Electromyographic Activity and Applied Load During Shoulder Rehabilitation Exercises Using Elastic Resistance

1998 ◽  
Vol 26 (2) ◽  
pp. 210-220 ◽  
Author(s):  
Robert A. Hintermeister ◽  
Gregory W. Lange ◽  
Jeanne M. Schultheis ◽  
Michael J. Bey ◽  
Richard J. Hawkins
Keyword(s):  
Muscle Activity ◽  
Applied Load ◽  
Activity Patterns ◽  
Electromyographic Activity ◽  
Serratus Anterior ◽  
Elastic Resistance ◽  
Intramuscular Electrodes ◽  
Anterior Deltoid ◽  
Voluntary Contractions ◽  
Rehabilitation Exercises

Muscle activity (measured by electromyography) and applied load were measured during seven shoulder rehabilitation exercises done with an elastic resistance device. Nineteen men with no shoulder abnormalities performed seven exercises: external and internal rotation, forward punch, shoulder shrug, and seated rowing with a narrow, middle, and wide grip. Qualitative video (60 Hz) was synchronized with the electromyography data from eight muscles (2000 Hz). Fine-wire intramuscular electrodes were inserted into the supraspinatus and subscapularis muscles, and surface electrodes were placed over the anterior deltoid, infraspinatus, pectoralis major, latissimus dorsi, serratus anterior, and trapezius muscles. Ten trials per subject were analyzed for average and peak amplitude, and the results were expressed as a percentage of maximum voluntary contractions. The peak loads for all exercises ranged from 21 to 54 N. The muscle activity patterns suggest that these shoulder rehabilitation exercises incorporating elastic resistance, controlled movements, and low initial loading effectively target the rotator cuff and supporting musculature and are appropriate for postinjury and postoperative patients.

scholarly journals Incorporation of the Kinetic Chain Into Shoulder-Elevation Exercises: Does It Affect Scapular Muscle Activity?

2020 ◽  
Vol 55 (4) ◽  
pp. 343-349
Author(s):  
Dorien Borms ◽  
Annelies Maenhout ◽  
Ann M Cools
Keyword(s):  
Lower Limb ◽  
Muscle Activity ◽  
Mean Difference ◽  
Hand Position ◽  
Electromyographic Activity ◽  
Kinetic Chain ◽  
Serratus Anterior ◽  
Single Plane ◽  
Rehabilitation Exercises ◽  
Shoulder Elevation

Context Scapular rehabilitation exercises should focus on selective activation of weaker muscles and minimal activation of hyperactive muscles. For rehabilitation of overhead athletes, single-plane open chain exercises below 90° of shoulder elevation are often recommended. Moreover, incorporating the kinetic chain in shoulder rehabilitation exercises is advised and has been suggested to influence scapular muscle activity levels. Objective To study the influence of kinetic chain incorporation during 5 variations of a shoulder-elevation exercise on scapular muscle activity. Design Cross-sectional study. Setting University laboratory. Patients or Other Participants Thirty-one asymptomatic participants (15 men, 16 women). Main Outcome Measure(s) The electromyographic activity of the upper (UT), middle (MT), and lower (LT) trapezius, and serratus anterior was determined during 5 variations of bilateral elevation with external rotation: (1) open-hand position (reference exercise), (2) closed-hand position, (3) dynamic bipedal squat, (4) static unipedal squat, and (5) dynamic unipedal squat on the contralateral leg. All data were normalized as a percentage of maximal voluntary isometric contraction (MVIC). Results A closed-hand position (exercise 2) instead of an open-hand position (exercise 1) resulted in lower MT (mean difference = 3.44% MVIC) and LT (mean difference = 7.76% MVIC) activity. Incorporating the lower limb (exercises 3–5) increased UT activity when compared with exercise 1 (mean differences = 3.67, 2.68, 5.02% MVIC, respectively), which in general resulted in increased UT : MT ratios. Additionally, LT activity decreased when a dynamic unipedal squat was added (mean difference: 4.90% MVIC). For the serratus anterior, the greatest activity occurred during elevation in a static unipedal squat position (exercise 4, 22.90% MVIC). Conclusions Incorporating the kinetic chain during shoulder-elevation exercises influenced scapular muscle activity and ratios. In particular, incorporating the lower limb resulted in more UT activity, whereas the open-hand position increased MT and LT activity.

