Medicine does love a TLA (three letter abbreviation). Pelvic Girdle Pain (PGP) is a fairly new term used for antenatal backpain which encompasses the traditional SPD (symphysis pubis dysfunction) but allows for the understanding that the pelvis is a ring made from 3 separate bones with problems able to originate in one place but be felt in another. That “pain is an unreliable witness” statement again.
A common complaint is to find that after sitting down for a while, quite fine, your first few steps on standing are agony, then you are ok again. This is usually a problem with one or both sacroiliac joints (SIJ if you want the TLA). Loose and open when sitting, they struggle to connect quickly as you stand and the brain tries to stop you taking weight through them by giving you pain.Physiotherapy treatment aims to use connective tissue massage (also know as fascial release) to change the imbalance, manual therapy to align the joints and then exercise to strengthen your ability to hold this position unaided. Sometimes support belts are needed until your muscles have a chance to develop.