Role of ischiocavernosus and bulbocavernosus in male pelvic health

Many therapists transition to treating men with the knowledge and training from female patients. When therapists apply this knowledge, for the most part, it works. When we spend some attention on learning what is a bit different, we might be drawn to the superficial muscles of the perineum. This old anatomy image does a wonderful job of "calling it like it is" or using anatomical terms that describe an action versus naming only the structure. In the image we are looking from below (inferior view) at the perineum and genitals. Just anterior to the anus we can see the anterior muscles within the urogenital triangle, with the base of the shaft of the penis located just anterior to (above in this image) the anus and perineal body. Notice that at the midline, we see muscle names the "accelerator urine". Modern textbooks refer to this muscle as the bulbocavernosus, or bulbospongiosus. Taking the name of accelerator urine, we can understand that this muscle will have an effect on aiding the body in emptying urine. It does this through rhythmic contractions, most often noted towards the end of urination, when the typical spurts of urine follow a more steady stream. This assistance with emptying can take place because the urethra is located within the lower part of the penis, the portion known as the corpus spongiosum. Because the bulbocavernosus muscle covers this part of the penis, and the inferior and lateral parts of the urethra are virtually wrapped within the bulbocavernosus, the muscle can have an effect on emptying the urine in the urethra.

Notice that if you follow the fibers of the accelerator urine muscle towards the top of the image, where the penis continues, you will notice fibers of the muscle wrapping around the sides of the penis. These fibers will continue as a fascial band that travels over the dorsal vessels of the penis. This allows the muscle to also have a significant action during sexual activity, in which blood flow (getting blood into, keeping blood in, and letting blood out of the penis) is paramount.

On either side of the penis we can see what is labeled the erector penis. As these muscles cover the legs, or crura which form the two upper parts of the penis, when the muscles contract, blood is shunted towards the main body of the penis. This of course helps with penile rigidity, as the smooth muscles in the artery walls of the penis allow blood to fill the spongy chambers.

Once we discuss the usual functions of these muscles, we can then imagine the dysfunctions potentially created by less than optimal activity. Consider the difficulty that these muscles will create in contracting or relaxing if they are either too weak, or too tense. These issues can create difficulty emptying well the urethra, often leading to post-void dribble. Blood flow and therefore penile rigidity with erections may be negatively impacted by inability of these muscles to contract or stay contracted, and blood flow leaving the penis may be impaired if the muscles cannot relax. When we work with patients who have genital pain, pelvic floor muscle weakness, dyscoordination, or tension, we can often improve sexual function, bladder emptying, and tasks that might otherwise be affected by pain.

If you are interested in learning more about how to assess and treat these muscles, you have one more opportunity this year to attend the 3-day Male Course instructed by Holly Tanner. Holly has been teaching this course for over 10 years when she co-wrote the first course with colleague and faculty member Stacey Futterman. The course has been updated and turned into a 3-day course to include more manual therapy techniques. Hurry to grab one of the remaining spots in the October 27-29 course in Grand Rapids!