Effects of the Additional Scapular Posterior Tilt Movement on Selective Muscle Activation of the Lower Trapezius during Prone Shoulder Extension

Context:Scapular proprioception is a key concern in managing shoulder impingement syndrome (SIS). However, no study has examined the effect of elastic taping on scapular proprioception performance.Objective:To investigate the immediate effect of kinesiology taping (KT) on scapular reposition accuracy, kinematics, and muscle activation in individuals with SIS.Design:Randomized controlled study.Setting:Musculoskeletal laboratory, National Yang-Ming University, Taiwan.Participants:Thirty overhead athletes with SIS.Interventions:KT or placebo taping over the upper and lower trapezius muscles.Main Outcome Measures:The primary outcome measures were scapular joint position sense, measured as the reposition errors, in the direction of scapular elevation and protraction. The secondary outcomes were scapular kinematics and muscle activity of the upper trapezius, lower trapezius, and serratus anterior during arm elevation in the scapular plane (scaption).Results:Compared with placebo taping, KT significantly decreased the reposition errors of upward/downward rotation (P = .04) and anterior/posterior tilt (P = .04) during scapular protraction. KT also improved scapular kinematics (significant group by taping effect for posterior tilt,P = .03) during scaption. Kinesiology and placebo tapings had a similar effect on upper trapezius muscle activation (significant taping effect,P = .003) during scaption.Conclusions:Our study identified the positive effects of KT on scapular joint position sense and movement control. Future studies with a longer period of follow-up and clinical measurement might help to clarify the clinical effect and mechanisms of elastic taping in individuals with SIS.

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Effects of Intended Scapular Posterior Tilt Motion on Trapezius Muscle Electromyography Activity

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18179147 ◽

2021 ◽

Vol 18 (17) ◽

pp. 9147

Author(s):

Soo-Yong Kim ◽

Il-Young Yu ◽

Jae-Seop Oh ◽

Min-Hyeok Kang

Keyword(s):

Tilt Angle ◽

Muscle Activity ◽

Muscle Activation ◽

Trapezius Muscle ◽

Emg Activity ◽

Upper Trapezius ◽

Posterior Tilt ◽

Lower Trapezius ◽

Trunk Extension ◽

Asymptomatic Men

The intended scapular motion is a strategy to strengthen the lower trapezius (LT). However, few studies have explored the effects of the intended scapular posterior tilt motion on selective LT activation. Thus, the present study investigated the effect of the intended scapular posterior tilt on the electromyography (EMG) activity of trapezius muscles during prone shoulder horizontal abduction (PSHA). Eighteen asymptomatic men performed three types of PSHA: (1) preferred PSHA, (2) PSHA with the intended scapular posterior tilt, and (3) PSHA with the intended scapular posterior tilt and trunk extension. EMG activity of the upper trapezius (UT), middle trapezius (MT), and LT were measured during PSHAs. Scapular posterior tilt angle, with and without the intended scapular posterior tilt, were measured using inclinometer. The results indicated that LT muscle activity increased when scapular posterior tilt was applied with and without trunk extension (14–16%), compared to the preferred condition, during PSHA (p < 0.05). However, the addition of trunk extension to PSHA with the intended scapular posterior tilt increased the UT muscle activity (28%) and the UT/LT (29%) and UT/MT (31%) ratios (p < 0.05). The scapular posterior tilt angle was higher (15%) when applying the intended scapular posterior tilt (p = 0.020). These findings suggest that the intended scapular posterior tilt may be a useful strategy for selective LT muscle activation.

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Function, strength, and muscle activation of the shoulder complex in Crossfit practitioners with and without pain: a cross-sectional observational study

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-022-02915-x ◽

2022 ◽

Vol 17 (1) ◽

Author(s):

Elisa Raulino Silva ◽

Nicola Maffulli ◽

Filippo Migliorini ◽

Gilmar Moraes Santos ◽

Fábio Sprada de Menezes ◽

...

