Background: The serratus anterior (SA) muscle is an important scapular stabilizer and has a profound role in retaining the scapulohumeral rhythm. Therefore, modifi, ed push-up plus (MPUP) has been advised to strengthen this muscle as a closed chain workout. However, few previous studies have reported the possibility of a reparative motion from pectoralis major (PM) that could replace and amend SA’, s function during push-up plus. Objectives: The current study examined MPUP’, s eff, ect using biofeedback EMG on some of the selected scapular stabilizers. Methods: Sixteen healthy young subjects voluntarily participated in this study. Each subject performed push-ups, from the quadruped position, under two conditions (i. e., with or without visual and auditory biofeedback). Surface EMG measured pectoralis major, serratus anterior, and upper trapezius activity. A paired t-test was used to determine any statistically signifi, cant diff, erence between the two conditions. Additionally, the eff, ect size was calculated to quantify the magnitude of EMG biofeedback in each muscle. Results: MPUP training using biofeedback signifi, cantly increased SA muscle activity and decreased PM muscle activity, but there was no signifi, cant change in UT activity. Conclusions: Excessive PM activity was repressed because of biofeedback, and the workout was done with the enhancement of SA muscular activity. Thus, including biofeedback while doing MPUPs helps limit PM’, s supplementary action and enhance SA muscle activity.

Background and Aim: Scapular muscles stabilization and neuromuscular control are important factors in shoulder function during dynamic activities. The three-dimensional pattern of integrated movement between gleno-humeral and scapula-thoracic joints is known as the scapula-humeral rhythm. More involved rotator cuff and scapular muscles causes more motor units are being recruited, therefore perhaps with loading on scapular muscles, can evaluate muscles role in scapular position more accurately and comprehensively.Materials and Methods: Thirty male basketball players, aged between 20 to 40 years were recruited for modified lateral scapular slide test. The linear distance between inferior angle of scapula and spinous process of T7-8 was examined in 90 degrees of scaption without load and with 1 kg loading by two examiners in one session using the caliper. One of the examiners repeated the test in next week.Results: Amount of inter and intra-rater intra-class correlation coefficient (ICC) for 90 degrees of unloaded scaption was 0.73 and 0.82, respectively and for 1 kg loading position was 0.54 and 0.86, respectively. Amount of standard error of measurement (SEM) in inter and intra-rater measurements for 90 degrees of unloaded scaption was 0.83 and 0.59 cm, respectively and for 1 kg loading position was 0.97 and 0.45 cm, respectively.Conclusion: 1 kg loading in scaption, did not significantly improve the reliability of the test that shows the amount of load is not appropriate to activate the muscles in the athletes.

Background and Aim: Scapular dyskinesis is a functional disorder of the shoulder girdle characterized by abnormal movement patterns and impaired neuromuscular control of the scapular stabilizing muscles. In bodybuilders, this disorder leads to muscle imbalances and poor scapular function due to repetitive movements with heavy weights. The aim of this study was to investigate the immediate effects of kinesio taping on the electromyographic activity of scapular stabilizing muscles in male bodybuilders with type one, two, and three dyskinesia. Methods: The study participants were 36 male bodybuilders (mean age: 25. 13 years) diagnosed with type I, II, and III scapular dyskinesis. They were non-randomly assigned to three equal groups of 12 participants each. Electromyographic (EMG) activity of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) muscles was measured during dynamic planks with an elastic band and rowing exercises combined with shoulder external rotation, both before and after the kinesio taping intervention. EMG signals were normalized to the maximum voluntary isometric contraction (MVIC). The kinesio taping intervention was applied according to the method of Toth et al. Post-test data were analyzed using two-way mixed ANOVA. Results: In both dynamic plank and boat movements, kinesiotaping led to a significant reduction in upper trapezius muscle activity across all three types of dyskinesia (P<0. 05). In all three dyskinesia groups, the activity of the middle and lower trapezius muscles significantly increased in both movements (P<0. 05). The response of the anterior serratus muscle was heterogeneous and showed a significant increase in activity only under certain conditions. In the intergroup comparison of boat movement, the group with type 1 dyskinesia showed higher activity in the UT muscle and lower activity in the LT muscle compared to type 2 (P<0. 05). Conclusion: Kinesio taping was able to immediately improve the scapular stabilizer muscle activity pattern in all three types of dyskinesia by reducing the activity of overactive muscles and facilitating inhibited muscles. However, limited effectiveness was observed in the anterior temporalis muscle, indicating the need for designing specific and tailored tapering for this muscle.

