Lower Trapezius Activity Research Articles

Does scapular corrective taping alter periscapular muscle activity and 3-dimensional scapular kinematics? A systematic review

Study DesignThis is a systematic review. IntroductionScapular taping is widely used in the management of scapular dysfunction. However, its effects on the scapular kinematics and the electromyography (EMG) activity of the periscapular muscles are not clear. Purpose of the StudyThe purpose of the study was to systematically review the current literature to examine whether scapular corrective taping alters the EMG activity of the periscapular muscles and the 3-dimensional scapular kinematics. MethodMEDLINE and Web of Science databases were searched using specific mesh terms up to April 2018. A hand search was also conducted on the reference list of the included articles. A total of 157 studies were identified, and they were further analyzed for the eligibility to the systematic review. Studies that investigated the effects of scapular corrective taping on the EMG activity of the periscapular muscles and on the 3-dimensional scapular kinematics on patients with shoulder problems or asymptomatic subjects were eligible for the systematic review. The Cochrane Effective Practice and Organization of Care criteria were modified and used for the risk-of-bias assessment. ResultsEleven articles met the inclusion criteria and were included in the systematic review. Five studies investigated the effects of corrective taping on the scapular kinematics and 8 studies reported the effects of corrective taping on the EMG activity of the periscapular muscles. There was an agreement among the studies that scapular upward rotation is increased with the corrective taping, while there are inconsistent results concerning the scapular external rotation and posterior tilt. In addition, studies mostly reported that corrective taping decreases the activity of the upper trapezius, while it has conflicting effects on the activity patterns of other periscapular muscles. DiscussionScapular corrective taping was found to increase the scapular upward rotation; however, its effects on scapular external rotation and posterior tilt are controversial. It was also found that corrective taping might decrease the EMG activity of the upper trapezius, while it had no effects on the activity of lower trapezius, and its effects on other periscapular muscles were controversial. ConclusionThe results of the studies indicated that scapular corrective taping might alter the 3-dimensional scapular kinematics, while there are controversies about the effects of corrective taping on the EMG activity of the periscapular muscles. Further studies are needed to clarify the conflicts.

Influence of reducing anterior pelvic tilt on shoulder posture and the electromyographic activity of scapular upward rotators

BackgroundModifications of posture in a segment may influence the posture of adjacent and nonadjacent segments and muscular activity. The spine–shoulder and spine–pelvis relationships suggest that the pelvis may influence shoulder posture. ObjectiveTo investigate the effect of the active reduction of the anterior pelvic tilt on shoulder and trunk posture during static standing posture and on the electromyographic activity of the scapular upward rotators during elevation and lowering of the arm. MethodsThirty-one young adults were assessed in a relaxed standing position and a standing position with 30% active reduction of the anterior pelvic tilt. The pelvic tilt, trunk posture, and forward shoulder posture during the static standing posture and the electromyographic activity during elevation and lowering of the arm were assessed. ResultsPaired t-tests indicated that the active reduction of the anterior pelvic tilt reduced the trunk extension (MD=1.09; 95%CI=−2.79 to −1.03). There were no effects on the forward shoulder posture (MD=0.09; 95%CI=−0.92 to 1.09). Repeated measures of analyses of variance indicated an increase in lower trapezius electromyographic activity (MD=3.6; 95%CI=1.28 to 5.92). There was a greater reduction in upper trapezius activity after pelvic tilt reduction during arm elevation (MD=1.52%; 95%CI=−2.79 to −0.25) compared to that during the lowering phase. There were no effects of pelvic tilt reduction on the electromyographic activity of the serratus anterior (MD=3.26; 95%CI=−3.36 to 9.87). ConclusionThe influence of pelvic posture on the trunk posture and lower trapezius activation should be considered when assessing or planning exercise for individuals with shoulder or trunk conditions.

