13 Facts About the Sciatic Nerve

If you say someone's getting on your nerves, you could just cut to the chase and say they're getting on your sciatic nerve—this nerve is plenty big enough for both minor and major irritations. It's the largest nerve in the body, running a lengthy route from each side of your lower spine, deep into your buttock, wrapping around to the back of the thigh and into the foot. Mental Floss spoke to Loren Fishman, medical director of Manhattan Physical Medicine and Rehabilitation in NYC and associate clinical professor at Columbia Medical School. Here are 13 things we learned about this important part of the nervous system.

1. AT ITS LARGEST POINT, IT'S ABOUT AS BIG AROUND AS A MAN'S THUMB.

No wonder this nerve hurts when it gets irritated—at its biggest point, it's one heck of a large nerve, says Fishman. 

2. THE SCIATIC NERVE IS ACTUALLY MADE UP OF FIVE NERVES.

The sciatic nerve is more accurately five nerves that come together on the right and left sides of the lower spine. Technically, the fourth and fifth lumbar nerves and the first three nerves in the sacral spine come together and merge into the unified sciatic.

3. WITHOUT SCIATIC NERVES, YOUR LEGS WOULD BE WEAK NOODLES.

"The sciatic nerve gives feeling and strength to the muscles and skin of the calf and foot, supplies sensation from the joints, bones, and just about everything else below the knee," says Fishman.

4. THE SPINAL CORD'S CONNECTED TO THE THIGH BONE.

The nerve connects the spinal cord with the outside of the thigh, the hamstring muscles in the back of the thigh, and the muscles in your lower leg and feet. This is why sciatic nerve impingement often results in muscle weakness, numbness and/or tingling in the leg, ankle, foot, and toes.

5. INJURIES TO THE SCIATIC NERVE OFTEN AFFECT THE CONNECTION TO THE BRAIN RATHER THAN THE NERVE ITSELF.

After severe spinal cord injury, the nerve itself is often just fine, but the connection between it and the brain has been severed, Fishman says. Until now, there's been no way to fix such injuries, but "recent work with stem cells has begun to restore the connection in dogs and other animals."

6. BACK INJURIES ARE THE MOST COMMON CAUSE OF SCIATIC PAIN.

A variety of lower back problems can lead to pain that radiates along the sciatic nerve. Most commonly, sciatica pain is caused when a herniated disc at the L5 (lower lumbar back) irritates the S1 (sacrum) nerve root in the lower spine. The exiting nerve roots are highly sensitive, and the bits of the disc that herniate contain inflammatory proteins such as interleukin and tumor necrosis factor that can also aggravate the nerve.

7. SCIATIC PAIN CAN BE A MEDICAL EMERGENCY.

In a small number of people, a condition called cauda equina syndrome (so named because the nerve bundle at the base of the spinal cord resembles a horse's tail) can masquerade as sciatica—but it also usually causes weakness that extends to bowel or bladder incontinence and sometimes weakness or loss of sensation in the legs that gets progressively worse. In this case, immediate medical attention should be sought, and recovery may not be as quick as with common sciatica.

8. ANCIENT GREEKS AND ROMANS COULDN'T DISTINGUISH BETWEEN JOINT AND NERVE PAIN …

When the ancient Greek and Roman physicians were treating the pain we now commonly know as sciatica, they believed it stemmed from "diseases of the hip joint," according to a 2007 study in Spinal Cord. It wasn't until 1764, write the authors, "that leg pain of 'nervous' origin was distinguished from pain of 'arthritic' origin."

9. …AND HIPPOCRATES TREATED IT WITH THE BOILED MILK OF A FEMALE ASS.

Among the many treatments Hippocrates and his ilk came up with for this painful condition were: "Fumigations, fasting, and subsequently, laxatives, and ingestion of boiled milk of the female ass." In his Treatise of the Predictions, Hippocrates noted that elderly patients with "cramps and colds at the loin and the legs" would experience their pain for up to a year, whereas young people could be free of pain in about 40 days.

