scholarly journals Scapular Retraction under Adduction Load: An Alternative to Overhead Exercises to Activate Infraspinatus, Upper, and Lower Trapezius in Subjects with and without Shoulder Pain

2021 ◽  
Vol 18 (17) ◽  
pp. 9251
Author(s):  
Jefferson James dos Santos ◽  
Rebeca Orozco Nagy ◽  
Matheus Almeida Souza ◽  
Leonardo Intelangelo ◽  
Michelle Almeida Barbosa ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Shoulder Pain ◽  
Maximal Voluntary Contraction ◽  
Voluntary Contraction ◽  
Load Cell ◽  
Subacromial Space ◽  
Painful Shoulder ◽  
Upper Trapezius ◽  
Condition Effect ◽  
Lower Trapezius

Exercises for lower trapezius (LT) often use overhead positions, causing compressive forces to the subacromial space. Scapular retraction would be an alternative to activate LT muscle. The present study aimed to assess the excitation levels of infraspinatus, upper trapezius, and lower trapezius muscles during a scapular retraction exercise under progressive adduction loads in subjects with and without painful shoulder. Electromyography of infraspinatus (IS), upper trapezius (UT), and LT was recorded during scapular retraction under progressive adduction loads of 42 participants, divided into two groups: with (SP, n = 26) and without shoulder pain (nSP, n = 16). The adduction loads of 20%, 30%, 40%, and 50% of the maximal voluntary contraction (MVC) were applied using a load cell. Normalized electromyography and the ratio between UT and LT (UT:LT) were used for statistical analysis. No differences were observed between groups, but a condition effect occurred for all muscles: UT showed higher values at 50% vs. 20% of MVC (p = 0.004); LT showed higher values on 40% and 50% of MVC (p = 0.001; 0.006). Higher values for IS were noted at 40% of MVC (vs. 20% of MVC; p = 0.04) and at 50% of MVC (vs. 20% of MVC; p = 0.001, vs. 30% of MVC, p = 0.001; vs. 40% of MVC; p = 0.001). UT:LT showed lower values at 50% of MVC (vs. 20% of MVC; p = 0.001 and vs. 30% of MVC; p = 0.016). Scapular retraction with adduction loads at 40–50% is an alternative to overhead exercises aiming to activate the LT and the IS muscles. The exercise ensures higher levels of LT and IS excitation without increasing UT excitation.

scholarly journals Scapular Retraction Under Adduction Load: an Alternative to Overhead Exercises to Activate Infraspinatus, Upper and Lower Trapezius in Subjects With and Without Shoulder Pain

2021 ◽  
Author(s):  
Jefferson James dos Santos ◽  
Rebeca Orozco Nagy ◽  
Matheus Almeida Souza ◽  
Leonardo Intelangelo ◽  
Michelle Almeida Barbosa ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Shoulder Pain ◽  
Maximal Voluntary Contraction ◽  
Voluntary Contraction ◽  
Load Cell ◽  
Subacromial Space ◽  
Condition Effect ◽  
Lower Trapezius

Exercises for lower trapezius (LT) often use overhead positions, causing compressive forces to the subacromial space. Scapular retraction would be an alternative to activate LT muscle. Electromyography of infraspinatus (IS), upper (UT) and LT was recorded during scapular retraction under progressive adduction loads of 42 participants, divided in 2 groups: with (SP, n=26) and without shoulder pain (nSP, n=16). The adduction loads of 20, 30, 40 and 50% of the maximal voluntary contraction were applied using a load cell. Normalized electromyography and the ratio between UT and LT (UT:LT) were used for statistical analysis. No differences were observed between groups, but a condition effect occurred for all muscles: UT showed higher values at 50% vs. 20% (p=0.004); LT showed higher values on 40% and 50% (p=0.001; 0.006). Higher values for IS were noted at 40% (vs 20%; p=0.04), and at 50% (vs. 20%; p=0.001, vs. 30%, p=0.001; vs. 40%; p=0.001). UT:LT showed lower values at 50% (vs. 20%; p=0.001, and vs. 30%; p=0.016). Scapular retraction with adduction loads at 40-50% is an alternative to overhead exercises aiming to activate the LT and the IS muscles. The exercise ensures higher levels of LT and IS excitation, without increasing UT excitation.

scholarly journals Lower trapezius and serratus anterior activation: which exercise to use for scapular neuromuscular reeducation?

