This is a guest post from Dr. Erika’s husband, Jason Krumbeck, DPT.  Jason is a physical therapist in Missoula who specializes in neurological rehabilitation.  Thanks to his wife he also knows a thing or two about back pain in pregnancy…

Humans are great. We have two legs instead of four. That really helps to run long distances efficiently and let’s us use our hands for interacting with the world, but it also means we’re not as stable as other creatures. Four-legged creatures have the benefit of distributing weight over four limbs, whereas humans transfer weight directly through the low back onto the legs.This is why the low back has a tendency to give out in even the healthiest person. Repetitive strain, or just one big awkward movement can cause the vertebral joints to move too much resulting in a variety of injuries. This can include muscle spasms (which is usually a protective mechanism to stabilize the joint), strains, sprains, disc injuries, pinched nerves, and even a fracture known as a spondylolisthesis. These injuries can cause local pain, pain traveling down the leg, numbness, tingling, or weakness.So what happens when you take a body part already prone to injury and add all the considerations of pregnancy to it? Well, to put it very simply, it is much easier to injure. Let’s just look at three factors in no particular order that can make injury more likely:

1. Increased weight in the abdomen. This shifts the center of gravity forward and puts a lot of force across the low back. Now imagine all the awkward ways in which you pick things up and move with this extra mass. It makes it that much harder to stabilize the low back effectively.
2. Relaxin. It’s a hormone produced a lot during pregnancy that has multiple effects in the body. It helps relax ligaments to make the pelvis open up allowing delivery. This relaxation of ligaments happens early in pregnancy and persists throughout. Ligaments are bands of connective tissue that connect bones to other bones; they provide stability to joints. So while you want to relax the pelvic ligaments, it does affect those in the rest of the body. For example, the sacroiliac joint connecting the pelvis to the low back can become quite loose.  In a pregnant woman this loosening can cause the joint to slide out of place, causing significant pain. (By the way, pain that doesn’t travel below the knee is usually sacroiliac pain, and NOT sciatica).  Belts that help keep the joint from moving can be useful. Regardless, relaxin predisposes women to having more injuries.
3. Core weakness. We use our abdominal muscles (rectus abdominus, internal oblique, external oblique, and transversus abdominus) to help stabilize the back. There is even a theory that activating transversus abdominus causes some of the muscles between the vertebrae in the low back called multifidi to contract and stabilize. Well…when the abdomen stretches out and makes room for the baby, these muscles get very weak. This means that on top of the changed mechanics from the new weight and the loose ligaments, now you lack the muscle stability to keep things in order.

1. First, exercise. If you haven’t exercised before pregnancy, be sure to start slowly. Keeping your muscles active and strong is incredibly important. Squats with good form can be a very good exercise (and a great prep for labor), while squats with bad form can be a catastrophically bad idea for your back. It is important if you don’t know what you are doing with exercises to make sure you are doing them safe. Consulting your doctor, physical therapist, or personal trainer is not a bad idea if you are unsure. Also, if you want to be a warrior mom and run a marathon or climb Mt. Everest when you’re 9 months pregnant…don’t. Maybe setting a goal like running a 5k can be fine, but unless you are already a high level athlete, it’s just not worth it to try to start doing crazy stuff you weren’t doing before. Do walk a lot though.
2. Second, watch your posture. As I said before repetitive stresses are a big cause of injury. Repetitive stress can include sitting in a slouched position. Picture a metal paperclip. If you just slowly and gently bend it from one spot that spot is going to get easier and easier to bend. If you stretch out the ligaments in your low back from slouching, those just get looser and looser. Then when you really need them, they won’t be there to protect you from injury. Posture at all times is huge. The same thing goes for letting your back arch too much due to the weight in your belly. You want your back to stay centered and not at end ranges. If you drive a lot, it’s important to actually adjust your car’s seat to support your back. If you work in an office, adjust your chair.
3. Third, body mechanics. Remember BLT. Bending/lifting/twisting. If you really want to injure your back (!) bend from the back, twist, and then abruptly pick up something heavy. (Please don’t.) It puts absolutely absurd pressures on your interverterbal discs. Even if you aren’t picking up anything, the position alone greatly increases your chance of injury. Lifitng from a deep squat (with good mechanics of course) while maintaining the normal curves of your spine is pretty much the safest way to lift. It’s also great exercise. If you happen to have a young child, watch them pick something up. 1 year olds will just do a perfect squat and can sit there for minutes. It is beautiful body mechanics. It’s ideal. As children get older they learn our awful habits. Ask a 3 year old and they will likely not pick things up quite as well. Ask a five year old and there’s a chance they’ll just bend from the back. By 10 most kids have learned to lift poorly from watching us for years. So start lifting right now! It’s great exercise too.
4. Fourth and finally, stretch your hips out. When you are walking or running, we need to get our legs behind us. If you have tight hip muscles, the movement often comes from the low back. So learning how to stretch your hips correctly can take some strain off the low back. Hold stretches 30-60 seconds and don’t bounce. And now my daughter is crying so that’s all I can write for now.