The term "pelvic girdle relaxation" is not uniformly used. For better understanding of pelvic joint pain during and after pregnancy it is crucial to have commonly accepted definitions for the different conditions. A committee appointed by the Norwegian Medical Association suggests the term "physiological pelvic girdle relaxation" for the ligament relaxation that occurs during any pregnancy. Ligament relaxation that causes considerable pain and/or pelvic instability during pregnancy and/or puerperium (so that daily function is impaired) is termed "symptom-giving pelvic girdle relaxation". A pain condition in one or more of the pelvic joints outside pregnancy and puerperium is called "pelvic joint syndrome".