This particular researcher (a really interesting guy in general - check out his bio http://en.wikipedia.org/wiki/Ahmed_Shafik_(sexologist)) has done dozens of gynecological, proctological, and urological experiments on muscle function. A lot of the studies seem to involve needle electrodes, saline injections, and electrical stimulation. You can read the abstracts of his publications by medical specialty here http://www.ahmedshafik.com/search.asp?parent=0
Interesting if you like realistic scenarios. Here are a few.
Response of the Labia Majora and Minora to Clitoral Stimulation: Mechanism and Role in the Sexual Act.
Normally, the labia majora touch each other in the midline. On sexual stimulation, they become thinner and spread apart. Continuation of stimulation produces labia majora congestion; also the labia minora get congested. The mechanism producing these labial sexual changes is unknown. We investigated the hypothesis that the response of the labia majora and labia minora to sexual stimulation is reflex. The response of the labia majora and labia minora to electrical and mechanical stimulation of glans clitoris was studied in 21 healthy women (mean age 35.2 years). Surface electrodes were applied to the glans clitoris (stimulating) and the labia majora and labia minora (recording). Mechanical stimulation was induced by gentle stroking of the glans clitoris by a pencil electrode. The response of the labia to glans clitoris stimulation was also tested after glans clitoris and labial anesthetization. The labia majora exhibited resting electric activity as slow waves (SWs) and action potentials (APs). The electric waves increased significantly on mechanical and electrical stimulation of the glans clitoris. Stimulation of the anesthetized glans clitoris, labia majora and labia minora did not evoke the response. The labia minora did not exhibit electric activity at rest or on stimulation. The data suggested the presence of a reproducible reflex relationship between the glans clitoris and labia majora which we call the "clitoro-labial reflex". During the sexual act when the penis buffets the glans clitoris, the clitoro-labial reflex appears to be evoked and initiates the labia majora response. The reflex may be incorporated, after further studies, as an investigative tool for the diagnosis of sexual disorders.
Effect of External Anal Sphincter on the Ischiocavernosus Muscle and Its Suggested Role in the Sexual Act. [FYI - the ischiocavernosus muscle contributes to forming erections in males and females]
Whereas the bulbocavernosus muscle shares its contractile activity with the external anal sphincter, the response of the ischiocavernosus muscle to external anal sphincter contraction could not be traced in the literature. We investigated the hypothesis that the ischiocavernosus contracts reflexly upon external anal sphincter contraction. The response of the ischiocavernosus to external anal sphincter squeeze and stimulation was recorded in 21 healthy volunteers (13 men, 8 women, age 36.8 +/- 10.7 [SD] years). An electromyographic (EMG) needle (stimulating) electrode was introduced into the external anal sphincter and another (recording) one was inserted into the ischiocavernosus. The test was repeated after individual anesthetization of the external anal sphincter and ischiocavernosus and after muscle infiltration with normal saline instead of lidocaine. external anal sphincter electrostimulation (10 stimuli, 200 micros duration, 0.2 Hz frequency, 0-100 mA intensity) produced an increase of ischiocavernosus EMG activity to a mean of 267.8 +/- 42.7 microV, whereas anal squeeze effected an increase to a mean of 224.5 +/- 45.3 microV. The ischiocavernosus did not respond to stimulation of the external anal sphincter after individual anesthetization of the ischiocavernosus and external anal sphincter, but it did after saline infiltration. The results were reproducible. Ischiocavernosus contracted upon external anal sphincter contraction. This effect seems to be mediated through a reflex that we call "anocavernosal excitatory reflex." The ischiocavernosus lever action is suggested to share in the erectile mechanism by elevating the penile shaft to above the horizontal level. The reflex may prove of diagnostic significance in sexual function disorders, a point that needs further study.