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10 Things You Might Not Know About the Elbow

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The human body is an amazing thing. For each one of us, it's the most intimate object we know. And yet most of us don't know enough about it: its features, functions, quirks, and mysteries. Our series The Body explores human anatomy, part by part. Think of it as a mini digital encyclopedia with a dose of wow.

Unless you bang your funny bone or regularly play tennis, it's unlikely you spend a lot of time thinking about your elbow. But without this crucial joint, many daily activities would be impossible, explains Anand Murthi, attending orthopedic surgeon and chief of shoulder and elbow surgery at MedStar Union Memorial Hospital, in Baltimore, Maryland.

1. THE ELBOW IS MORE COMPLEX THAN IT MAY SEEM.

The elbow may seem small, but it requires three bones to make its simple hinging action possible. The humerus is a long bone that runs from the shoulder socket to the radius and ulna. (And yes, there's a school of thought that believes your "funny bone"—actually your ulnar nerve—is named as a play on the word humorous.) The radius is one of the two forearm bones, running down from the elbow to the thumb side of the wrist. Lastly, the ulna stretches away from the pinkie side of the wrist. Thanks to those three bones, your arm can hinge—making it possible to do a bicep curl, lift a bag, or rotate your hand.

2. IT'S ALL HELD TOGETHER BY A KEY LIGAMENT, AS INJURED ATHLETES KNOW WELL …

The bones of the elbow are connected by numerous tendons and ligaments, including the ulnar collateral ligament, a fibrous tissue that connects the humerus to the forearm bones. This tendon is both important and vulnerable. When it ruptures or tears, you feel severe pain and can sometimes even see bruising on the inside of your arm. It's a surprisingly common sports injury, plaguing players of baseball, football, ice hockey, and golf. The other major ligament in the joint is called the radial collateral ligament. Located on the outside of the elbow, it prevents excessive extension of the elbow, and is less prone to injury.

3. … BUT THAT'S NOT THE ONLY VULNERABLE PART OF YOUR ELBOW.

At the lower end of the humerus are two rounded protrusions called epicondyles, which flare out from the bone. This is where muscles attach. The upper end of the ulna also has two protrusions, called the olecranon—which forms the pointy part of the elbow—and the caronoid process, a projection from the front of the ulna. Bone fractures, especially in children, often occur at these epicondyles, and are the most common short-term injuries of the elbow. Certain kinds of arthritis, especially in older patients with osteoarthritis, can also cause such severe degeneration here that an elbow replacement is necessary. (Since bones become more brittle as we age, it's wise to take steps to prevent falling or stumbling, as elbows are among the most likely casualties.)

4. TRAMPOLINES ARE COMMON ELBOW-BREAKERS.

Children love the thrill of a jump on the trampoline, but Barbara Bergin, an orthopedic surgeon in Austin, Texas, tells Mental Floss that she sees numerous fractures around the elbow in kids from doing just that. It's so common to break elbows and wrists this way, the American Board of Pediatrics warns against trampolines.

5. TWENTY-THREE MUSCLES GIVE YOUR ELBOW STABILITY AND FLEXIBILITY.

But the major muscles involved in bending your arm are the triceps—on the back of your arm—and biceps, on the front of your arm. Your many smaller flexor and extensor muscles allow you to move your wrists and fingers and rotate your forearm.

6. YOU DON'T HAVE TO PLAY TENNIS TO GET TENNIS ELBOW.

One of the most common conditions of the elbow is called "tennis elbow"—or lateral epicondylitis. Tennis players are prone to it, but it can be caused by any repetitive bending and flexing of the elbow, says Bergin. It's a painful degeneration of the tendons that attach to the bone on the outside of the elbow. It's so common, she says, "I probably see tennis elbow every day in my office." If the condition should strike you, Bergin says, "It's critical to stop doing whatever hurts. It will not get better if you continue to participate in whatever activity is causing pain." Full and total healing is required before you can return to the activities that gave you the condition in the first place.

7. IF IT GETS BAD ENOUGH, YOU MAY NEED "TOMMY JOHN" SURGERY.

When major league pitcher Tommy John injured his ulnar collateral ligament in 1974, his doctor opted to try a unique surgery to replace the deteriorated ligament with a tendon from somewhere else. Though the surgery can require a full year's recovery time—in Tommy John's case, it was nearly two and a half years and two surgeries—it's since become a time-tested method to repair this damaged ligament. Murthi tells Mental Floss, "New research on repairing the medial collateral ligament (versus reconstructing it) may lead to earlier recovery for Tommy John surgery. Also new treatments for articular cartilage damage, ligament reconstruction, and joint sparing techniques are evolving."

