- Sesame Street has enchanted adults and children alike for over 40 years
- Creator Jim Henson died in 1990, inspired a new generation of "Muppeteers"
- Puppeteering tough physical work, with some artists needing shoulder operations
- Sneak peek inside workshop reveals Frankenstein's lab of spare eyes and noses
Art of Movement is CNN's monthly show exploring the latest innovations in art, culture, science and technology.
New York (CNN) -- Since the 1960s, Sesame Street's puppets have been running, singing and dancing their way across our TV screens as if possessed of a life of their own.
But behind Sesame Street's Muppet puppets is a world almost as surreal -- where "Muppeteers" and Muppet makers create the comedic illusions that have bewitched generations of children, and earned the show over 100 Emmy Awards.
The life of a Sesame Street Muppeteer
If you thought the job of the Muppeteer -- putting your hand in a puppet and putting on a funny voice -- was child's play, think again. From hiding inside Oscar's trashcan to lip-syncing Kermit singing "It's Not Easy Bein' Green," Sesame Street's puppeteers must be prepared to stretch their bodies -- and imaginations -- to the limit.
"We get into all sorts of crazy positions," says Muppeteer Eric Jacobson. Most of his time is spent with at least one arm above his head. "Sometimes we'll be lying on the ground. Sometimes we'll be inside a piece of furniture with our arms sticking through a hole in a seat," he says.
Read this: 10 greatest movie puppets
Indeed, it's not uncommon for long-time puppeteers to undergo shoulder and hip operations after years of straining skyward. What makes it all worthwhile, says Jacobson, is making the human connection.
"Normally I'm looking at a monitor and making sure that you at home can see the puppet's eyes, because they just don't have a soul without their eyes," he says. "When you can see their eyes you can tell where they're looking, you can tell that they're engaged, that they're thinking, that they're listening."
Henson's legacy
When Jim Henson started work on Sesame Street 44 years ago, he never could have known that it would become one of America's most influential children's television shows.
The father-of-five tragically died from pneumonia in 1990, at the age of 53. But his legacy lives on in the new generation of puppeteers, like Jacobson, who bring Sesame Street's fantastical creatures to life.
"I was in my freshman year at film school, thinking I was going to be a director, writer, producer," explains Jacobson. "When Jim Henson passed away I suddenly realized how much this man meant to me growing up and I felt like I had to do something to continue his legacy.
"I was a part of that first generation of kids who grew up watching Sesame Street, so those characters were like family to me."
Watch this: 'War Horse' puppet comes to life
Today, Jacobson is the puppeteer behind legendary Sesame Street residents Grover and Bert.
Bringing to life the unique personalities and voices of these creations demands huge coordination and quick-fire comic timing to keep the viewers engaged with the characters.
First and foremost, says Jacobson, the puppet must look like a creature from the real world. "You're conscious of the puppet's posture and making sure that it looks as though it has a believable skeleton -- you want to make sure it doesn't have a broken neck," he says.
Material world
If bringing Muppets to life is an art form, so is creating them. Step inside New York's Muppet Workshop and it's a bit like stumbling into Frankenstein's laboratory, with drawers full of spare eyeballs, noses and mouths.
Watch this: Master puppeteer Basil Twist
The puppets are made from foam and rubber with the seams hand stitched to allow for greater flexibility. The big gaping mouths are created with the same gasket rubber found in cars, with each character usually taking around two-and-a-half weeks to create from scratch.
"We'd like to think they last forever but they don't," explains Rollie Krewson, who has been making Muppets for Sesame Street and other Jim Henson productions for almost 40 years.
Years of singing and dancing their way along Sesame Street inevitably take their toll and, sadly, every Muppet has its expiry date.
"Over the years it just deteriorates, and after 15 to 18 years you have to totally replace it -- it just goes to little toast crumbs."
The Muppets of Sesame Street might not last forever, but after more than four decades bewitching audiences, it seems their appeal is as strong as ever.