Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Nov 13;18(11):e0293457.
doi: 10.1371/journal.pone.0293457. eCollection 2023.

Isometric versus isotonic exercise in individuals with rotator cuff tendinopathy-Effects on shoulder pain, functioning, muscle strength, and electromyographic activity: A protocol for randomized clinical trial

Bianca Rodrigues da Silva Barros  1 , Denise Dal'Ava Augusto  1 , João Felipe de Medeiros Neto  2 , Lori Ann Michener  3 , Rodrigo Scattone Silva  4 , Catarina de Oliveira Sousa  1
Affiliations

Isometric versus isotonic exercise in individuals with rotator cuff tendinopathy-Effects on shoulder pain, functioning, muscle strength, and electromyographic activity: A protocol for randomized clinical trial

Bianca Rodrigues da Silva Barros et al. PLoS One. .

Erratum in

Abstract

Introduction: Rotator cuff tendinopathy is a common shoulder disorder in which the primary treatment is resistance exercises. Isometric exercises are being studied for lower limb tendinopathies but not for rotator cuff tendinopathy. This protocol for a randomized clinical trial aims to compare the effects of two types of exercise (isometric and isotonic) on shoulder pain, functioning, muscle strength, and electromyographic activity in individuals with rotator cuff tendinopathy.

Methods: Forty-six individuals (18 to 60 years old) with shoulder pain for more than three months and unilateral supraspinatus and/or infraspinatus tendinopathy will participate in this trial. Individuals will be randomized into two exercise groups: isometric or isotonic. The following outcomes will be evaluated before and after the first session and after six weeks of intervention: shoulder pain and functioning; isometric strength of shoulder elevation and lateral and medial rotation; and electromyographic activity of medial deltoid, infraspinatus, serratus anterior, and lower trapezius. Groups will perform stretching and strengthening of periscapular muscles. The isometric group will perform three sets of 32 s, at 70% of maximal isometric strength. The isotonic group will perform concentric and eccentric exercises (2 s for each phase) in three sets of eight repetitions at a load of eight repetition maximum. The total time under tension of 96 s will be equal for both groups, and load will be adjusted in weeks three and five of the protocol. Treatment effect between groups will be analyzed using linear mixed model.

Trial registration: Trial registration number: Universal Trial Number (UTN) code U1111-1284-7528 and Brazilian Clinical Trials Registry platform-RBR-3pvdvfk.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Schedule of enrollment, interventions, and assessments.
Fig 2
Fig 2. Flow diagram for consolidated standards of reporting trials.
Fig 3
Fig 3. Positioning of electromyography and isometric strength test.
(A) shoulder elevation, (B) external rotation, and (C) internal rotation; (D) use of inclinometer to measure degrees of arm elevation; isometric arm elevation at (E) 30, (F) 60, (G) 90, and (H) 120 degrees.
Fig 4
Fig 4. Flow diagram of intervention protocol and progression of groups.
RC: Rotator cuff; s: Seconds; RM: Repetition maximum.
Fig 5
Fig 5. Stretching and strengthening of periscapular muscles.
(A) upper trapezius, (B) pectoralis minor, (C) cross-body stretch, (D) serratus anterior and (E) lower trapezius.
Fig 6
Fig 6. Positioning for intervention.
(A) isometric shoulder elevation in scapular plane, (B) isometric external rotation, and (C) isometric internal rotation; (D) isotonic shoulder elevation in scapular plane, (E) isotonic external rotation, and (F) isotonic internal rotation.
See this image and copyright information in PMC

References

    1. Lewis J. Rotator cuff related shoulder pain: Assessment, management and uncertainties. Man Ther. 2015;23:57–68. - PubMed
    1. Seitz AL, McClure PW, Finucane S, Boardman ND, Michener LA. Mechanisms of rotator cuff tendinopathy: Intrinsic, extrinsic, or both? Clinical Biomechanics. 2011;26(1):1–12. doi: 10.1016/j.clinbiomech.2010.08.001 - DOI - PubMed
    1. Luime JJ, Koes BW, Hendriksen IJM, Burdorf A, Verhagen AP, Miedema HS, et al.. Prevalence and incidence of shoulder pain in the general population; a systematic review. Scand J Rheumatol. 2004;33(2):73–81. doi: 10.1080/03009740310004667 - DOI - PubMed
    1. Dang A, Davies M. Rotator Cuff Disease: Treatment Options and Considerations [Internet]. 2018. www.sportsmedarthro.com. - PubMed
    1. Leong HT, Fu SC, He X, Oh JH, Yamamoto N, Yung SHP. Risk factors for rotator cuff tendinopathy: A systematic review and meta-analysis. Vol. 51, Journal of Rehabilitation Medicine. Foundation for Rehabilitation Information; 2019. p. 627–37. - PubMed

Publication types