Pregnancy is an amazing experience that some women are blessed to experience. However, research shows that the majority of women will suffer some pain or discomfort during pregnancy. The incidence of low back pain in pregnancy is stated at between 50% and 66% (1,2,3,4)
Many women are aware of the hormonal changes of pregnancy and common symptoms such as morning sickness this may cause. However understanding the mechanics of how the body adapts is usually less understood.
Physical changes start early in pregnancy. In the first 12-16 weeks the uterus becomes more upright. (A non pregnant uterus is normally angled forward over the bladder). As the uterus straightens ligaments that support the uterus (round ligament and broad ligament) move and adjust. Restrictions or adhesions in these ligaments may cause pain, often felt as a deep burning pain. Previous infections, surgery or ovarian cysts may be causes of adhesions of the ligaments. After 16 weeks, the growth of the uterus is from expansion of the top of the uterus and the ligament pain described is less likely to start.
As the pregnancy progresses the uterus moves up into the abdominal cavity pushing the abdominal organs (intestines, liver, kidneys) up and out to the side. To help compensate for this, the diaphragm is pushed up and the rib cage widens. At this time women may experience mid back pain or rib pain. Often asymptomatic restrictions in the thoracic cage restrict the body’s ability to adapt to the physical changes required and symptoms may start.
The increasing weight of the growing baby creates a shift in the body’s centre of gravity. The belly extends forward and the this is compensated for by an increase in spinal curves. Whilst the abdominal muscles are being stretched they are still important in helping support the back. Poor muscle tone (especially with subsequent pregnancies) can lead to increased compression through the low back and contribute to low back pain.
Alternatively a woman may compensate for the increased weight by standing with her feet turned out (giving the waddle of pregnancy). In this way she tightens her buttock muscles to help stabilise her back. However, by doing this she restricts the movement of her sacrum and increases pressure on her low back, especially when she wants to bend. As well, once labour starts her sacrum will be less mobile.
The increase in spinal curves and increasing breast size can lead to rolling forward of the shoulders and an increase in strain at the base of the skull. This may aggravate headaches (especially if the woman has been susceptible to headaches in the past) or lead to fluid congestion in the arms and symptoms such as carpal tunnel syndrome. This is because the drainage from the arms is affected by the position of the thoracic inlet area - scapula(shoulder blade), clavicle (collar bone) upper ribs and associated muscles.
One of the most common complaints of pregnancy is low back pain and pelvic pain. Along with the issues described above the pelvis can be put under increased stress from restrictions in the thoracic cage, lumbar spine or sacroiliac joints. If the diaphragm and thoracic cage are not able to widen and accommodate the growing baby, then increased pressure can be exerted back down into the pelvis. This increased pressure on the pelvis, including the pubic symphysis and contribute to conditions such as symphysis pubis dysfunction (SPD) that some women experience. Along with this, underlying asymptomatic restrictions in the lumbar spine and pelvis can limit the body’s ability to adjust to the growing baby and create symptoms later in pregnancy.
It is not only during the pregnancy that body needs to be mobile and able to adapt. The labour and delivery of the baby requires good mobility through the pelvis as well.
As the baby enters the pelvis (engages) the pelvis must outflare, that is the top of the pelvis (iliac crests) roll out and the base of the pelvis (pubic rami) move in. This creates more space for the baby to move into the pelvis. This movement involves movement of the pelvic bones around the hips. As the baby descends into the pelvis the head is guided to the midline position by the deep pelvic muscles, in preparation for delivery.
For the birth of the baby, the pelvis inflares, that is it gets wider at the base and narrower at the top. Along with this, the sacrum and coccyx move down and backward. Restrictions of the movement of the joints can reduce the amount of space created for the birth of the baby.
Hurray the baby is born! However, the body still has lot of work to do. The physical changes of pregnancy took place gradually over 9 months. Post partum the body has a sudden change of forces. Whilst pregnant, the baby does offer some support for the spine as it is taking up space and restricting the spine collapsing. After delivery, the abdominals have been stretched and there is no baby to help hold up the spine, Along with this, the increased breast size and weight and time spent holding and looking at the baby, lead to increased compression through the spine. It is common for women to experience back, neck and shoulder pain during this time, As well, women may also experience pelvic or coccyx pain as a result of the delivery or from prior issues that have not resolved.
Osteopathic treatment during pregnancy or the post partum period may help ease the aches and pains you are experiencing. Treatment aims to address any restrictions in the tissues of the body that may be contributing to your pain or limiting your body's ability to adapt to the pregnancy. Stretches or other exercises may be given to help improve your symptoms. In some cases supports may be recommended to manage hypermobile joints (joints that move too much) related to the hormones of pregnancy.
(1) Intervention for preventing and treating pelvic and back pain in pregnancy. Pennick V, Liddle SD. Publichsed in Crochrane Database Syst Rev. 2013 Aug 1;8:CD001139.doi:10.1002/14651858.CD001139.pub.3.
(2)Andersson, GB. Haagstad, A. Jansson, PO.Svensson, HO. The relationship of low-back pain to pregnancy and gynaecological factors. Spine August 1990.
(3) Colliton, J. Managing Back Pain During Pregnancy. MedGenMed. 1(2), 1999.
(4) Galleher, C. Functional Changes in Back Muscle Activity Correlate With Pain Intensity and Prediction of Low Back Pain During Pregnancy. (Statistical Data Included). Physical Therapy. July 1999 v79 i7 p711.
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