Effect of Scapular Retraction on Lower Trapezius, Infraspinatus, and Deltoid Muscle Electromyographic Activity During the Side-Lying Abduction Exercise

Overview

Journal Int J Sports Phys Ther

Specialty Rehabilitation Medicine

Date 2023 Jul 10

PMID 37425105

Authors

Masaaki Tsuruike

Todd S Ellenbecker

Affiliations

Soon will be listed here.

Abstract

Background: The lower trapezius (LT) muscle, which stabilizes the scapula posteriorly during arm elevation, has been interesting to both clinicians and researchers for its importance in throwing-related shoulder rehabilitation and injury prevention.

Purpose: The purpose of this study was to investigate the electromyographic activity of the LT and other relevant muscles during scapular and shoulder activities in the side-lying position.

Methods: Twenty collegiate baseball players volunteered to participate in this study. Electromyographic (EMG) output of the lower trapezius, infraspinatus, posterior deltoid, middle deltoid, serratus anterior, and upper trapezius muscles were collected. All the subjects performed isometric resistance exercises in four arm positions: 0° horizontal abduction from the coronal plane (NEUT) with protraction (NEUT-PRO), 15° horizontal adduction from the coronal plane (HADD) with protraction (HADD-PRO), and NEUT with retraction (NEUT-RET), and HADD-RET in a side-lying isometric abduction exercise with two external loads: a 9.1 kg dumbbell and 40% of the manual muscle test (MMT). The subjects also performed two more isometric resistance exercises: supine protraction and side-lying external rotation (ER) of the glenohumeral (GH) joint in GH adduction at 90° of GH ER or with as much ER as possible. All raw EMG data were normalized to maximal voluntary isometric contraction (% MVIC) of the corresponding muscle.

Results: LT activity was significantly greater in HADD-RET with 9.1 kg than that of HADD-PRO (p < 0.001) (55 vs 21% MVIC) while middle deltoid muscle activity was significantly decreased in both NEUT and HADD-RET compared to that of NEUT and HADD-PRO (p < 0.001). In contrast, IS muscle activity was significantly increased in HADD-RET with 9.1 kg compared with that 40% MMT (p < 0.001) (41 vs 22% MVIC).

Conclusion: LT activity was modulated by changes in scapulothoracic and glenohumeral joint positioning during a side-lying isometric abduction exercise. These findings may help clinicians to select exercises to improve scapular muscle balance ratios during rehabilitation of the shoulder complex.

Level Of Evidence: Level 3b, Controlled laboratory study.

References

Alizadehkhaiyat O, Hawkes D, Kemp G, Frostick S . Electromyographic Analysis of the Shoulder Girdle Musculature During External Rotation Exercises. Orthop J Sports Med. 2016; 3(11):2325967115613988. PMC: 4687830. DOI: 10.1177/2325967115613988. View

Tsuruike M, Ellenbecker T . Adaptation of muscle activity in scapular dyskinesis test for collegiate baseball players. J Shoulder Elbow Surg. 2016; 25(10):1583-91. DOI: 10.1016/j.jse.2016.03.004. View

Cools A, Dewitte V, Lanszweert F, Notebaert D, Roets A, Soetens B . Rehabilitation of scapular muscle balance: which exercises to prescribe?. Am J Sports Med. 2007; 35(10):1744-51. DOI: 10.1177/0363546507303560. View

Cools A, Struyf F, De Mey K, Maenhout A, Castelein B, Cagnie B . Rehabilitation of scapular dyskinesis: from the office worker to the elite overhead athlete. Br J Sports Med. 2013; 48(8):692-7. DOI: 10.1136/bjsports-2013-092148. View

Castelein B, Cools A, Parlevliet T, Cagnie B . Modifying the shoulder joint position during shrugging and retraction exercises alters the activation of the medial scapular muscles. Man Ther. 2015; 21:250-5. DOI: 10.1016/j.math.2015.09.005. View

Konda S, Yanai T, Sakurai S . Scapular rotation to attain the peak shoulder external rotation in tennis serve. Med Sci Sports Exerc. 2010; 42(9):1745-53. DOI: 10.1249/MSS.0b013e3181d64103. View