10. SCIATICA DERIVES ITS NAME FROM THE 15TH CENTURY.

The modern name for the disease, according to Fishman, comes from 15th-century Florence. "They called sciatica ischiatica, since they thought it came from tuberculosis that worked its way down to the ischial tuberosity (the sit-bones)," Fishman says. These medieval doctors had the cause wrong, but the name stuck.

11. SOMEWHERE BETWEEN 1900 AND 1925 PHYSICIANS CONNECTED HERNIATED DISCS TO SCIATIC PAIN.

Different researchers in different countries began to make sciatic breakthroughs when doing autopsies on corpses with fractured or herniated discs, where they noticed compression on the sciatic nerve.

12. WEIGHT HAS LITTLE INFLUENCE ON SCIATIC PAIN, BUT HEIGHT DOES.

A 1991 cross sectional study of 2946 women and 2727 men published in Spine found that neither gender nor body mass made any difference in the likelihood of developing sciatica. Body height did, however, in males between the ages of 50 and 64, with taller men being more likely to have the condition. Other studies have found a similar link [PDF]. Over 5'8"? Your risk is higher. 

13. SUFFERING FROM SCIATICA? YOU'RE NOT ALONE.

Sciatica has a surprisingly common negative impact on daily life. "Low back pain and sciatica are the second biggest reason for lost days of work—just behind the common cold," says Fishman. The condition is most commonly found in people over 50 and rarely seen in anyone under 20 years old—and then it most often has a genetic cause.

Wayfair’s Fourth of July Clearance Sale Takes Up to 60 Percent Off Grills and Outdoor Furniture

Wayfair/Weber
Wayfair/Weber

This Fourth of July, Wayfair is making sure you can turn your backyard into an oasis while keeping your bank account intact with a clearance sale that features savings of up to 60 percent on essentials like chairs, hammocks, games, and grills. Take a look at some of the highlights below.

Outdoor Furniture

Brisbane bench from Wayfair
Brisbane/Wayfair

- Jericho 9-Foot Market Umbrella $92 (Save 15 percent)
- Woodstock Patio Chairs (Set of Two) $310 (Save 54 percent)
- Brisbane Wooden Storage Bench $243 (Save 62 percent)
- Kordell Nine-Piece Rattan Sectional Seating Group with Cushions $1800 (Save 27 percent)
- Nelsonville 12-Piece Multiple Chairs Seating Group $1860 (Save 56 percent)
- Collingswood Three-Piece Seating Group with Cushions $410 (Save 33 percent)

Grills and Accessories

Dyna-Glo electric smoker.
Dyna-Glo/Wayfair

- Spirit® II E-310 Gas Grill $479 (Save 17 percent)
- Portable Three-Burner Propane Gas Grill $104 (Save 20 percent)
- Digital Bluetooth Electric Smoker $224 (Save 25 percent)
- Cuisinart Grilling Tool Set $38 (Save 5 percent)

Outdoor games

American flag cornhole game.
GoSports

- American Flag Cornhole Board $57 (Save 19 percent)
- Giant Four in a Row Game $30 (Save 6 percent)
- Giant Jenga Game $119 (Save 30 percent)

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30 Pungent Facts About Farts

This man is clearly not trying to hide the fact he just passed gas.
This man is clearly not trying to hide the fact he just passed gas.
BrilliantEye/iStock via Getty Images

Whether you openly admit it or desperately try to hide it, it’s an undeniable fact that every living and breathing human being farts. And while passing what you thought was going to be silent gas only to be wrong in certain situations can definitely be embarrassing, there’s something undeniably humorous about flatulence—no matter your age.

If you do love a good fart joke, you’re in good company. The very first recorded joke, which was written by the Sumerians and dates all the way back to 1900 BCE, was about—you guessed it—breaking wind. And some of the world's great thinkers, from William Shakespeare to J.D. Salinger, have slipped a fart joke (or 10) into their work.

In this episode of The List Show, we're sniffing out 30 fascinating facts about farts—from why humans expel gas to how often the average adult squeezes the cheese. You can watch the full episode below.

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