Rehabilitation of scapular muscle balance: which exercises to prescribe?

Electromyographic activity of shoulder muscles on two preventive exercise programmes for swimmer's shoulder: elastic band versus weight

Strength programmes have shown good results in preventing swimmer's shoulder. However, there aren't studies based on electromyographic (EMG) analysis in these programmes. This study aims to compare an EMG activity of the middle trapezius (MT), lower trapezius (LT), infraspinatus (IS), serratus anterior (SA), and pectoralis major (PM) in two swimmer's shoulder preventive programmes - one performed with elastic band and the other with weights. Twenty competitive swimmers performed two strength programmes consisting of five exercises each, while the analysis of EMG activity in MT, LT, IS, SA, and PM for each exercise was recorded. The superficial EMG was used to collect data at a sampling frequency of 1000 hz. The Paired Sample T-test or the Wilcoxon test was applied to compare EMG activity between programmes. The internal rotation at 90º (p < 0.001) and external rotation at 90º (p ≤ 0.01) exercises produced high myoelectric shoulder muscle activity with an elastic band. Conversely, scapular punches (p < 0.001) exercise has high shoulder EMG activity when performed with weights. Performing the same preventive exercise programme with two different instruments produces great variability in the myoelectric activity of the shoulder muscles.

Effects of Using a Special Weighted Vest on Muscle Activity around the Scapula during Knee Push-Up Plus in Healthy Subjects

Muscle imbalances in the upper body can lead to ineffective movement patterns and potential injury. The purpose of this study was to investigate the muscle activity, impact, and muscle activation ratio of the serratus anterior (SA), upper trapezius (UT), lower trapezius (LT), and pectoralis major (PM) during the knee push-up plus (KPUP) exercise under various loads.

METHOD

Electromyography assessed scapular muscle activity in 32 healthy adults (15 males, 17 females) during three KPUP variations.

RESULTS

PM and UT showed no significant activity differences across loads, whereas SA and LT did. SA activity was significantly higher in the weighted KPUP (WKPUP) 3 kg than that in KPUP and WKPUP 1 kg. LT activity was also significantly higher in WKPUP 3 kg compared to KPUP and WKPUP 1 kg, with KPUP showing higher activity than WKPUP 1 kg. PM/SA ratios remained consistent across loads, while UT/LT ratios varied significantly, being notably lower at 3 kg compared to 0 kg and 1 kg. Similarly, UT/SA ratios differed significantly among loads, being notably lower at 3 kg and 1 kg compared to 0 kg.

CONCLUSION

WKPUP with 3 kg demonstrated significantly higher SA and LT activity compared to KPUP and WKPUP 1 kg. The lowest UT/LT ratio was observed during the WKPUP 3 kg, suggesting its effectiveness for optimizing muscle activation balance during KPUP exercises. These findings may inform the development of exercise protocols aimed at improving scapular stabilization.

Assessing the Feasibility of EMG Biofeedback to Reduce the Upper Trapezius Muscle Excitation during a Seated Row Exercise, a Non-randomized Comparative Study

The upper trapezius muscle is often excessively excited during resistance training exercises, increasing the shoulder's liability to musculoskeletal disorders of individuals participating in overhead sports or throwing activities. Different approaches have been proposed for reducing the potentially harmful loading of the upper trapezius. None, however, has been devised to deal directly with the main culprit: the muscle excitation. This non-randomized comparative study explores the feasibility of biofeedback based on surface electromyograms (EMGs) in suppressing undue excitation of the upper trapezius during a seated row exercise. Eight male volunteers were instructed to perform the wide-grip seated row exercise without and with the EMG biofeedback of the upper trapezius. Surface EMGs from the three portions of the trapezius and the serratus anterior were sampled with pairs of surface electrodes. A triaxial accelerometer was positioned on the weight stack for the identification of the exercise phase and repetition. This study showed that during the "with biofeedback" condition, the participants were able to activate the upper trapezius and serratus anterior to a lower degree (~ 10%) compared to the "without biofeedback" condition. Future studies should explore if this can lead to greater gains in muscle performance and/or reduce the risk of shoulder injury.

Strength and activity of the protractor and retractor muscles of the asymptomatic dyskinetic scapula

The role of scapular dyskinesis as a risk factor of shoulder injury has been largely discussed. However, most studies have focused on symptomatic patients and less is known on the asymptomatic dyskinetic scapula. Removing the confounding effects of the pathologies could contribute to better characterize the scapula dyskinesis. As muscle properties (strength, fatigue, nerve injury …) have been identified as causative factors of scapular dyskinesis, this study focuses specifically on characterizing the protractor and retractor muscles of the dyskinetic scapula. Thirteen asymptomatic dyskinetic volunteers were compared to eleven asymptomatic non-dyskinetic control volunteers. Muscle characteristics were evaluated in terms of maximal strength, fatigue resistance and electromyographic activity during a functional closed-chained task. The results did not identify kinematic or muscle activity significant differences between the dyskinetic and the control group even in fatigue conditions. However, the results demonstrated that protractors vs. retractors fatigue resistance ratios were imbalanced (<0.8) in the dyskinetic group and significantly lower than in the non-dyskinetic one. Our study suggests that that strength imbalances are not necessarily related to the presence of pain at the shoulder joint. These results demonstrated the importance to complete the clinical assessments of the scapula with strength evaluations even for asymptomatic sport practitioners.

Analysis of the three-dimensional scapular kinematics and associated scapular muscle activity during scapular muscle exercises

OBJECTIVE

To compare scapular kinematics and muscle activity among various scapular muscle exercises.

DESIGN

A cross-sectional study.

SETTING

A university research laboratory.

PARTICIPANTS

Eighteen healthy men participated in this study.

MAIN OUTCOME MEASURES

Three-dimensional scapular kinematics was measured with an electromagnetic motion capture system. Activities of the upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA) were measured by using surface electromyography (EMG). In addition, the ratio of LT to the UT (LT/UT) and SA to the UT (SA/UT) was calculated. A repeated one-way analysis of variance and Shaffer's post-hoc analysis were used to detect the differences in each outcome during five exercises.

RESULTS

The scapula was rotated upwardly during all exercises except push-up plus. The LT/UT ratio during side-lying external rotation and side-lying flexion were significantly higher than that for scapular plane elevation (P < .05), although the highest activity of the lower trapezius was produced during scapular plane elevation. The activities of the serratus anterior and SA/UT ratio during horizontal adducted elevation and push-up plus were significantly higher than that during scapular plane elevation (P < .05).

CONCLUSION

Horizontal adducted elevation might be more appropriate for increasing scapular upward rotation with high serratus anterior activity and SA/UT ratio than push-up plus.

The ISAKOS subclassification of Rockwood type III AC joint dislocations in a stable type A and an unstable type B is not clinically relevant

PURPOSE

The treatment of Rockwood type III AC joint dislocations has been debated for decades. In 2014, the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) Upper Extremity Committee suggested a subclassification of the injury into type A, considered stable and best treated nonsurgically, and type B, considered unstable and best treated surgically. Type B is defined by the presence of scapular dyskinesis and overriding of the clavicle to the acromion on a modified lateral radiograph. The objective of the study was to investigate if this subclassification is clinically relevant.

METHODS

This was a prospective cohort study. Inclusion criteria were patients aged 18-60 years with acute AC joint dislocation and a baseline Zanca radiograph with an increase in the CC distance of >25% compared to the uninjured side. All patients were treated nonsurgically with 3 months of home-based training and with the option of delayed surgical intervention. Patients were assessed at baseline and at follow-ups 6 weeks, 3 months, 6 months and 1 year after the injury. At the 6-week follow-up, patients were graded as stable and unstable according to the ISAKOS criteria. Outcomes were the Western Ontario Shoulder Instability Index (WOSI) and referral for surgery.

RESULTS

At 6 weeks of follow-up, 20 patients were classified as stable type A and 69 were classified as unstable type B. The ISAKOS subclassification was not clinically relevant, but patients graded as stable had statistically significantly better WOSI scores at 6 months compared to the unstable group (p = 0.03) but not at 3 months or 1 year. Nine patients (9.5%), all from the unstable group, were referred for surgery. No patients from the stable group underwent surgery (n.s).

CONCLUSION

The ISAKOS subclassification of Rockwood type III in a stable type A and an unstable type B is not clinically applicable.

LEVEL OF EVIDENCE

Level II.

Investigation of muscle activation during kinetic chain based exercises in individuals with and without forward head posture

BACKGROUND

The Band Pull-Apart (BPA) exercise is used to strengthen the periscapular muscles. It was recently stated that the lower extremity and trunk movements should be included in the shoulder rehabilitation programs to optimize an effective energy transfer throughout the kinetic chain.

