Effects of inner muscle resistance exercise on stress urinary incontinence: a randomized clinical controlled trial

[Purpose] This study investigated the effects of co-contraction resistance exercises of the transverse abdominal and pelvic floor muscles in middle-aged females with stress urinary incontinence. [Participants and Methods] We included 32 females with stress urinary incontinence and divided them into two groups: the inner muscle training group and the pelvic floor muscle group. The thickness of the transverse abdominal muscle was measured during four tasks: (1) rest, (2) maximum contraction of the transverse abdominal muscle, (3) maximum contraction of the pelvic floor muscle, and (4) maximum co-contraction of the transverse abdominal and pelvic floor muscles. In the latter three tasks, measurements were obtained while the participants performed resistance movements using a Thera-band^®. A home program was conducted in both groups, and the intervention lasted for 8 weeks. [Results] The cure rates for SUI were 87.5% and 68.8% in the inner muscle training and pelvic floor muscle groups, respectively. After the intervention, the thickness of the transverse abdominal muscle significantly increased in the inner muscle training groups performing maximum co-contraction of the transverse abdominal and pelvic floor muscles and maximum contraction of the transverse abdominal muscle. [Conclusion] Inner muscle training exercises are more effective than pelvic floor muscle exercises in improving inner muscle function and urinary incontinence in middle-aged females.