Effects of using a document holder when typing on head excursion and neck muscle activity among computer users with and without neck pain

Purpose. The aim of this study was to examine the effects of using a document holder while typing on head excursion and neck muscle activity among computer users with and without neck pain. Method. An experimental study including 52 individuals with (n = 26) and without (n = 26) neck pain was conducted. Head excursion and neck muscle activity were measured using an accelerometer and surface electromyography, respectively. Two-way analysis of variance was conducted to examine the effects of using a document holder between computer users with and without neck pain. Results. The results demonstrated a decrease in head excursion (p < 0.001) and muscle activity of both the right and left upper trapezius and the left lower trapezius and right anterior deltoid (p < 0.05) with the use of a document holder. Computer users with neck pain had significantly (p < 0.001) higher right lower trapezius muscle activity compared to the group without neck pain. Conclusion. The results of the study supported the use of a document holder to assist in decreasing head excursion and neck muscle activity. The use of a document holder while typing may be beneficial in preventing repetitive strain injuries among computer users.

Tactile cues change trunk and scapular muscle activity, scapular winging, and thoracic kyphosis during knee push-up plus in subjects with scapular winging: The cross-sectional study.

Serratus anterior muscle weakness causes scapular winging, characterized by scapular downward rotation and scapular anterior tipping in the resting position. Knee push-up plus (KPP), a modified push-up plus that is generally used in early rehabilitation programs, is performed to elicit SA activation. However, excessive thoracic kyphosis can easily occur as a compensatory movement during KPP. Therefore, the aim of this study was to examine the effect of tactile cues during KPP on activities of the thoracic erector spinae, rectus abdominis, lower trapezius, serratus anterior, and upper trapezius; scapular winging; and thoracic kyphosis in subjects with scapular winging.Thirteen men with scapular winging performed KPP exercises under 3 different tactile cue conditions (no cue, to the thoracic spinous process [TSP], and to the interscapular region [ISR]). Electromyography was used to collect the muscle activity; in addition, a scapulometer and ImageJ software were used to measure the amount of scapular winging and thoracic kyphosis, respectively. One-way repeated-measures analysis of variance and Bonferroni correction were used to assess for statistical significance.The activity of the thoracic erector spinae, rectus abdominis, serratus anterior, and upper trapezius had significant difference among three conditions (P < .05). Lower trapezius activity was no significantly different among 3 conditions. Degrees of scapular winging and thoracic kyphosis had also significant difference among 3 conditions (P < .05).These results suggest that the tactile cue to the TSP and ISR in KPP exercise can be an effective method for decreasing scapular winging as well as correcting compensatory thoracic kyphosis during the KPP in subjects with scapular winging.

Effects of selected rehabilitative exercises on external rotator muscles and trapezius muscles of masonry workers.

Masonry workers engaged in occupational work-activities have high risk of shoulder injury that often develops to functional loss and disability. Rehabilitative exercises (REs) have potential for slowing this development. The objective is to study the effects of three selected REs on integrated electromyography activations of the external rotator muscles and trapezius muscles of masonry workers. Ten subjects, masonry workers having shoulder pain, have volunteered for this study. Each subject performs three selected REs: (1) Prone horizontal abduction at 90° with full external rotation with thumb right up. (2) Side lying external rotation (ER) with elbow on the trunk. (3) ER at 90° abduction and elbow flexion at 90° in standing position. Selection of REs is based on their superior performance in earlier studies. Electromyography (EMG) differences among the exercises are tested for statistical significance. A cross comparison of REs shows that exercises (1) and (3) produce high rotator cuff synergy, an average of infraspinatus and teres-minor activities. Exercise (3) minimizes the risk of subacromial impingement by presenting the least posterior deltoid activity. However, exercise (1) reduces the risk of abnormal scapular movement by producing higher middle trapezius and lower trapezius activities than upper trapezius activity. The results provide basic information to design appropriate rehabilitation programs for masonry workers having shoulder pain.