OBJECTIVE

The aim of this study is to investigate the effects of kinetic chain based BPA exercise on the muscle activations of the sternocleidomasteideous (SCM) and the trapezius muscles in individuals with and without forward head posture (FHP).

METHODS

Eighteen individuals with FHP and 18 individuals without FHP were included. Photographic measurements were made to identify individuals with FHP. The muscle activations of SCM, Upper Trapezius (UT), Middle Trapezius (MT), and Lower Trapezius (LT) were measured with surface EMG. BPA exercise was performed in the standing, unipedal standing, squat, unipedal squat, and Bulgarian split squat (BSS).

RESULTS

There was no Group × Exercise interaction for the SCM, UT, MT, LT muscle activations, or for the UT/MT and UT/LT ratios (p> 0.05). While there was a difference in the activation of all muscles between individuals with and without FHP (p< 0.05), both ratios were similar (p> 0.05). There was a statistically significant difference between exercises for SCM, MT, and LT muscle activations (p< 0.000 for these muscles), UT/MT (p< 0.000) and UT/LT ratios (p= 0.004). SCM muscle activation in squat was lower than activation in standing (Mean Difference (MD) = 2.5% Maximal Voluntary Isometric Contractions (MVIC); p= 0.004) and in unipedal standing (MD = 2.1% MVIC; p= 0.002). MT muscle activation in squat was higher than activation in standing (MD = 9.7% MVIC), unipedal standing (MD = 7.8% MVIC), unipedal squat (MD = 6.9% MVIC) and BSS (MD = 9.4% MVIC; p< 0.000 for these positions). LT muscle activation in the squat was higher than activation in the standing (MD = 8.5% MVIC) and unipedal squat (MD = 8.1% MVIC; p< 0.004 for these positions). UT/MT ratio in the squat was lower than standing (MD = 0.3), unipedal standing (MD = 0.2) and BSS (MD = 0.3; p< 0.000 for these positions). UT/LT ratio in squat was lower than unipedal squat (MD = 0.5) and BSS (MD = 0.6; p= 0.002; for these positions).

CONCLUSION

Performing the BPA exercise in the squat position is suggested in cases where lower SCM and UT muscle activation, lower UT/MT, and UT/LT ratios and higher MT and LT muscle activations are needed for individuals with and without FHP.

Scapula-Focused Exercises With or Without Biofeedback and Corticospinal Excitability in Recreational Overhead Athletes With Shoulder Impingement

CONTEXT

Individuals with shoulder impingement syndrome (SIS) exhibit changes in corticospinal excitability, scapular kinematics, and scapular muscle-activation patterns. To restore the scapular kinematics and muscle-activation patterns in individuals with SIS, treatment protocols usually include scapula-focused exercises, such as scapular-orientation and strength training.

OBJECTIVE

To investigate whether scapular-orientation and strength training can reverse the altered corticospinal excitability of recreational overhead athletes with SIS.

DESIGN

Randomized controlled clinical trial.

SETTING

University laboratory.

PATIENTS OR OTHER PARTICIPANTS

Forty-one recreational overhead athletes with SIS: 20 in the scapular-orientation group (age = 26.45 ± 4.13 years, height = 171.85 ± 7.88 cm, mass = 66.70 ± 10.68 kg) and 21 in the strengthening group (age = 26.43 ± 5.55 years, height = 171.62 ± 5.87 cm, mass = 68.67 ± 10.18 kg).

INTERVENTION(S)

Both groups performed a 30-minute training protocol consisting of 3 exercises to strengthen the lower trapezius (LT) and serratus anterior muscles without overactivating the upper trapezius muscles. Participants in the scapular-orientation group were instructed to consciously activate their scapular muscles with electromyographic biofeedback and cues, whereas the strengthening group did not receive biofeedback or cues for scapular motion.

MAIN OUTCOME MEASURE(S)

Corticospinal excitability was assessed using transcranial magnetic stimulation. Scapular kinematics and muscle activation during arm elevation were also measured.

RESULTS

After training, both groups demonstrated an increase in motor-evoked potentials in the LT (P = .004) and increases in scapular upward rotation (P = .03), LT activation (P < .001), and serratus anterior activation (P < .001) during arm elevation. Moreover, the scapular-orientation group showed higher LT activation levels during arm elevation after training than the strengthening group (P = .03).

CONCLUSIONS

With or without biofeedback and cues, scapula-focused exercises improved scapular control and increased corticospinal excitability. Adding biofeedback and cues for scapular control during exercise helped facilitate greater LT activation, so feedback and cues are recommended during scapula-focused training.

Droopy Shoulder Syndrome: A Gateway to Thoracic Outlet Syndrome

Droopy shoulder syndrome (DSS) manifests as discomfort or abnormal sensations in the neck, shoulder, chest, and upper limbs, resulting from tension on the brachial plexus caused by abnormally low shoulder positioning. This case report examines the presentation and management of a patient with DSS, a rare but crucial precursor to thoracic outlet syndrome (TOS). The patient, a 22-year-old male, presented with progressive pain and tingling in his left upper limb, shoulder, chest, and neck. Comprehensive examination and imaging studies led to a diagnosis of DSS. Physical therapy prevented progression to full-blown TOS, highlighting the importance of early recognition and intervention. This case underscores the diagnostic challenges and therapeutic strategies essential for managing this syndrome, preventing complications, and restoring patient function.

Comparative Electromyographic Study of Scapular Stabilizing Muscles During Five Main Rehabilitation Exercises

OBJECTIVE

The aim of the study is to compare the surface electromyographic amplitude, activation ratio, and onset latency of the main scapular stabilizing muscles between five typical rehabilitative exercises.

DESIGN

Twenty-seven healthy participants performed five scapular exercises (wall slide, wall push-up plus, prone horizontal abduction with external rotation, external rotation in side lying, and low row) while simultaneously recording surface electromyographic of serratus anterior, middle trapezius, lower trapezius, and upper trapezius. Surface electromyographic amplitudes, onset latencies, and activation ratios were calculated.

RESULTS

Prone horizontal abduction with external rotation showed an excellent upper trapezius/middle trapezius (0.43) and upper trapezius/lower trapezius (0.30) muscle balance with high (>50% maximum voluntary isometric contraction) middle trapezius and lower trapezius amplitudes, a low (<20% maximum voluntary isometric contraction) upper trapezius amplitude, and an early activation of the scapular stabilizing muscles (-474.7 to 89.9 ms) relative to upper trapezius. External rotation in side lying showed excellent upper trapezius/serratus anterior (0.26), upper trapezius/middle trapezius (0.32), and upper trapezius/lower trapezius (0.21) activation ratios and, along with low row and wall slide, showed early activation of the scapular stabilizing muscles (-378.1 to -26.6 ms).

CONCLUSIONS

Prone horizontal abduction with external rotation presented optimal scapular neuromuscular control. Although external rotation in side lying, low row, and wall slide did not meet all the criteria associated with optimal scapular neuromuscular control, these exercises could be used in early stages of shoulder rehabilitation because they favor early activation of the scapular stabilizing muscles.

Neuromuscular electrical stimulation of humeral adductors in subjects with rotator cuff tear

INTRODUCTION

In symptomatic patients with rotator cuff tear, MRI and radiographic studies have ascribed the pain symptom to insufficient humeral head depression during arm elevations. The arm adductors such as the teres major and pectoralis major may contribute to depression of the humerus head during arm elevations. Researchers have demonstrated that neuromuscular electrical stimulation (NMES) of the serratus anterior and lower trapezius can control scapular motions and improve acromiohumeral distance. It is unknown, however, if adductor neuromuscular training could help patients with rotator cuff tear.

MATERIALS AND METHODS

A cross-sectional study of NMES of the teres major and pectoralis major was conducted on 30 symptomatic subjects with rotator cuff tear. We measured the acromiohumeral distance by ultrasonography and scapular kinematics during arm elevation with a three-dimensional motion tracking system.

RESULTS

The acromiohumeral distance significantly increased during NMES of the teres major (0.73 mm, p < 0.001). However, the distance significantly decreased with NMES of the pectoralis major (0.78 mm, p < 0.001). Additionally, scapular upward rotation was greater during NMES of the teres major than during NMES of the pectoralis major (3.4°, p < 0.001). Scapular external rotation decreased significantly more during NMES of the pectoralis major than during NMES of the teres major (1.6°, p = 0.003).

CONCLUSIONS

NMES of the teres major can increase acromiohumeral distance and scapular upward rotation during arm elevation. However, the decreased upward and external rotation of the scapula during arm elevation with NMES of the pectoralis major may be associated with subacromial impingement.

