentric Exercise; Supraspinatus Muscle; Full Can Exercise
• Additional Relevant MeSH Terms: Shoulder Injuries; Wounds and Injuries; Rupture; Tendon Injuries; Rotator Cuff Injuries
• Other Study ID Numbers: FU_MGBeydagi_RC_B_2026/05

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No