Scapular muscles strengthening on pain, functional outcome and muscle activity in chronic lateral epicondylalgia

AimThe aim of the study was to investigate the effect of lower trapezius (LT), middle trapezius (MT) and serratus anterior (SA) strengthening on pain, pain free grip strength, functional outcome, scapular muscles strength, scapular position and electromyographic (EMG) activity of lower trapezius, serratus anterior, extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC) in individuals with chronic lateral epicondylalgia (LE). MethodsTwenty six patients with chronic lateral epicondylalgia were recruited. Subjects were divided into two groups. Group 1 received scapular muscles strengthening along with conventional physiotherapy and Group 2 received only conventional physiotherapy for 6 weeks. Subjects were measured for pain (VAS), pain free grip strength, functional outcome (PRTEE), scapular muscle strength, scapular positioning (LSST) and EMG activity before and after the intervention.2 × 2 mixed ANOVA was used to investigate for main effect of time and group and interaction effect (time × group). ResultsThe results revealed that there was statistically significant difference for time effect for all the outcome measures. In time × group interaction there was significant difference for all the outcome measures except scapular position (LSST3). Significant difference for group effect was observed in EMG activity of LT and ECRB. ConclusionThe scapular muscle strengthening should be used along with the conventional physiotherapy in individuals with chronic LE to improve pain, pain free grip strength, functional outcome, muscle strength, scapular position and muscle activity.

Effect of strengthening lower trapezius muscle on scapular tipping in patients with diabetic frozen shoulder: A randomized controlled study

Background: The muscle imbalances between upper and lower trapezius muscle activity are related to abnormal scapular motion in patients with frozen shoulder. This explains the importance of rehabilitation of the lower trapezius muscle in addition to common stretching and mobilizing treatment protocols for patients with frozen shoulder. Purpose: This study aims to investigate the effect of additional strengthening exercises of lower fibers of trapezius muscle on the scapular tipping in patients with Diabetic Frozen Shoulder (DFS). Subjects and Methods: Thirty patients with DFS were randomly assigned into two equal groups A and B. Both groups received a traditional physical therapy program, however group B additionally received strengthening exercises for lower fibers of trapezius. Baseline and post-treatment assessment for the scapular tipping were evaluated by using (A-T) distance test. Results: After treatment; mixed design MANOVA revealed significant improvement in scapular tipping (A-T) distance from supine position, supine position with scapula retraction, standing position, and standing position with scapula retraction, for group B more than group A (P<0.05). There were significant improvements in scapular tipping when comparing the post-treatment mean value with pretreatment in group B only (P<0.05). Conclusion: Strengthening of the lower trapezius fibers plus traditional physical therapy program yields improvement in scapular tipping in patients with DFS more than traditional physical therapy alone.

Tailored Exercise with an Innovative Mechanical Device: Effects on Cervical-Dorsal Rachis

Trapezius muscle has a fundamental role in cervico-dorsal pain and posture. Often, in movements involving trapezius, the predominant activity is carried out by the upper trapezius, and many times this may be a risk factor for the integrity of the cervico-dorsal structures. To investigate the effects of physical exercise with the new device called the “Angel’s Wings” on a sample of different professionals. We enrolled 15 volunteers for electromyography (EMG) data, which was collected during the physical performance; 3 volunteers for magnetic resonance imaging (MRI) data, collected before and after a training period; and 73 workers of Ferrari S.p.A. and the Scuderia Ferrari racing team division for a visual analogue scale (VAS) pain score, collected before and after one session of training. EMG shows a decoupling of upper and lower trapezius activity; MRI shows a realignment of cervical-dorsal rachis after one month of training; VAS pain score significantly decreased after the physical exercise with the “Angel’s Wings”. Results show that the use of the “Angel’s Wings” is applicable to counteract and decrease the neck pain by a decontraction of the upper trapezius and correct postural defects of the cervico-dorsal column.