Keyword(s):

Shoulder Pain ◽

Surface Electromyography ◽

Shoulder Joint ◽

Muscle Activation ◽

National Registry ◽

Kinetic Chain ◽

Balance Test ◽

Cross Sectional ◽

Significant Difference ◽

Lower Trapezius

Abstract Background The shoulder joint is the most commonly injured joint in CrossFit practitioners, because of the high intensity and loads associated with this sport. Despite the large number of clinical cases, there is a shortage of studies that investigate influence of biomechanical aspects of upper limbs' injuries on CrossFit practitioners. This study hypothesized that there would be a difference in function, strength, and muscle activation between Crossfit practitioners with and without shoulder pain. Methods We divided 79 Crossfit practitioners into two groups according to whether they reported pain (n = 29) or no pain (n = 50) in the shoulder during Crossfit training. Muscle function, strength, and activation were assessed using the Disability Arm, Shoulder and Hand function questionnaire, Upper Quarter Y Balance Test and Closed Kinetic Chain Upper Extremity Stability Test shoulder tests, isometric muscle strength assessment by manual dynamometry and muscle activation by surface electromyography and pain report. Results The function based on questionnaire was associated with pain (p = 0.004). We observed a statistically significant difference between the two groups only in the surface electromyography activity of the lower trapezius, and in the variables of shoulder pain and function (p = 0.038). Conclusion Crossfit practitioners with shoulder pain occurring during training showed good function and stability of the shoulder joint, but there was a reduction in the activation of stabilizing muscles, especially the lower trapezius. Trial registration Registro Brasileiro de Ensaios Clinico (Brasilian National Registry) with the ID: RBR-2gycyv.

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Shoulder External Rotation Fatigue and Scapular Muscle Activation and Kinematics in Overhead Athletes

Journal of Athletic Training ◽

10.4085/1062-6050-46.4.349 ◽

2011 ◽

Vol 46 (4) ◽

pp. 349-357 ◽

Cited By ~ 27

Author(s):

Mithun Joshi ◽

Charles A. Thigpen ◽

Kevin Bunn ◽

Spero G. Karas ◽

Darin A. Padua

Keyword(s):

Muscle Fatigue ◽

Muscle Activation ◽

External Rotation ◽

Shoulder Injuries ◽

Serratus Anterior ◽

Overhead Athletes ◽

Scapular Kinematics ◽

Fatigue Protocol ◽

Upper Trapezius ◽

Lower Trapezius

Context: Glenohumeral external rotation (GH ER) muscle fatigue might contribute to shoulder injuries in overhead athletes. Few researchers have examined the effect of such fatigue on scapular kinematics and muscle activation during a functional movement pattern. Objective: To examine the effects of GH ER muscle fatigue on upper trapezius, lower trapezius, serratus anterior, and infraspinatus muscle activation and to examine scapular kinematics during a diagonal movement task in overhead athletes. Setting: Human performance research laboratory. Design: Descriptive laboratory study. Patients or Other Participants: Our study included 25 overhead athletes (15 men, 10 women; age = 20 ± 2 years, height = 180 ± 11 cm, mass = 80 ± 11 kg) without a history of shoulder pain on the dominant side. Intervention(s): We tested the healthy, dominant shoulder through a diagonal movement task before and after a fatiguing exercise involving low-resistance, high-repetition, prone GH ER from 0° to 75° with the shoulder in 90° of abduction. Main Outcome Measure(s): Surface electromyography was used to measure muscle activity for the upper trapezius, lower trapezius, serratus anterior, and infraspinatus. An electromyographic motion analysis system was used to assess 3-dimensional scapular kinematics. Repeated-measures analyses of variance (phase × condition) were used to test for differences. Results: We found a decrease in ascending-phase and descending-phase lower trapezius activity (F1,25 = 5.098, P = .03) and an increase in descending-phase infraspinatus activity (F1,25 = 5.534, P = .03) after the fatigue protocol. We also found an increase in scapular upward rotation (F1,24 = 3.7, P = .04) postfatigue. Conclusions: The GH ER muscle fatigue protocol used in this study caused decreased lower trapezius and increased infraspinatus activation concurrent with increased scapular upward rotation range of motion during the functional task. This highlights the interdependence of scapular and glenohumeral force couples. Fatigue-induced alterations in the lower trapezius might predispose the infraspinatus to injury through chronically increased activation.