scholarly journals Alterations in Shoulder Kinematics and Associated Muscle Activity in People With Symptoms of Shoulder Impingement

2000 ◽  
Vol 80 (3) ◽  
pp. 276-291 ◽  
Author(s):  
Paula M Ludewig ◽  
Thomas M Cook
Keyword(s):  
Occupational Exposure ◽  
Muscle Activity ◽  
Load Condition ◽  
Trapezius Muscle ◽  
Electromyographic Activity ◽  
Serratus Anterior Muscle ◽  
Serratus Anterior ◽  
Shoulder Impingement ◽  
Upper Trapezius ◽  
Load Conditions

AbstractBackground and Purpose. Treatment of patients with impingement symptoms commonly includes exercises intended to restore “normal” movement patterns. Evidence that indicates the existence of abnormal patterns in people with shoulder pain is limited. The purpose of this investigation was to analyze glenohumeral and scapulothoracic kinematics and associated scapulothoracic muscle activity in a group of subjects with symptoms of shoulder impingement relative to a group of subjects without symptoms of shoulder impingement matched for occupational exposure to overhead work. Subjects. Fifty-two subjects were recruited from a population of construction workers with routine exposure to overhead work. Methods. Surface electromyographic data were collected from the upper and lower parts of the trapezius muscle and from the serratus anterior muscle. Electromagnetic sensors simultaneously tracked 3-dimensional motion of the trunk, scapula, and humerus during humeral elevation in the scapular plane in 3 hand-held load conditions: (1) no load, (2) 2.3-kg load, and (3) 4.6-kg load. An analysis of variance model was used to test for group and load effects for 3 phases of motion (31°–60°, 61°–90°, and 91°–120°). Results. Relative to the group without impingement, the group with impingement showed decreased scapular upward rotation at the end of the first of the 3 phases of interest, increased anterior tipping at the end of the third phase of interest, and increased scapular medial rotation under the load conditions. At the same time, upper and lower trapezius muscle electromyographic activity increased in the group with impingement as compared with the group without impingement in the final 2 phases, although the upper trapezius muscle changes were apparent only during the 4.6-kg load condition. The serratus anterior muscle demonstrated decreased activity in the group with impingement across all loads and phases. Conclusion and Discussion. Scapular tipping (rotation about a medial to lateral axis) and serratus anterior muscle function are important to consider in the rehabilitation of patients with symptoms of shoulder impingement related to occupational exposure to overhead work.

scholarly journals Electromyographic Activity and Applied Load During High Intensity Elastic Resistance and Nautilus Machine Exercises

2011 ◽  
Vol 30 (1) ◽  
Author(s):  
Saied Aboodarda ◽  
Mohamad Shariff ◽  
Ahmad Muhamed ◽  
Fatimah Ibrahim ◽  
Ashril Yusof
Keyword(s):  
High Intensity ◽  
Applied Load ◽  
Electromyographic Activity ◽  
Elastic Resistance

Effect of Humeral-Elevation Angle on Electromyographic Activity in the Serratus Anterior During the Push-Up-Plus Exercise

2017 ◽  
Vol 26 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Ui-jae Hwang ◽  
Oh-yun Kwon ◽  
In-cheol Jeon ◽  
Si-hyun Kim ◽  
Jong-hyuck Weon
Keyword(s):  
Outcome Measures ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Elevation Angle ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Serratus Anterior ◽  
Repeated Measures Design ◽  
Activity Ratios ◽  
Push Up

Context:The push-up-plus (PP) exercise has been recommended for strengthening of the serratus anterior (SA). Previous studies have investigated the effect of different stability properties of the base of support to adjust the difficulty level of SA muscle-strengthening exercises in the PP position. However, the optimal humeral-elevation angle (HEA) for selective activation and maximum contraction of the SA during PP has not been investigated.Objectives:To assess the effects of HEA during PP on electromyographic (EMG) activity in the SA, upper trapezius (UT), and pectoralis major (PM) and on the UT:SA and PM:SA activity ratios.Design:Comparative, repeated-measures design.Setting:University research laboratory.Participants:29 healthy men.Main Outcome Measures:The subjects performed PP at 3 different HEAs (60°, 90°, and 120°); EMG activity in the SA, UT, and PM was measured, and the UT:SA and PM:SA activity ratios were calculated. Differences in muscle activity and ratios between the 60°, 90°, and 120° HEAs were assessed using 1-way repeated-measures analysis of variance; the Bonferroni correction was applied.Results:SA muscle activity was significantly increased, in order of magnitude, at the 120°, 90°, and 60° HEAs. UT:SA and PM:SA activity ratios were significantly greater during performance of the PP at an HEA of 60° than at HEAs of 120° and 90°.Conclusion:The results suggest that an HEA of 120° should be used during performance of the PP because it produces greater SA activation than HEAs of 60° and 90°.

