How driving hurts your back: back health and the car seat.

Car seats are made to support the “ideal” body. Unfortunately, the “ideal” body these seats are designed for doesn’t exist.  Depending on your car, you will have multiple adjustments to help customize the fit, but unfortunately, we usually set ourselves up to be comfortable (proof in point: why don’t we all have ergonomic couches if we prefer perfect posture to comfort?), and that comfort is hurting our backs in the long run.

What is most commonly adjusted incorrectly is the “lumbar” support option.  It makes sense that this should fit into our lumbar spine — being that it is the “lumbar support” option — however, this option serves a poor bolster against a slumping spine. Having something against our lower back to keep it in the “correct position” doesn’t mean it actually changes the position, or if it does, that it is for the better. In fact, by having a something hold our back can possibly weaken muscles and cause more compression (read: pain) and more bad posture and pain going forward.

How do you change this? First thing: level out your seat to be as flat as possible. The lumbar spine support should actually be hitting just above your buttocks, at the sacrum (It’s crude, but the most convex portion should hit a couple of inches above your butt crack). You should feel your pelvis slightly tipped forward and it should be harder to round your lower back even if you try. If you cannot level your seating surface, fold up a towel to make it as flat as possible – remember that the towel will flatten when you sit on it for any period of time, so account for that when first making it.

If your seat is declined downward so that the portion under your knees is higher than your butt, two problems arise: First, it increases hip flexion — leading to more shortening of important postural muscles: in any chair your knees should be just lower than your hips. And, second, it encourages a tucking under of the pelvis so you end up sitting on your tailbone and further rounding the lower back.  The lumbar support is supposed to abate this, but if your seat is set to decline, it will work against you instead.

You should be able to sit solidly on top your sit bones, not rest against your lower back. If you don’t know where your sit bones are, sit on your hands and feel for a small round bone in the middle of each buttocks. Your tail bone should hang freely in between these bones, you should NOT be resting much weight on your tailbone. Visualize your tailbone like the tail fin of a fish – it should be able to freely swing at the end of your spine. If you cannot get into a position that allows for the free swing of your tailbone, you are contributing to poor posture and possible pain.

We also forget that driving is really, really stressful. We have become inured to it over years of daily commuting and errand running, but our body still releases stress hormones when we see anything that could possibly hit us or get hit by us – the car that didn’t stop all the way or the one that stopped too suddenly, for example. (Not to mention the red lights when we are running late and that guy doing 40 mph in the fast lane.)

Any time we release stress hormones we are simulating our sympathetic system and causing our muscles to tighten and get ready for “fight or flight” from whatever triggering our stress response, and instead of having a healthy walk or relaxing stretch to diffuse them, we go sit for 8 hours, allowing stress to build and muscles to get tighter. Just the act remembering that driving is stressful, and deeply breathing at a red lights or sitting and relaxing for (literally!) a minute before you rush off to your next appointment goes a long way to keep the stress building.

To summarize:

  • Get your seat as level as possible so the lumbar support is resting closer to your pelvis at the sacrum, not against lower back.
  • Your knees should be lower than your hips, or as low as your car will allow. Prop as necessary.
  • You should be able to easily sit on your sit bones, not behind them or on your tailbone. Play with your adjustments until you can find the combination that allows you to do this best.
  • You shouldn’t feel that the seat has to “hold” your spine upright, get on your sit bones!
  • Relax! Breathing and reducing stress in the car as much as possible goes a long way for long term health.
Try these suggestions, even if you don’t spend much time in the car. Any time in a bad position enforces bad mechanics and spills over into all your activities.  Think about doing yoga or pilates – you feel great after doing something good; it’s the same with bad habits, you’ll feel miserable after doing something bad, even if that bad is just for a little while.

If you would like a free car consultation to help you position yourself in your car better, please contact Morgan Perry at to schedule.   Also, the upcoming Healthy Back Series: The Pelvic Floor addresses many of the problems we have with sitting and poor posture if you would like to learn more about healthy sitting and to help reduce other causes of back pain.