Effectiveness of specific scapular therapeutic exercises in patients with shoulder pain: a systematic review with meta-analysis

Background

Therapeutic exercise has been considered a useful tool to rehabilitate shoulder pain, namely through its influence on scapular dynamics. Accordingly, the effectiveness of scapular therapeutic exercise needs to be explored. The present study aims to evaluate the effectiveness of scapular therapeutic exercises in shoulder pain and to identify the most effective exercise type (focal or multijoint) and ways of delivering them (as dose and progression).

Methods

Search was conducted at EMBASE, Cochrane Library, MEDLINE via PubMed, Web of Science, PEDro (Physiotherapy Evidence Database), and trial registration databases. The meta-analysis considered randomized controlled/crossover trials that compared the effect of scapular exercises against other types of intervention in the shoulder pain, shoulder function, scapular motion, and/or muscular activity. The risk of bias was assessed through the PEDro scale.

Results

From the 8318 records identified, 8 (high to low risk of bias- scoring from 4 to 8 on the PEDro scale) were included. The overall data, before sensitivity analysis, indicated that the scapular therapeutic exercises are: a) more effective than comparators in improving shoulder function (standardized mean difference [SMD] = 0.52 [95% Cl: 0.05, 0.99], P = .03, I2 = 76%); and b) as effective as comparators in reducing shoulder pain (SMD = 0.32 [95% Cl: -0.09, 0.73], P = .13, I2 = 70%). Subgroup analysis revealed that scapular exercises are more effective in improving shoulder function when the program duration is equal to or higher than 6 weeks (SMD = 0.43 [95% Cl: 0.09, 0.76] P = .01, I2 = 21%) and/or when the maximum number of exercise repetitions per session is lower than 30 (SMD = 0.79 [95% Cl: 0.15, 1.42], P = .01, I2 = 77%). Only 1 study considered scapular motion as an outcome measure, revealing therapeutic exercise effectiveness to improve scapular range of motion.

Conclusions

Intervention programs involving scapular therapeutic exercises are effective in improving shoulder function, presenting benefits when performed for 6 or more weeks and/or when used up to a maximum of 30 repetitions per exercise, per session.

The effects of an 8-week selective corrective exercises program on the worker's productivity with the upper crossed syndrome - a randomized controlled trial

BACKGROUND

The purpose of this study was to investigate the effectiveness of a corrective exercise program on workers' productivity with Upper Crossed Syndrome (UCS).

METHODS

We used Randomized Controlled Trial (RCT) with parallel groups, double-blind, randomized. The participants were workers recruited at a company of Markazi Province that 23 persons in test group and 25 in control group participated. Before and after the intervention, work productivity and activity impairment was measured by the WPAI-GH questionnaire. In addition, angles of FH and RS were measured by Goniometer, and kyphosis angle was measured by a flexible ruler. The exercise program consisted of stretching, strengthening, and stabilization exercises, conducted three times a week for eight weeks. The primary outcome was work productivity and activity impairment, and the secondary outcomes were FH, RS, and KY. All primary and secondary outcomes were measured before the interventions, one week after intervention.

RESULTS

Results revealed significant differences for KY (MD = 3.84, 95% CI: 0.75,6.94, p = 0.017), RS (MD = -1.83, 95% CI: -2.88, -0.88, p = 0.001), and FH (MD = 3.01, 95% CI: 1.98,4.04, p = 0.001) before and after the intervention. In addition, within-group differences showed a significant difference in work time missed (MD = -2.60, CI: -4.84, -0.37, p = 0.003**), and overall work productivity loss (MD = -2.02, CI: -3.78, -0.26, p = 0.013**) in exercise group. However, there were no significant effects on impairment at work and activity.

CONCLUSIONS

Since significant differences were detected in a selective exercise program on productivity, a continuous exercise program for more than 8-week could be effective in managing productivity and increasing practical working hours.

Scapular muscle dynamic stiffness of asymptomatic subjects and subjects with chronic shoulder pain, at rest and isometric contraction conditions

Muscle stiffness had a crucial role in joint stability, particularly, at the shoulder complex. Although changes in upper trapezius muscle stiffness have been described for shoulder pain, contradictory findings have been obtained. Also, existing data regarding scapular muscles are, majorly, about trapezius. Myotonometry is a method used to assess stiffness; however, the reliability values of scapular muscle stiffness through this method have not been assessed in shoulder pain conditions. The present study aims to compare scapular muscles' stiffness (trapezius, serratus anterior, and levator scapulae) between subjects with and without chronic shoulder pain and to evaluate the related test-retest reliability. Twenty-two symptomatic and twenty-two asymptomatic subjects participated in a cross-sectional study. The dynamic muscular stiffness of scapular muscles, at rest and during an isometric contraction, was measured bilaterally with myotonometry, in two moments. The differences in bilateral averaged values between symptomatic and asymptomatic subjects and the effect of the group (group presenting pain in the dominant or non-dominant side, and asymptomatic group) and of the limb (unilateral painful or asymptomatic limb, and bilateral asymptomatic limbs) were investigated. Test-retest intra-rater reliability was determined. An effect of the group was observed at rest, for middle trapezius stiffness, and during contraction, for middle and lower trapezius stiffness. For middle trapezius, increased values were observed in the group presenting pain in non-dominant side comparing to both groups or to group presenting pain in dominant side. The intraclass correlation coefficient, majorly, ranged between 0.775 and 0.989. Participants with pain in the non-dominant side presented an increased middle trapezius' stiffness. Globally, high reliability was observed for scapular muscles dynamic stiffness.

Effect of Adding Shoulder Stabilization Exercises to the Rehabilitation of Postoperative Hand Injuries in Young Adult Patients

BACKGROUND

Hand injuries are common and could have an impact on all upper limb functions. Engaging shoulder muscle training during the rehabilitation protocol postoperatively could have a significant impact on regaining all upper limb function. The purpose of this study was to assess the effect of adding shoulder stabilization exercise to hand rehabilitation postoperatively.

METHODS

Forty patients were randomly assigned to 2 equal groups. Group A received a standard physical therapy program plus shoulder exercise protocol and group B received only a standard physical therapy protocol for hand rehabilitation. Outcome measures were pain intensity; grip strength; Arabic modified Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire; and range of motion (ROM). All outcome measures were assessed before and after treatment.

RESULTS

Statistical analysis revealed that both groups, the experimental and control, showed significant improvement in all outcome measures, but experimental group A showed significant improvement than the control group B posttreatment for hand grip strength, ROM, and QuickDASH questioners (P < .001).

CONCLUSION

Adding shoulder stabilizer muscle training to the hand rehabilitation protocol postoperatively has a significant impact on hand function outcomes.

Rotator cuff tears

Rotator cuff tears are the most common upper extremity condition seen by primary care and orthopaedic surgeons, with a spectrum ranging from tendinopathy to full-thickness tears with arthritic change. Some tears are traumatic, but most rotator cuff problems are degenerative. Not all tears are symptomatic and not all progress, and many patients in whom tears become more extensive do not experience symptom worsening. Hence, a standard algorithm for managing patients is challenging. The pathophysiology of rotator cuff tears is complex and encompasses an interplay between the tendon, bone and muscle. Rotator cuff tears begin as degenerative changes within the tendon, with matrix disorganization and inflammatory changes. Subsequently, tears progress to partial-thickness and then full-thickness tears. Muscle quality, as evidenced by the overall size of the muscle and intramuscular fatty infiltration, also influences symptoms, tear progression and the outcomes of surgery. Treatment depends primarily on symptoms, with non-operative management sufficient for most patients with rotator cuff problems. Modern arthroscopic repair techniques have improved recovery, but outcomes are still limited by a lack of understanding of how to improve tendon to bone healing in many patients.

Shoulder and Scapular Muscle Activity During Low and High Plank Variations With Different Body-Weight-Bearing Statuses

ABSTRACT

Can, EN, Harput, G, and Turgut, E. Shoulder and scapular muscle activity during low and high plank variations with different body-weight-bearing statuses. J Strength Cond Res 38(2): 245-252, 2024-This study investigated the activation levels and activation ratios of shoulder and scapular muscles during low plank (LP) and high plank (HP) variations, with varying levels of body-mass support, including 4-point, 3-pod, and 2-point body-weight-bearing (BWB) statuses. The study was conducted with 21 healthy men (mean ± SD , 26 ± 6.5 years of age and 24.4 ± 2.4 kg·m -2 BMI). Ten different plank exercises were performed in a mixed order by changing elbow joint positions (LP and HP) and BWB statuses (2-point, 3-pod, and 4-point). Activation levels of the lower trapezius (LT), middle trapezius (MT), upper trapezius (UT), biceps brachii, triceps brachii, infraspinatus, and serratus anterior (SA) muscles were assessed with a surface electromyography device. Results of this study showed that elbow position changes resulted in higher LT ( p = 0.01) and TB ( p = 0.001) activation in HP exercises. In general, it was observed that an increase in BWB status was effective in increasing activation for the scapula and shoulder girdle muscles. The ratios of the UT muscle to the SA, LT, and MT muscles were less than 1 during side plank, bird dog, front reach, shoulder taps, and plank with shoulder external rotation exercises. High plank with toe touch exercise resulted in a marked increase in the UT activation. Therefore, it was concluded plank variations alter activation levels and activation ratios of shoulder and scapular muscles. Plank exercises may be used in shoulder rehabilitation and the progression in plank variations can be achieved by changing elbow position and BWB status based on individual requirements.

