What Causes Low Back Pain When Crossing My Legs And What Can I Do To Stop The Habit?

A report found that 25% of adults in the US said they had experienced lower back pain in the last three months. It can be debilitating and frustrating, especially if you don’t know what’s causing your pain.

Adults and teenagers spend approximately 7.7 hours¹ sitting each day, whether that’s sitting in the car, on a train or bus, sitting at a work or school desk, or sitting on the sofa. If you sit for a long time, you might find it more comfortable to sit with your legs crossed either by resting a knee on your thigh, resting your outer knee on your thigh, or crossing your ankles.

It may seem fairly harmless to cross your legs when sitting, and you might do it every day and not even realize. While sitting cross-legged doesn’t pose any immediate risks, it could be the cause of your lower back pain.

How does sitting cross-legged cause lower back pain?

If you often sit cross-legged and it has become a habit, it might be hard for you to stop. Over time, sitting cross-legged can cause asymmetry or a muscular imbalance between your right and left sides which can eventually lead to injuries caused by tightness, weakness, and reduced range of motion.

When you regularly cross your legs, small imbalances can become noticeable in your hips and lower back. You might also experience posterior pelvic tilt², which occurs when the top of your pelvis rolls backward. Over time, poor hip and spine alignment can increase pressure across your lower back.

The way you sit could impact how you stand and you might adopt a poor standing position. You might find yourself placing more weight on the leg that you cross, which can cause tight muscles on one side and weakness and overstretched muscles on the other.

Sitting cross-legged can cause one side to sit higher than the other. If you sit like this continually for hours each day, it could lead to conditions like sciatica.

Conditions that cause lower back pain by sitting cross-legged

Crossing your legs may lead to conditions that are associated with lower back pain, including:

1. Lower cross syndrome (LCS)

This condition is caused by muscular imbalances and poor posture. Uneven stress and strain across the body caused by sitting cross-legged can eventually lead to aches and pains. Prolonged sitting can shorten your hip flexor muscles which can tighten the muscles in the lower back. You might eventually notice other problems too, such as weaker gluteal (bottom) muscles and core.

You might begin to notice changes in your posture if you have LCS, including the top of your pelvis rolling backward and a flat lower-back arch. Over time, these changes can cause weakness in your thighs, hamstrings, and back, leading to injury and pain.

2. Sciatica

Sciatica is caused when your sciatic nerve (a nerve that extends from your lower back through your hips, bottom, and legs) is compressed, causing symptoms like numbness, weakness, and tingling.

When you cross your legs, it creates asymmetry along your hip and pressure on your bottom. Over time, the constant pressure from your body weight can squeeze your muscles and sciatic nerve.

3. Greater trochanteric pain syndrome (GTPS)

GTPS can also be called trochanteric bursitis or lateral hip pain. It's a common condition that causes tenderness and pain outside of your bottom and hip region.

When you cross your legs, the greater trochanter (the widest part of the body or the top part of the thigh bone) can press on several structures, including the muscles and tendons. Constant pressure can cause inflammation and pain in these areas.

Tips for sitting with a neutral lower back

It might take some time to kick the habit of sitting cross-legged and learn to sit in a neutral position.

Here are some tips for sitting with a neutral lower back:

1.  Sit with your spine in a neutral position

Try to keep your chin back, your shoulders down, your stomach in, and your lower back supported against the backrest. You might not feel the urge to cross your legs when you keep your spine neutral.

Sit in a chair that's low enough to keep your feet flat on the ground and your knees aligned with your hips. You can use a footrest to help support your knees if your desk or chair is too high. If your chair doesn’t provide enough support, you can use a rolled-up towel or pillow to keep your lower back supported.

If you find sitting in this way painful, speak to your doctor or a physical therapist for advice and guidance.

2. Try active (dynamic) sitting

Your body can get used to sitting in the same position for long periods, leading to stiffness and tension. Active sitting encourages you to keep moving even when you’re sitting down. It involves regularly changing your body position and posture throughout the day, which might discourage you from crossing your legs. You don’t need an ergonomic chair for active sitting as you can simply adjust the height of a normal office chair or change the way you sit.

3. Be aware of leg-crossing

Try to pay attention to your leg position while sitting. Many people cross their legs to make their couch or chair more comfortable. If this sounds familiar, you may want to consider investing in ergonomic furniture that’s both comfortable and supportive.

When to see a doctor about lower back pain

Lower back pain could be a dull ache that lasts several days or severe pain that lasts several weeks, and there are many potential causes. If the habit of crossing your legs is causing your lower back pain, it should go away when you start to sit neutrally. However, if you have a more serious back problem like sciatica or LCS, you might need to see a doctor.

Signs that you need to see a medical professional include:

1. Your pain lasts longer than a week

Most lower back pain subsides after several days, but if your pain lasts longer than this, make an appointment to see your doctor. Your doctor can perform a physical examination and recommend tests to diagnose your symptoms. Left untreated, lower back pain can lead to serious complications.

2. Your pain is worse in certain positions or at certain times

Lower back pain that gets worse at night or when you’re resting could indicate inflammation. Inflammation could be a symptom of a more serious problem, such as:

• Fracture

• Infection

• Tumor 

• Severe nerve compression

3. You have tingling, numbness, or weakness

Lower back pain accompanied by a tingling sensation, numbness, or weakness may be a sign of nerve damage or irritation. Although over-the-counter medications and exercise can help, it’s always important to identify the cause and determine the most effective treatment.

The lowdown

Sitting cross-legged can cause asymmetrical changes to your spine and hip, which might lead to a condition like sciatica, lower cross syndrome, or greater trochanteric pain syndrome. These conditions can cause lower back pain, stiffness, and discomfort.

Your doctor or physical therapist may recommend that you stop or limit crossing your legs, but it can be a challenging habit to break, especially if you sit for long periods. Strategies like sitting with your spine in a neutral position, active sitting, and being mindful of leg-crossing can help improve your posture, ease pain, and prevent injury.