Anatomy of the Lower Back | Healthy Posture and Exercises

Today we're diving into lower back physiology to better understand how the parts of the lower back fit and work together. We'll look at how bad posture affects your lower back, and how you can correct bad posture and strengthen your lumbar spine.

A Quick Look at Lower Back Anatomy

The Lordotic Curve: The natural curve in your lower back (lumbar spine) is known as lordosis. Its purpose is to balance out and evenly distribute weight between your upper body and lower extremities.

Bones, Discs, and Joints: The lower back hosts the vertebrae L1 to L5. Between the vertebrae, you will find intervertebral discs which act as shock-absorbing cushions that protect the vertebrae during spinal movement. At the back of your spine, the vertebrae are connected with paired facet joints. These joints help to stabilize the spine and allow movement of the spine in different directions.

Nerves: The lumbar spine hosts five pairs of lumbar spinal nerves (L1-L5). These lumbar spine nerves consist of two kinds of fibers. Sensory fibers send messages to your brain, alerting you for example to pain when you stubbed your toe or knocked your knee. Next up are the motor fibers, which catch messages sent from your brain telling them to make your leg or foot move.

Spinal Cord and Cauda Equina: The spinal cord begins in the brain, moves through the spine, and ends at the beginning of your lower back. The point where it ends is known as the conus medullaris. At this point, the spinal cord splits into a bunch of nerves that travel to the pelvic organs and lower limbs. The bunch of nerves is also known as the cauda equina, meaning horse's tail.

How Posture Affects Your Back

The list of potential causes of lower back pain is long. Anything from kidney stones to gallbladder problems may cause lower back pain. But bad posture is one of the most infamous culprits. Not only can bad posture cause back pain, but it can also worsen back pain that is being caused by something else entirely. 

With the spine, balance is everything. Remember lordosis? When the natural curve in your spine becomes increased or decreased, it can lead to pain. If for example, you are lying on your stomach reading a book, or slouching forward while sitting at your desk, you are extending the spinal curve excessively. Extending that curve completely changes the dynamics of your lower back. The longer you leave poor posture unaddressed, the higher the chances are that the shape of the spine may change. At that point correcting the structure of your spine would take more than some effort to readjust your posture.

Poor Posture and Back Pain

A lot of what happens in your lower back revolves around balancing and evenly distributing weight throughout your body. This delicate balancing act can very easily be thrown out of sync by bad and unsupported posture. Think of it this way, if you are sitting or standing in an unsupported posture, the load being placed on your spine is being dispersed incorrectly, which can weaken certain tissues in your lower back. This places too much pressure on the intricate network of spinal joints, discs, and muscles in your lower back and will inevitably lead to pain and discomfort.

Ways to Improve Posture at Work

Many of us spend a good eight hours a day sitting at a desk in front of a computer. That is a long time to be sitting in a rather unnatural position. It is incredibly important to be aware of your lower back posture while sitting at your desk. Maintaining good posture may take some effort on your part, but if you keep at it long enough, it should become second nature to you.

Let's specify: poor posture at your desk does not just come down to whether or not you are sitting up with a straight back. Everything from the height of your chair, or the height of your monitor, to the angle of your wrist when using the mouse, counts towards ensuring good posture.

Here are a few basic office ergonimics tips to follow to achieve good posture while sitting in front of a computer:

• The top of the computer monitor should be at eye level.
• Keep your shoulders low and relaxed. Not rounded or hunched over.
• Make sure that your lower arms are parallel to the floor.
• Keep your mouse and keyboard close enough that your elbows are at about a 90° angle.
• Keep your feet flat on the ground.
• Make sure your upper back is straight and that your chair supports your lower back.
• Keep your upper legs at a 90° angle in relation to your body.
• Your monitor should be an arm's length from you.

Easy Exercises to Help Strengthen Your Lower Back for Better Posture

Weak core muscles mean less support for your lower back. You need strong core muscles to help support your lower back and avoid extra pressure being put onto parts of the lumbar spine. Luckily there are many exercises you can do to help strengthen and support your lower back. Make sure when planning your exercise routine, that you factor in some lower back exercises. 

And remember, dynamic posture (your posture when you're moving) is just as important as static posture (your posture when you are standing or sitting still). Make sure that you maintain good posture while doing any back exercises.

The Arch

• Lie flat on your back. Arms at your sides.
• Raise your hips using your abdominal, back, and buttocks muscles.
• Hold the position for 5-10 seconds and release.

The Plank

• Move into a pushup position. Forearms on the ground.
• Keep both elbows in line with the shoulders and push up onto your toes and your forearms. Remember to keep your back straight and those elbows firmly on the ground.
• Hold that position for 20-30 seconds before lowering yourself back down to the floor.

 The Bird Dog

• Move onto your hands and knees. Your spine should be straight.
• Extend your right leg and your left arm
• Hold that position for 5-10 seconds and release.
• Repeat on the other side.

Nina Kulenkampff is a freelance copywriter and editor based in South Africa. She is passionate about the written word and loves diving deep into research on any given topic. When not at her desk you will find her deeply absorbed in a book or out on a hike in the great outdoors.