Pelvic floor dysfunction, most notably pelvic floor overactivity, is often associated with lower urinary tract, bowel, and gynecological symptoms [1–4] that may have negative cognitive, behavioral, sexual, and emotional consequences. In women, pelvic floor overactivity may be involved in bladder pain syndrome/interstitial cystitis, irritable bowel syndrome, chronic pelvic pain, and in sexual conditions such as dyspareunia and Provoked Vulvodynia (PVD) as defined by the International Society for the Study of Vulvovaginal Disease [5–8]. Less is known about the relationship between pelvic floor overactivity and sexual arousal, desire, and orgasm problems.

Pelvic floor dysfunction is generally regarded as a musculoskeletal dysfunction and/or poor sphincter function associated with pregnancy, vaginal deliveries, obesity, a collagen deficiency, or prolonged overexertion of the pelvic floor [9, 10]. The fact that a history of physical or sexual abuse is common among women with pelvic floor overactivity [11–13] suggests that in many cases, pelvic floor overactivity may be a symptom of chronic activation of the defensive stress-system and should thus be regarded a physical manifestation of emotional dysregulation.

This chapter addresses the relationship between pelvic floor overactivity and sexual arousal, desire, and orgasm problems in women and how this relationship may be mediated by trauma such as sexual abuse and attachment problems. The psychosocial aspects of pelvic floor overactivity and sexual pain is the topic of Chap. 20 in this book.

The pelvic floor muscles attach from the pubic bone anteriorly, to the coccyx (tailbone) posteriorly and form a bowl-like structure, along with ligaments and fascial tissue [14]. The muscles of the pelvic floor consist of superficial muscles including the bulbospongiosus, ischiocavernosus, superficial transverse perineal and external ani sphincter muscles, an intermediate layer consisting of the deep transverse perineal, and the deeper muscles known collectively as the “levator ani” muscles, which consist of the pubococcygeus and iliococcygeus [15]. The levator ani acts to lift up the pelvic organs and is active during defecation. The puborectalis muscles act together with the external anal and urethral sphincters to close the urinary and anal openings, contract the sphincters, and prevent urinary or fecal leakage.

The joint guideline of the International Continence Society and the International Urogynecological Association denotes function and dysfunction of the pelvic floor muscles as normal, overactive (high tone), underactive (low tone), and non-functioning [16, 17]. “High-tone” pelvic floor functioning refers to a state of muscular tension or contraction when muscle relaxation is desired or functionally required [18]. Pelvic floor muscles that cannot voluntarily contract are characterized as “low tone,” whereas the term “non-functioning” signifies the absence of any muscle activity.

The pelvis and the pelvic floor have an important role in protecting and supporting the abdominal organs and maintaining good posture. A flexible pelvic floor that is neither too tense nor too lax is of great significance for effortless micturition and defecation [14]. A “low-tone” pelvic floor may be a consequence of vaginal delivery, damage to the nerves that innervate the pelvic floor muscles or by weakening of the ligaments, but also heavy manual labor, obesity, or frequent coughing may result in long-lasting overtaxing of the pelvic floor. A “high-tone” pelvic floor is often associated with toilet-training executed too early or too intensely [1], but may also be the consequence of a habit to suspend micturition or defecation, of holding in one’s abdominal musculature to appear slim, or of performing intense sports that involve extreme flexing of the pelvic floor, such as ballet or gymnastics.

To date, little is known about the role of the pelvic floor in sexual arousal and orgasm. In 1948, Kegel was the first to describe a technique for toning and strengthening the striated pelvic floor musculature as a treatment for urinary stress incontinence [19]. During this treatment, several women reported to have enhanced erotic sensations in their genitals and a greater ability to experience orgasm. Kegel’s findings were supported by a retrospective correlational study in which pubococcygeal muscle strength was found to be higher in orgasmic than anorgasmic women [20].

In their 1966 book, Masters and Johnson described voluntary and involuntary pelvic floor contractions during sexual arousal in both genders [21]. They obtained their data on the behavior of pelvic floor contractions through direct observation. Involuntary and rhythmic contractions of the pelvic floor muscles were seen during orgasm, with 0.8-s intervals. Masters and Johnson noted that the intensity of the pelvic floor contractions during arousal and orgasm appeared to decrease with age. These involuntary and rhythmic contractions during orgasm may function to restore the vasocongested pelvic tissue to their basal state, or to stimulate the male to ejaculate [21, 22].