2013 ◽  
Vol 11 (4) ◽  
pp. 660-667
Author(s):  
Rodrigo Py Gonçalves Barreto ◽  
Caroline Cabral Robinson ◽  
Clarice Sperotto dos Santos Rocha ◽  
Fernando Carlos Mothes ◽  
Fábio Matsumoto ◽  
...  
Keyword(s):  
Functional Recovery ◽  
Surface Electromyography ◽  
Maximal Voluntary Contraction ◽  
Healthy Subjects ◽  
Voluntary Contraction ◽  
Serratus Anterior ◽  
Low Levels ◽  
Lower Trapezius ◽  
The Military ◽  
Muscular Activation

Introduction: Low levels of activation of the serratus anterior (SA) and lower trapezius (LT) muscles are associated with kinematics dysfunctions of the scapular belt, for which the focus of functional recovery is neuromuscular reeducation. Hence, the proposed exercises should keep muscular activation at levels between 20% and 40% of the maximal voluntary contraction. Objectives: To compare the activation of SA and LT muscles in different exercises by using surface electromyography. Methods: Five exercises (modified crucifix, scaption, modified military press, pull over and low row) were executed by ten healthy subjects. Results: The highest SA activation was found during scaption, and the adequate activation occurred in the modified military press. The highest LT activation was found during scaption and low row exercises. Conclusions: The exercises that kept the recommended range of activation for neuromuscular reeducation were the military press, for the SA muscle, and the low row and scaption, for the LT muscle.

scholarly journals Scapular Muscle Tests in Subjects With Shoulder Pain and Functional Loss: Reliability and Construct Validity

2005 ◽  
Vol 85 (11) ◽  
pp. 1128-1138 ◽  
Author(s):  
Lori A Michener ◽  
N Douglas Boardman ◽  
Peter E Pidcoe ◽  
Angela M Frith
Keyword(s):  
Construct Validity ◽  
Shoulder Pain ◽  
Muscle Activity ◽  
Trapezius Muscle ◽  
Muscle Performance ◽  
Serratus Anterior ◽  
Functional Loss ◽  
Upper Trapezius ◽  
Lower Trapezius ◽  
Isometric Muscle

Abstract Background and Purpose. Scapular muscle performance evaluated with a handheld dynamometer (HHD) has been investigated only in people without shoulder dysfunction for test-retest reliability of data obtained with a single scapular muscle test. The purpose of this study was to assess the reliability, error, and validity of data obtained with an HHD for 4 scapular muscle tests in subjects with shoulder pain and functional loss. Subjects and Methods. Subjects (N=40) with shoulder pain and functional loss were tested bymeasuring the kilograms applied with an HHD during 3 trials for muscle tests for the lower trapezius, upper trapezius, middle trapezius, and serratus anterior muscles. Concurrently, surface electromyography (sEMG) data were collected for the 4 muscles. The same procedures were performed 24 to 72 hours after the initial testing by the same tester. Muscle tests were performed 3 times, and the results were averaged for data analysis. Results. Intraclass correlation coefficients for intratester reliability of measurements of isometricforce obtained using an HHD ranged from .89 to .96. The standard error of the measure (90% confidenceinterval [CI]) ranged from 1.3 to 2.7 kg; the minimal detectable change (90% CI) ranged from 1.8 to 3.6 kg. Construct validity assessment, done by comparing the amounts of isometric muscle activity (sEMG) for each muscle across the 4 muscle tests, revealed that the muscle activity of the upper trapezius and lower trapezius muscles washighest during their respective tests. Conversely, the isometric muscle activity of the middle trapezius and serratus anterior muscles was not highest during their respective tests. Discussion and Conclusion. In people with shoulder pain and functional loss, the intrarater reliability and error over 1 to 3 days were established using an HHD for measurement of isometric force for the assessment of scapular muscle performance. Error values can be used to make decisions regarding individual patients. Construct validity was established for the lower and upper trapezius muscle tests; therefore, these tests are advocated for use. However, construct validity was not demonstrated for the serratus anterior and middle trapezius muscle tests as performed in this study. Further investigation of these muscle tests is warranted.

