n Perineal body and perineum (the “body” is part of the perineum) n Levator ani: pubococcygeus (pubovaginalis, puborectalis, puboanalis) and iliococcygeus n Ischiococcygeus n External anal sphincter n Superficial pelvic floor muscles n Nerves n Blood vessels. The main structures of the female pelvic floor are illustrated in Figure 1.

Muscle fibre types

The pelvic floor muscles are striated and contain two different types of fibre (4): n About 70% are type I (slow oxidative endurance fibres). n About 30% are type II (fast glycolytic power fibres). To function well, the pelvic floor muscle needs to have the right balance of both types of fibre. It is important to bear this in mind when planning training regimens for the pelvic floor.

ROLE OF THE PELVIC FLOOR MUSCLES In support The main role of the pelvic floor muscles is to support the contents of the pelvis – namely the bladder, the uterus and the bowel in women, and the bladder and the bowel in men. If this supportive function is damaged in a woman, then these organs can push down in the pelvis and bulge against the walls of the vagina. This is called a prolapse. Normally it is not a problem, but a mild degree of prolapse occurs in around 40% of women who give birth vaginally. If the muscles are not strengthened after delivery, over time the small bulge can increase in size and begin to cause symptoms. The woman may experience difficulty inserting a tampon, or discomfort during intercourse or a heavy dragging sensation after physical activity. Further failure to strengthen the muscles means the bulge gets larger still, eventually becoming very uncomfortable and possibly causing problems with the bladder or bowel, preventing them from emptying correctly. Often by this stage the only option is surgical repair.

In sexual function The superficial layer of pelvic floor muscles is thought to have an important role in sexual function. In women it encircles the vagina and the muscles also insert into the base of the clitoris, allowing for effective stimulation during penetrative intercourse. In males the pelvic floor muscles have been shown to be effective in improving and maintaining an erection (5).

In bladder and bowel control

The pelvic floor muscles also help to control the bladder and bowel and prevent the accidental loss of urine or faeces. The most common type of leakage in women is of urine, when the pressure in the abdomen increases during coughing, sneezing, exercising or laughing. This is called “urinary stress incontinence”. The pelvic floor muscles also help control how often the bladder empties. As the bladder fills, it signals when it needs to be emptied – a healthy pelvic floor makes it possible to “hold on” until it is convenient to go to the toilet. With a weakened pelvic floor, the message to empty the

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Deep transverse perineal muscle

Levator ani: pubococcygeus

Piriformis Obturator

fascia

Levator ani: iliococcygeus

Coccygeus External anal

sphincter

bladder cannot be ignored and emptying must follow quickly. This is called “bladder urgency”. “Urgency incontinence” is experienced by people who are unable to “hold on” at all, so there is leakage of urine before they reach a toilet. Some women can experience both urinary stress incontinence and urgency incontinence, which is called “mixed incontinence”. The posterior pelvic floor muscles contribute to bowel

control, preventing the accidental loss of wind, liquid or formed stools. Usually these posterior pelvic floor muscles work at a subconscious level and we are only really aware of them when we have an upset bowel. For example, with a “holiday tummy” we are very aware about holding on with the anal sphincter muscles to prevent leakage before reaching a toilet.

Pelvic floor muscles and core stability The pelvic floor muscles also form part of a multistructural unit known as the “lumbopelvic cylinder”. This consists of the respiratory diaphragm (above), the transversus abdominus or trans-abs (anteriorly and laterally), and the spinal column supported by segmental attachments of multifidus (posteriorly) (6). The muscles within this unit constantly work at low levels to maintain postural support but they also have to be able to respond when the central nervous system detects an increased load. Based on this knowledge about the close interactions of these muscles, there was a trend during the 1990s for teaching

BOX 1: TYPES OF URINARY INCONTINENCE n Stress incontinence

n Bladder urgency n Urgency incontinence n Mixed incontinence

ESSENTIAL PART OF ANY FITNESS TRAINING PLAN

PELVIC FLOOR MUSCLE FITNESS SHOULD BE CONSIDERED AS AN

sportEX medicine 2010;46(Oct):23-27

Figure 1: Muscles of the female pelvic floor

2010 Primal Pictures

Levator ani: pubo-analis

Levator ani: puborectalis

Peroneal body