Using vaginal and anal pressure probes to study pelvic floor contractions during orgasm, Bohlen and colleagues observed three different patterns of orgasmic contractions during masturbation in eleven women aged 24–33, with unknown pelvic floor function [22]. The first type consisted of a small number of regular contractions at subjectively indicated orgasm onset, and the second type consisted of, on average, twice as many regular contractions followed by additional irregular contractions. The latter type of orgasm lasted almost four times longer than the first type. The irregular contractions may have been the result of continued voluntary stimulation beyond the initial series of regular contractions. A small number of women reported experiencing orgasm without exhibiting any pelvic floor contractions. Anal contractions were found to occur simultaneously with vaginal contractions.

In 1974, Sherfey forwarded her “unromantic view” (p. 102) that there is no such thing as a vaginal, clitoral, or even penile orgasm [23]. According to her, the only type of orgasm is a “myovascular” orgasm (p. 103), which is a strictly mechanic (i.e., muscular) and hydraulic (i.e., venous) affair, with stimulation of an erotic arousal zone—be it the vagina, clitoris, penis, rectum, breasts, or mind—causing the venous networks of the pelvis to expand. According to Sherfey, increased venous congestion and stretching of the pelvic muscles stimulate the muscle nerve endings such that they begin to contract. These muscular contractions, which are usually perceived as pleasurable, constitute the experience of orgasm.

More recently, using surface electromyography (EMG) and vaginal pressure measures , Shafik observed involuntary pelvic floor activity during stimulation of the clitoris, which he considered to be a clitoromotor reflex [24]. Involvement of the levator ani in vaginal elongation, uterine elevation, and vaginal muscle contractions was mainly described in terms of facilitation of male genital response, resulting from penile thrusting [25].

Almost four decades after Kegel’s first studies, Messe and Geer tested Kegel’s assertion about the sexual arousal enhancing properties of pubococcygeus muscle exercises in a psychophysiological study [26]. In their study, they asked women to perform vaginal contractions while engaging in sexual fantasy and compared their genital and subjective sexual responses with engaging in sexual fantasy without performing these contractions and with performing vaginal contractions without engaging in sexual fantasy. Their results showed that performing vaginal contractions without additional sexual stimulation enhanced both genital and subjective sexual arousal relative to baseline. Tensing pelvic floor muscles while engaging in sexual fantasy increased genital and subjective sexual arousal more than tensing alone and fantasizing alone. One additional week of training, the effect of which was tested in an identical second test session, did not further enhance genital and subjective sexual arousal. Messe and Geer speculated about the mechanism through which these contractions may enhance sexual arousal. Increased muscle tone may result in increased stimulation of stretch and pressure receptors during intercourse, leading to enhanced arousal and orgasmic potential. Alternatively, pubococcygeus exercises might focus a woman’s attention on her genitals; this shift in attention might result in an increased perception of pleasure, with positive expectations that these exercises would enhance arousal contributing to the effect [26].

In contrast to Messe and Geer’s findings, in a small group of women who were coitally orgasmic in less than 30 % of intercourse events, Kegel exercises compared to a waiting list control group and an attention control group did increase pubococcygeus strength [27], but did not show differential improvement on coital orgasmic frequency at posttest compared to the control groups. In a similar study, women with orgasm difficulties were hypothesized be more likely to become orgasmic by practicing exercises to strengthen the pelvic floor muscles over a 12-week period than women practicing relaxation exercises or than women in an attention control group [28]. Results indicated, however, that there was no difference in orgasmic outcome for the three groups during the experimental period. Finally, a recent study in 32 sexually active postmenopausal women who all had the ability to contract their pelvic floor muscles tested the hypothesis that 3 months of physical exercise including pelvic floor muscle training under biweekly guidance of a physiotherapist, and exercises performed at home three times a week, would enhance sexual function [29]. Even though pelvic floor muscle strength was significantly enhanced at posttest, this study found no effect on sexual function.

The majority of studies discussed above investigated the involvement of pelvic floor musculature in sexual arousal and orgasm in individuals of whom pelvic floor status was not reported. Given that these were generally small studies aimed at studying underlying mechanisms of arousal and orgasm, chances are that most participants did not have pelvic floor dysfunction. We conclude that, contrary to the promising findings of the early studies and contrary to common opinion, women who do not have a low-tone pelvic floor and who seek to enhance sexual arousal and more frequent orgasms have not much to gain from pelvic floor muscle training. Actually, a relaxed pelvic floor and mindful attention to sexual stimuli and bodily sensations seem a more effective means of enhancing sexual arousal and orgasm [30].