8. BUT IT'S HARD TO OPERATE ON YOUR ELBOW.

The elbow's close proximity to important blood vessels and nerves in your hand and arm make it a challenge to perform surgery on, Murthi says: "Careful, precise surgery is required to provide a good outcome. Often, rehabilitation with a skilled therapist is crucial to a good recovery." Currently, many operations are performed arthroscopically, so that surgeons can see all the various components as they make delicate maneuvers.

9. IF YOU HAVE TO GET AN AMPUTATION, HOPE FOR ONE BELOW THE ELBOW.

Should you have the misfortune of losing part of an arm, it's better to lose the parts below the elbow, Bergin says. This helps you maintain a range of motion and allows you to better manipulate a prosthesis. Fortunately, upper extremity amputations are rare and almost always result from accidents, as compared to lower arm amputations, which are often caused by some form of vascular disease.

10. EVEN JUST READING A BOOK CAN CAUSE AN ELBOW CONDITION.

While you may be tempted to read that latest hefty bestseller late into the night, if you're keeping your elbows bent in a sitting position for too long, you can get a case of ulnar neuritis, inflammation of the ulnar nerve—which can lead to numbness or weakness of the fingers and hand. Bergin warns, "It's much more common now than it used to be because we sit around for hours at a time on our phones." If you experience a "little tingly feeling in the pinky and fourth finger," she says, you've probably got a case. Her recommendation is to take as many breaks with your arms straight out as you can. Switch to a kindle or laptop that you can prop up to read at night. Be conscious of your ergonomics when you drive, type, and use your electronics.

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The Body
6 Quick Facts About the Buttocks
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The human body is an amazing thing. For each one of us, it's the most intimate object we know. And yet most of us don't know enough about it: its features, functions, quirks, and mysteries. Our series The Body explores human anatomy, part by part. Think of it as a mini digital encyclopedia with a dose of wow.

You can thank your buttocks for a number of physical actions you take every day, from moving your hip and thigh during walking or running, to rising from a sitting position, climbing, and even just standing upright. While lack of exercise can make these muscles soft, in general they're some of the hardest working muscles in your body. To learn more, Mental Floss spoke with Clifford Stark, medical director of Sports Medicine at Chelsea in New York City, and Vivian Eisenstadt, an orthopedic and spine specialist in physical therapy in Los Angeles. Here are six quick facts we picked up about the glutes.

1. WHEN IT COMES TO THE BOOTY, BIGGER MIGHT BE BETTER.

Your glutes are your body's largest and most powerful muscle group, Stark tells Mental Floss. Your powerful buttocks are actually comprised of three gluteal muscles: the gluteus maximus, gluteus medius, and gluteus minimus, often shorthanded to "the glutes."

"They are extremely important in preventing all sorts of injuries," Stark adds. Many injuries, from hips to knee, stem from weak gluteal muscles. It's important to keep your glutes strong—but not tight.

2. IF YOU'RE NOT BORN WITH IT, YOU CAN PAY FOR IT.

In 2016, 4251 people in the U.S. got a butt lift, and another 2999 got butt implants, according to the American Society of Plastic Surgeons' 2016 Report [PDF]. These numbers make sense, because according to the professional organization, butt implants were the fastest growing type of plastic surgery in 2015. Yet while butt surgery may be increasingly popular, it still hasn't cracked the top 5 of cosmetic surgical procedures (breast augmentation, liposuction, nose reshaping, eyelid surgery, and facelift, in that order).

3. WHY DO WE CALL A BARE BUTT A "FULL MOON"?

In the Ming dynasty in China, bare buttocks were seen as quite erotic and they were often compared to a full moon, perhaps because of their pert roundness.

4. VICTORIANS WERE REALLY INTO EROTIC SPANKING.

While spanking has been proven bad for kids, it may be good for your sex life. Victorians were particularly obsessed with "erotic spanking." According to Deborah Lutz, author of Pleasure Bound: Victorian Sex Rebels and the New Eroticism, "something like 50 percent of the pornography of the time was flagellation pornography," she told Salon. One prevailing theory suggests that the practice has its roots in the upper-class men who as children had attended private schools, where a common punishment was to be whipped in front of their classmates with birch switches. "Any schoolboys who wanted to could come and watch. For many of these boys, of course, it was traumatic, but for other boys it's an erotic experience. It developed into this masochistic eroticism," Lutz said.

5. BACK PAIN MAY ORIGINATE IN YOUR BUTTOCKS.

"A little-known fact is that strengthening your buttocks helps decrease back pain," Eisenstadt tells Mental Floss. "While physical and occupational therapists know this, many people are not aware and increase risk of injury by neglecting this important muscle." In her practice, when people come in complaining of back pain, she checks out their butts first.

6. A SMALL NUMBER OF PEOPLE HAVE THIS UNUSUAL POSITIONING OF THE SCIATIC NERVE.

"Sciatica is a laymen's term for pain down the leg," says Stark. The sciatic nerve typically lies right on top of the piriformis muscle, a small muscle that lives deep in the buttock, behind the gluteus maximus. For a certain percentage of the population, however, he says, the sciatic nerve sometimes pierces right through the muscle. Those people are especially prone to sciatic pain, he says: "All it takes is a spasm to cut off that nerve."

