Sciatic Nerve: Definition and What it is

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

Sciatic Nerve Definition and Meaning

The sciatic nerve is the largest and thickest nerve in the human body. It isn’t a single nerve  — it’s actually a bundle of nerve roots that branch off from the base of the spine. All the roots on the left side combine to form the left sciatic nerve; all the roots on the right side form the right sciatic nerve.

Each nerve then travels from your lumbar spine (low back), through your buttocks (glutes), and down the back of each leg. Once it reaches just below your knee, it splits into other nerves that connect to your lower leg, feet, and toes. Along this pathway, the nerves control movements and sensations of the leg.

Function of the Sciatic Nerve

The primary function of the sciatic nerve, just like all nerves, is to facilitate communication between the central nervous system (CNS), which includes the brain and spinal cord, and the peripheral nervous system (PNS), which encompasses nerves in the limbs and other body parts. This crucial connection enables the brain to send messages to muscles in the lower body, triggering movement, such as walking, running, and jumping. 

The sciatic nerve also plays a vital role in conveying sensory information (such as pain, temperature, and touch) from the lower limbs back to the brain, enabling us to feel and respond to our environment.

Common Sciatic Nerve Issues

The sciatic nerve can get irritated anywhere along its path, making it susceptible to various conditions that can cause pain and discomfort. Common sciatic nerve conditions include:

• Sciatica: Sciatica refers to symptoms of pain, as well as numbness, tingling, or weakness, that’s felt along the sciatic nerve when the nerve gets inflamed or compressed. The pain often radiates from the low back down one or both legs. Areas like the back of the calf, the knee, and the foot can also be affected. 

• Piriformis muscle issues: The piriformis muscle is a small, band-like muscle located in the buttocks, near the top of the hip joint. When the piriformis muscle becomes inflamed, it can irritate or compress the nearby sciatic nerve. This can lead to pain in the buttocks and muscle spasms, as well as numbness, tingling, and pain down the back of the leg and into the foot. These symptoms are sometimes referred to as “piriformis syndrome,”  but there’s actually some debate about whether this is different from sciatica. 

• Spinal stenosis: Spinal stenosis occurs when the spaces within the spinal canal narrow. As space diminishes, there’s more pressure or irritation on the nerves, which can result in lower back pain and stiffness along with tingling or numbness down one or both legs. 

• Herniated disc: A herniated disc occurs when the center of one (or more) of the flat, round discs — located between vertebrae in the spine that act as shock absorbers to enable the spine to be flexible — pushes against its outer ring. If the disc is pressing on a nerve, it may cause sciatica symptoms. 

Sciatic Nerve Pain: A Hinge Health Perspective

When sciatic nerve pain strikes, it can feel worrisome and disruptive to your daily activities. You may feel like you should avoid movement and rest. While it's certainly okay to scale back and take it easy for a few days, it's important to know that gentle movement is actually key for relieving sciatic nerve irritation.

Try to stick with your usual activities as much as possible, and do some gentle exercises and stretches since these are the tools that help your body heal best. Yes, it might involve some pain. But, no, that doesn’t mean you’re making the problem worse. In fact, some sort of movement, whatever that looks like for you, is helpful to increase muscle strength (a strong core can help alleviate sciatica pain) and reduce stiffness (improving mobility can decrease pain flares). 

How Physical Therapy Can Help With Sciatic Nerve Conditions

Physical therapy can help provide relief for sciatic nerve pain by reducing discomfort, increasing mobility, and strengthening the muscles supporting the spine. Physical therapists (PTs) can design customized programs tailored to what’s contributing to your nerve pain. This often includes exercises to improve flexibility and strengthen the muscles of the back, abs, and legs. A PT can also show you stretches that help relieve tension and pressure on the sciatic nerve. 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.

References

1. Atlas, S. J. (2022, March 15). Taming the pain of sciatica: For most people, time heals and less is more. Harvard Health. https://www.health.harvard.edu/blog/taming-pain-sciatica-people-time-heals-less-2017071212048 

2. Sciatica Treatment. (n.d.). Bodylogic. Retrieved from https://bodylogic.physio/conditions/sciatica-treatment/.

3. Sciatica. (n.d.). Hospital for Special Surgery. Retrieved from https://www.hss.edu/condition-list_sciatica.asp.