Electromyographic analysis of shoulder-complex muscles performing overhead presses with dumbbell, kettlebell, and bottom-up kettlebell

INTRODUCTION

Kettlebell exercises, specifically the bottom-up grip, have become increasingly popular in training programs. The purpose of this research was to determine if a bottom-up kettlebell grip favorably alters the electromyography (EMG), activity in the medial deltoid (MD), serratus anterior (SA), and lower trapezius (LT), muscles compared to using a dumbbell or traditional kettlebell grip during overhead shoulder presses.

METHODS

Twenty-eight healthy, male, Division III collegiate baseball players (mean age = 19.8 ± 1.28 years) performed five overhead presses of equal weight, 11.34 kg (25 lbs), using a dumbbell (DB), kettlebell w/traditional grip (KB), and kettlebell held with a bottom-up grip (KBU).

RESULTS

For the MD, there was significantly greater EMG activity using the DB compared to KBU, but no significant differences between the DB and KB, or KB and KBU. For the SA, greater EMG activity was noted using the KBU compared to KB, and KBU compared to DB, but no differences between KB and DB. For the LT, greater EMG activity was noted using the DB compared to KB, but no differences between DB and KBU, or KB and KBU.

CONCLUSION

The KBU press only elicited greater EMG activity in the SA. The DB elicited greater EMG activity in both the MD and LT. Shoulder-complex EMG activity varies with different types of overhead presses using equivalent loads.

Indian surgery Trainee's perspective on surgical ergonomics principles and education: A long road ahead

INTRODUCTION

This study aimed to determine the baseline knowledge and beliefs, along with the impact of incorporating surgical ergonomics lectures during a residency.

METHODS

A cohort of 123 Indian surgical residents participated in this educational intervention, which consisted of two educational webinars on ergonomics. Both pre- and post-intervention surveys were electronically sent to the participants. These included questions related to their demographics, prevalence of musculoskeletal (MSK) symptoms, and factors affecting participant awareness of ergonomic recommendations.

RESULTS

Seventy-one residents responded to the pre-webinar survey. Eighty-five percent of respondents reported MSK symptoms, with the most common being pain (70%) and stiffness (40%), which the residents attributed to their surgical training. Forty-six residents completed the post-webinar survey. The majority of respondents strongly agreed or agreed that surgical ergonomic educational sessions improved their understanding of the fundamental causes of MSK symptoms and increased their awareness of options available for prevention MSK injuries.

CONCLUSION

The rate of MSK symptoms and/or injury was high among this cohort of surgical residents. These surveys and educational session demonstrated there is limited awareness of the comprehension of ergonomics related to surgical procedures. Our study shows that a simple surgical ergonomic educational intervention can lead to improved understanding of prevention and ergonomic changes.

Midterm Clinical Outcomes After Arthroscopic Rotator Cuff Repair in Olympic Volleyball Players: Return to Sports and Return to Performance

Background

The decision-making process and predicting the time to return to sport (RTS) and return to performance (RTP) after arthroscopic rotator cuff repair (ARCR) in elite volleyball players are difficult issues to address, even among experienced shoulder surgeons.

Purpose/Hypothesis

The purpose of the study was to evaluate the results in Olympic-level volleyball players treated with arthroscopic supraspinatus repair and to report the RTS and the RTP. It was hypothesized that these athletes had higher RTS and faster RTP.

Study Design

Case series; Level of evidence, 4.

Methods

This study included 17 elite volleyball athletes (11 male, 6 female; mean age, 26.2 years) who underwent ARCR for partial- and full-thickness supraspinatus tears that did not improve despite nonoperative treatment. The clinical results were evaluated at 12 months postoperatively. The authors compared the athletes' preoperative, 6-month, and 12-month Kerlan-Jobe Orthopaedic Clinic (KJOC) scores and the visual analog scale (VAS) for pain after competition and conducted 6- and 12-month isometric strength analyses. The athletes' RTS and RTP times were recorded.

Results

All tears were on the dominant side (15 right, 2 left), and 82% were partial tears (14 partial thickness, 3 full thickness). The mean time from the onset of symptoms to surgery was 11.3 ± 6.7 months. While the mean Kerlan-Jobe Orthopaedic Clinic score was 31 preoperatively, it was 89 after 6 months (P < .001 vs preoperative) and 96 after 12 months (P = .003 vs 6 months). The mean VAS for pain was 7.9 preoperatively, 0.4 at 6 months (P < .001 vs preoperative), and 0.1 at 12 months (P = .02 vs 6 months). All athletes were able to reach their preinjury level, with RTS at a mean of 6.9 months and RTP at a mean of 12.4 months.

Conclusion

ARCR appears to be an effective option for Olympic-level volleyball players who do not benefit from nonoperative treatment. All athletes returned to their preinjury level of sports. The surgeon and athlete can plan surgical decision-making and timing based on the mean RTS time of 6.9 months and mean RTP time of 12.4 months.

The Effects of Body Positions and Abduction Angles on Shoulder Muscle Activity Patterns during External Rotation Exercises

BACKGROUND

Excess and repetitive glenohumeral external rotation (ER) is at a higher risk for shoulder injuries, which occurs frequently in professional sports and specific occupations. Current rehabilitation programs emphasize selective targeting of muscle activity, which can help restore dysfunctional muscle imbalances or prevent injuries. However, the impact of different body postures on GH muscle activity during ER exercises has not been fully understood. Therefore, the purpose of this study was to investigate shoulder EMG activity for different body positions and humeral abduction angles during ER exercises.

METHOD

Twenty-three healthy young men (age: 22.3 ± 2.3, height: 175.75 ± 4.02, mass: 75.37 ± 9.14) participated in this study. Surface Electromyography was recorded from seven shoulder muscles: upper trapezius, lower trapezius, serratus anterior, infraspinatus, and deltoid. Six ER exercises: three postures (sitting, supine lying, and prone lying) and two abduction angles (ABD; 45° and 90°) were tested using an isokinetic dynamometer.

RESULTS

During a sitting position, the lower trapezius/upper trapezius muscle activity ratios were significantly increased for sitting compared to supine lying and prone lying (p < 0.001, p = 0.004). Serratus anterior/upper trapezius co-contraction indices were significantly increased for 90° than 45° ABD (p < 0.001).

CONCLUSION

These findings can provide insight into new training programs aimed at restoring GH muscle imbalances.

Scapular kinematics and muscle activity during Yi Jin Bang exercises

Introduction: Scapular dyskinesis is commonly associated with subacromial pain syndrome (SAPS). Addressing scapular dyskinesis is widely accepted as an important component of shoulder rehabilitation. Our previous randomized controlled trial showed that Yi Jin Bang (YJB) exercises could effectively manage SAPS, but scapular motions and muscle activity during YJB exercises remain unknown. This study examined scapular kinematics synchronously with scapular muscle activation during YJB exercises. Methods: Thirty healthy participants with no shoulder complaints were enrolled in this study. Three-dimensional (3D) scapular kinematics and electromyography (EMG) activation of the upper trapezius, middle trapezius, lower trapezius, serratus anterior, anterior deltoid, middle deltoid, and posterior deltoid were synchronously measured during nine YJB movements. Results: During all YJB movements, the scapula was upwardly rotated and anteriorly tilted, with more upward rotation and a similar or less anterior tilt than the mean resting scapular angle. Column rotation, arm crossover, shoulder support circle, and armpit support high lift generated more internal rotation than the mean resting scapular angle, with the angles of internal rotation significantly greater than the other five movements (p < 0.001). Regarding EMG activity, all YJB movements elicited low activity (1.42%-19.19% maximal voluntary isometric contraction [MVIC]) from the upper trapezius and posterior deltoid and low to moderate activity (0.52%-29.50% MVIC) from the middle trapezius, lower trapezius, serratus anterior, anterior deltoid, and middle deltoid. Conclusion: YJB exercises could be useful in the middle to later phases of shoulder rehabilitation. For patients with insufficient external rotation, some YJB movements should be prescribed with caution.

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

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.

