Urethral Rotation Angles and Foot Pronation Mechanical Changes in Postmenopausal Women

Stress urinary incontinence (SUI) affects about 26% of women between 30 and 59 years of age. It is the sudden involuntary urine leakage secondary to increased intra abdominal pressure related to physical activities as laughing, sneezing, straining, coughing, or exercising . There are two common mechanisms for SUI: urethral hypermobility due to loss of support of the bladder neck and urethra (affected by increased intra-abdominal pressure), and weakness of the urinary sphincter that may result from trauma, repeated urogynaecological surgeries, neurological disease, ageing or diseases leading to systemic muscular atrophy. SUI is the most common pelvic floor dysfunction linked to the vaginal delivery. However the prevalence of stress incontinence peaks occurs in the fifth decade of life . and all types of incontinence are commonly occurring with ageing and obesity.

Urethral hypermobility means that the proximal part of the urethra may exhibit a rotational movement in a postero-inferior direction. And it was diagnosed when the urethra rotated during strain over 30° from its resting axis . Urethral rotation angles may assist in both assessment and diagnosis of patients with SUI, which may in turn decreases requires for any other investigations .The ultrasonography assessment of the angle of inclination (α angle: the angle between the axis of the proximal urethra and the central axis of the symphysis pubis) and posterior urethrovesical angle (β angle: the angle between the proximal urethra and the posterior vesical wall) has been investigated by several researchers. However, recently transperineal ultrasonography is a practical, reliable, non-invasive and comfortable method for evaluation of SUI. Additionally, it has the advantage of dynamic evaluation during the Valsalva maneuver .

Urinary sphincter composed of; internal urethral sphincter that is predominantly smooth muscle without voluntary control, and the external urethral sphincter and pelvic floor muscles (PFMs) that are predominantly striated muscle with voluntary control. During activities the PFMs contract to prevent the leakage of urine, in addition, they play a significant role in trunk stabilization through its connections with abdominal muscles, diaphragm, and gluteus by myofascial continuity . Contractions of PFMs lead to activation of gluteal muscles especially the levator ani through their connection by the fossa ischioanalis . Additionally, rotators mainly the internal obturator and piriformis muscles are important for maintaining pelvic stability and PFM functionality .Moreover, the tension of the rotator cuff and gluteal muscles is also primarily determined by position of the foot. So, the tension of PFM may affect the tension and functioning of the rotators and gluteal muscles, thus influencing the biomechanics and position of whole lower limb even the foot position .