This study is a multi-center survey of surface electromyography (sEMG) of pelvic floor muscles in healthy female. The aim of the study is to get the reference interval of normal pelvic floor sEMG from Chinese women.

Pelvic floor dysfunction is a group of diseases caused by the damage of pelvic floor supporting structure. Pelvic floor muscles play an important role in the maintenance of pelvic floor function. Surface electromyography (sEMG) has been widely used to evaluate the function of pelvic floor muscles. The sEMG tests, which include pretest and posttest resting amplitude (µV), as well as phasic, tonic and endurance contractile amplitude (µV), are performed using Vishee neuro-muscle stimulator (MyoTrac Infiniti, model SA9800, Thought Technology Ltd., Montreal, Canada), following the Glazer protocols. A pear-shaped vaginal probe (serial number DYS180610, type VET-A, produced by Nanjing Vishee Medical Technology, Ltd.) is placed into the vagina when sEMG tests are performed. This is a cross-sectional survey. The reference intervals of pelvic floor sEMG in healthy female are evaluated.

Inclusion Criteria:

• a. Having sex life and tolerable to vaginal examination b. There were no symptoms related to pelvic floor dysfunction; c. The modified Oxford grading system was 4 or 5; d. No birth or 2 years after the last delivery;

Exclusion Criteria:

• a. Duration of pregnancy and lactation; b. Within 2 years after delivery; c. Acute inflammation of vagina or discomfort of vagina; d. History of pelvic floor dysfunction: leakage of urine in the past 1 month when coughing / sneezing / lifting; leakage of urine in the past 1 month when urgency fecal incontinence in the past 1 month; usually have a bulge or something falling out that can be seen or felt in vaginal area; Pain in the abdomen or lumbosacral and buttocks below the navel for more than 6 months; e. History of radical pelvic surgery (cervical cancer, rectal cancer, bladder cancer, etc.); f. History of hysterectomy and subtotal hysterectomy; g. History of pelvic floor surgery (anti-incontinence and prolapse surgery); h. History of pelvic radiotherapy; i. Nervous system diseases that significantly affect muscle function; j. Those who can't cooperate with pelvic floor contraction

female

healthy females with no symptoms of pelvic floor dysfunciton and normal contraciton strength, and at least 2 yrs postpartum.