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Thoracic posture, shoulder muscle activation patterns and isokinetic strength of semi-professional rugby union players

South African Journal of Sports Medicine ◽

10.17159/2413-3108/2013/v25i1a386 ◽

2013 ◽

Vol 25 (1) ◽

pp. 12 ◽

Cited By ~ 1

Author(s):

G Bolton ◽

SJ Moss ◽

M Sparks ◽

PC Venter

Keyword(s):

Rotator Cuff ◽

Muscle Strength ◽

Muscle Activation ◽

Rugby Union ◽

Lateral View ◽

Isokinetic Strength ◽

Serratus Anterior ◽

Activation Patterns ◽

Muscle Activation Patterns ◽

Lower Trapezius

Background. Shoulder injuries are the most severe injuries in rugby union players, accounting for almost 20% of injuries related to the sport and resulting in lost playing hours.Objective. To profile the thoracic posture, scapular muscle activation patterns and rotator cuff muscle isokinetic strength of semi-professionalrugby union players.Methods. Using the hand-behind-the-neck and -back methods, we manually tested the range of motion (ROM) of the shoulder joints of 91 uninjured semi-professional rugby union players who consented to participate in the study. Profiling and classification of thoracic posture was performed according to the New York Posture Test. Activation patterns of the upper and lower trapezius, serratus anterior and infraspinatus scapular muscles were determined by electromyography. The isokinetic muscle strength of the rotator cuff muscles was determined at 60°/sec by measuring the concentric and eccentric forces during internal rotation (IR) and external rotation (ER).Results. Participants presented with non-ideal or unsatisfactory internal (59%) and external (85%) rotators of the shoulder. A slightly abnormal or abnormal forward head posture was observed in 55% of participants, while 68% had an abnormal shoulder position in the lateral view. The muscle activation sequence of the rotator cuff muscles was: (i) serratus anterior, (ii) lower trapezius, (iii) infraspinatus, and (iv) upper trapezius. The isokinetic ER/IR muscle-strength ratio during concentric muscle contraction was 64% (standard deviation (SD) ±14) for the left shoulder and 54% (SD ±10) for the right shoulder. The ER/IR ratio for eccentric muscle contraction was 67% (SD ±12) and 61% (SD ±9) for the left and right shoulders, respectively.Conclusions. Non-ideal or unsatisfactory flexibility of the external rotators of the shoulder, a forward shoulder posture in the lateral view, and weakness of the external rotators did not result in an abnormal rotator cuff muscle activation pattern in this study. Postural deviations may, however, increase the risk of shoulder injury in rugby union players in the long term, and should be corrected.

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Analysis of neck and back muscle activity during the application of various pillow designs in patients with forward head posture

Journal of Back and Musculoskeletal Rehabilitation ◽

10.3233/bmr-200038 ◽

2021 ◽

pp. 1-9

Author(s):

Sirirat Kiatkulanusorn ◽

Bhornluck Paepetch Suato ◽

Phurichaya Werasirirat

Keyword(s):

Muscle Activity ◽

Muscle Activation ◽

Trapezius Muscle ◽

Back Muscle ◽

Forward Head Posture ◽

Sleeping Position ◽

Head Posture ◽

Upper Trapezius ◽

Activation Response ◽

Lower Trapezius

BACKGROUND: There are currently no reports of biomechanical changes in patients with forward head posture (FHP) that result in altered muscle activation throughout various functions with muscle activation response during diverse sleep postures. OBJECTIVE: This study investigated neck and back muscle activity in individuals with and without FHP during a maintained side-sleeping position by incorporating various pillow designs. METHODS: Thirty-four participants (i.e. 17 in each group) were enrolled. The muscle activity was investigated via surface electromyography during the use of three trial pillows: orthopedic pillow, hollow pillow, and Thai neck support pillow. RESULTS: With the application of all three trial pillows the FHP group demonstrated significantly greater lower trapezius muscle activity than the normal head posture group (p< 0.05). Sternocleidomastoid and upper trapezius (UT) muscle activity were similar between the two groups (p> 0.05). Only UT muscle activity was affected by variations in pillow design. In the normal group no difference was observed in the muscle activity between all three pillows (p> 0.05). CONCLUSIONS: Feasibly, the ability to appropriately modify a pillow configuration without creating undesired muscle activation was limited to those exhibiting FHP. Therefore, specially designed pillows or mattresses should be investigated in terms of their relevance to muscle fatigue and potential musculoskeletal pain in FHP patients.

