Lumbar Spine: Definition and What it is

Medically and clinically reviewed by Jonathan Lee, MD and Dylan Peterson, PT, DPT

Lumbar Spine Definition and Meaning

The term "lumbar spine" refers to the lower section of the spine situated between the thoracic spine and the sacral spine, commonly referred to as the low back. It is composed of five vertebrae, labeled L1 to L5, which are the largest vertebrae in the entire spine.

The lumbar spine provides robust structural support to the upper body and enables a range of motions, like bending and twisting. It also protects the spinal cord and spinal nerve roots, offering a passage for nerves that go to the legs and pelvic organs.

Anatomy of the Lumbar Spine

The lumbar spine consists of five large vertebrae. Unlike the cervical spine (located in the neck), these vertebrae are not built for as much movement but are instead designed for strength and stability. They are separated by intervertebral discs that act as cushions and shock absorbers. Each vertebra (detailed below) has a central hole, and these holes collectively form the spinal canal that houses the spinal cord and nerve roots.

  • L1: Located immediately below the last thoracic vertebra, L1 serves as the transition from the mid to lower back.

  • L2-L4: These vertebrae are similar in structure but gradually increase in size as you go down the spine in order to support and stabilize a significant amount of the upper body's weight.

  • L5: The largest and strongest vertebrae in the lumbar region, located just above the sacrum, L5 is responsible for supporting most of the body’s weight, especially when sitting.

Muscles and ligaments surround these vertebrae, aiding in movement and providing additional support.

Common Lumbar Spine Issues

The lumbar spine has a big job — not only does it provide support and stability for the upper body, but it’s also responsible for the flexibility we need to move and bend. As a result, it’s incredibly durable and resilient with built-in shock absorbers that usually help us manage impact and pressure without pain. Still, certain issues can arise in the lumbar spine that cause low back pain, including:

  • Herniated discs: This occurs when the center of one (or more) of the flat, round discs that are located between vertebrae in the spine pushes against the outer ring, which can cause pain. However, it’s common to have herniated discs without any discomfort. 

  • Spinal stenosis: This condition occurs when the spinal column narrows and puts pressure on the spinal cord and nerves. It’s often characterized by pain that gets worse when walking and improves upon sitting.

  • Lumbar degenerative disc disease: When the discs between vertebrae change and can no longer provide the same level of cushion and support to the spine (which is natural with age), this may cause low back pain.  But in most cases, these changes are harmless.

Lumbar Spine in Daily Life

The lumbar spine plays an essential role in everyday activities such as lifting, bending, and walking. Proper lumbar spine health is crucial for maintaining an upright posture and avoiding chronic low back pain.

Lumbar Spine: A Hinge Health Perspective

Back pain in the lumbar spine can feel frustrating, upsetting, or even a little hopeless, especially when it persists or interferes with your daily activities. No matter how bad your back pain is, or how long it’s been going on, you can always do something to help improve it. And that usually starts with moving more. Although moving through back pain can be scary and uncomfortable, small changes to your habits can yield huge benefits. 

And no matter what might be causing your back pain, exercises and stretches that focus on the low back (and the muscles and ligaments that support it) can help because they’re designed to improve mobility and function. There’s a lot you can do at home to strengthen your low back. Or you can work with a physical therapist to help restore function and health so you can improve your quality of life and get back to the activities you enjoy. You can see a physical therapist in person or use a program like Hinge Health to access a PT via telehealth/video visit.

How Hinge Health Can Help You 

If you have joint or muscle pain that makes it hard to move, you can get the relief you’ve been looking for with Hinge Health’s online exercise therapy program.

The best part: You don’t have to leave your home because our program is digital. That means you can easily get the care you need through our app, when and where it works for you. 

Through our program, you’ll have access to therapeutic exercises and stretches for your condition. 

Additionally, you’ll have a personal care team to guide, support, and tailor our program to you. See if you qualify for Hinge Health and confirm free coverage through your employer or benefit plan here.

This article and its contents are provided for educational and informational purposes only and do not constitute medical advice or professional services specific to you or your medical condition.


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