Middle Eastern Journal of Disability Studies

Abstract
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.