The Effects of the Position of Ipsilateral Neck Rotation on the Inhibition of the Upper Trapezius Muscle During Lower Trapezius Exercises

Background: The unilateral prone arm lift (UPAL) is commonly used to exercise the lower trapezius muscle. However, overactivation of the upper trapezius can induce pain during UPAL exercises in subjects with upper trapezius tenderness. Objects: The purpose of this study was to investigate the effects of position of ipsilateral neck rotation (INR) on the inhibition of upper trapezius muscle activity and the facilitation of the lower trapezius muscle when performing UPAL exercises. Methods: In total, 19 subjects with upper trapezius tenderness were recruited for the study. Electromyographic (EMG) activity was measured in the upper, middle, and lower trapezius muscles during UPAL with and without INR position. Wilcoxon signed-rank test was used to compare EMG activity in the trapezius muscles and the muscle ratios. Results: EMG activity in the upper trapezius muscles was decreased significantly in the INR condition compared to without the position with INR during UPAL exercises (p .05). However, the ratio of lower to upper trapezius activation showed a significant increase in the INR condition compared to the without INR condition (p<.05), indicating greater lower trapezius activation relative to the upper trapezius in the INR position than in the without INR position. Conclusions: The EMG results obtained in this study suggest that the position with INR reduced overactivation in the upper trapezius and improved muscle imbalance during lower trapezius exercises in individuals with upper trapezius tenderness.

Scapular dyskinesis: patterns, functional disability and associated factors in people with shoulder disorders

Abstract Background Patterns of scapular dyskinesis have unique scapular kinematics and associated muscular activation. The characteristics of unique dyskinesis patterns may be associated with functional disability. Objectives To investigate whether the shoulder function level and primary dysfunction items were different in unique dyskinesis pattern. The factors associated with shoulder dysfunction in different dyskinesis patterns were identified. Design Cross-sectional study. Methods Fifty-one participants with unilateral shoulder pain were classified as having a single dyskinesis pattern (inferior angle prominence, pattern I; medial border prominence, pattern II) or a mixed dyskinesis pattern (patterns I + II). Clinical measurements with the Flexilevel Scale of Shoulder Function (FLEX-SF), shoulder range of motion and pectoralis minor index were recorded. These clinical measurements, 3-D scapular kinematics (electromagnetic-based motion analysis), and associated muscular activation (electromyography on the upper/middle/lower trapezius and serratus anterior muscles) during arm elevation were analyzed for associations with functional disability. Results We found FLEX-SF scores and primary dysfunction items were similar among the patterns of dyskinesis. In inferior angle prominence, increased shoulder function was associated with decreased upper trapezius activity (R 2 = 0.155, p = 0.035), which accounted for approximately 16% of the variance of FLEX-SF scores. In medial border prominence, increased shoulder function was associated with increased lower trapezius activity (R 2 = 0.131, p = 0.017), which accounted for approximately 13% of the variance of FLEX-SF scores. Conclusion Upper and lower trapezius activities are important to consider in the evaluation of patients with pattern I and II, respectively. No other factors were related to shoulder dysfunction due to insufficient challenge of arm elevation tasks.

Serratus anterior and lower trapezius muscle activities during multi-joint isotonic scapular exercises and isometric contractions.

Proper scapular function during humeral elevation, such as upward rotation, external rotation, and posterior tilting of the scapula, is necessary to prevent shoulder injury. However, the appropriate intensity of rehabilitation exercise for the periscapular muscles has yet to be clarified. To identify the serratus anterior, lower trapezius, infraspinatus, and posterior deltoid muscle activities during 2 free-motion exercises using 3 intensities and to compare these muscle activities with isometric contractions during quadruped shoulder flexion and external rotation and abduction of the glenohumeral joint. Cross-sectional study. Health Science Laboratory. A total of 16 uninjured, healthy, active, male college students (age = 19.5 ± 1.2 years, height = 173.1 ± 6.5 cm, weight = 68.8 ± 6.6 kg). Mean electromyographic activity normalized by the maximal voluntary isometric contraction was analyzed across 3 intensities and 5 exercises. Intraclass correlation coefficients were calculated for electromyographic activity of the 4 muscles in each free-motion exercise. Significant interactions in electromyographic activity were observed between intensities and exercises (P < .05). The quadruped shoulder-flexion exercise activated all 4 muscles compared with other exercises. Also, the modified robbery free-motion exercise activated the serratus anterior, lower trapezius, and infraspinatus compared with the lawn-mower free-motion exercise. However, neither exercise showed a difference in posterior deltoid electromyographic activity. Three intensities exposed the nature of the periscapular muscle activities across the different exercises. The free-motion exercise in periscapular muscle rehabilitation may not modify serratus anterior, lower trapezius, and infraspinatus muscle activities unless knee-joint extension is limited.

