Under the Covers With Jonathan Eilenberg, Ergonomist

April 21, 2023 | Casper Editorial Team

Having a good head on your shoulders isn’t just about being grounded and balanced. According to Jonathan Eilenberg, your spinal alignment is key to everything, including good sleep.

We recently sat down with Jonathan Eilenberg, Casper Lab’s expert Ergonomist to discuss all things posture and sleep. Side and stomach sleepers, we’ve got news for you!

If we have you on the edge of your seat, good. But please let it only be figuratively and momentarily because Jonathan would argue that sitting on the edge of your seat for too long will compromise that all important spinal alignment.

Ergonomics sounds complicated. What is it and how did you get into it?

With a straight back and his head squarely over his shoulders, Jonathan explains that ergonomics is, quite simply, the science of optimizing the interaction between a human being and their environment. “More specifically, it’s the science behind how design can foster a better fit between a person and their environment using nuanced tasks and tools.” The goal: to improve overall system performance and productivity while also reducing the likelihood of physical injury.

After studying Design and Environmental Analysis with a focus on Human Factors and Ergonomics at Cornell University during his undergrad years, Jonathan is no stranger to how human behavior and performance are impacted by the built environment. With coursework in industrial, graphic, and interior design on top of ergonomics, anthropometrics, and biomechanics, Jonathan is well acquainted with the complex systems that shape our daily experiences. “Small things, like the amount of light or the arrangement of tools at a workstation, can have a huge impact on people’s productivity and comfort.”

After college, Jonathan has applied his niche knowledge to help companies improve their workplace ergonomics — be it for employees on a factory floor or behind a desk. Jonathan provides the insight and tools necessary to reduce long-term wear-and-tear injuries like neck pain, shoulder pain, and carpal tunnel syndrome.

What does an ergonomist do at Casper? How do you help people sleep better?

After 6 years working in occupational injury prevention, Jonathan transitioned to a less conscious interaction: Yes, we’re talking about sleep.

At Casper, Jonathan looks at how to develop mattresses that are not only comfortable, but also biomechanically supportive for the widest possible range of sleepers. “We are doing more than just reducing sleep-induced discomfort or injuries. We’re actively trying to provide and maximize more comfort to our sleepers.”

Now, you might be wondering how anyone could get injured when they’re technically not moving for eight hours (on a good night!). It turns out: When you’re sleeping, your body is recovering from a day of musculoskeletal stress and fatigue. If you have poor posture while you sleep, or your mattress and pillow aren’t supporting you in the right ways, you compromise your body’s ability to recover properly. Even if you’re not a professional athlete, you should certainly try to recover like one.

“During short periods of exposure, the body is actually quite resilient,” Jonathan suggests. “But when we sleep, we are actually our most vulnerable because we can’t actively correct our posture.” In many ways, the work Jonathan does at Casper is similar to his previous roles – just designing products rather than workstations to encourage good posture and minimize discomfort and injury risk.

This is nothing to lose sleep over though, right? Or is it?

If someone’s mattress, pillow, or overall bed system is not the right fit for their body, they might end up staying in an awkward posture for seven-to-eight hours (again, on a good night). That can lead to both discomfort and eventual injury in the long run.


Jonathan likens a mismatched bed system to some of the awkward postures we take on at work or with our devices. “We have people looking at laptops, tablets, and cell phones and creating ‘tech neck.’ These show a mismatch between how the human body is built and the task we are performing.”

The same is true for a mismatch between your bed and the task you are meant to be performing in it — sleep.

“My main responsibility is to help guide the design of sleep products that will be optimal for the greatest number of people. It’s a challenge because every person needs something different because every body is unique. We want our products to provide excellent performance for everyone, regardless of if they are tall or short, large or small, have broad or narrow shoulders.” With that in mind, Jonathan works to test, test, and retest new ways to create mattresses with layered interactions so each person will have a more custom, versatile experience.

What is the ideal position for sleep?

Stomach and side sleepers, it’s time to flip over; back sleeping is the safest and healthiest sleeping posture.

Ideal sleep posture all boils down to our anatomy. Stomach sleeping is pretty intense on our internal structures and can leave us with a lot of chronic back and neck pain. According to Jonathan, our spines are very flexible – but only in the forward direction. As a result, stomach sleeping may leave us in face-down backbends while we’re sleeping – especially if our mattresses aren’t firm enough. Eight hours-worth of compressing your spine and keeping your head to one side sounds like one big “ouch.” To minimize (but not eliminate) the ouch, try placing a low loft pillow under one side of your torso to prop up your shoulder and hip on the side you usually turn your head to.

“If you’re side sleeping,” Jonathan advises, “make sure you have an appropriately sized pillow to help keep your cervical spine in alignment.” Otherwise, your head will be cranked to the side while you sleep and you might wake up on the wrong side of the bed. A knee pillow can also help keep your pelvis stabilized.

Pillow dos and don’ts? According to Jonathan, if you’re always sleeping on your back, a thinner pillow is ideal for neck support. If you’re on your side, however, consider a thicker pillow (especially for firmer mattresses) to help align your head and neck with your spine.

What about our mattresses? How can mattresses improve our sleep posture?

Mattress mechanics matter. This year, Casper’s newest models are designed with a special focus on decreasing sink in the waist and hip region — thereby reducing the spinal misalignment that can face side sleepers. Basically, the goal is that the mattress adapts to a side sleeper as if it knows you’re faced in that direction. (Don’t worry, it’s not AI, it’s just clever layering of foam).

Think of buying the right mattress (and pillow!) as a safety net against falling into bad habits. The best mattress will accommodate your way of sleeping in a manner that optimizes comfort and long-term physical health.

The perk? Sleeping with good posture will also lead to better, deeper sleep. “They go hand in hand,” says Jonathan. You want your body to “let go” of the tension in your muscles so that it can truly relax and recuperate — and that’s a goal we can all lean on. Err… stand up straight on?

OK, great. But how can we make ergonomic change right here, right now?

During the day:
If nothing else, the one habit Jonathan advocates for is knowing where your neck and shoulders are. Especially if you work at a desk, take 20-30 second breaks to get up, move around, and realign your head directly above your shoulders. The human head weighs about as much as a bowling ball, so even an inch of forward head movement takes a heavy toll on your neck muscles.
At night:
Find the mattress and pillow combination that allows you to sleep most comfortably with the straightest spine possible. Try to avoid falling asleep in funky positions. (Cuddling — Jonathan explains — is cute and fine so long as you don’t stay there all night, every night). Try rearranging your pillows in a manner that keeps your spine even, especially if you’re sleeping on your side.
Think about your ergonomic well-being as a long, long, very long marathon. “Pragmatically, we often say that ergonomic risk factors are two-fold: repetition and exposure,” explains Jonathan. Take small steps to ensure you’re not repeating bad habits every night. You’ll feel better (rested) for it.