A back support for car may not be the most important thing you need for a more pain-free back but it is nonetheless important.
This is especially true if you spend a lot time in your automobile commuting to and from work, traveling or as a traveling salesperson.
Your lumbar spine has an inward curve known as a lordosis. This lordosis is a normal curve that affects proper structure needed for upright function.
When there is too much or too little lordotic curve then there exists added stress on your lower back discs and joints. In addition, your muscles must now work overtime to help with their structural and functional responsibility.
When sitting a car back support or a lumbar cushion that gives you some support to your lower back will be very beneficial. Without a car back support your lumbar spine will assume a flat-back or even a reversal of the normal lordotic curve. This reversal of the lordosis creates what is known as kyphosis. This not only creates an increase in disk pressure it also elongates your back muscles and thus causes stress on your discs, joints and muscles.
In order to minimize disc, joint and muscle stress the lumbar spine, when it rest (sitting), should be in its neutral position.
Some automobiles do have an adjustable lumbar support built in to them. My experience is that most of the time the amount of forward support is too little. Any amount is better than none; but, usually it is inadequate. What is probably needed is a separate car back support in addition to the factory lumbar support. This seems to be especially true if you are overweight or obese.
Now, as already stated, a back support for car may seem like a minor need yet it may make a major difference in your lower back condition.
Even if it only makes a 10% difference, that 10% along with 5-10 other actions you take will only add to your overall improvement. Cumulatively they can make 50-60-75% or more improvement in the long haul.
It is a small investment; but the return on your investment can be 100 fold more when you consider that it may reduce your need for one or two chiropractic visits per month, reduce your pain medications, and created better sleep and more energy.
Make sure the car seat back cushion is firm enough and large enough to give you the resistance forward and fits across your back. One that is too soft will essentially offer no support.
It is not necessary to purchase a full length back cushion. Not only is it not necessary, the full back length will minimize the amount of forward support that you need in your lower back.
You may want to purchase two or three lumbar support cushions. I have three that I use. I have one in my automobile, one in the truck and another that I use when I'm in a recliner chair.