Serratus Anterior and Lower Trapezius Muscle Activities During Multi-Joint Isotonic Scapular Exercises and Isometric Contractions.

Context : Proper scapular function during humeral elevation, such as upward rotation, external rotation, and posterior tilting of the scapula, is necessary to prevent shoulder injury. However, the appropriate intensity of rehabilitation exercise for the periscapular muscles has yet to be clarified. Objective : To identify the serratus anterior, lower trapezius, infraspinatus, and posterior deltoid muscle activities during 2 free-motion exercises using 3 intensities and to compare these muscle activities with isometric contractions during quadruped shoulder flexion and external rotation and abduction of the glenohumeral joint. Design : Cross-sectional study. Setting : Health Science Laboratory. Patients or Other Participants : A total of 16 uninjured, healthy, active, male college students (age = 19.5 ± 1.2 years, height = 173.1 ± 6.5 cm, weight = 68.8 ± 6.6 kg). Main Outcome Measure(s) : Mean electromyographic activity normalized by the maximal voluntary isometric contraction was analyzed across 3 intensities and 5 exercises. Intraclass correlation coefficients were calculated for electromyographic activity of the 4 muscles in each free-motion exercise. Results : Significant interactions in electromyographic activity were observed between intensities and exercises (P < .05). The quadruped shoulder-flexion exercise activated all 4 muscles compared with other exercises. Also, the modified robbery free-motion exercise activated the serratus anterior, lower trapezius, and infraspinatus compared with the lawn-mower free-motion exercise. However, neither exercise showed a difference in posterior deltoid electromyographic activity. Conclusions : Three intensities exposed the nature of the periscapular muscle activities across the different exercises. The free-motion exercise in periscapular muscle rehabilitation may not modify serratus anterior, lower trapezius, and infraspinatus muscle activities unless knee-joint extension is limited.

Immediate effects and short-term retention of multi-modal instruction compared to written only on muscle activity during the prone horizontal abduction exercise in individuals with shoulder pain

In rehabilitation, exercise instructions are multi-modal and can include a focus of increasing mean activity of a target muscle and inhibiting aberrant synergistic muscle activity, particularly during shoulder exercises, such as the prone horizontal abduction (PHA). The objective was to compare the immediate effects and short-term retention of multi-modal exercise instruction by a physical therapist written only instruction on normalized mean upper and lower trapezius muscle activity during three phases (concentric/isometric/eccentric) versus of an isotonic PHA exercise between participants with and without shoulder pain. Surface electromyography (EMG) was recorded from fourteen healthy participants and twelve participants with shoulder pain during the PHA exercise under two conditions: (1) written only instructions and (2) multi-modal instruction. Retention of multi-modal instruction on muscle activity was assessed one week later. Results demonstrate 12.8–16.0% increase in lower trapezius muscle activity during the concentric and isometric phases with multi-modal instructions in both groups. Inhibition of the upper trapezius did not occur in either group. Facilitation effects were maintained in short-term follow-up. Findings suggest that regardless of shoulder pain, multi-modal instruction by a physical therapist facilitates greater neuromuscular activity of a targeted muscle compared to written instructions alone and these effects are retained.

아급성 편마비환자의 어깨관절 Scapular Taping적용이 근 활성도와 통증, 관절가동범위 및 고유수용성감각에 미치는 영향

Abstract The purpose of this study was to determine the effects of scapular taping on muscle activities of the scapular rotators and anterior deltoid, ROM, shoulder pain, proprioception in subacute stroke patients. Twenty-eight patients were randomly assigned to an experimental and control groups of fourteen patients respectively. Muscle activity of upper and lower trapezius, serratus anterior, anterior deltoid was measured using surface electromyography. Visual analog scale was used for shoulder pain. Electro-Goniometry was used for shoulder elevation ROM. Assessment board was used for shoulder elevation proprioception. The muscle activity of the lower trapezius and serratus anterior increased significantly after scapular tape application (p 0.05).The proprioception in the shoulder no significantly increased after scapular tape application (p>0.05). The results of this study suggest that scapular taping can be used an additional therapy for increasing muscle activity of lower trapezius and serratus anterior and ROM during shoulder elevation in subacute stroke patients.

