What is the pubococcygeus muscle

The pubococcygeus muscle (abbreviated PC, from the Latin musculus pubococcygeus) is the thickest and most important component of the levator ani, the main muscle group of the pelvic floor. Its name literally describes its path: it runs from the pubis to the coccyx (tailbone), forming a hammock-like sling that supports the pelvic organs.

It was Dr Arnold Kegel who, in 1948, identified this muscle as the target of pelvic training, publishing the first clinical results in the American Journal of Obstetrics and Gynecology. Eight decades of research have since confirmed its central importance to both male and female health.

You may also see it referred to as the PC muscle, the Kegel muscle or simply as part of the pelvic floor. All these terms generally refer to the pubococcygeus and its surrounding muscle group.

Location and structure

The PC muscle originates on the posterior surface of the pubic symphysis and extends back to the coccyx and anococcygeal ligament. Along its path it surrounds and supports:

  • The urethra — urinary flow control
  • The rectum — bowel continence
  • The vagina in women
  • The prostate and penile root in men

The levator ani, of which the PC is the central part, also includes the puborectalis and iliococcygeus muscles. However, the pubococcygeus is the muscle most directly and effectively activated during standard Kegel exercises.

How to locate your PC muscle

Before starting Kegel training, it is essential to identify the right muscle. Many people inadvertently contract the buttocks, thighs or abdomen — which does not train the PC and can even increase pelvic pressure, worsening symptoms.

Step-by-step: finding your pelvic floor

  1. Imagine stopping mid-stream: Picture yourself stopping the flow of urine mid-urination. The internal squeeze and lift you feel is the PC muscle contracting. (Do not actually practise stopping urine flow regularly — it can disrupt normal bladder reflexes.)
  2. Check for compensation: Place one hand on your lower abdomen and one on your buttocks. Neither should move significantly during a correct Kegel contraction. If they do, you are recruiting the wrong muscles.
  3. Feel the lift, not the push: A correct contraction feels like a gentle upward lift inside the pelvis. If you feel a downward push or bearing-down sensation, reverse the direction.
  4. Breathe normally: Do not hold your breath. Breath-holding creates abdominal pressure that works against pelvic floor engagement.

Once you can reliably isolate the muscle, you are ready to follow a progressive Kegel programme. PrimeFlow Core guides you through this identification process in the first session, then adapts the training load to your individual response session by session.

Main functions of the pubococcygeus muscle

Urinary and bowel control

The PC muscle keeps the external urethral sphincter closed at rest and relaxes when you urinate. When intra-abdominal pressure spikes suddenly — during a cough, sneeze or jump — the PC must contract rapidly to prevent leakage. This emergency closure function depends on the muscle's fast-twitch fibres and is the primary mechanism behind Kegel exercises reducing bladder leakage.

Sexual function

In men, the PC muscle and the adjacent muscles (ischiocavernosus and bulbocavernosus) are directly involved in:

  • Maintaining erectile rigidity by compressing the dorsal penile vein
  • The ejaculatory mechanism
  • Orgasmic contractions
Clinical reference: Dorey G. et al. (2005), BJU International — the first randomised controlled trial demonstrating improvement of erectile dysfunction through pelvic floor training in men, with 40% achieving normal function at 6 months.

In women, the PC muscle actively contributes to vaginal sensation, orgasm intensity and overall pelvic tone. A strong pubococcygeus improves sexual experience and can reduce pain during intercourse (dyspareunia). Its weakening, common after childbirth or during menopause, directly affects quality of sexual life.

Clinical reference: Bo K. et al. (2015), Neurourology and Urodynamics — pelvic floor training significantly improves female sexual function in women with pelvic floor dysfunction.

Pelvic organ support

The PC muscle acts as the structural floor of the pelvis. A weak PC cannot adequately support the weight of the pelvic organs, which can lead to prolapse — the descent of the bladder, uterus or rectum. This is especially relevant in women after childbirth, but also affects older men.

Differences between men and women

The basic anatomy is identical, but there are important functional differences:

In men

Erectile function and post-surgical control

The male PC muscle is more involved in erection and ejaculatory control. Its post-prostatectomy weakening is the leading cause of surgically acquired male urinary incontinence, and the primary target of pre- and post-operative Kegel training.

In women

Childbirth, continence and pelvic health

The female PC muscle is broader, surrounds the vagina and supports the uterus. Vaginal delivery is the main cause of weakening. Kegel exercises are the first-line treatment for post-partum incontinence according to ACOG (American College of Obstetricians and Gynecologists).

Muscle fibre composition

The pelvic floor has a mixed fibre composition that explains why training must combine two exercise types:

  • ~70% type I (slow-twitch) fibres: responsible for continuous postural tone. They keep the urethral sphincter closed at rest. Trained with sustained holds (3–10 seconds).
  • ~30% type II (fast-twitch) fibres: activated during emergency contractions. Key for preventing sudden leaks when coughing or sneezing. Trained with quick pulses (1–2 seconds).

This is the scientific reason why Kegel protocols include two exercise types: slow holds and quick flicks. A programme that only performs one type trains just 70% or 30% of the muscle. That is why PrimeFlow Core integrates both types in every session, in the ratio recommended by clinical studies.

What weakens the pubococcygeus muscle

The PC muscle can weaken through several factors:

  • Ageing: sarcopenia (age-related muscle loss) affects the pelvic floor like any other muscle group.
  • Prostate surgery: radical prostatectomy can damage the nerves and muscles of the pelvic floor.
  • Vaginal childbirth (in women): especially after prolonged or instrumental deliveries.
  • Menopause: the drop in oestrogen reduces pelvic connective tissue collagen and decreases pelvic floor muscle tone, increasing risk of incontinence and sexual discomfort.
  • Obesity: excess body weight increases chronic downward pressure on the pelvic floor.
  • Sedentary lifestyle: lack of physical activity reduces overall core and pelvic floor tone.
  • Chronic cough: repeated abdominal pressure episodes gradually wear down the fast-twitch muscle fibres.

Learn how Kegel training addresses these factors in our complete guide to Kegel exercises for men.