Healthy for Two (eBook)

1

Our Pelvis

When anthropologists dig up human skeletons, they generally can determine gender by the width of the pelvis, by the density of the bones, and by the shape of the sacrum. Our tailbones (sacrum) are shorter and wider than our male counterparts, and our bones are thinner. Our pelvis is designed to afford the flexibility of allowing a baby, with exponentially larger baby head to vaginal opening ratio, to deliver seamlessly.

Hormones secreted throughout our pregnancy help ligamentous connections relax allowing for this to happen. It is believed that with the rise of certain hormones, mainly progesterone, estrogen, and relaxin during the second trimester, joint laxity occurs. However, not all studies are in agreement with which hormone or what combination of the hormones can cause this effect.1

One interesting study measured the amount of ligament laxity in a major knee-stabilizing ligament. Measurements of the anterior cruciate ligament were taken by moving the lower leg in relation to the upper leg (tibial translation) during the third trimester of pregnancy. In this study, the levels of estradiol (the prominent estrogen) were measured as well. It was reported that higher levels of estradiol indicated more tibial translation.2 This affirms joint laxity (loosey-goosey joints) will occur with the increases of estrogen production in pregnancy. There is clear agreement in regards to joint laxity in pregnancy, but research at this point is not conclusive as to what is the cause. The joints that are most troublesome to our pregnant patients are in the pelvis, the pubic symphysis, and sacroiliac joints. The joint that connects the two pelvic bones together in the front is known as our pubic bone/ pubic symphysis. The joint in the back of the pelvis that connects the pelvis to the sacrum bone is called the Sacroiliac joints/ SI joints.

The presence of joint laxity is a natural phenomenon that occurs during preparation for childbirth, but may also set the stage for pain and or instability of the pelvis during pregnancy and post-partum. Any joints that contain connective tissue are susceptible to this increase in laxity. We have found in those patients who were very flexible at the onset of pregnancy tend to be more at risk to developing joint pain. Their hypermobile joints may be caused by a history of dance, gymnastics or cheerleading, genetics or by following an intense stretching schedule for their sport or activity throughout their lives.

One of our recent patients was a principal in the Houston Ballet for many years. She was pregnant with her second child and was experiencing pain in her low back and SI joint areas. These pains were not present in her first pregnancy. We find that your joints may still be secure with strong muscles during the first pregnancy. But if a new mom does not strengthen her muscles in between pregnancies, multiple pregnancies may lead to discomfort due to deconditioning and less muscle tone.

Ligaments attach bones to bones. Tendons attach muscles to bones. All joints are surrounded by ligaments. Once the ligaments are stretched out, they rarely recoil to their natural, original position, similarly to silly putty. Once you stretch it out, it won’t stretch back like a rubber band would. We rely on our muscles to maintain the integrity of the joints during pregnancy and afterward. Weak muscles will hinder your joint’s ideal mechanical path.

Imagine a model skeleton being strung tightly together joint by joint with a tough, durable cord and just the right amount of tension to allow appropriate motion at each joint. Continue to picture the skeletal structures and joints receiving further support by being wrapped tightly in cellophane. The tough cords represent the ligaments attaching bone to bone, and the cellophane represents muscles that are toned and strong in a pre-pregnant, fit woman. Once the hormones are released, those tough cords are now represented by elastic bands due to the hormonal effects. Fortunately, if an individual is in shape, they still have the tight cellophane wrap helping to hold the bones in place. This is why it is so important to get into shape prior to and in between multiple pregnancies. A woman without tone or strength in her muscles during pregnancy would be represented by a skeletal structure being held together by elastic bands and surrounded by Jell-O instead of cellophane. This visual concept may help a woman stick to a much-needed workout plan prior to, during and after pregnancy.

We will discuss further exercise guidelines with pregnancy in chapter 6. Most doctors recommend as a general good health guideline, 30 minutes of moderate movement (walking, biking, swimming, or another form of movement) 5 days a week. Additionally, the new American Heart Association guidelines suggest 150 minutes of exercise per week to reduce cardiovascular events such as a stroke or heart attack. This equals to about 30 min 5 days a week. Have we convinced you yet of the importance of strength training and cardiovascular conditioning workouts?