Modifying a shrug exercise can facilitate the upward rotator muscles of the scapula

BackgroundScapular dyskinesis, characterised by drooping scapulae and reduced upward rotation, has been implicated in the presentation of a number of shoulder disorders. Traditionally, in shoulder rehabilitation programmes, the shrug exercise has been prescribed to facilitate upward rotation of the scapula by strengthening the upper trapezius muscle. The aim of this research was to compare muscle activation levels during the standard shrug and the upward rotation shrug in a normal and pathological population. MethodsSurface electrodes recorded electromyographical activity from upper trapezius, middle trapezius, lower trapezius and serratus anterior muscles in 23 normal participants and 14 participants with multi-directional shoulder instability. Participants completed 10 trials of the standard shrug exercise at 0° of shoulder abduction and the upward rotation shrug exercise at 30° of shoulder abduction in the coronal plane. Muscle activity was expressed as a percentage of maximum voluntary isometric contraction. FindingsThe four muscles tested performed at a higher intensity during the modified shrug than the standard shrug. Upper trapezius and lower trapezius activity was significantly greater (P<0.05) in both populations. Though for middle trapezius and serratus anterior muscles, the modified shrug was statistically significant only in the normal population, P=0.031 and P=<0.001 respectively. InterpretationThe upward rotation shrug is a more effective exercise for eliciting muscle activity of the upper and lower trapezius than the standard shrug in a normal and multi-directional instability population. Clinically, the upward rotation shrug might be useful to address scapular dyskinesis involving drooping shoulders and reduced scapula upward rotation.

Immediate Effect of Posture Correction of Trapezius Activity in Computer Users Having Neck Pain – An Electromyographic Analysis

Objectives: Aberrant activity of the trapezius muscle and associated postural abnormalities have been identified as potential factors for neck pain in computer users, thus postural correction is often advocated. The purpose of this trial was to examine the effect of specific scapular postural correction exercises on middle and lower trapezius activity. Methods: Sixty participants matched for the duration of daily computer use were included in the study. Twenty had no neck pain and exhibited “good” scapular posture (constituting Control group C), while forty reported pain (Neck Disability Index ≥ 15/100) for ≥ 3 months over 12 month period. The latter were randomly allocated to one of the two groups (A and B). Electromyographic recordings were taken from the middle and lower trapezius at rest and during typing. After 20-minutes of typing participants in group A (n=20) practiced scapular postural correction exercises while participants in group B (n=20) relaxed. Electromyographic recordings were repeated in a second typing task. Results: Following correction of the scapular posture in group A, middle trapezius activity became similar to the control group (P = 0.229) with no effect on lower trapezius activity (P &lt; 0.001). Significant normalization did not occur after relaxation exercises (P = 0.004). Conclusion: Intermittent scapular postural correction exercises were effective in altering the middle and lower trapezius activity during computer use and may be advised for prevention of neck pain.

Comparisons of Trunk Muscle Activity During Arm Lift in Prone and Standing Positions With and Without Abdominal Drawing-in Maneuver

The aim of this study is to compare the effect of abdominal drawing-in maneuver (ADIM) on lower trapezius (LT), serratus anterior (SA), and erector spinae (ES) muscle activity during arm lifts in prone and standing positions. Twenty healthy subjects were recruited, and NoraxonTeleMyo 2400T was used to collect electromyographic signals from the LT, SA, and ES muscles. A two-way repeated analysis of variance (ANOVA) used a significance level of .05. If a significant interaction was found, pairwise comparisons were performed with a Bonferroni adjustment (.05/4=.013). The results of the study were as follows: 1) In LT, no significant ADIM by position interaction was found (=.356, p=.558). There was a significant main effect for ADIM. LT muscle activity with ADIM was significantly greater compared with muscle activity without ADIM (=82.863, p=116.401, p=8.687, p=.008). There were significant differences in all pairwise comparisons. The greatest SA muscle activity was observed in the standing position with ADIM. 3) In ES, significant ADIM by position interaction was found (=122.473, p

