There are a number of reasons you can develop back pain during pregnancy. "It's a multifactorial issue," Dr. Peters says. "Hormonal alterations in soft tissue and even bone tissue play a part, along with changes in weight, spinal alignment, and activity level."
The hormones that are released during pregnancy allow joints and ligaments in the pelvic area to become more pliant and loose, in preparation for the birthing process, Dr. Peters explains. The downside of this softening is that it can affect the natural support your back normally receives, particularly as the weight of your baby increases.
A growing baby also causes your center of gravity to shift. Abdominal muscles stretch and weaken, making it more difficult to maintain good posture and further challenging your natural spinal alignment. "In the third trimester, for example, the forward flexion of the hips brings the pelvis and sacrum forward as well, contributing to a 'swayback' effect in the lumbar spine," Dr. Peters says. "Increasing breast tissue can also accentuate this shift in spinal realignment. Some of these tissue and mechanical alignment alterations are good for the body, in order to distribute weight gain to the middle of the body where, structurally, it's the strongest. But in a woman whose structure is weak where stress is magnified, low back pain can be the result."
Common patterns of pregnancy-related back pain include pain in the lower back, or lumbar spine, and pain that feels like it's centered even lower in the body, in the back, or posterior, of the pelvic area. If pressure is placed on the sciatic nerve or presses on a spinal disc, pain may extend through the hips, buttocks and legs.
參考資料 : http://www.back.com/
The
information aims to provide educational purpose only. Anyone reading it should
consult neurosurgeon before
considering treatment and should not rely on the information above.