Studies on the prevalence of sexual dysfunction among women with pelvic floor dysfunction, compared with women without such dysfunctions, have been contradictory. In several studies, sexual dysfunction was found in women with urinary incontinence and/or pelvic organ prolapse [31–37]. A large prospective study in women scheduled to undergo hysterectomy for a benign gynecological disorder investigated the relationship between sexual dysfunction and pelvic floor complaints. Of the entire sample, 495 women (38 %) had pelvic floor disorders. Compared to the women without pelvic floor symptoms, sexually active women with pelvic floor disorders were more likely to report reduced or absent sexual desire, sexual arousal problems (vaginal dryness), painful intercourse, decreased rates of orgasm occurrence and intensity, and decreased overall sexual satisfaction [34]. In another study, impaired sexual arousal was significantly associated with lower urinary tract symptoms (LUTS) in women, with 40–46 % of women with LUTS suffering from at least one sexual impairment [37]. However, other studies did not find differences in sexual function among women with or without pelvic floor dysfunction [38–40]. These differential findings may be related to age and partner status, but also to the nature of the pelvic floor dysfunction. In many studies in women with urinary incontinence or prolapse, it is unknown whether these women have a “low-tone” or “high-tone” pelvic floor dysfunction. Although a low-tone pelvic floor may be more prevalent in women with pelvic organ prolapse, many women with urinary incontinence, particularly urge incontinence, have an overactive pelvic floor [16] likely due to sustained contraction as a measure to prevent leakage. Sexual problems may differ depending on the type of pelvic floor dysfunction.

Fortunately, in a recent study [18], 85 mainly premenopausal consecutive patients referred to a physical therapy private practice were divided in a high and low pelvic floor tone group based on presented symptoms [17]. In this study, the majority of women (82.3 %) presented symptoms related to pelvic floor overactivity, and only 6 % reported non-dysfunctional sexual activity. Vulvodynia was the most common complaint (54 %). Results showed that age was significantly related to sexual function, such that women in the middle age group reported better sexual function than younger (<30 years) and older (>50 years) women. In addition, women with low-tone pelvic floor muscles had higher sexual function scores than women with pelvic floor overactivity. Women with a low-tone pelvic floor had lower FSFI sexual pain scores.

There is Level 1, Grade A evidence that pelvic floor muscle training is effective in treating stress urinary incontinence (for a recent review, see [41]). Nevertheless, there is a lack of randomized controlled trials addressing the effect of pelvic floor physiotherapy on sexual dysfunction. This is not surprising, given that most trials treating (mixed) pelvic floor disorders are aimed at enhancing pelvic floor muscle tone, whereas sexual problems are likely often, if not mostly, related to pelvic floor overactivity [18].

In all, the findings in women with pelvic floor dysfunction seem to add to the earlier conclusion that a relaxed or low-tone pelvic floor is associated with better sexual function. Clearly, that involuntary and rhythmic smooth muscle pelvic floor contractions contribute to the peak sensation of pleasure during orgasm does not imply that sexual arousal and orgasmic pleasure are enhanced by high tonus of the voluntary, striated muscles of the pelvic floor.

Only a handful of studies directly investigated sexual arousal in women with sexual pain disorders. Using vaginal photoplethysmography, diminished genital and subjective sexual arousal was observed in women with dyspareunia, relative to sexually functional women, during exposure to an erotic film clip depicting intercourse [42]. In a similar study by Brauer and colleagues, these results were not replicated [43]. Women with and without dyspareunia had equally high levels of genital arousal during an oral sex clip and an intercourse clip.

Apparently, genital response in women with dyspareunia is not impaired. Genital response was found to be impaired, however, by fear of pain. In a second study by Brauer and colleagues, diminished genital arousal was observed in a threatening experimental context, which was created by the suggestion that during erotic film viewing the participant could receive a painful stimulus at her ankle [44]. This detrimental effect of fear of pain—not actual pain as the painful stimulus was never delivered—did not only occur in women with dyspareunia, but was equally great in sexually functioning women. The result of this latter study supports Spano and Lamont’s hypothesis that fear of pain results in diminished genital response [45].

Fear of pain may result not only in inhibited sexual arousal but also in increased pelvic floor activity, as part of a defensive reaction. There is accumulating research that supports the idea that the pelvic floor musculature, like other muscle groups, is indirectly innervated by the limbic system and therefore highly reactive to emotional stimuli and states [46, 47]. In line with this, van der Velde and colleagues observed increased pelvic floor EMG in women with and without vaginismus in response to an anxiety provoking film, and suggested that pelvic floor muscles may, involuntarily, contract as part of a defensive response [48].