Background & Objective: The scapula's optimal movement and position depend on the scapular stabilizers' normal function. Treatment for scapular dyskinesia relies on the severity of the dysfunction. Typically, scapular dyskinesia is treated with a program to strengthen the scapular stabilizers, assess for any muscle imbalances, stretch tight muscles, and develop conscious control of proper shoulder position and movement. There are a variety of treatments for scapular disorders, including manual therapy, electrotherapy, scapular mobilization, cervical and lumbar spine manipulation, and surgery. Conscious control or exercises with feedback are other training components that improve proprioception, normalize the resting position of the shoulder, and enhance the activity of the trapezius muscle. Research has shown that decreased strength of these muscles is common among people with scapular dyskinesia. Biofeedback can be a valuable tool for treating scapular dyskinesia by increasing motivation and improving adherence to the rehabilitation program. Therefore, this research aimed to collect and combine the results of the electrical activity of scapular muscles in verbal and visual feedback for scapular dyskinesia. Methods: The present study was quasi–experimental with a pretest–posttest design, using two intervention groups and one control group. The study's statistical population consisted of women with scapular dyskinesia living in Karaj City, Iran. Of whom, 45 women were purposefully included in the study based on the inclusion criteria. Then, they were randomly assigned to two intervention groups (verbal and visual feedback) and one control group. To determine the sample size, G*Power software was used. Based on the effect size of 0.4, alpha of 0.05, and power of 0.85, 15 people were determined in each group. The inclusion criteria for the study were as follows: women aged 20 to 30 years with no history of regular exercise, having scapular dyskinesia, positive scapular lateral glide test, no shoulder pain on the day of the test, no shoulder joint instability injury and no history of dislocation in the past year, no history of trauma, fracture, or surgery in the shoulder joint, no pain or limited range of motion in the shoulder joint (10,11), no abnormal body mass index (outside the range of 18 to 25), no history of fracture or surgery of the spine, upper limbs, or shoulders, and no use of sedatives or painkillers 24 hours before the test. The exclusion criteria were unwillingness to continue the study or injury or pain during the study. Ethical considerations included the confidentiality of personal information and the researchers' commitment to reporting information collected from the study. The scapular lateral sliding test, presented by Kibler, was used to diagnose scapular dyskinesia. An electromyography device was used to record muscle activity. Verbal or visual feedback was used to correct shoulder alignment. Data were analyzed using analysis of variance, analysis of covariance, and Bonferroni post hoc test in SPSS software version 19 at a significance level of 0.05. Results: The results showed a significant difference between the effect of verbal and visual feedback on the amount of electrical activity of selected scapular muscles in shoulder flexion movement in female athletes with scapular dyskinesis (p<0.05). In the activity ratio of the upper trapezius to the lower trapezius, the visual feedback group significantly improved compared to the verbal feedback group (p<0.05). Conclusion: According to the study results, visual feedback has a more positive effect than verbal feedback on improving muscle activity in both the sagittal and frontal planes. Therefore, it is suggested that visual feedback be used along with corrective interventions to improve muscle activity and shoulder movement in people with scapular dyskinesia.

