Two p.m. hits. You should be working, but you can only think about the pain lighting up your lower back like a flare. You can’t remember lifting anything heavy, and you don’t think you slept weirdly (although, it’s certainly possible). If anything, your back should feel great—you’ve been sitting all day.
Except, that might be the problem.
Within the past few years, Americans increased their time sitting an additional four to seven hours per day (1). Sitting for long periods has been associated with a higher risk of all-cause mortality and cardiovascular disease (2). And the risk is independent of physical activity (3)—meaning you can’t outrun or outlift a long day sitting at your desk (but a standing desk can help).
“We’re not designed to sit (we evolved to hunt and gather), and we’re certainly not designed to sit an average of eight hours a day,” says Dr. Turner Osler, M.D., an emeritus professor of surgery at the University of Vermont.
Sitting too much or incorrectly can be linked to back pain according to Osler and physical therapist Heather Swain, PT, DPT, CIDN.
What causes lower back pain from sitting, and how to fix it? Here’s the scoop.
Can Sitting Cause Lower Back Pain?
In short, yes. “It can be hard to pinpoint an exact cause of back pain because there are so many factors,” says Swain. “However, sitting can contribute.” Here’s how.
Sitting can stress your lumbar spine
Sitting at the wrong angle can wreak havoc on your lumbar spine—the five vertebrae located in your lower back. “Ideally, your knees should be at a 90-degree bend when seated,” says Swain. “Any greater angle will tip your pelvis forward and round your lower back (decreased lumbar lordosis), a lesser angle will cause your lower back to arch (increased lumbar lordosis).”
The lumbar spine has a natural lordotic curve, but too much can be a bad thing. “Increased lumbar lordosis can close off the space that your nerve roots have to exit between the vertebrae, which can lead to pinched nerves,” says Swain.
The opposite isn’t great either. “Over time, decreased lumbar lordosis places strain on your ligaments, stretching them out, and creating instability,” she adds. “If your ligaments aren’t holding your spine stable, your muscles have to do more work to pick up the slack.”
Sitting with bad posture can cause tight muscles
“Poor posture places excessive stress on some tissues,” says Swain. She notes the most commonly overstressed muscles in your lower back are your lumbar paraspinals, also known as the erector spinae. The paraspinals include three muscle groups—the iliocostalis, longissimus, and spinalis—which work together to provide postural support and stability.
“If you have excessive lumbar lordosis, the paraspinals overcompensate and become tight,” she says. “If you have decreased lumbar lordosis, the paraspinals will try to resist the stress that this posture puts on the ligaments. As they resist, they’re lengthened, creating what we call passive insufficiency—a phenomenon that makes it harder for the muscle to work.”
Ergonomic chairs can contribute to core weakness
“Your abdominal muscles and multifidus (the muscles that support the spinal column) stabilize your spine when sitting,” says Swain. “If they’re weak, people tend to overcompensate with their back muscles. This can place too much pressure on the nerves in your back, generating pain.”
That’s where a supportive chair swoops in and saves the day, right? Nope. “I typically don’t encourage people to buy fancy, ergonomic chairs,” Swain adds. “They allow your muscles to be lazy, and don’t promote core strength.”
Sitting passively (even in a supportive chair) isn’t great for spine health
“Our office chairs are predicated on the idea that we require support in order to sit,” Osler told TEDx. While certainly comfortable, excess chair support can decrease your ability to actively support and protect your spine.
Swain points out that the inherent problem isn’t the chair but rather your reliance on the backrest. “You can choose to sit actively in just about any chair,” she adds. “You have the choice to lean on the backrest or sit up independently.” Both Swain and Osler are advocates of the latter.
Long periods of sitting can cause inflammation
“The human body was made to move,” says Swain. When you move, your heart rate and blood pressure elevate and supply oxygen to your tissues.
“When you sit for long periods of time, blood can pool down in your legs and pelvis,” Swain explains. “The swelling and inflammation place pressure on your nerves. Pinched and compressed nerves can generate pain.”
Sitting can contribute to discogenic back pain
Under pressure, vertebral discs can bulge out and rupture, pressing on nearby nerves and causing pain that can worsen when your spine is compressed from sitting. “That’s why standing or lying down typically relieves discogenic back pain,” says Swain.
How to Fix Lower Back Pain From Sitting
“Changing how you sit, which can improve posture and core strength, goes a long way in preventing back pain,” says Osler. Here, a few methods Swain uses with her clients to relieve pain, provide support, and build core strength.
Get the right chair
According to Swain, a chair that allows you to sit with your knees bent at a 90-degree angle is ideal for proper posture. The right height for you will depend on your leg length. If your current chair doesn’t let you hit this angle, shop for options with an adjustable height.
“If you have good core stability actively sit in your current chair by limiting your use of the back rest, or try sitting on a stability ball—which forces you to have good posture,” she says.
“For those who need more support, use a chair that supports the natural lordotic curve of the lower back,” she adds. “If your chair doesn’t have back support, you can roll up a hand towel to put behind you, or purchase a lumbar roller.” She prefers the McKenzie Lumbar Roller by OPTP.
Train to sit actively
Think of lumbar support as a tool to reduce back pain in the short term rather than a long-term solution. “Just like a supportive chair, lumbar rollers can help you get through the workday pain-free,” she says, “however, the end goal is to no longer need the support.”
Most people don’t have enough core endurance to sit actively for long periods of time. If not, you’re more likely to get tired, slouch, and overcompensate with your back muscles—which can make back pain worse.
“If you don’t have the core strength, you can work up to periods of active sitting,” Swain says. She recommends using a lumbar roller intermittently—shifting between periods of active sitting and using the lumbar roller for support. “As your endurance improves, you’ll need less and less help from the lumbar roller, and you can sit actively in your chair on your own,” she says.
Improve core strength
Training to sit actively isn’t the only way to improve core strength and endurance. Training your core muscles outside of time seated at your desk helps you build strength that translates to your seated posture.
Outside of core-specific workouts, “for people who like gadgets, I’d recommend the Upright Go— a device that trains you to sit and move throughout your day with better posture,” she says.
When to Talk to a Doctor
“If your back pain persists for more than a week or two and is limiting your functional ability to complete your work, sleep, or regular daily activities, talk to your doctor,” says Swain.
Your doctor can refer you for testing to help determine the underlying cause of back pain and prescribe medication if necessary. They may also refer you to a licensed physical therapist who can create an individualized care plan based on your specific symptoms.
“If lower back pain is accompanied by a loss of bowel or bladder function, numbness and tingling on the inside of the legs—also known as saddle anesthesia—or you develop drop foot where the muscles in your feet become weak or unresponsive to commands from your brain telling them to move, seek immediate medical attention,” says Swain. Either symptom could be a sign of cauda equina syndrome, a dysfunction of lumbar and sacral nerve roots that in severe cases may require prompt surgical intervention.