From the Guidelines
The primary muscles weakened in Stress Urinary Incontinence (SUI) are the pelvic floor muscles, particularly the levator ani complex and the external urethral sphincter. These muscles play a crucial role in maintaining continence during activities that increase intra-abdominal pressure, such as coughing, sneezing, or physical exertion 1. The weakening of these muscles can be due to various factors, including childbirth, aging, obesity, or chronic straining.
Key Muscles Involved
- The levator ani complex, which includes the pubococcygeus muscle, forms a sling around the urethra, providing crucial support.
- The external urethral sphincter also contributes to urethral closure pressure, helping to prevent involuntary urine leakage. When these muscles are weakened, they cannot effectively counteract increased abdominal pressure, resulting in SUI.
Treatment Approach
Treatment for SUI often involves pelvic floor muscle training, as recommended by the American College of Physicians 1, which can help strengthen these muscles and improve urethral closure pressure, thereby reducing incontinence episodes. This approach is supported by high-quality evidence and is considered a first-line treatment for women with stress UI 1.
From the Research
Muscles Weakened in Stress Urinary Incontinence (SUI)
The muscles weakened in Stress Urinary Incontinence (SUI) include:
Pathophysiology of SUI
The pathophysiology of SUI involves damage to the muscles, nerves, and connective tissue of the pelvic floor 3. This damage can lead to:
- Increased tonic stress on the pelvic fascia due to PFM tears 4
- Fascial tearing due to PFM denervation 4
- Fascial weakness resulting from tears 4
- Inefficient PFM contraction due to altered motor control 4
Treatment Implications
The weakening of these muscles has implications for the treatment of SUI, including: