International Urogynecology Journal

, Volume 27, Issue 11, pp 1689–1696 | Cite as

Functional mapping of the pelvic floor and sphincter muscles from high-density surface EMG recordings

  • Yun Peng
  • Jinbao He
  • Rose Khavari
  • Timothy B. Boone
  • Yingchun ZhangEmail author
Original Article


Introduction and hypothesis

Knowledge of the innervation of pelvic floor and sphincter muscles is of great importance to understanding the pathophysiology of female pelvic floor dysfunctions. This report presents our high-density intravaginal and intrarectal electromyography (EMG) probes and a comprehensive innervation zone (IZ) imaging technique based on high-density EMG readings to characterize the IZ distribution.


Both intravaginal and intrarectal probes are covered with a high-density surface electromyography electrode grid (8 × 8). Surface EMG signals were acquired in ten healthy women performing maximum voluntary contractions of their pelvic floor. EMG decomposition was performed to separate motor-unit action potentials (MUAPs) and then localize their IZs.


High-density surface EMG signals were successfully acquired over the vaginal and rectal surfaces. The propagation patterns of muscle activity were clearly visualized for multiple muscle groups of the pelvic floor and anal sphincter. During each contraction, up to 218 and 456 repetitions of motor units were detected by the vaginal and rectal probes, respectively. MUAPs were separated with their IZs identified at various orientations and depths.


The proposed probes are capable of providing a comprehensive mapping of IZs of the pelvic floor and sphincter muscles. They can be employed as diagnostic and preventative tools in clinical practices.


Pelvic floor muscles Electromyography Motor unit Innervation zone Intravaginal EMG Probe Intrarectal 



This work was supported in part by NIH DK082644 and the University of Houston.

Conflicts of interest



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Copyright information

© The International Urogynecological Association 2016

Authors and Affiliations

  • Yun Peng
    • 1
  • Jinbao He
    • 2
  • Rose Khavari
    • 3
  • Timothy B. Boone
    • 3
  • Yingchun Zhang
    • 1
    Email author
  1. 1.Department of Biomedical Engineering, Cullen College of EngineeringUniversity of HoustonHoustonUSA
  2. 2.School of Electronic and Information EngineeringNingbo University of TechnologyNingboChina
  3. 3.Department of UrologyHouston Methodist Hospital and Research InstituteHoustonUSA

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