If my chair doesn't have built-in lumbar support, should I use a lumbar support pillow? Or just put any pillow behind my back?
As with most ergonomics questions, the answer to this one begins with "it depends."
Let's talk a bit about how the lumbar spine is structured, what kind of built-in support your body has for it, and what external support should look like.
Caitlin McGee is a physical therapist with a background in neuroscience and exercise/sport science. She is the co-owner and performance and esports medicine director of 1HP, a company that provides health and performance services to esports players, teams, and organizations. She has been working in esports medicine for six years.
The lumbar spine has what's called a lordotic curve, meaning that it curves inward towards the bellybutton. This is the opposite of the direction that the thoracic, or mid/upper back, curves. The spine has a number of active and passive support structures. Passive support structures are the ligaments and intervertebral discs, while active support consists of the core muscles and the muscles that surround the spine.
Even when you're sitting still, your core and postural muscles are engaged to some extent (or should be). However, most support when you're sitting comes from the internal passive support structures and any external support you provide. If that support (the back of your chair) is completely flat, it may not provide you with what you need to maintain the lordotic curve your lumbar spine should have. At the same time, a too-thick lumbar support will force you into excessive lordosis, or a “swaybacked” position, where there's too much curvature.
The easiest way to make sure that you’ve got good ergonomics is to start from good posture and then to build your setup around that. To find your natural lordotic curve, you’ll want to start with your hips and pelvis. If they’re tipped forward, your back will be arched too much; if they’re tipped backwards, you’ll be in a slumped position that reverses your lordotic curve. You want to find a happy medium, or a neutral pelvic position.
Once you find that neutral position, it’s time to maintain it. In that neutral position, with your normal lordotic curve, check to see if your back is fully in contact with the chair. If it is, great! You probably don’t need a lumbar support pillow. If it isn’t, though, a lumbar support pillow may be a good choice for you. Make sure it’s just thick enough to keep your lumbar curve where it is.
In my experience, most of the lumbar pillows I've seen that come with gaming chairs are too thick. You can find more reasonably-sized ones online or in office supply stores. If a purchase isn’t in your budget right now, a folded towel or blanket is easily adjustable to the right thickness.
No matter whether you use a lumbar support pillow or not, the most important thing is that your back support fits the curve of your particular spine in a comfortable, neutral position.
For more ergonomics tips, see our guide to PC gaming ergonomics.