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Comparison of Diagonal Shoulder Exercises With and Without Visual Trace

International Journal of Athletic Therapy & Training ◽

10.1123/ijatt.2014-0062 ◽

2015 ◽

Vol 20 (1) ◽

pp. 52-56

Author(s):

Jwa-jun Kim ◽

So-youn Ann ◽

Se-yeon Park

Keyword(s):

Repeated Measures ◽

Muscle Activation ◽

Outcome Measure ◽

Specific Pattern ◽

Repeated Measure ◽

Serratus Anterior ◽

Additional Advantage ◽

Main Outcome Measure ◽

Anterior Deltoid ◽

Lower Trapezius

Objectives:The aim of this study was to investigate the effects of visual trace on shoulder muscle activation during diagonal pattern of exercises. Sixteen healthy male participants volunteered to participate.Design:Repeated-measure design.Setting:Laboratory setting.Participants:Sixteen physically active male participants volunteered to participate.Intervention:Five muscles of the shoulder were investigated during standing performance of diagonal shoulder exercises with and without visual trace. Two patterns of the diagonal exercises were used: diagonal 1 flexion (D1F) and diagonal 2 fexion (D2F). Two-way repeated measures analysis of variance was used, with factors being the presence of visual trace and exercise variations.Main Outcome Measure:Electromyography (EMG).Results:The average muscle activity values of the lower trapezius and anterior deltoid were higher with the D2F compared with the D1F (P < .05). The visual trace effect was observed within the serratus anterior, with values significantly greater in exercise with visual trace (P < .05). There was a significant increase of the lower trapezius during the exercise with the visual trace condition compared with the exercise without visual trace, which was only observed during D2F (P < .05).Conclusions:Present results suggest that the D2F exercise pattern is effective for activating lower trapezius and anterior deltoid muscles. The visual trace condition has the additional advantage of activating the scapulothoracic muscle activities depending on the specific pattern of diagonal shoulder exercise.

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Thoracic posture, shoulder muscle activation patterns and isokinetic strength of semi-professional rugby union players

South African Journal of Sports Medicine ◽

10.17159/2078-516x/2013/v25i1a386 ◽

2013 ◽

Vol 25 (1) ◽

pp. 12 ◽

Cited By ~ 2

Author(s):

G Bolton ◽

SJ Moss ◽

M Sparks ◽

PC Venter

Keyword(s):

Rotator Cuff ◽

Muscle Strength ◽

Muscle Activation ◽

Rugby Union ◽

Lateral View ◽

Isokinetic Strength ◽

Serratus Anterior ◽

Activation Patterns ◽

Muscle Activation Patterns ◽

Lower Trapezius

Background. Shoulder injuries are the most severe injuries in rugby union players, accounting for almost 20% of injuries related to the sport and resulting in lost playing hours.Objective. To profile the thoracic posture, scapular muscle activation patterns and rotator cuff muscle isokinetic strength of semi-professionalrugby union players.Methods. Using the hand-behind-the-neck and -back methods, we manually tested the range of motion (ROM) of the shoulder joints of 91 uninjured semi-professional rugby union players who consented to participate in the study. Profiling and classification of thoracic posture was performed according to the New York Posture Test. Activation patterns of the upper and lower trapezius, serratus anterior and infraspinatus scapular muscles were determined by electromyography. The isokinetic muscle strength of the rotator cuff muscles was determined at 60°/sec by measuring the concentric and eccentric forces during internal rotation (IR) and external rotation (ER).Results. Participants presented with non-ideal or unsatisfactory internal (59%) and external (85%) rotators of the shoulder. A slightly abnormal or abnormal forward head posture was observed in 55% of participants, while 68% had an abnormal shoulder position in the lateral view. The muscle activation sequence of the rotator cuff muscles was: (i) serratus anterior, (ii) lower trapezius, (iii) infraspinatus, and (iv) upper trapezius. The isokinetic ER/IR muscle-strength ratio during concentric muscle contraction was 64% (standard deviation (SD) ±14) for the left shoulder and 54% (SD ±10) for the right shoulder. The ER/IR ratio for eccentric muscle contraction was 67% (SD ±12) and 61% (SD ±9) for the left and right shoulders, respectively.Conclusions. Non-ideal or unsatisfactory flexibility of the external rotators of the shoulder, a forward shoulder posture in the lateral view, and weakness of the external rotators did not result in an abnormal rotator cuff muscle activation pattern in this study. Postural deviations may, however, increase the risk of shoulder injury in rugby union players in the long term, and should be corrected.

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