Ergonomics for Your Car

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By:  Corey Vanderwouw. MPT, Photo by Adam Niescioruk on Unsplash

Ergonomics is the art and strategy of fitting the environment around you to your body, rather than adjusting your body to fit the environment around you. Using ergonomic strategies can help you avoid body pain and limit injury to joints and tissues, and help keep your body mechanically healthy.

 

Desk ergonomics has been popular for decades. This is because working in a sitting position for many hours regularly has commonly led to neck, back and hip pain, as well as injuries that include disc herniations, carpal tunnel syndrome, shoulder, wrist and hand injuries. Thankfully most of us do not drive as much as the full-time desk worker sits at a desk. However, a poor sitting position, even for shorter durations, can be a literal pain. And for those of us who have underlying injuries, driving can be excruciating.

 

Let’s consider what a mechanically healthy sitting position is first, then apply it to a car seat. A mechanically healthy sitting position includes the position of the thighs, pelvis and spine. Since our body parts are connected, the position of each part affects its subsequent parts. The thighs should ideally point downward, with the knees positioned lower than the hips.

This opens up the hip joints, relieving them from so much compression. When the thighs slant downward, the pelvis can be easily positioned into an upright position. In sitting with an upright, properly-positioned pelvis, the back has a sturdy base to stack on top of. The spine is ideally upright with one vertebral bone stacked neatly upon the next, with the head sitting right on top. 

Try sitting on a regular chair with your feet planted on the floor with your knees lower than your hips.  You can try this while sitting in a normal chair as long as the chair is supportive and not squishy. If you are average height or tall, a taller chair can be a better fit. As you go to sit down, stick your bottom out instead of tucking it under. This will help your sit bones aim toward the chair. 

 

It is easiest to obtain this position if you first learn it while sitting toward the front of the chair, so scoot forward in your chair. Place your hands around the sides of your pelvis to assess its position.  The pelvis should be upright and directly over your hip joints. Another way to think of this is having two-thirds of your body weight over your sit bones (located inward to the lowest part of your buttocks). One-third of your body weight should be on the pubic bones at the front. When you get your pelvis aligned upright, then it is much easier for your spine to stack upright, on top. Unless you have special circumstances, this is the least stressful sitting position for your hips, back and neck.

 

A common, poorly-aligned pelvis will be in a rocked-back position, with the body weight coming off the pubic bone, causing increased weight and pressure on the tailbone. When the pelvis is rocked back like this, the lower back is pulled into a slouched curve. The rest of the back and neck will continue the curve resulting in a C- shape of the spine with the head positioned forward. In this slouched position, the spine is supporting the body weight in an uneven way, which increases stress on its structures and can therefore lead to pain and injury. You can test out this slouched position and feel how it differs from the upright position.

 

These principles are beneficial to apply to sitting in a car. There is an increased level of difficulty in achieving a great position due to many car seats that are built without ergonomics in mind. You may love your seat! If it feels great, then great job choosing! For the rest of us, the contours built into seats or the lack of adjustment choices can make a car seat just plain uncomfortable. 

Here are a few examples of poor ergonomics in car seats. The bucket seat is built with the greatest accentuation of hips low and knees high. Some seats are also created with the sides of the backrest coming forward (I call them the seat’s wings), which for some people push their shoulders forward, creating a forward hunch. There is also a feature in many cars where the headrest pokes forward, pushing the head forward compared to the spine, stressing the neck. Seemingly, it is created this way in case there is a car accident, in which case it may hold your head forward, potentially reducing the chance for whiplash. So, there may be benefits to the forward head rest, although there is also the daily stress of having your head pushed into a forward position.

 

If you feel that your car seat could use some improvements, check-out your seat adjustments.  When helping others adjust their positioning, I start with the angle of the seat first. See if you can raise the back of your seat and/or lower the front of the seat to angle it downward. If your seat doesn’t adjust this way, try folding some towels to go just under your sit bones, but not your thighs, and see how this feels. If you like the hips-higher position and the seat doesn’t adjust this way on it’s own you can keep using the towels or purchase a two-to-four inch seat wedge for about twenty dollars.

 

Next, adjust the backrest to comfort. If low back support isn’t built into the backrest, added support can often make a difference in how your back feels. Use a folded towel to figure out where you like additional support and how much. If you like that additional support, you can create the shape you like and put a pillowcase over it and use the support that way. Back supports in different shapes and sizes are also available and many come with a strap to secure it to your seat. Check these out online and find the shape that you found most comfortable. 

 

You can also check the adjustment of your steering wheel to find the right height for yourself. And, the forward/back adjustment is made to your comfort and safety. All adjustments should include that you feel safe while driving. If you drive a lot, also consider taking breaks to get out of the car and move and stretch. Taking movement breaks are very good for your body. They give your body a break, lubricate joints and increase blood flow.

 

Move better, live better!

Resources:

Driving Ergonomics – 7 Tips to Make Your Journey better

Vehicle Ergonomic Educational Poster For Free