Nonoperative Treatment of Rotator Cuff Tears

Rotator cuff tears are common with prevalence increasing with age. Diagnosis by physical examination may require a cluster of tests. Although radiographs can be helpful, MRI, MRI arthrography, and ultrasound represent the most used imaging technique to identify rotator cuff tears. Although surgery is sometimes necessary, a large portion of patients may respond to conservative treatment including physical therapy and injections. Physical therapy should include restoring the range of motion, addressing any pectoralis minor or posterior capsule stiffness, and restoring motor control/strength to the scapula and rotator cuff. Other conservative treatments may include nonsteroidal anti-inflammatory drugs, corticosteroid injects, and platelet-rich plasma.

Variation of muscle recruitment during exercises performed below horizontal arm elevation that target the lower trapezius: A repeated measures cross-sectional study on asymptomatic individuals

The gold standard exercise for recruitment of the lower trapezius is the Y prone exercise which is performed above 90° of shoulder elevation. However, clinicians often prescribe exercises that avoid high elevation postures during early stages of rehabilitation. Comparatively little data exists on relative muscle recruitment during lower arm elevation exercises. This study examined the EMG activity of four shoulder girdle muscles during four exercises accomplished below 90° of shoulder elevation and compared them to the Y prone while considering sex effects. Variance across exercises of the ratio between upper trapezius and lower trapezius was also explored. 32 healthy participants completed standardized muscle-specific MVCs and two repetitions of each exercise. The side lying external rotation and the wall slide exercises produced the highest peak EMG for the lower trapezius, both 33 and 29% lower than the Y Prone. For the upper trapezius to lower trapezius ratio, the side lying external rotation elicited the lowest value, followed by the Y prone and wall slide (53 and 59% respectively higher). Sex influenced some EMG values, typically interacting with exercise type. Thus, side lying external rotation and the wall slide are recommended for targeting the lower trapezius muscle during early rehabilitation.

Differences in Trapezius Muscle H-Reflex between Asymptomatic Subjects and Symptomatic Shoulder Pain Subjects

In chronic shoulder pain, adaptations in the nervous system such as in motoneuron excitability, could contribute to impairments in scapular muscles, perpetuation and recurrence of pain and reduced improvements during rehabilitation. The present cross-sectional study aims to compare trapezius neural excitability between symptomatic and asymptomatic subjects. In 12 participants with chronic shoulder pain (symptomatic group) and 12 without shoulder pain (asymptomatic group), the H reflex was evoked in all trapezius muscle parts, through C3/4 nerve stimulation, and the M-wave through accessory nerve stimulation. The current intensity to evoke the maximum H reflex, the latency and the maximum peak-to-peak amplitude of both the H reflex and M-wave, as well as the ratio between these two variables, were calculated. The percentage of responses was considered. Overall, M-waves were elicited in most participants, while the H reflex was elicited only in 58-75% or in 42-58% of the asymptomatic and symptomatic participants, respectively. A comparison between groups revealed that the symptomatic group presented a smaller maximum H reflex as a percentage of M-wave from upper trapezius and longer maximal H reflex latency from the lower trapezius (p < 0.05). Subjects with chronic shoulder pain present changes in trapezius H reflex parameters, highlighting the need to consider trapezius neuromuscular control in these individuals' rehabilitation.

Effect of 8-week Shoulder External Rotation Exercise with Low Intensity and Slow Movement on Infraspinatus

OBJECTIVE

Generally, low-intensity training is recommended as selective training of the infraspinatus muscle. This study aimed to investigate whether an 8-week intervention of low-intensity, slow-movement, external rotation exercise of the shoulder led to an increase in muscle strength with shoulder external rotation and cross-sectional area (CSA) infraspinatus muscle.

METHODS

Sixteen healthy male volunteers were randomly assigned to the low-intensity and slow-movement (LS) group (N = 8) or the normal-intensity and normal-speed (NN) group (N = 8). The LS and NN groups performed shoulder external rotation exercises with low intensity and slow movement, and normal intensity and normal speed, respectively. The exercise session consisted of three sets of 10 repetitions, which were performed three times per week for 8 weeks. We measured the CSA of the infraspinatus and muscle strength of the shoulder external rotation before and after the 8-week intervention.

RESULTS

A significant increase in infraspinatus CSA from baseline to 8 weeks was found in the LS group (7.3% of baseline) but not in the NN group. No significant differences were found in the muscle strength of shoulder external rotation.

CONCLUSION

Our results suggest that low-intensity exercise of the infraspinatus is effective for muscle hypertrophy when performed with slow movement. This finding may help patients who should avoid excessive stress in the early phase of rehabilitation.

The influence of shoulder position during multi-joint exercises in the relative scapular muscles activity in symptomatic and asymptomatic conditions

BACKGROUND

Scapular muscles changes, as increased upper trapezius activity and decreased middle and lower trapezius and serratus anterior muscle activity, have been demonstrated in shoulder pain specific or non-specific conditions. Shoulder external rotation exercises have been recommended to improve scapular activity in shoulder pain.

OBJECTIVE

To evaluate the relative scapular muscles activity during multi-joint exercises combining shoulder external rotation, trunk rotation and scapular squeeze.

METHODS

Forty-one participants with and without shoulder pain were assessed in a cross-sectional study. They performed isometric multi-joint exercises at 0∘ and 90∘ of shoulder abduction with and without support. The relative activity of upper, middle, and lower trapezius and serratus anterior (upper/middle and lower portions) was measured through electromyography. The scapular muscular balance was assessed by the ratio between relative activity of the upper trapezius and the other muscles.

Effect of Functional Scapular Stabilization Training on Function and Pain in Frozen Shoulder Syndrome: A Randomized Controlled Trial

OBJECTIVE

The purpose of this study was to determine the effect of functional scapular stabilization training compared with the standard physical therapy on function and pain in people with frozen shoulder syndrome (FSS).

METHODS

In a single-blind randomized controlled trial, 86 people with FSS were randomly allocated into the intervention group (functional stabilization training [n = 43]) and control group (standard physical therapy [n = 43]) using block randomization for 12 weeks. The primary outcome measures were the Shoulder Pain and Disability Index and the numeric pain rating scale. The secondary outcome measures were range of motion (ROM), range of passive abduction, and coracoid pain test. All the outcome measures were carried out by an independent blind outcome assessor at baseline and at the end of 12 weeks.

RESULTS

A significant group × time interaction effect was observed for the Shoulder Pain and Disability Index (95% CI, 2.95-16.74; P < .01) and the numeric pain rating scale (95% CI, 0.67-2.07; P < .01) at the end of 12 weeks. The external rotation ROM showed a statistical significance with a mean change of 7.8° and P value of <.01.

CONCLUSION

The present findings show that scapular functional stabilization training resulted in improvement of function, reduction in pain, and greater improvement in external rotation ROM in patients with FSS. Also, our study findings suggest the involvement of rotator interval and inferior soft-tissue structures as indicated by the coracoid pain test and range of passive abduction.

Parsonage-Turner Syndrome mimicking musculoskeletal shoulder pain: A case report during the SARS-CoV-2 pandemic era

Parsonage-Turner Syndrome or neuralgic amyotrophy is a peripheral neuropathy typically characterized by an abrupt onset of pain, followed by progressive neurological deficits (e.g. weakness, atrophy, occasionally sensory abnormalities) that involve the upper limb, mainly the shoulder, encompassing an extensive spectrum of clinical manifestations, somehow difficult to recognize. This case report describes the proper management of a 35-year-old, bank employee and sports amateur who reported subtle and progressive upper limb disorder with previous history of neck pain. SARS-CoV-2 pandemic era made patient's access to the healthcare system more complicated. Nevertheless, proper management of knowledge, relevant aspects of telerehabilitation-based consultation for musculoskeletal pain, advanced skills, tools and technologies led the physiotherapist to suspect an atypical presentation of Parsonage-Turner Syndrome. Further, neurologist consultation and electromyography suggested signs of denervation in the serratus anterior and supraspinatus muscle. Therefore, an appropriate physiotherapist's screening for referral is conducted to correct diagnosis and thorough treatment.

Altered muscle recruitment patterns during isometric shoulder abduction in individuals with chronic upper trapezius pain: a cross sectional study

BACKGROUND

Upper trapezius (UT) pain with myofascial trigger points (MTrPs) can affect movement at the glenohumeral joint as well as at the scapulothoracic joint. The investigation of muscle recruitment patterns can discern motor control strategies. The purpose of this study was to compare shoulder muscle recruitment patterns and muscle activity according to various loads between individuals with and without chronic UT pain.

METHODS

In this cross-sectional study, twenty-four participants that had UT pain with MTrPs and sex, age, body weight matched 24 controls with no UT pain were recruited. Surface EMG electrodes were attached to the UT, the serratus anterior (SA), the lower trapezius (LT) and the middle deltoid (MD). All participants performed isometric shoulder abduction with a load of 25%, 50%, or 75% of the maximum strength at 60° of shoulder abduction. The EMG activity, the activity ratio (SA/UT, LT/UT, MD/UT), and the relative contribution of each muscle activity were calculated.

