Effects of Lower Limb Position and Peri-Hip Muscle Co-Contraction on the Efficiency of Voluntary Pelvic Floor Muscle (PFM) Contraction During PFM Exercises

Pelvic floor muscle (PFM) exercises are essential for managing stress urinary incontinence (SUI), and various approaches, including differing lower limb positions and the use of assistive devices, have been proposed to enhance their effectiveness. This study aimed to evaluate how different lower limb positions and co-contraction of peri-hip muscles affect the efficiency of voluntary PFM contractions. Nineteen healthy female participants performed four types of PFM exercises: supine (Exercise A, Ex-A), supine kneeling (Exercise B,Ex-B), supine kneeling with hip abduction (Exercise C,Ex-C), and supine kneeling with hip adduction (Exercise D,Ex-D). Bladder base elevation, as an indicator of PFM contraction efficiency, was assessed using ultrasound. The results showed that the supine kneeling position (Ex-B) produced significantly greater bladder base elevation compared to the standard supine position (Ex-A) (p < 0.01). However, adding hip abduction or adduction (Ex-C and Ex-D) led to significantly lower elevations than Ex-B (p < 0.01), suggesting that co-contraction of the peri-hip muscles may reduce the efficiency of voluntary PFM contractions. This study indicates that the supine kneeling position is the most effective posture for PFM exercises, emphasizing the importance of avoiding unnecessary peri-hip muscle engagement to maximize contraction efficiency. These findings may help improve exercise protocols for preventing and managing SUI. However, a limitation of the study is the exclusive inclusion of young, healthy women; further research is needed in SUI patients or at-risk populations to confirm these results and develop more targeted exercise strategies.