Background: Shoulder joint function and the athletic performance of overhead athletes are influenced by scapular dyskinesis (SD) due to its high prevalence among these athletes and the motor interaction between the scapula and the arm. The present study investigated the prediction of SD through the electromyographic indices of scapulothoracic muscles in female overhead athletes. Methods: The present descriptive-correlational study was carried out on 60 female volleyball, handball, basketball, and badminton athletes. The lateral scapular slide test was used to examine their SD. The required electromyography and electrogoniometry data was recorded simultaneously to measure the activity and onset time of scapulothoracic muscles, including upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA). The collected data was analyzed using Spearman correlation and multiple regression tests. Results: Significant correlations were found between all electromyographic variables and SD (P<0. 01). The regression effects of all predictive variables on SD were significant (P=0. 001). In terms of predictive power, UT/SA co-contraction (β =0. 765), UT/LT co-contraction (β =0. 716), LT onset time (β =0. 672), LT activity (β =0. 612), and SA onset time (β =0. 576) had the highest regression effects on SD, respectively. The analysis of the study model showed that there was a strong correlation (r=0. 694) between the predictive variables and SD and that the independent variables predicted 48% of the variance. Conclusion: The presence of imbalance in the scapulothoracic muscles of overhead athletes with SD indicates that athletes should be monitored by coaches, physiotherapists, and physicians for SD screening. It is also necessary to carry out prospective studies to examine and explore other variables related to SD.

Objective Alteration of scapular position and motion is called scapular dyskinesis. Scapular dyskinesis is a common clinical problem. Strength of shoulder girdle muscles is important in shoulder motions and stability, so their weakness may lead to scapular dyskinesis. The aim of this study was to compare the maximum voluntary isometric force of shoulder girdle movements in subjects with and without scapular dyskinesis.Materials & Methods: A case-control study was designed where the participants were selected by nonprobability sampling; 30 subjects with scapular dyskinesis and an average age of 22.95±2.62 years and 30 subjects without scapular dyskinesis and an average age of 22.43±2.50 years. The subjects were instructed to stand with their arms resting on each side of the body. The examiner stood behind them at a distance of 1.5 meter and asked them to elevate their arms to the highest level possible. Scapular dyskinesis test was used to visually examine alteration in scapulohumeral rhythm during arm elevation in sagittal and frontal planes. The shoulder flexion and abduction were repeated for 5 times. At the same time, the examiner rated the scapular movement as normal or observable dyskinesis. The maximal voluntary isometric force of shoulder internal and external rotation on both sides, such as "scaption with external rotation", "scapular abduction and upward rotation", "scapular adduction and downward rotation", "scapular adduction" and "adduction and depression of scapula" were measured with manual Dynamometer. For determining the maximal shoulder isometric rotational force, subjects were positioned prone on tables, arm brought into 90o abduction in frontal plane with 90o elbow flexion and resistance given to distal forearm into shoulder external and internal rotations. The maximal isometric force of scaption (supraspinatus strength) was measured in seated position; shoulder elevated 70o into scapular plane abduction (scaption) with external rotation. The maximal isometric force of scapular abduction and upward rotation was determined in supine position while the arm was elevated to 90o flexion with elbow extension and resistance given against forward pushing. For determining the maximal isometric force of rhomboids and middle trapezius muscles, resistance was given against scapular adduction and downward rotation, and scapular adduction, respectively. The maximal isometric force of lower trapezius was determined in prone position while the arm was elevated to 135o shoulder elevation with elbow extension. Independent t-test was performed to compare the maximal voluntary isometric force of shoulder girdle motions in individuals with and without scapular dyskinesis.Results: The mean±SD of age, weight and height of the participants without and with scapular dyskinesis were 22.43±2.50 years/ 22.95±2.62 years, 64.39±13.38 kg/ 65.67 (±12.2) kg and 171.35 (±11.29) cm/ 173.43 (±8.66) cm, respectively. No statistically significant differences were found between the participants of the two groups with regard to the age, weight and height. Our result showed that the isometric force of "scaption with external rotation", "scapular abduction and external rotation", "adduction and depression of scapula", "scapular adduction and downward rotation" and "scapular adduction" were significantly different between the two groups (P<0.05). In comparison to the control group, the individual with scapular dyskinesis had weaker supraspinatus, serratus anterior, rhomboids and middle and lower trapezius muscles.Conclusion: Scapular dyskinesia or altered kinematics of the scapula (downward rotation, anterior tilt and internal rotation) contributes to impingement syndrome by decreasing the subacromial space. The tissues that occupy the subacromial space are the supraspinatus tendon, subacromial bursa and long head of the biceps brachii tendon. The supraspinatus is the major rotator cuff muscle that is susceptible to tendinopathy in subacromial space. The inflammatory processes or tension overload during shoulder activities, which may result from altered kinematics of the scapula and decrease in the subacromial space, may lead to supraspinatus weakness. It has been shown that scapular stabilizers, such as serratus anterior, rhomboids and middle and lower trapezius muscles are more prone to weakness than the other shoulder muscles. So, the weakness in these muscles may relate to scapular dyskinesis. Scapular muscle exercises are executed in the rehabilitation of patients with subacromial impingement syndrome and scapular dyskinesis, as the muscular system is one of the major contributors to scapular positioning, both at rest and during movements. It seems that improving the strength of shoulder girdle muscles especially supraspinatus, serratus anterior, rhomboids, and middle and lower trapezius muscles would be necessary in individual with scapular dyskinesis.