The few studies that have monitored pelvic floor activity in women with sexual pain disorders using vaginal surface EMG concerned women with dyspareunia diagnosed as provoked vestibulodynia (PVD), as well as women with vaginismus. PVD is the most common form of superficial dyspareunia in premenopausal women and is defined as a sharp/burning pain at the entrance of the vagina in response to vestibular touch or attempted vaginal entry [49, 50]. Vaginismus, described in the DSMIV-TR as recurrent or persistent involuntary spasm of the musculature of the outer third of the vagina interfering with intercourse, may be characterized by high-tone pelvic floor, chronically or in situations of attempted penetration (by any object) [51, 52]. As dyspareunia may be associated with increased pelvic floor muscle tone and most women with vaginismus report pain during attempted penetration, there is considerable overlap between the two diagnoses [53, 54]. Therefore, vaginismus and dyspareunia have been integrated in DSM 5 as genito-pelvic pain/penetration disorder [55]. Studies in women with PVD and/or vaginismus and no-pain controls revealed some evidence for differences in pelvic floor muscle tone or strength; however, these differences are not well established [56]. In women with PVD, an elevated resting EMG and stronger contractile responses to a painful vestibular pressure stimulus have been observed [57, 58]. In contrast, other studies reported lower muscle strength in women with vaginismus or PVD [59, 60].

To avoid difficulties in interpretation between various studies due to differences in specific procedures and equipment, Both and colleagues developed a vaginal probe that enables simultaneous measurement of pelvic floor EMG and vaginal pulse amplitude (VPA) [61]. To investigate the sensitivity of the device for changes in genital blood flow and involuntary changes in pelvic floor activity, VPA and vaginal surface EMG were monitored in 36 women without pelvic floor dysfunction during exposure to sexual and anxiety-evoking film clips. In addition, vaginal surface EMG was monitored during voluntary flick and hold contractions. The device appeared sensitive to changes in vaginal blood flow in response to sexual stimuli and able to pick up small, involuntary changes in pelvic floor activity associated with anxiety. Also, the device was able to record changes in pelvic floor activity during voluntary pelvic floor contractions. Results showed that VPA increased in response to the sexual film, and that EMG values were significantly higher in response to the anxiety-evoking film. Interestingly, higher EMG values in response to the sexual film were associated with lower VPA. This observation provides the first empirical support for the hypothesis that increased pelvic muscle activity may be associated with reduced blood flow to the vagina during sexual stimulation [4, 62]. According to that hypothesis, in women with PVD the combination of increased pelvic floor muscle activity and lack of lubrication during intercourse results in friction between penis and vulvar skin, resulting in pain and possibly in tissue damage or irritation of the skin. Or, beside s making vaginal entry more difficult, increased pelvic muscle activity may result in muscle pain, reduced blood flow to the vulva and vagina, and consequently, as a result of fear of pain, in reduced lubrication.

Very relevant when it comes to understanding its role in sexual functioning, is the fact that the pelvic floor is involved in emotional processing . In cases of actual or imminent physical or mental pain, the pelvic floor muscles will involuntarily, and often unconsciously, contract. In a number of psychophysiological studies in which pelvic floor muscle tone was measured using EMG, exposure to threatening film excerpts resulted in a significant increase in pelvic floor muscle activity relative to neutral film exposure, both in women with [47, 63] and without sexual pain problems [63]. Pelvic floor activity in each of these studies was not only significantly enhanced during sexually threatening film excerpts, but also during anxiety-evoking film clips without sexual content. During a film clip with consensual sexual content, pelvic floor activity was not enhanced. In one of these studies, activity in the shoulder muscles (trapezius muscle) was measured concurrently and was also significantly enhanced during exposure to the anxiety-evoking and sexually threatening film excerpts. This suggests that pelvic floor overactivity in threatening situations should be regarded as part of a general defense mechanism [47]. For women who had been sexually abused in the past, the pattern of activity in the pelvic floor was different than for women without such experiences. For them, pelvic floor muscle activity was highest during the sexually threatening film clip and the film clip with consensual sexual content, whereas the women without such experiences had strongest pelvic floor muscle activity during the anxiety-evoking film clip and lowest levels of pelvic floor activity during the consensual sex clip [63]. Reported emotional experience after film exposure concurred with these findings. Women with negative sexual experiences reported significantly greater feelings of threat and lower levels of sexual arousal during the consensual sex clip than women without such experiences. Apparently, for women with sexual abuse experiences even consensual sexual situations can be experienced as threatening and generate a protective pelvic floor response. In support with these findings, Yehuda, Lehrner, and Rosenbaum have recently suggested that sexual difficulties in individuals with posttraumatic stress disorder (PTSD) occur because the hormonal and neural circuit activation that normally leads to positively valenced sexual arousal and activity is already overactive in PTSD, possibly through reduced anterior cingulated activity, but leads to anxiety, fear, and other PTSD symptoms, such that sexual arousal signals impending threat rather than pleasure [64].

