Earticle

Background: Lumbopelvic stability is highly important for exercise therapy for patients with low back pain and shoulder dysfunction. It can be attained using a pelvic compression belt. Previous studies showed that external pelvic compression (EPC) enhances form closure by reducing sacroiliac joint laxity and selectively strengthens force closure and motor control by reducing the compensatory activity of the stabilizer. In addition, when the pelvic compression belt was placed directly on the anterior superior iliac spine, the laxity of the sacroiliac cephalic joint could be significantly reduced. Objects: This study aimed to compare the effects of EPC on lumbopelvic and shoulder muscle surface electromyography (EMG) activities during push-up plus (PUP) and deadlift (DL) exercise, trunk extensor strength during DL exercise. Methods: Thirty-eight subjects (21 men and 17 women) volunteered to participate in this study. The subjects were instructed to perform PUP and DL with and without the EPC. EMG data were collect from serratus anterior (SA), pectoralis major (PM), erector spinae (ES), and multifidus (MF). Trunk extensor strength were tested in DL exercise. The data were collected during 3 repetitions of all exercise and the mean of root mean square was used for analysis. Results: The EMG activities of the SA and PM were significantly increased in PUP with pelvic compression as compared with PUP without pelvic compression (p<.05). In DL exercise, a significant improvement in trunk extensor strength was observed during DL exercise with pelvic compression (p<.05). Conclusion: The results of this study indicate that lumbopelvic stabilization reinforced with external pelvic compression may be propitious to strengthen PUP in more-active SA and PM muscles. Applying EPC can improve the trunk extensor strength during DL exercise. Our study shows that EPC was beneficial to improve the PUP and DL exercise efficiency.

Background: The shoulder functions as a critical biomechanical link between the upper extremity and the trunk, providing both mobility and stability necessary for efficient functional movement. Adequate trunk stability is essential for optimal force transmission and coordinated muscle activation within the shoulder complex. Deficits in trunk stability may disrupt normal neuromuscular control, leading to altered activation patterns of scapular and glenohumeral muscles, reduced strength output, and the development of compensatory movement strategies. Despite its clinical importance, the influence of external trunk stabilization on shoulder muscle performance has not been fully clarified. Therefore, this study aimed to investigate the effects of different external trunk compression conditions on isometric shoulder rotator strength and scapular muscle activity in healthy young adults, with the goal of identifying the most effective trunk compression site. Methods: Twenty-eight healthy adults in their twenties voluntarily participated in this study. Isometric shoulder internal and external rotation strength was assessed under three experimental conditions: no trunk compression, pelvic compression only, and combined thoracic and pelvic compression. Surface electromyography was used to measure muscle activity of the upper trapezius, lower trapezius, serratus anterior, and middle deltoid during standardized isometric tasks. All measurements were performed in a controlled laboratory setting, and data were analyzed to compare differences across conditions. Results: Isometric shoulder internal and external rotational strength significantly increased with greater levels of external trunk support. Electromyographic analysis revealed significant differences in muscle activation among the three compression conditions (p < .01). Specifically, scapular stabilizing muscles demonstrated progressively increased activation as the number of compression sites increased, indicating enhanced neuromuscular engagement. Conclusion: External trunk compression effectively enhances shoulder rotational strength and facilitates increased activation of scapular stabilizing muscles. These findings suggest that improving trunk stability may optimize shoulder function during isometric tasks. Incorporating trunk stabilization strategies into rehabilitation programs may be beneficial for individuals with shoulder dysfunction, potentially improving clinical outcomes and functional performance.