Background: Effective trunk stabilization has been a cornerstone in physiotherapy, particularly for individuals with lower back issues. While bridging exercises were traditionally employed for this purpose, there has been a growing interest in their modified versions to optimize therapeutic benefits. Objectives: To investigated the differential effects of traditional and modified bridging exercises, particularly when varying leg support and integrating abduction maneuvers during sling-assisted exercises, on trunk muscle responsiveness. Design: Cross-Sectional study. Methods: A group of twenty participants was subjected to three exercise protocols: Bilateral Limb Bridging (BLB), Single Limb Bridging (SLB), and Single Limb Bridging combined with Hip Abduction (SLBHA). Using Surface Electromyography (EMG), the study captured the activation patterns of the Internal Oblique (IO), Erector Spinae (ES), and Multifidus (MF) muscles. Statistical analysis was conducted using the Kruskal-Wallis test, with post-hoc examination for detailed insights. For data consistency, normalization was executed based on Maximum Voluntary Isometric Contractions, and EMG data interpretation was conducted using the RMS technique. Results: The most prominent variations in muscle activation were identified in the IO muscles on both sides. The left IO displayed marked activation disparities between BLB vs. SLB and SLB vs. SLBHA. Analogous observations were made for the right IO when comparing BLB to SLBHA and BLB to SLB. Conversely, ES and MF muscle activations remained consistent across the different exercises. Conclusion: Modified bridge exercises with sling-assisted leg supports with abduction can selectively activate IO muscles, with a noticeable asymmetrical effect favoring the left side.

INTRODUCTION
METHODS
    Subjects
    Experimental Procedures
    Statistical Analysis
RESULTS
    Left limb sling suspension
    Right limb sling suspension
DISCUSSION
CONCLUSION
ACKNOWLEDGEMENT
REFERENCES

• Okkon Moon(PT, Prof., PhD, Department of Physical Therapy, Howon University, Gunsan, Republic of Korea)
• Taeseok Choi(PT, PhD, Department of Physical Therapy, Howon University, Gunsan, Republic of Korea) Corresponding author