Prevelance:
It is estimated that approximately 50% of pregnant women will experience some kind of low back pain during their pregnancy, or during the postpartum period. Of those that experience low back pain, only about 50% of them will seek advice from a healthcare professional; with only 70% of those women actually receiving treatment.
Causes:
- Mechanical: Weight gain during pregnancy, increased abdominal size, shifting of the center of mass forward; all can increase the stress on the low back. When the abdominal muscles stretch to accommodate the growing uterus, muscle fatigue typically occurs which results in an increased load on the spine. Another common finding is weakness of their gluteus medius, or the outer glute/hip muscle.
- Hormonal: Relaxin is a hormone secreted during pregnancy, and it causes your ligaments to get lax, which in turn can cause your pelvis to become unstable. This includes not only the SIJ (sacroiliac joint), but the entire low back resulting in instability of the pelvis and poor alignment of the spine.