RESULTS

MD activity was significantly decreased in the UT pain group compared to that in the control group (p < 0.05). The EMG activity ratio of SA/UT (p < 0.025) and the relative contribution of SA activity to shoulder abduction (p < 0.05) were significantly greater in the UT pain group than in the control group in the 25% loading condition.

CONCLUSION

The results of present study showed that UT pain with MTrPs may increase the relative contribution of SA activity and decrease MD activity at low loads. Altered recruitment patterns of scapular upward rotators can be altered in the proper scapular position, which results in decreased MD activity. Clinicians should consider altered recruitment patterns when managing UT pain.

TRIAL REGISTRATION

Clinical Research Information Service: Clinical Research Information Service (KCT0007370; 08/06/2022).

Optimal bipolar system positioning to provide information about the trapezius activity associated with scapular retraction during shoulder exercises for resistance training

Objective. Recently, the use of EMG biofeedback to make subjects aware of the stabilizer activation associated with scapular retraction during exercise has been of interest, and challenges related to EMG detection have been addressed. Whether there is an optimal bipolar positioning that discriminates the stabilizer activation with retraction from a neutral scapular position during resistance exercises is an open issue that we address here by simultaneously mapping different positions using high-density surface electromyography (HD-sEMG).Approach. Sixteen resistance-trained males performed five pulling exercises with and without scapular retraction, namely barbell rows, dumbbell rows, pull-downs at a lat machine, seated rows, and TRX (total resistance exercises) system rows. HD-sEMG was acquired in a monopolar mode from the medial and lower trapezius (8 × 4 electrodes and inter-electrode distance (ied): 10 mm) and different bipolar systems were simulated in terms of positioning, interelectrode distance, and orientation with respect to the spine: longitudinal with three ieds (20 mm, 30 mm, and 40 mm), one transversal, and two diagonals (ied: 20 mm), totalling six EMG sets. To identify the optimal electrode pair that was able to distinguish between the presence or absence of scapular retraction, we computed: (i) the root mean square (RMS) map for each condition and the difference between them, obtaining a differential RMS map per subject; and (ii) the intersection of cumulative maps, by summing the differential (binary) maps from all subjects.Main results. For the lower trapezius, the results revealed that the diagonal direction (45 degrees; ied: 20 mm) obtained the greater occurrence of intersecting segments within and between exercises than the other electrode configurations, showing low variability for the optimal positioning across exercises. Electrode configuration varied within and between the pulling exercises for the medial trapezius.Significance. This study allows us to identify an optimal bipolar positioning (consistent across subjects and exercises) for lower trapezius activity assessment, representing a guideline for electrode positioning when EMG biofeedback is adopted for selective activation of the lower trapezius during pulling exercises.

Cervical and scapula-focused resistance exercise program versus trapezius massage in patients with chronic neck pain: A randomized controlled trial

OBJECTIVE

The purpose of this study was to investigate the effects of resistance exercise in comparison with those of common exercise on chronic neck pain (CNP) to provide useful clinical guidelines for reducing pain or increasing cervical range of motion (ROM), upper trapezius tone, disability level, and quality of life (QOL).

METHODS

The subjects were randomized into a cervical and scapula-focused resistance exercise group (CSREG, n = 21) or trapezius massage group (TMG, n = 20). All groups received a 4-week, five times per week CSRE or TM program for CNP. The visual analogue scale (VAS) score, cervical ROM, myotonometer measures (upper trapezius tone, stiffness, and elasticity), neck disability index (NDI), and short form-36 (SF-36) were identified as the primary outcomes.

RESULTS

Within-group changes in VAS, cervical ROM, myotonometer measures, NDI, and SF-36 were significant in the CSREG and TMG (P < .05). The between-group changes in VAS, cervical rotation, myotonometer (upper trapezius tone and stiffness), NDI, and SF-36 after intervention showed significant differences between the CSREG and TMG (P < .05).

CONCLUSION

These results suggest that the CSRE program is effective in improving pain, cervical ROM, upper trapezius tone, disability level, and QOL in patients with CNP. More comprehensive studies with longer follow-up durations are needed to better understand the potential effects of the CSRE program in patients with CNP.

Impact of Different Isokinetic Movement Patterns on Shoulder Rehabilitation Outcome

Shoulder pain is regularly associated with limited mobility and limitations in activities of daily living. In occupational therapy, various interventions, including active isokinetic training with a Baltimore Therapeutic Equipment (BTE) Work Simulator, help the patient improve shoulder mobility and alleviate pain. This randomized controlled cohort study aims to evaluate the impact of different isokinetic movement patterns on the DASH score, pain, and objective performance measures, such as range of motion (ROM) and hand grip strength. Patients that participated in a specific 3-week inpatient orthopedic rehabilitation were divided into two groups. The first group (UNI-group, n = 9) carried out uniplanar exercises for shoulder flexion, abduction, and external rotation. The patients in the second group (ADL-group, n = 10) imitated multiplanar everyday movements, such as climbing on a ladder, loading a shopping cart, and raising a glass to their mouth. Compared to the UNI-group, the ADL-group improved significantly in DASH scores (mean -10.92 ± 12.59 vs. -22.83 ± 11.31), pain (NPRS -1.11 ± 2.37 vs. 3.70 ± 2.00), and shoulder abduction (+2.77 ± 15.22 vs. +25.50 ± 21.66 degrees). In conclusion, the specific BTE exercise program with multiplanar movement patterns contributed considerably to the therapeutic improvement.

Influencing factors of pressure pain hypersensitivity of the upper trapezius in food service workers with nonspecific neck/shoulder myofascial pain: A cross-sectional study

It is unclear which factors contribute to the developing pressure pain hypersensitivity of the upper trapezius, a type of neurophysiological hyperexcitability. The present study investigated the relationship between physical and psychological factors and pressure pain hypersensitivity of the upper trapezius for each sex. In total, 154 individuals with neck/shoulder myofascial pain participated, among 372 food service workers. Participants completed a questionnaire (Beck Depression Inventory, and Borg Rating of Perceived Exertion scale) and were photographed to measure posture. Pressure pain sensitivity, 2 range of motions (cervical lateral bending and rotation), and 4 muscle strengths (serratus anterior, lower trapezius [LT], biceps, and glenohumeral external rotator) were measured by a pressure algometer, iPhone application, and handheld dynamometer, respectively. For each sex, forward multivariate logistic regression was used to test our a priori hypothesis among selected variables that a combination of psychosocial and physical factors contributed to the risk for pressure pain hypersensitivity. In multivariate analyses, LT strength (odds ratio = 0.94, 95% confidence interval = 0.91-0.97, P = .001) was the only significant influencing factor for pressure pain hypersensitivity in men. Dominant painful ipsilateral cervical rotation range of motion (odds ratio = 0.96, 95% confidence interval = 0.92-0.99, P = .037) was the only influencing factor for pressure pain hypersensitivity in women. LT strength and dominant painful ipsilateral cervical rotation range of motion could serve as guidelines for preventing and managing pressure pain hypersensitivity of the upper trapezius in food service workers with nonspecific neck/shoulder myofascial pain.

Electromyographic analysis of the serratus anterior and upper trapezius in closed kinetic chain exercises performed on different unstable support surfaces: a systematic review and meta-analysis

Background

Multiple investigations have compared the electromyographic (EMG) activity of the scapular muscles between stable and unstable support surfaces during the execution of closed kinetic chain exercises. However, these comparative analyses have grouped different unstable surfaces (wobble board, BOSU, therapeutic ball, and suspension equipment) into a single data pool, without considering the possible differences in neuromuscular demand induced by each unstable support surface. This study aimed to analyze the individual effect of different unstable support surfaces compared to a stable support surface on scapular muscles EMG activity during the execution of closed kinetic chain exercises.

Methodology

A literature search was conducted of the Pubmed Central, ScienceDirect and SPORTDiscus databases. Studies which investigated scapular muscles EMG during push-ups and compared at least two support surfaces were included. The risk of bias of included articles was assessed using a standardized quality assessment form for descriptive, observational and EMG studies, and the certainty of the evidence was measured with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. A random-effects model was used to calculate effect sizes (ES, Hedge's g).

Results

Thirty studies were selected in the systematic review. Of these, twenty-three low-to-high quality studies (498 participants) were included in the meta-analysis. The main analyzes revealed, in decreasing order, greater UT EMG activity during push-ups performed on suspension equipment (ES = 2.92; p = 0.004), therapeutic ball (ES = 1.03; p < 0.001) and wobble board (ES = 0.33; p = 0.003); without effect on the BOSU ball. In addition, no effect was observed for SA on any unstable device. The certainty of the evidence ranged from low to very low due to the inclusion of descriptive studies, as well as high imprecision, inconsistency, and risk of publication bias.