몸통 굽힘이 어깨위팔리듬과 어깨뼈의 움직임 및 근육 활성도에 미치는 영향

The purpose of this study was to determine the effect of trunk posture on muscle activity and motion of scapular and scapulohumeral rhythm. Thirty-one healthy subjects performed right-arm abduction and adduction along the frontal plane while standing in both upright and flexed posture of trunk. Scapular upward rotation, anterior tilting and internal rotation ware recorded using a motion analysis system and muscle activity of upper trapezius, lower trapezius and serratus anterior ware recorded using surface electromyography during abduction and adduction in both trunk postures. then, scapulohumeral rhythm was calculated. Scapulohumeral rhythm and scapular posterior tilting in flexed posture was significantly decreased than in upright posture. Also, muscle activity of lower trapezius in flexed posture was significantly increased and serratus anterior was significantly decreased than in general posture. The result of this study revealed that flexed posture of trunk altered the muscle activity and kinematic of scapular. Measurement of trunk posture should be included the evaluation of dysfunction and disorder of shoulder girdle since rehabilitation of trunk posture is important to restore of upper limbs function.

Influence of forward head posture on scapular upward rotators during isometric shoulder flexion

We assessed the effects of forward head posture in the sitting position on the activity of the scapular upward rotators during loaded isometric shoulder flexion in the sagittal plane. Healthy volunteers (n = 21; 11 men, 10 women) with no history of pathology participated in the study. Subjects were instructed to perform isometric shoulder flexion with the right upper extremity in both the forward head posture (FHP) and neutral head posture (NHP) while sitting. Surface electromyography (EMG) was recorded from the upper trapezius, lower trapezius, and serratus anterior muscles. Dependent variables were examined by 2 (posture)×3 (muscle) repeated measures analysis of variance. Significantly increased EMG activity in the upper trapezius and lower trapezius and significantly decreased EMG activity in the serratus anterior were found during loaded isometric shoulder flexion with FHP. Thus, FHP may contribute to work-related neck and shoulder pain during loaded shoulder flexion while sitting. These results suggest that maintaining NHP is advantageous in reducing sustained upper and lower trapezius activity and enhancing serratus anterior activity as compared with FHP during loaded shoulder flexion.

Upper and lower trapezius muscle activity in subjects with subacromial impingement symptoms: Is there imbalance and can taping change it?

Objectives To investigate (i) whether subacromial impingement symptoms (SIS) were associated with upper and lower trapezius muscle imbalance and (ii) the effect of a scapula taping technique on upper and lower trapezius muscle activity. Design Cross-sectional study with nested within-subject intervention. Setting University research laboratory. Participants Subjects who demonstrated SIS ( n = 16) on clinical testing and an age and gender matched group of asymptomatic subjects ( n = 32). Main outcome measures Surface electromyography (EMG) to measure activity in the upper (UFT) and lower (LFT) fibres of trapezius during repeated humeral elevation in the scapular plane. Results Symptomatic subjects demonstrated a significantly (95% CI 2.13 to 4.17, p = 0.019) higher ratio of UFT:LFT activity than the asymptomatic subjects (95% CI 1.35 to 2.25). With tape in situ the symptomatic subjects demonstrated a significant (95% CI −8.6% to −17.3%, p < 0.001) reduction in UFT activity but no significant (95% CI +2.8% to −17.5%, p = 0.145) change in activity of LFT. No relationship ( r = − 0.116, p = 0.669) was found between the degree of underlying muscle imbalance and the reduction in UFT under the taped condition for the symptomatic group. Conclusion Subacromial impingement symptoms are associated with altered upper and lower trapezius muscle activity which can be partially addressed by the application of tape.