The aim of this study was to assess the activity of scapular muscles in subjects with forward head posture. The statistical population consisted of female students living in University of Tehran dormitories. 14 healthy girls and 18 girls with forward head posture aged between 23 and 30 were selected. The electromyography activity of serratus anterior, upper trapezius and lower trapezius were recorded during arm abduction. To normalize the data, the mean square of level of electromyography of each muscle was divided by the mean square of level of isometric contraction. Independent t test was used to compare the results in the two groups. The results showed that the electric activity of upper trapezius (P=0.002) in subjects with forward head posture was higher than the healthy group while lower trapezius and serratus anterior showed no difference between the groups. The results showed a difference in electromyography activity of upper trapezius during arm abduction between the healthy group and forward head group. Thus, it can be concluded that normal head posture during arm abduction can support the biomechanical head posture to reduce excessive activity of the upper trapezius.

Purpose: One of the most significant risk factors for throwing athletes is an internal rotation deficit of the shoulder joint. This study aims to investigate 8-week online scapular-focused training on the scapular kinematics, proprioception, and strength of particular shoulder muscles in female volleyball players with glenohumeral internal rotation deficit. Methods: The present study was conducted using a two-group with pre and post-test design. Based on the inclusion and exclusion criteria, 30 female athletes with abnormalities in the shoulder joint’s internal rotation were split into two groups, experimental (n=15) and control (n=15). In the pre-test, goniometers were used to measure shoulder range of motion, isokinetic devices were used to measure proprioception and rotator cuff muscle strength, and inclinometers were used to measure scapular kinematics. The experimental group’s participants underwent 8-week online scapular-focused training, lasting 30 minutes over three sessions each week. These exercises encompassed strength (with TheraBand) and stretching activities. Ultimately, intra-group and inter-group differences were examined using SPSS software, version 20 using paired t-tests and analysis of covariance (ANCOVA) at a significance level of 0. 95. Results: The results of paired t-test revealed that only the experimental group and the pre-test and post-test had a significant difference in all study variables (P<0. 05). Additionally, the results of the analysis of covariance (ANCOVA) demonstrated a significant difference between the two groups’ shoulder proprioception at 45° and 90° in the post-test (P=0. 001 and P=0. 01, respectively). The two groups also differed significantly in the scapular kinematics at all angles of 45°, 90°, and 135° as well as at the limit of the shoulder’s range of motion (P=0. 01, P=0. 04, P=0. 001, and P=0. 001, respectively). Additionally, significant differences were observed between the two groups in all variables of isokinetic strength of concentric internal rotation, isokinetic strength of concentric external rotation, isokinetic strength of eccentric internal rotation, and isokinetic strength of eccentric external rotation (P=0. 001, P=0. 02, and P=0. 001, respectively). Conclusion: Based on the results, it can be concluded that 8-week online scapular-focused training improves scapular kinematics, proprioception, and shoulder internal and external rotator muscle strength in female volleyball players experiencing internal rotation deficiencies of the shoulder joint. It is advised that coaches, experts, and occupational therapists employ these workouts to enhance the aforementioned factors in female volleyball players experiencing shoulder internal rotation deficiencies.