The Performance of Female Young Adults in Perception of Efforts of Varied Nature and Magnitudes

1993 ◽  
Vol 37 (10) ◽  
pp. 793-797
Author(s):  
Shrawan Kumar ◽  
Maureen Simmonds ◽  
David Lechelt
Keyword(s):  
Young Adults ◽  
Statistical Analysis ◽  
Young Adult ◽  
Maximal Voluntary Contraction ◽  
Voluntary Contraction ◽  
Test Analysis ◽  
Hand Grip ◽  
Adult Females ◽  
Significant Difference ◽  
Entire Experiment

Ten normal young adult females performed maximal and graded exertions of the stoop lift, hand grip, and finger pinch. The levels of graded exertion required were 80%, 60%, 40% and 20% of maximal voluntary contraction (MVC). The sequence of all conditions were fully randomized. Each of the randomized conditions was tried three times in succession. The entire experiment was carried out on four different days at the same time of the day on Monday, Wednesday, Friday of one week and Friday of the next week. The data obtained were subjected to descriptive and statistical analysis with t-test, analysis of variance, and correlation and regression. There were significant differences in the efforts produced in three different activities (p<0.01). The levels of exertion from 20% to 80% were significantly different from each other (p<0.01). However, there were no significant differences between the three trials of any given condition and the exertions produced on four different days. The 80% and 60% of exertions were overestimated and 20% was underestimated compared to the objective values based on MVC (p<0.01). At 40% effort there was no significant difference between the objective level of exertion and subjectively gauged and produced effort. The reliability of perception among the female subjects was similar for finger pinch, hand grip, and stoop lift activities.

Normalization to Maximal Voluntary Contraction is Influenced by Subacromial Pain

2016 ◽  
Vol 32 (5) ◽  
pp. 433-440 ◽  
Author(s):  
Lucas Ettinger ◽  
Jason Weiss ◽  
Matthew Shapiro ◽  
Andrew Karduna
Keyword(s):  
Trapezius Muscle ◽  
Pain Scale ◽  
Voluntary Contraction ◽  
Subacromial Impingement Syndrome ◽  
Serratus Anterior ◽  
Upper Trapezius ◽  
Subacromial Injection ◽  
Shoulder Muscle ◽  
Before And After ◽  
Lower Trapezius

In this study, we aimed to determine if electromyography (EMG) normalization to maximal voluntary isometric contractions (MVIC) was influenced by subacromial pain in patients with subacromial impingement syndrome. Patients performed MVICs in unique testing positions for each shoulder muscle tested before and after subacromial injection of local anesthetic. In addition to collection of MVIC data, EMG data during an arm elevation task were recorded before and after injection. From a visual analog pain scale, patients had a 64% decrease in pain following the injection. Significant increases in MVICs were noted in 4 of the 7 shoulder muscles tested: anterior, middle and posterior deltoid, and lower trapezius. No significant differences were noticed for the upper trapezius, latissimus dorsi, or serratus anterior. MVIC condition (pre and post injection) had a significant influence on EMG normalization for the anterior deltoid and lower trapezius muscle. Results indicate that subacromial pain can influence shoulder muscle activity, especially for the deltoid muscles and lower trapezius. In addition, normalization to MVIC in the presence of pain can have unpredictable results. Caution should be taken when normalizing EMG data to MVIC in the presence of pain.