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The Body
8 Little Known Facts About the Temple
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The human body is an amazing thing. For each one of us, it’s the most intimate object we know. And yet most of us don’t know enough about it: its features, functions, quirks, and mysteries. Our series The Body explores human anatomy, part by part. Think of it as a mini digital encyclopedia with a dose of wow.

 

At the edges of the eyebrows, you’ll find the temple, the flat, tender side of the head where you often press your fingers to relieve a headache. In movies, one karate chop to this area can allegedly kill a person, but is this really true? What lies beneath that smooth surface of skin that’s so delicate? To learn more, Mental Floss spoke to Dr. Abbas Anwar, an otolaryngologist and head and neck surgeon at Southern California Head and Neck Medical Group in Santa Monica.

1. THE TEMPLE IS A JUNCTURE.

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It's technically where four skull bones—the frontal, parietal, temporal, and sphenoid—meet in the skull. This vulnerable juncture is called the pterion, which means "wing" in Greek but sounds like a kind of dinosaur.

2. IT REVEALS A DISTANT LINK TO REPTILES.

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The temporal bone itself is made up of five smaller parts, which fuse together before birth. One of these pieces, called the tympanic part, may be evolutionarily linked to the angular bone in the lower jaws of reptiles.

3. IT'S THE THINNEST PART OF THE SKULL …

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While these skull bones are "relatively strong," though thin, Anwar tells Mental Floss, the point at which they meet is the weakest point because there's no solid bone beneath them. "As such, this area is at risk with direct horizontal blows."

4. … WHICH IS WHY MAORI WARRIORS CRAFTED A SPECIAL WEAPON TO CRUSH IT.

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When Maori warriors of the first nations tribes of New Zealand and Australia went into battle, one weapon they took with them was the patu onewa, a flat, heavy club carved from stones such as basalt, and sometimes jade, for the specific purpose of delivering a fatal, crushing blow to the temple.

5. THE TEMPLE COVERS A MAJOR ARTERY.

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Running below these bones is a large artery known as the middle meningeal artery. It supplies blood to the outer covering of the brain, the meninges. "If hit hard enough, one of the four bones at this point can fracture inward and lacerate the middle meningeal artery," Anwar explains. This can cause an epidural hematoma, essentially "a collection of blood that builds up around the brain and compresses it."

Severe bleeding can cause "catastrophic consequences" if not recognized and treated promptly, including brain herniation (bulging brain tissue), hemiparesis (weakness of one side of the body), and death.

6. IS YOUR TEMPLE A SACRED SPACE?

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Etymologists don't entirely agree on the meaning of the word temple, which has multiple origins. It may derive from the Latin word for time, tempus, according to a Dartmouth Medical School anatomy course: "The connection may be that with the passage of time, grey hairs appear here early on. Or it may relate to the pulsations of the underlying superficial temporal artery, marking the time we have left here."

It could also possibly hail from the Greek word temenos, meaning "place cut off," which would explain the idea of a temple of worship as well as that juncture of bones at the side of the head. 

In Old English, tempel meant "any place regarded as occupied by divine presence," which might be code for the brain as the residence of consciousness or God.

More likely it's related to the Greek pterion, which as you'll recall means "wing." In Greek mythology, Hermes, messenger of the gods, wore a helmet with wings, which were positioned over the temples.  

7. IT'S PRONE TO SKIN CANCER THAT'S HARD TO REMOVE.

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Surgeon Gabriel Weston writes in The Guardian that skin cancers frequently turn up in this area from over exposure to the Sun, which makes for a challenging surgical procedure. "It is often not possible simply to sew up the hole in the skin after cutting a cancer out, since doing so can easily distort the contour of the eye," he writes.

To get around the problem, Weston uses a special technique called a Wolfe graft. After cutting away the cancerous lesion, "I measure out a circle of equal size in the skin above the collar-bone (where the skin is similar) and remove it." He grafts this skin patch to the patient's temple "with tiny silk sutures." 

8. BRAIN FREEZE ISN'T IN YOUR BRAIN.

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Sometimes when you eat or drink something cold too quickly, you get brain freeze, which can feel like someone has taken knives to your temples. But the pain isn't actually in your brain at all, as brains have no pain receptors. While researchers haven't been able to determine a cause of what's technically called sphenopalatine ganglioneuralgia, or sometimes HICS ("headache attributed to ingestion or inhalation of a cold stimulus"), they theorize that the painful freeze you experience is likely caused by a quick cooling of the blood in the back of your throat at the juncture your internal carotid and anterior cerebral arteries, which can cause spasms or constrictions of the arterial branches.

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