Conclusion

These findings could be applied in scapular muscles strengthening in healthy individuals. The use of suspension equipment achieves higher UT activation levels. Conversely, the use of any type of unstable devices to increase the activation levels of the SA in shoulder musculoskeletal dysfunctions is not recommended. These conclusions should be interpreted with caution as the available evidence showed a low to very low certainty of evidence, downgraded mostly by inconsistency and imprecision.

Shoulder electromyography activity during push-up variations: a scoping review

BACKGROUND

Push-ups (PU) are a common closed chain exercise used to enhance shoulder girdle stability, with variations that alter the difficulty or target specific muscles. To appropriately select and prescribe PU exercises, an understanding of muscle activity during variations of the PU is needed. The purpose of this scoping review was to identify common PU variations and describe their muscle activation levels.

METHODS

Databases searched included PubMed, CINAHL, Scopus, and SPORTDiscus for articles published between January 2000 and November 2019.

RESULTS

Three hundred three articles were screened for eligibility with 30 articles included in the analysis. Six PU types and five muscles met the criteria for analysis. Weighted mean electromyography (EMG) amplitude was calculated for each muscle across PU types and for each PU type as a measure of global muscle activity. Triceps and pectoralis major had the highest EMG amplitude during unstable, suspension, incline with hands on a ball and the standard PU. Serratus anterior had the highest EMG amplitude during PU plus and incline PU. The greatest global EMG amplitude occurred during unstable surface PU.

DISCUSSION

These results provide clinicians with a framework for prescribing PU to target specific muscles and scale exercise difficulty to facilitate rehabilitation outcomes.

Electromyographic Analysis of a Selective Exercise for the Serratus Anterior Muscle Among Patients With Frozen Shoulder and Subacromial Impingement Syndrome

OBJECTIVE

Patients with shoulder disorders show altered periscapular muscle activity (e.g., decreased serratus anterior and increased upper trapezius activities). We herein devised a novel method for strengthening serratus anterior without excessive upper trapezius activation, named squeezing ball exercise in which patients squeezed a ball between both elbows with maximum voluntary isometric contraction in the horizontal adduction direction with the arms elevated at a 45-degree angle. The present study aimed to investigate whether the squeezing ball exercise could produce high muscle activity in the serratus anterior in patients with frozen shoulder and subacromial impingement syndrome before the rehabilitation intervention.

DESIGN

This is a proof-of-concept study. Serratus anterior and upper trapezius activities during squeezing ball exercise were evaluated using electromyography in 16 patients with frozen shoulders and subacromial impingement syndrome. Electromyography signals were normalized using maximal voluntary isometric contraction, and the muscle balance ratios (upper trapezius/serratus anterior) were calculated.

RESULTS

The average serratus anterior and upper trapezius activity was 69.9% ± 30.8% and 10.2% ± 6.3% maximal voluntary isometric contraction during the squeezing ball exercise, respectively, whereas the upper trapezius-serratus anterior ratio of the affected side was 0.15 ± 0.07.

CONCLUSIONS

The high serratus anterior activation and low upper trapezius-serratus anterior ratio during squeezing ball exercise could be attributed to the limb position where shortened serratus anterior exerts itself without painful subacromial impingement. Squeezing ball exercise could be a novel rehabilitation tool for patients with frozen shoulders and subacromial impingement syndrome.

Co-creation of an exercise inventory to improve scapular stabilization and control among individuals with rotator cuff-related shoulder pain: a survey-based study amongst physiotherapists

Background

Scapular stabilization exercises (SSE) are often included in the treatment of individuals with rotator cuff-related shoulder pain (RCRSP) to decrease pain and improve function. These SSE typically aim to strengthen the scapular muscles and optimize dynamic neuromuscular control of the scapula, which may improve overall shoulder stability and movement quality. No consensus of the recommended SSE for the management of RCRSP is available. Hence, this study aimed to consult physiotherapists to co-create an inventory of recommended SSE based on the exercise’s relevance and frequency of prescriptions for the rehabilitation of individuals with RCRSP.

Methods

A group of 16 physiotherapists with experience in treating shoulder pain participated in a sequential consultation incorporating two distinct rounds of consultation focusing on SSE (modified Delphi design). In round 1, physiotherapists identified and demonstrated up to 10 SSE that they commonly recommend or use among individuals with RCRSP. The description and performance of all SSE were audio and video recorded. All SSE suggested by more than one participant in round 1 advanced to round 2. In round 2, physiotherapists rated these SSE on a 4-point Likert scale according to their perceived relevance and frequency of prescription for this population.

Results

In round 1, out of the 25 SSE recommended by participants, 19 SSE (76.0%) were recommended by more than one physiotherapist and advanced to round 2. In round 2, 13 SSE were consensually classified (agreement ≥75%) as being relevant for the rehabilitation of individuals with RCRSP. SSE targeting the recruitment of the serratus anterior and lower trapezius muscles were considered the most relevant for the management of RCRSP, whereas SSE targeting neuromuscular scapular control were the most prescribed SSE for the management of RCRSP.

Conclusions

An inventory composed of 13 SSE was co-created by physiotherapists based on their relevance and frequency of prescription for the rehabilitation of individuals with RCRSP. When designing an exercise program, physiotherapists can use this SSE inventory to inform their exercise selection, in combination with their current knowledge on shoulder rehabilitation, as well as patients’ preferences.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40945-022-00132-7.

Band Pull-Apart Exercise: Effects of Movement Direction and Hand Position on Shoulder Muscle Activity

Background/Purpose

The Elastic band pull-apart exercise is commonly used in rehabilitation. It involves pulling an elastic resistance band with both hands in horizontal abduction or diagonal arm movements. The extent of muscle activation during this exercise is unknown. The purpose of this study was to measure the electromyographic (EMG) activity of shoulder-girdle muscles during the pull-apart exercise using resistance bands and to determine the effects of arm position and movement direction on shoulder-girdle muscle activity.

Materials/Methods

Surface EMG activity was measured on the infraspinatus, upper trapezius, middle trapezius, lower trapezius and posterior deltoid of the dominant shoulder. After measurement of maximal voluntary contraction (MVC) for each muscle, subjects performed the band pull-apart exercise in three hand positions (palm up, neutral, palm down) and three movement directions (diagonal up, horizontal, diagonal down). Elastic band resistance was chosen to elicit moderate exertion (5/10 on the Borg CR10 scale). The order of the exercises was randomized and three repetitions of each exercise were performed. Mean peak EMG activity in each muscle across the repetitions was calculated and expressed as a percentage of MVC. Peak normalized EMG activity in each muscle was compared in two-way (hand position x direction) repeated-measures ANOVA.

Results

Data were collected from 10 healthy subjects (all males, age 36±12 years). Peak muscle activity ranged from 15.3% to 72.6% of MVC across muscles and exercise conditions. There was a significant main effect of hand position for the infraspinatus and lower trapezius, where muscle activity was highest with the palm up hand position (p < 0.001), and for the upper trapezius and posterior deltoid, where muscle activity was highest with the palm down position (p-value range < 0.001-0.004). There was a significant main effect of movement direction, where the diagonal up direction demonstrated the highest muscle activity for the infraspinatus, upper trapezius, lower trapezius, and posterior deltoid (p-value range < 0.001-0.02).

Conclusion

Altering hand position and movement direction during performance of an elastic band pull-apart exercise can affect magnitudes of shoulder-girdle muscle activity. Clinicians may alter a patient's hand position and movement direction while performing the band pull-apart exercise in order to increase muscle activity in target muscles or diminish muscle activity in other muscles.

Level of Evidence

2b.

Comparing exercises with and without electromyographic biofeedback in subacromial pain syndrome: A randomized controlled trial

BACKGROUND

Deficits in movement and muscle activation of scapulohumeral joint are related to Subacromial Pain Syndrome. Electromyography biofeedback during exercise may enhance muscle activation and coordination, and consequently improve pain and shoulder function.

METHODS

This study compared the effects of an exercise protocol with and without using electromyographic biofeedback on pain, function and movement of the shoulder complex in subjects with Subacromial Pain Syndrome. A total of 24 patients with subacromial pain (mean age = 46.2 + 8.1;18 women) were randomized to either therapeutic exercise or exercise plus biofeedback to the trapezius and serratus muscles. Pain and shoulder function were evaluated as the primary outcome and range of motion, muscle strength, electromyographic activity and scapulohumeral kinematics as secondary outcomes. The subjects underwent eight weeks of intervention and comparisons were made between groups in baseline, at 4 weeks, 8 weeks, and at 4 weeks post intervention.