Shoulder-Muscle Activation in Individuals With Previous Shoulder Injuries

2015 ◽  
Vol 24 (3) ◽  
pp. 278-285 ◽  
Author(s):  
Alyssa Muething ◽  
Shellie Acocello ◽  
Kimberly A. Pritchard ◽  
Stephen F. Brockmeier ◽  
Susan A. Saliba ◽  
...  
Keyword(s):  
Shoulder Pain ◽  
Outcome Measures ◽  
Muscle Activation ◽  
Treatment Plan ◽  
Isometric Contractions ◽  
Shoulder Injuries ◽  
Upper Trapezius ◽  
History Of ◽  
Anterior Deltoid ◽  
Lower Trapezius

Context:Understanding how muscles activate in a population with a previous glenohumeral-joint (GH) injury may help clinicians understand how to build a conservative treatment plan to strengthen or activate the specific muscles in an attempt to reduce recurrent shoulder injury and development of GH laxity.Objective:To investigate muscle-activation differences between the previously injured limb of individuals with a history of GH-joint injury and healthy matched controls during functional isometric contractions.Design:Case control.Setting:University research laboratory.Participants:17 individuals (8 women, 9 men; age 22.3 ± 2.6 y, height 172.4 ± 8.8 cm, mass 75.4 ± 16.5 kg) with previous unilateral shoulder pain and 17 (8 women, 9 men; age 22.9 ± 3.9 y, height 170.9 ± 11.3 cm, mass 73.6 ± 22.9 kg) with no history of shoulder pain or injury.Intervention(s):Diagnostic ultrasound measurements of the supraspinatus were completed in both resting and contracted states to assess changes in muscle thickness. Manual muscle tests (anterior deltoid, upper trapezius, infraspinatus, lower trapezius, serratus anterior) and functional isometric contractions (forward flexion, scaption, abduction) were measured using electromyography.Main Outcome Measures:Peak, normalized activation of each muscle and supraspinatus thickness activation ratio were compared between groups and bilaterally within groups using separate ANOVAs.Results:The anterior deltoid was significantly less activated during all functional isometric tasks in previously injured subjects than in healthy subjects (P = .024). In previously injured subjects, the involved limb-lower trapezius was significantly less activated during scaption and abduction tasks than the contralateral side (P = .022 and P = .031, respectively).Conclusions:There were decreases in muscle activation in the anterior deltoid between previously injured and healthy people, as well as in the lower trapezius, in previously injured subjects. Understanding the source of muscle-activation deficits can help clinicians focus rehabilitation exercises on specific muscles.

scholarly journals Shoulder Muscle Activity in Sport Climbing in Naturally Chosen and Corrected Shoulder Positions

2017 ◽  
Vol 10 (1) ◽  
pp. 107-113
Author(s):  
Jiří Baláš ◽  
Alena Duchačová ◽  
David Giles ◽  
Kateřina Kotalíková ◽  
David Pánek ◽  
...  
Keyword(s):  
Muscle Activity ◽  
External Rotation ◽  
Voluntary Contraction ◽  
The Other ◽  
Electromyographic Activity ◽  
Serratus Anterior ◽  
Upper Trapezius ◽  
Shoulder Muscle ◽  
Sport Climbing ◽  
Lower Trapezius

Objective:The aim of the study was to determine electromyographic activity of the scapula stabilizing muscles in naturally chosen and corrected shoulder positions in typical static climbing postures.Methods:Six male participants undertook surface electromyography measurement in four climbing postures for two different shoulder positions. The activity of the lower, middle and upper trapezius, serratus anterior, pectoralis major, and sternocleidomastoid was recorded. Electromyographic activity was expressed as the percentage of maximal voluntary contraction (MVC) for each muscle.Results:Climbing postures induced higher activation of middle and lower trapezius in corrected shoulder positions (35.3 ± 11.8 and 61.7 ± 15.4% MVC respectively) than in naturally chosen shoulder positions (18.4 ± 8.9 and 30.1 ± 13.8% MVC respectively). The highest activity of the middle and lower trapezius was found in postures with the arm in external rotation and 90° abduction and in an overhanging posture. Low activation was stated for the other muscles in both shoulder conditions.Conclusion:Results showed that climbers naturally elevate the shoulder during typical static postures. Corrected shoulder positions induce higher activation of the scapula stabilizing muscles than naturally chosen shoulder positions.

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