Serratus Anterior Muscle Activity During Selected Rehabilitation Exercises

1999 ◽  
Vol 27 (6) ◽  
pp. 784-791 ◽  
Author(s):  
Michael J. Decker ◽  
Robert A. Hintermeister ◽  
Kenneth J. Faber ◽  
Richard J. Hawkins
Keyword(s):  
Muscle Activity ◽  
Serratus Anterior Muscle ◽  
Serratus Anterior ◽  
Rehabilitation Exercises

Comparison of Shoulder Protraction Strength and Electromyography Activity of Serratus Anterior and Pectoralis Major in Subjects With or Without a Winged Scapula

2019 ◽  
Vol 28 (3) ◽  
pp. 272-277 ◽  
Author(s):  
Jun-Seok Kim ◽  
Moon-Hwan Kim ◽  
Duk-Hyun Ahn ◽  
Jae-Seop Oh
Keyword(s):  
Muscle Activity ◽  
Cross Sectional Study ◽  
Pectoralis Major ◽  
Serratus Anterior ◽  
Cross Sectional ◽  
Winged Scapula ◽  
Upper Trapezius ◽  
Shoulder Muscles ◽  
Strengthening Exercises ◽  
Anterior Deltoid

Context:A winged scapula (WS) is associated with faulty posture caused by weakness of the serratus anterior (SA), which mainly acts as a scapular stabilizer muscle. It is important to accurately assess and train the SA muscle with a focus on scapula stabilizers during musculoskeletal rehabilitation of individuals with a WS.Objective:The authors examined muscle activity in the SA and pectoralis major (PM), upper trapezius (UT), and anterior deltoid (AD) as well as shoulder protraction strength during isometric shoulder protraction in individuals with and without a WS.Design:Cross-sectional study.Setting:A clinical biomechanics laboratory.Participants:In total, 27 males with no shoulder, neck, or upper-extremity pain participated.Main Outcome Measures:Isometric shoulder protraction strength was collected and surface electromyography used to measure the activity of the SA, PM, UT, and AD muscles and selective SA activity ratio to other shoulder muscles.Results:Electromyography activity of the SA muscle and shoulder protraction strength were significantly lower in individuals with a WS compared with the non-WS group (P < .05). In contrast, PM muscle activity and the PM-to-SA, UT-to-SA, and AD-to-SA ratios were significantly greater in individuals with a WS than in individuals without winging (P < .05).Conclusions:Isometric shoulder protraction for measuring SA strength in individuals with a WS should focus on isolated muscle activity of the SA, and SA strengthening exercises are important for individuals with a WS.

scholarly journals Electromyographic Activity of Scapular Muscle Control in Free-Motion Exercise

2016 ◽  
Vol 51 (3) ◽  
pp. 195-204 ◽  
Author(s):  
Yukiko Nakamura ◽  
Masaaki Tsuruike ◽  
Todd S. Ellenbecker
Keyword(s):  
Body Weight ◽  
Standing Position ◽  
Free Motion ◽  
Emg Activity ◽  
Shoulder Abduction ◽  
Electromyographic Activity ◽  
Serratus Anterior ◽  
Maximal Voluntary Isometric Contraction ◽  
Upper Trapezius ◽  
Anterior Deltoid

