Figure 1. Two-channel EMG recording of pelvic muscles during stimulation. RED line is "napkin ring myograph", which is situated in the vaginal entrance and detects the main portion of the pubococcygeus (PC) muscle. BLACK line is the output of the "cervical cap myograph", which is mounted on the cervix itself and detects EMG activity in the uterine muscles. Note that the PC muscle (red) is often more active, but not always, as at just before minute 5. [Scanned printout of data from Verimed's Myoexerciser. There was slight yellowing of the chart paper, which became exaggerated when Photoshop was used to enhance the contrast to make tracings themselves more vivid. Yellow background was mostly removed, but the tracings are unretouched except for greater contrast settings.] Pictures of the two electrodes have recently been posted.
Figure 2. This is the same data as Figure 1, but with an expanded time base (and printed at a shrunken size), with stimulation intervals labeled as "clitoral" or "G Spot". The Figure will be shown below in greater detail, in two parts, for discussion purposes.
Figure 2a. In Panel A, we see the effects of clitoral and G Spot stimulation on both muscles. The uterine sEMG (black line) is very low during clitoral stimulation, and not much more active during G Spot stimulation, until the moment of orgasm. The PC muscle (red line) is still twice as active, however. In Panel B, we see a traditional "clitoral" orgasm brought on by clitoral stimulation; there is little uterine activity during clitoral stimulation. During G Spot stimulation, there is much PC activity, and more uterine activity, until they are almost equal at the reported orgasm (which wasn't very big).
Figure 2b. In Panel C we observe that there is only slight involvement of the uterine muscles to a pair of clitorally-stimulated orgasms. In panel D, however, stimulation of the G Spot increased activity in both the uterus and in the PC muscle, and the amplitude of the two muscle groups was similar in all three orgasms. However, note the separation in time of the two peaks in the third orgasm; this will be shown in detail in the next image.
Figure 3. This is another printout of the same data but at a higher resolution, showing three consecutive "blended" orgasms derived from G Spot stimulation over a 30 second interval. We observe that the uterine muscles peaked higher than the PC muscles in most of the orgasmic contractions of the first two orgasms. However, it is especially interesting that in the third "blended" orgasm, the uterine muscles peaked fully 1.3 seconds BEFORE the PC muscle did, which substantially proves that the two orgasmic contractions are mediated by different nerve fibers and reflexes. They can occur together, or separately. Note the "aftershock" in the PC muscle (at 4:46:30).
This data was collected on June 16, 1984, in Portland, Maine, USA. The research subject was an established AASECT Sex Therapist residing in a nearby state.
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