The Hormonal Connection

Hormone levels begin to rise with the onset of pregnancy. Estrogen and progesterone levels increase, keeping menstruation from happening. The placenta produces another hormone called (β-hCG) human chorionic gonadotropin. Along with progesterone and estrogen levels, this hormone helps promote smooth muscles to relax.3 As mentioned previously, after the second trimester, our bodies are flooded with a combination of hormones. These hormones may help relax the pubic symphysis and sacroiliac joints in preparation for childbirth. Relaxin, in particular, will stick around after delivery during breastfeeding. It helps produce the letdown response for milk flow (lactation).

For those women who have hypermobile, flexible joints in combination with deconditioned pelvic and gluteal muscles, this can result in pelvic instability. The joints tend to lock in the low back; the pelvic bones can become misaligned, and/or the sacrum can jam easily. Going off of a step wrong can cause the sacrum (backbone) to displace in relation to the ilium (pelvic bone). Refer to chapter 4 — SI joint problems and Sciatica for self-exercise to correct this imbalance if it should present itself.

The Bonding Hormone

Another hormone worth mentioning is oxytocin. It is present during pregnancy but really floods the body systems at childbirth. Some suggest this hormone is responsible for the strong bond we develop with our babies. It surges through our system during breastfeeding and is also released during orgasm in women. It’s no wonder we become so attached to our mates!

Our Shifting Center of Gravity

As your pregnancy progresses, your center of gravity shifts forward along with your expanding belly, which can cause precarious ambulation. Shoulders tend to round forward allowing for the neck to flatten and the head to protrude. Increased lumbar curvature of the spine may occur with the expanding anterior growth of the belly. Good posture requires strong upper and mid-back muscles that pull our shoulders back. Imagine a string being pulled through the top of your head while keeping the chin down slightly toward the chest. Improved neck posture will reduce the neck and shoulder aches and discomfort. Our abdominals are key in maintaining a strong neutral placement of our lumbar spine. The stomach muscles, when activated and strong, will help to avoid an exaggerated anterior placement of the pelvis. We refer to it as “duck back,” which results in collapsing and promoting increased stress on the lower back vertebra (excessive lordotic posture).

We suggest to our patients to try engaging the lower abdominals by pulling your belly button towards the spine. Next think of dropping the tailbone toward the floor just slightly to create space in the lower back. In this position, the low back will be supported and comfortable. This may seem impossible in the midst of growing with the baby. However, just increased awareness and attempts to activate these muscles throughout the day will help to support the lower back and reduce strain.

The pelvic floor muscles also contribute to a stronger core. If you haven’t been introduced to the Kegel exercise (common name for pelvic floor exercises), being pregnant is the perfect time to start Kegeling. We will discuss proper Kegeling in Chapter 2.

Jackie’s Story

Jackie came into the office with extreme pain in the front of her pelvis. She reported the pain increased with getting up and down from a sitting position. Jackie did not know how to engage her lower stomach muscles to decrease the pressure and stress on her front pubic bone. She learned how to engage her lower stomach muscles prior to sitting or standing to lift the baby weight off her front pelvic joint. She also practiced a simple modified supported squat at the wall with lower abdominal activation. She reported that her prior complaints had diminished, and no longer had to dread moving or getting up from her chair.

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1 Obstet Gynecol. 2003 Feb;101(2):331-5. Characterization of the relationship between joint laxity and maternal hormones in pregnancy. 1Marnach ML, Ramin KD, Ramsey PS, Song SW, Stensland JJ, An KN. Source Department of Obstetrics and Gynecology, Mayo Clinic, Rochester, Minnesota, USA.

2 Obstet Gynecol. 2003 Feb;101(2):331-5. Characterization of the relationship between joint laxity and maternal hormones in pregnancy. 1Marnach ML, Ramin KD, Ramsey PS, Song SW, Stensland JJ, An KN. Source Department of Obstetrics and Gynecology, Mayo...