The appropriate resistance intensity to prescribe for shoulder rehabilitative exercise is not completely known. Excessive activation of the deltoid and upper trapezius muscles could be counterproductive for scapulohumeral rhythm during humeral elevation.Context: To identify the effects of different exercise intensities on the scapular muscles during a free-motion “robbery” exercise performed in different degrees of shoulder abduction in seated and standing positions.Objective: Descriptive laboratory study.Design: Kinesiology Adapted Physical Education Laboratory.Setting: A total of 15 healthy male college students (age = 20.5 ± 2.2 years, height = 174.5 ± 5.3 cm, mass = 63.8 ± 6.0 kg).Patients or Other Participants: Participants performed 5 repetitions of a randomized exercise sequence of the robbery exercise in 2 body positions (seated, standing), 2 shoulder-abducted positions (W [20°], 90/90 [90°]) at 3 intensities (0%, 3%, and 7% body weight).Intervention(s): Electromyographic (EMG) activity of the upper trapezius, lower trapezius, serratus anterior, anterior deltoid, and infraspinatus muscles of the upper extremity was collected. All EMG activities were normalized by the maximal voluntary isometric contraction of each corresponding muscle (%).Main Outcome Measure(s): The serratus anterior, anterior deltoid, and infraspinatus EMG activities were greater at 7% body weight in the seated position compared with the standing position (P &lt; .05). The EMG activities in all 5 muscles were greater in the 90/90 position than in the W position (P &lt; .05).Results: Scapular muscle activity modulated relative to changes in body posture and resistance intensity. These findings will enable clinicians to prescribe the appropriate level of exercise intensity and positioning during shoulder rehabilitation.Conclusions:

Analysis of Scapular Kinematics and Muscle Activity by Use of Fine-Wire Electrodes During Shoulder Exercises

2020 ◽  
Vol 48 (5) ◽  
pp. 1213-1219
Author(s):  
Kelly Berckmans ◽  
Birgit Castelein ◽  
Dorien Borms ◽  
Tanneke Palmans ◽  
Thierry Parlevliet ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Moderate Activity ◽  
Limited Information ◽  
Serratus Anterior ◽  
Postoperative Rehabilitation ◽  
Scapular Kinematics ◽  
Fine Wire ◽  
Rehabilitation Exercises

Background: During nonoperative or postoperative rehabilitation after sports injuries, exercise selection is often based on minimal load on the injured/repaired glenohumeral structures, while optimally activating scapulothoracic muscles. Previous research explored scapular muscle activity during rehabilitation exercises using surface electromyography (EMG). However, limited information exists about the deeper lying muscle activity, measured with fine-wire electrodes, even more in combination with 3-dimensional scapular kinematics. Purpose: To report scapular kinematics synchronously with surface and fine-wire EMG during specific shoulder exercises for early rehabilitation. Study Design: Descriptive laboratory study. Methods: A total of 23 healthy male patients were recruited. Three-dimensional scapular kinematics were measured combined with EMG recording of 8 muscles during 4 commonly used shoulder exercises (inferior glide, low row, lawnmower, and robbery). Upper (UT), middle (MT), and lower (LT) trapezius and serratus anterior muscle activities were measured with bipolar surface electrodes. Intramuscular electrodes were placed in the levator scapulae (LS), rhomboid major (RM), pectoralis minor (Pm), and infraspinatus (IS) muscles. All data were normalized as a percentage of maximal voluntary isometric contraction (%MVIC). A linear mixed model with Bonferroni correction was applied for statistical analysis. Results: Scapular kinematics revealed an anterior tilt position during the inferior glide, low row, and robbery ( P < .05). An upward rotation position between 20° and 30° was reached in all exercises except low row. Inferior glide (31°) and low row (42°) represented a significantly increased internal rotation position compared with lawnmower and robbery. Lawnmower and robbery showed significantly ( P < .05) more MT (lawnmower, 36% MVIC; robbery, 39% MVIC) and RM (lawnmower, 59% MVIC; robbery, 66% MVIC) activation compared with inferior glide and low row. Lawnmower and robbery showed significantly ( P < .05) less Pm activation (9.5%-12% MVIC). LS was significantly more active during robbery (58% MVIC) compared with inferior glide and low row (27%-36% MVIC) ( P < .05). IS showed moderate activity (24%-37% MVIC) for all exercises, except low row (13% MVIC). Conclusion/Clinical Relevance: This study provides new insights about scapular positions and activation of the deeper layer muscles during 4 commonly used shoulder rehabilitation exercises. The lawnmower showed a favorable position of the scapula with less Pm activity in contrast to the low row. The inferior glide, lawnmower, and robbery should not be implemented in early phases of shoulder rehabilitation because of their moderate muscle activity.

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