FINDINGS

There were differences between groups for pain [mean difference = 1.5 (CI 0.3, 3.2) p = 0.01] at 8 weeks in the Exercise group and scapular upward rotation at 60° of arm elevation [mean difference = 13.9 (CI 0.9, 9.3), p = 0.006] in the Biofeedback group. There was no difference for the other variables of scapular kinematics as well as for shoulder function (DASH), muscle strength, range of motion and electromyographic variables.

INTERPRETATION

The addition of Biofeedback to the exercise protocol increased upward rotation of the scapula. However, the volunteers who performed only the Exercises had a better response in reducing pain.

Effectiveness of physical therapy given by telerehabilitation on pain and disability of individuals with shoulder pain: A systematic review

OBJECTIVE

To systematically review the effects of physical therapy given by telerehabilitation on pain and disability in individuals with shoulder pain.

DATA SOURCES

PubMed, Embase, CINAHL, LILACS, Cochrane, Web of Science, SCOPUS, SciELO and Ibecs were searched in January/2022.

METHODS

This systematic review followed PRISMA guidelines. Randomized controlled trials investigating the effects of physical therapy given by telerehabilitation on pain and disability in patients with shoulder pain were included. The quality and level of the evidence were assessed with the Cochrane Risk of Bias tool and GRADE, respectively. The effect sizes of the main outcomes were also calculated.

RESULTS

Six randomized controlled trials were included with a total sample of 368 patients with shoulder pain. Four and two randomized controlled trials were assessed as low and high risk of bias, respectively. Three randomized controlled trials assessed shoulder post-operative care, two assessed chronic shoulder pain, and one assessed frozen shoulder. Very low to low evidence suggests that there is no difference between telerehabilitation and in-person physical therapy or home-based exercises programs to improve pain and disability in patients with shoulder pain. Low evidence suggests that telerehabilitation is superior to advice only to improve shoulder pain (effect size: 2.42; 95% Confidence Interval: 1.72, 3.06) and disability (effect size: 1.61; 95% Confidence Interval: 1.01, 2.18).

CONCLUSIONS

Although telerehabilitation may be a promising tool to treat patients with shoulder pain and disability, the very low to low quality of evidence does not support a definite recommendation of its use in this population.

Electromyography activation of shoulder and trunk muscles is greater during closed chain compared to open chain exercises

BACKGROUND

To compare the activation of shoulder and trunk muscles between six pairs of closed (CC) and open chain (OC) exercises for the upper extremity, matched for performance characteristics. The secondary aims were to compare shoulder and trunk muscle activation and shoulder activation ratios during each pair of CC and OC exercise.

METHODS

Twenty-two healthy young adults were recruited. During visit 1, the 5-repetition maximum resistance was established for each CC and OC exercise. During visit 2, electromyography activation from the infraspinatus (INF), deltoid (DEL), serratus anterior (SA), upper, middle and lower trapezius (UT, MT, LT), erector spinae (ES) and external oblique (EO) muscles was collected during 5-repetition max of each exercise. Average activation was calculated during the concentric and eccentric phases of each exercises. Activation ratios (DEL/INF, UT/LT, UT/MT, UT/SA) were also calculated. Linear mixed models compared the activation by muscle collapsed across CC and OC exercises. A paired t-test compared the activation of each muscle and the activation ratios (DEL/INF, UT/LT, UT/MT, UT/SA) between each pair of CC and OC exercises.

RESULTS

The INF, LT, ES, and EO had greater activation during both concentric (p = 0.03) and eccentric (p < 0.01) phases of CC versus OC exercises. Activation ratios were lower in CC exercises compared to OC exercises (DEL/INF, 3 pairs; UT/LT, 2 pairs; UT/MT, 1 pair; UT/SA, 3 pairs).

CONCLUSION

Upper extremity CC exercises generated greater activation of shoulder and trunk muscles compared to OC exercises. Some of the CC exercises produced lower activation ratios compared to OC exercises.

Shoulder muscle activation during scapular protraction exercise with arm rotation

BACKGROUND

The role of the serratus anterior is to maintain scapular stability. To strengthen this muscle, scapular protraction exercises are typically performed. Although the angle of arm rotation leads to changes in shoulder muscle activation, the arm rotation position is not normally determined.

OBJECTIVE

To investigate if scapular muscle activations were changed by combining arm external rotation during scapular protraction exercises.

METHODS

Thirty-four healthy men were enrolled in this study. Participants were instructed to perform scapular protraction exercises at 90∘ and 120∘ of shoulder flexion while in the standing and supine positions. Two different arm rotation angles were used: the thumb-up position (neutral position) and the maximum arm external rotation (ER) position. The percentages of maximum voluntary contractions (%MVCs) were measured, and %MVCs in the neutral and arm ER positions were compared.

RESULTS

Muscle activities of the middle serratus anterior (MSA) and lower serratus anterior (LSA) in the arm ER position were significantly higher than those in the neutral position during all tasks. The highest MSA and LSA positions were observed with the arm ER position of 120∘ while standing.

CONCLUSIONS

Scapular protraction exercises with arm ER resulted in a higher serratus anterior activity.

Comprehensive supervised heavy training program versus home training regimen in patients with subacromial impingement syndrome: a randomized trial

Background

There is no consensus on the best training regimen for subacromial impingement syndrome (SIS). Several have been suggested, but never tested.

The purpose of the study is to compare a comprehensive supervised training regimen (STR) based on latest evidence including heavy slow resistance training with a validated home-based regimen (HTR). We hypothesized that the STR would be superior to the HTR.

Methods

Randomised control trial with blinded assessor. 126 consecutive patients with SIS were recruited and equally randomised to 12 weeks of either supervised training regimen (STR), or home-based training regimen (HTR). Primary outcomes were Constant Score (CS) and Shoulder Rating Questionnaire (SRQ) from baseline and 6 months after completed training. Results were analyzed according to intention-to treat principles. The study was retrospectively registered in ClinicalTrials.gov. Date of registration: 07/06/2021. Identification number: NCT04915430.

Results

CS improved by 22.7 points for the STR group and by 23,7 points for the HTR (p = 0.0001). The SRQ improved by 17.7 and 18.1 points for the STR and the HTR groups respectively (p = 0.0001). The inter-group changes were non-significant. All secondary outcomes (passive and active range of motion, pain on impingement test, and resisted muscle tests) improved in both groups, without significant inter-group difference.

Conclusion

We found no significant difference between a comprehensive supervised training regimen including heavy training principles, and a home-based training program in patients with SIS.

Effects of a combination of scapular stabilization and thoracic extension exercises for office workers with forward head posture on the craniovertebral angle, respiration, pain, and disability: A randomized-controlled trial

Objectives

This study aims to investigate how exercise programs not directly applied to the cervical spine affect office workers with forward head posture (FHP).

Patients and methods

Between March 2018 and June 2018, a total of 32 office workers with FHP (13 males, 19 females; mean age 36.63 years; range, 23 to 57 years) were randomized either to experimental (n=16) or control groups (n=16). Scapular stabilization and thoracic extension exercises were applied to the experimental group and cervical stabilization and stretching exercises to the control group. The results of the pre-intervention and after six weeks measurement of the craniovertebral angle (CVA), respiration, pain, and disability were compared and analyzed.

Results

For intra-group comparison, both groups showed significant differences (p<0.05) in CVA, forced expiratory volume at 1 sec (FEV1), Visual Analog Scale (VAS), and neck disability index at pre- and post-intervention, while only the experimental group showed a significant difference (p<0.05) in maximum inspiratory pressure, maximum expiratory pressure, and forced vital capacity. For inter-group comparison, a significant difference (p<0.05) between FEV1 and VAS was observed.

Conclusion

The combination of scapular stabilization and thoracic extension exercises, not directly applied to the cervical spine, has an effect on improving the posture, respiration, neck pain, and disability in office workers with FHP.

The Youth Throwers Ten Exercise Program: A variation of an exercise series for enhanced dynamic shoulder control in the youth overhead throwing athlete

The overhead throwing motion is an extremely stressful athletic movement. The high velocity and repetitive nature of this activity places immense pressure on the entire body, which can frequently result in injury to the throwing arm. Extensive literature exists with regards to the management of these injuries in the collegiate and professional level athlete; and it is well understood that a multiphasic approach is required to return an individual to prior level of play. However, there is a gap in the literature which fails to address the management of youth individuals. This article presents a new and innovative approach to the rehabilitation, training and management of the youth overhead throwing athlete, The Youth Throwers Ten Exercise Program. This program addresses principles of: coactivation, coordination, dynamic stabilization, neuromuscular control, proprioception, muscle strength, endurance and scapular rhythm all of which are vital for successful performance. This exercise series utilizes bodyweight and Theraband exercises that cater to the unique characteristics of the youth athlete making it a safe way to prepare for the demands of overhead throwing activities.