The effect of aging on the electromyographic activity of pelvic floor muscles - A comparative study among stress incontinent patients and asymptomatic women

Objectives: Pelvic floor muscle training (PFMT) is commonly used in combination with biofeedback devices for stress urinary incontinence. A new electromyography (EMG)-based home-use device for PFMT is tested for healthy and stress incontinent patients. Subjects and methods: Altogether 31 women with genuine stress incontinence (GSI) and 35 controls without urinary symptoms were measured with a vaginal surface EMG probe. EMG activity during three rapid contractions (5 s) in supine and standing positions were observed. Results: Mean values of three rapid contractions were 17.0 muV (range 6.5-59.0, S.D. 10.5) in the supine position and 12.9 muV (range 5.0-33.0, S.D. 5.9) in the standing position among incontinent patients and 19.5 muV (range 9.0-43.5, S.D. 8.4) and 18.2 muV (range 8.0-43.5, S.D. 8.7) among the controls, respectively. A significant difference (P = 0.006) was found in the mean values of three rapid contractions in the standing position between GSI patients and asymptomatic women. In regression analysis, EMG values were dependent on age (P = 0.004 in the supine, P = 0.009 in the standing) in both groups, but not on parity, body mass index (BMI) or episiotomies. Conclusions: In the study groups, the EMG activity of pelvic floor muscles (PFMs) decreased during aging. Although the tested surface EMG device showed a tendency that incontinent patients have lower PFM activities especially in the standing position, the value of surface EMG method as a diagnostic tool is not well established. However, the tested EMG-based device for PFMT will be helpful as guidance for incontinent patients.(C) 2003 Elsevier Science Ireland Ltd. All rights reserved.