It is therefore highly likely that chronically enhanced pelvic floor activity is more prevalent in women with negative sexual experiences such as rape or incest. A systematic literature search of electronic databases from January 1980 to December 2008 found significant associations between sexual abuse and chronic pelvic pain (OR, 2.73) [12]. When the definition of abuse was restricted to rape, the OR for chronic pelvic pain increased (3.27). A prospective study in 89 women with chronic pelvic pain who were individually assessed by all members of a multidisciplinary team showed that irritable bowel syndrome, pelvic floor overactivity, and physical or sexual abuse were the most common diagnosed etiologies [65]. Another study found the effect between documented childhood victimization and pain in adulthood to be moderated by the presence of PTSD in adulthood, such that only individuals who had experienced childhood abuse/neglect and who had PTSD in adulthood were at significantly increased risk for adult pain [66]. PTSD has been found to be a major mediator in the relationship between the experience of rape and adverse health outcomes [67] and a direct predictor of sexual problems ([68, 69] and see [64], for a review). Hypothetically, therefore, PTSD (as an anxiety disorder) may manifest itself in an overactive pelvic floor, as part of a generalized protective defense mechanism, which in turn might act as a mediator in the relation between rape and sexual problems [47].

In an attempt to find empirical support for the involvement of PTSD in the relationship between pelvic floor overactivity and sexual function in women, in a recent study 89 young Dutch women aged 18–25 years who had been victimized by rape in adolescence were compared with 114 non-victimized controls with respect to sexual and pelvic floor complaints [70]. The rape victims had been successfully treated for PTSD. Three years posttreatment, the rape victims were still 2.7 times more likely to have pelvic floor dysfunction (symptoms of PVD, general stress, lower urinary tract, and irritable bowel syndrome) and 2.4 times more likely to have a sexual dysfunction (sexual arousal difficulties and sexual pain) than non-victimized controls. The relationship between rape and sexual problems was partially mediated by the presence of pelvic floor problems. These findings suggest that rape negatively affects the sexual arousal response, enhancing the likelihood of sexual pain, and that this effect is greater in women who also have pelvic floor overactivity.

Characteristically, women with dyspareunia do not cease sexual activity that is painful for them. They ignore the primary function of pain as signaling damage to the body [4]. While intercourse frequency of women with dyspareunia is lower than that of women without sexual pain [71], not engaging in sexual intercourse is, by definition, not a behavioral choice that women with dyspareunia make [72, 73]. The wish to be “normal” seems to be an important underlying mechanism [74]. In heterosexual partnered sex, many women forego their own needs for fear of the negative impact this might have on the male partner’s ego [75]. A very recent study found that women with dyspareunia exhibited more mate-guarding and duty/pressure motives for engaging in intercourse and had more maladaptive penetration-related beliefs than women without sexual pain. The factor that best predicted continuation of painful intercourse (attempts) was the partner’s negative response to pain [76]. Many women with vaginismus, in contrast, avoid any form of vaginal penetration because of negative cognitions and expectations about vaginal penetration. As a consequence, anxiety-inducing penetration-related thoughts cannot be disconfirmed, and thereby maintain the condition [77–79].

In recent years, attachment processes and attachment styles are increasingly acknowledged as important determinants of sexual problems in intimate relationships [80, 81]. Secure attachment, associated with positive beliefs about oneself of being worthy of love, follows from repeated interactions with an available attachment figure that is reliable and supportive. However, when the attachment figure is unavailable and unresponsive, negative beliefs about the self or the other develop, which is characteristic of insecure attachment [82]. From an attachment perspective, securely attached individuals’ beliefs about self and others and their effective emotion regulation strategies allow them to approach sexuality in a relaxed state of mind such that they can enjoy sex for the pleasures involved (for an excellent overview of the interplay between sex and attachment see [82]). In contrast, insecurely attached individuals may use sex to fulfill their attachment needs, leading to sexual experiences tarnished with anxiety, making it difficult to relax and enjoy sex [81]. There is growing evidence that attachment style is related to sexual pain. For instance, Granot and colleagues found that women with dyspareunia were more likely to be insecurely attached [83].