Rigi10™ Malleable Penile Prosthesis
Also Known As
Levator ani muscles, Pelvic diaphragm, Pelvic floor musculature, Perineal muscles, Pubococcygeus muscles, Pubovisceral muscles, Pelvic floor complex, Pelvic musculature, Levator plate, Pelvic floor support system
Definition
The pelvic floor muscles comprise a complex group of muscles that form a supportive sling or hammock at the base of the pelvis. They span from the pubic bone at the front to the coccyx (tailbone) at the back, and from one sitting bone to the other laterally.1,2 These muscles play a fundamental role in the physiological functioning of all the structures contained within the pelvic cavity.3
Anatomically, the pelvic floor can be divided into four compartments:
- Anterior or urinary (bladder, bladder neck, and urethra)
- Medium or genital (vagina and uterus in women, prostate in men)
- Posterior or anterior (anus, anal canal, sigmoid, and rectum)
- Peritoneal (endopelvic fascia and perineal membrane)3
The pelvic diaphragm consists of the levator ani, formed by several muscles including the coccygeus muscle (ischiococcygien), ileococcygien, pubococcygeus muscles, and the puborectal muscle.3,4 The first three originate from the pectineal line of the pubic bone and from the fascia of the obturator muscle, extending to the coccyx through the ischiatic spine, the ileum and sacrum, and the triangular ligament (urogenital diaphragm). The puborectal muscle involves the lower middle portion of the pubic branch.3
Approximately two-thirds of the contractile fibers of these muscles are red aerobic or type 1 fibers, while the remainder consists of anaerobic white fibers or type 2. These muscles function as a single unit and work in all planes in a functional and anatomical three-dimensional manner.3
The pelvic floor muscles serve two major functions:
- They provide support or act as a “floor” for the abdominal viscera including the rectum
- They serve as a constrictor or continence mechanism to the urethral, anal, and vaginal orifices4
At rest, the pelvic floor maintains a cupuliform shape resembling the respiratory diaphragm. During contraction, the pelvic floor ascends anterosuperiorly (toward the pubis), and during relaxation, it moves in a posteroinferior direction (toward the sacral bone and the ischium) with a displacement of about 3 cm.3 This coordinated movement is essential for optimal visceral function, including urination, defecation, and sexual activity.
The pelvic floor muscles also play a crucial role in postural control, working in conjunction with the respiratory diaphragm and abdominal muscles to maintain stability of the thoracolumbar and lumbosacral spine during movement and activities such as coughing and sneezing.3 There is myofascial continuity among these muscular districts, creating an integrated system that distributes loads throughout the body.
Innervation of the pelvic floor muscles is complex, involving both the autonomic and somatic nervous systems. The superior hypogastric plexus (sympathetic), the pelvic splanchnic nerves, the inferior hypogastric (pelvic) plexus, and the pudendal nerve all contribute to the neural control of these muscles.3,5 This dual innervation allows for both voluntary and involuntary control of the pelvic floor.
Dysfunction of the pelvic floor muscles can lead to various clinical conditions, including urinary incontinence, fecal incontinence, pelvic organ prolapse, and chronic pelvic pain syndromes.3,6 These disorders are estimated to affect a significant portion of the population and are projected to increase by 35% over the next two decades.3
Clinical Context
The pelvic floor muscles play a critical role in multiple physiological functions and are implicated in various clinical conditions when dysfunction occurs. Understanding the clinical context of these muscles is essential for both prevention and treatment of pelvic floor disorders.
Normal Function and Clinical Relevance
The pelvic floor muscles provide essential support to the pelvic organs and contribute to urinary and fecal continence mechanisms.1,3 During normal function, these muscles maintain a baseline tone at rest and can contract voluntarily to enhance support and continence during activities that increase intra-abdominal pressure, such as coughing, sneezing, or lifting.3,5
The pelvic floor also works in coordination with the respiratory diaphragm and abdominal muscles to maintain postural stability.3 This coordinated action is crucial for distributing loads from the trunk and upper limbs to the lower limbs during walking and standing.3
Patient Selection and Assessment
Clinical assessment of the pelvic floor muscles typically involves:
- Digital palpation to assess muscle tone, strength, and coordination
- Surface or internal electromyography (EMG) to measure electrical activity
- Dynamometry to measure muscle strength
- Manometry to assess pressure generation
- Ultrasound or MRI for structural assessment6
These assessment methods help clinicians determine appropriate interventions based on the specific dysfunction identified.
Pelvic Floor Disorders
A deficiency in pelvic floor muscle tension or electrical abnormality can lead to various disorders, including:
Urinary Incontinence
Stress urinary incontinence (SUI), the most common form of incontinence, affects approximately 26% of women between 30 and 59 years of age, with peak prevalence at 40-49 years.3 SUI occurs when increased pressure inside the pelvic cavity exceeds the muscular control ability during activities like coughing or sneezing.3 In men, SUI is primarily related to previous surgical prostatectomy.3
Pelvic Organ Prolapse
Weakness of the pelvic floor muscles can lead to prolapse of pelvic organs, affecting 30-50% of women.3 This condition can cause urinary and rectal problems, as well as sexual dysfunction.3 The prolapse may involve the anterior compartment (cystocele), central compartment (uterine or vaginal vault prolapse), or posterior compartment (rectocele).3
Fecal Incontinence and Constipation
Pelvic floor dysfunction can contribute to fecal incontinence and constipation, which affects approximately 27% of the population, especially women.3 Constipation related to pelvic floor dysfunction may be due to paradoxical contraction of the musculature, general muscular weakness, or incomplete relaxation after contraction.3
Pelvic Pain Syndromes
Myofascial pelvic pain (MPP) affects approximately 14-23% of women and is characterized by painful muscle dysfunction, including spasm, trigger points, or hypotonia.3 This pain can present as a single symptom or as part of a complex of urological, gynecological, and colorectal symptoms.3
Treatment Approaches
Treatment of pelvic floor muscle dysfunction typically includes:
Conservative Management
- Pelvic floor muscle training (PFMT) to improve strength, endurance, and coordination5,6
- Biofeedback to enhance awareness and control of muscle function
- Electrical stimulation to improve muscle recruitment and reduce pain
- Manual therapy techniques to address myofascial restrictions and trigger points
Surgical Interventions
Surgical approaches may be considered for severe cases of pelvic organ prolapse or stress urinary incontinence when conservative measures have failed.3
Multidisciplinary Approach
Due to the complex nature of pelvic floor disorders, a multidisciplinary approach involving urogynecologists, colorectal surgeons, urologists, physical therapists, and pain specialists is often recommended for optimal outcomes.4,6
Preventive Strategies
Preventive strategies for pelvic floor dysfunction include:
- Maintaining appropriate weight to reduce pressure on pelvic structures3
- Proper body mechanics during lifting and daily activities
- Regular pelvic floor exercises, especially during and after pregnancy
- Avoiding chronic constipation and straining during bowel movements
- Early intervention for symptoms of pelvic floor dysfunction
The prevalence of pelvic floor muscle disorders is projected to increase by 35% over the next two decades, highlighting the importance of both preventive measures and effective treatment strategies.3