Where is the Symphysis Pubis?

The pelvic girdle is made up of three large bones, the Sacrum (base of the spine) and two large isometric bones which form a joint at the front, the Symphysis Pubis, and join with the Sacrum at the back, at the Sacro-iliac joints.  The Coccyx or tailbone is attached to the Sacrum.  Separation of the Symphysis Pubis is known as Diastasis Symphysis Pubis but there can be other causes of Symphysis Pubis pain during pregnancy and after the baby is born.

The difference between DSP & SPD

There is understandable confusion about the meaning of the two terms. The symptoms are the same so what is the difference?

DSP (Diastasis Symphysis Pubis) means an abnormally wide gap between the two pubic bones at the symphysis pubis joint situated at the front of the pelvis. It can only be diagnosed conclusively by investigation such as x-ray, ultrasound or MRI scan. The non-pregnant gap is 4-5mm but in every pregnancy there will be an increase of at least 2-3mm due to the fact that ligaments which ‘tie’ the joint become slightly slacker under the influence of the pregnancy hormones. Therefore, it is considered that a total width of up to 9mm between the two bones is normal for a pregnant woman. Following delivery, this natural extra gapping decreases within days although the supporting ligaments will take three to five months to fully return to their normal state to make the symphysis pubis a strong joint again. An abnormal gap is considered to be 1cm or more, sometimes with the two bones being slightly out of alignment, and remains evident after the time that the joint should have regained the normal non-pregnant width.

SPD (Symphysis Pubis Dysfunction) simply means that the joint is apparently not working, as it should be. Together with the two sacroiliac joints at the back of the pelvis, the symphysis pubis plays an important part in holding the pelvis absolutely steady during any activity, in any position, which involves the legs. If the joint is not firmly ‘tied’ by all its ligaments it cannot effectively perform its role and excessive strain is placed on all the pelvic joints giving rise to the all too familiar painful symptoms. It is important to remember that the sacroiliac joints are equally affected by the hormones of pregnancy and become slightly looser. It is very common to find that although a woman might be complaining of groin and pubic pain, the main cause of the symptoms is actually at one or both of the sacroiliac joints and this puts extra stress on the symphysis.

In other words the term SPD is flagging up the fact that the pelvic girdle is not functioning correctly and, unless an abnormal gap is definitely shown at the symphysis pubis, the condition will be termed SPD.

(Taken from:  http://www.spd-uk.org/dspspd.htm)