Ryan G, Johnston H, Moreside J . Infraspinatus Isolation During External Rotation Exercise at Varying Degrees of Abduction. J Sport Rehabil. 2017; 27(4):334-339. DOI: 10.1123/jsr.2016-0217. View

Kurokawa D, Sano H, Nagamoto H, Omi R, Shinozaki N, Watanuki S . Muscle activity pattern of the shoulder external rotators differs in adduction and abduction: an analysis using positron emission tomography. J Shoulder Elbow Surg. 2014; 23(5):658-64. DOI: 10.1016/j.jse.2013.12.021. View

Tsuruike M, Ellenbecker T, Lauffenburger C . The Application of Double Elastic Band Exercise in the 90/90 Arm Position for Overhead Athletes. Sports Health. 2020; 12(5):495-500. PMC: 7485019. DOI: 10.1177/1941738120935441. View

10.

Tsuruike M, Ellenbecker T, Lauffenburger C . Electromyography activity of the teres minor muscle with varying positions of horizontal abduction in the quadruped position. JSES Int. 2021; 5(3):480-485. PMC: 8178592. DOI: 10.1016/j.jseint.2020.12.014. View

11.

Michener L, Sharma S, Cools A, Timmons M . Relative scapular muscle activity ratios are altered in subacromial pain syndrome. J Shoulder Elbow Surg. 2016; 25(11):1861-1867. DOI: 10.1016/j.jse.2016.04.010. View

12.

Ben Kibler W, Sciascia A . Evaluation and Management of Scapular Dyskinesis in Overhead Athletes. Curr Rev Musculoskelet Med. 2019; 12(4):515-526. PMC: 6942103. DOI: 10.1007/s12178-019-09591-1. View

13.

Tsuruike M, Ellenbecker T . Serratus anterior and lower trapezius muscle activities during multi-joint isotonic scapular exercises and isometric contractions. J Athl Train. 2015; 50(2):199-210. PMC: 4495440. DOI: 10.4085/1062-6050-49.3.80. View

14.

Ben Kibler W, Sciascia A, Uhl T, Tambay N, Cunningham T . Electromyographic analysis of specific exercises for scapular control in early phases of shoulder rehabilitation. Am J Sports Med. 2008; 36(9):1789-98. DOI: 10.1177/0363546508316281. View

15.

Ellenbecker T, Sueyoshi T, Bailie D . Muscular activation during plyometric exercises in 90° of glenohumeral joint abduction. Sports Health. 2015; 7(1):75-9. PMC: 4272695. DOI: 10.1177/1941738114553165. View

16.

Cools A, Borms D, Cottens S, Himpe M, Meersdom S, Cagnie B . Rehabilitation Exercises for Athletes With Biceps Disorders and SLAP Lesions: A Continuum of Exercises With Increasing Loads on the Biceps. Am J Sports Med. 2014; 42(6):1315-22. DOI: 10.1177/0363546514526692. View

17.

De Mey K, Danneels L, Cagnie B, Cools A . Scapular muscle rehabilitation exercises in overhead athletes with impingement symptoms: effect of a 6-week training program on muscle recruitment and functional outcome. Am J Sports Med. 2012; 40(8):1906-15. DOI: 10.1177/0363546512453297. View

18.

Clisby E, Bitter N, Sandow M, Jones M, Magarey M, Jaberzadeh S . Relative contributions of the infraspinatus and deltoid during external rotation in patients with symptomatic subacromial impingement. J Shoulder Elbow Surg. 2007; 17(1 Suppl):87S-92S. DOI: 10.1016/j.jse.2007.05.019. View

19.

Berckmans K, Castelein B, Borms D, Parlevliet T, Cools A . Rehabilitation Exercises for Dysfunction of the Scapula: Exploration of Muscle Activity Using Fine-Wire EMG. Am J Sports Med. 2021; 49(10):2729-2736. DOI: 10.1177/03635465211025002. View

20.

Tsuruike M, Ellenbecker T, Nishime R . ELECTROMYOGRAPHIC ANALYSIS OF THE SCAPULAR DYSKINESIS TEST IN A BASEBALL PITCHER WITH A SLAP LESION: A CASE REPORT. Int J Sports Phys Ther. 2020; 15(3):471-477. PMC: 7297006. View