Apple famously bent a cardinal rule of industrial design when it introduced the iPhone 6. Featuring a sprawling 5.5-inch diagonal glassy screen, the device proved simply too large for users with smaller hands to comfortably reach the top corners. To compensate for this physical mismatch, the company engineered Reachability—a software workaround triggered by a quick double-tap of the home button that shifts the entire user interface downward by two inches, bringing applications temporarily into the range of tiny hands.
The feature was not merely a clever salve for an ergonomic oversight; it served as a stark acknowledgment of an unavoidable truth in modern manufacturing: when building a product meant to scale across millions of human bodies, one size can never truly fit all.
"The double tap is the most obvious human factors workaround," says Luke Westra, a designer at the Chicago-based innovation and design studio IA Collaborative.
When Westra speaks about human factors, he is referring to a critical discipline of design concerned primarily with how human bodies interact with their physical environments, a field more commonly known as ergonomics. All competent industrial designers think about human factors when developing a product, from consumer electronics to heavy machinery. Those who fail to account for these biological realities inevitably end up crafting products that fail in everyday use—stools that sit too high or too low for the dining table, or office chairs that leave employees with chronic backaches.
While contemporary icons like Steve Jobs and Jony Ive relied heavily on advanced computers and computer-aided design (CAD) software to shape the sleek final form of the iPhone and other modern electronics, designers decades prior utilized an entirely different kind of instrument to understand the human body. Long before digital modeling software dominated the industry, industrial designers relied on a brilliant, analog tool called Humanscale to help them bridge the gap between machinery and anatomy.
Humanscale was not a digital database or a computer program, but rather a sophisticated physical set of nine rotating disks packed with more than 60,000 distinct data points. By spinning the cardboard and plastic selectors in any direction, a user could align a series of numbers within clear windows, instantly revealing the correct measurement values and anthropometric statistics for whatever demographic subject they happened to be designing for at the moment.
During the 1970s and 1980s, industrial designers treated the reference tool as an indispensable cheat sheet, relying on it for rapid data points that governed everything from furniture height to control panel layouts. But after MIT Press halted its production and distribution in the mid-1980s, the physical disks gradually faded from mainstream use and transformed into rare collector’s items. Pristine copies began fetching upwards of $2,000 on online auction sites like eBay. Now, however, Humanscale is officially making a comeback. Thanks to Westra and a dedicated team at IA Collaborative’s Venture arm, design professionals and enthusiasts alike can purchase newly minted reprints of the classic design tool, priced at $79 per individual print or $199 for the complete set.
The historical roots of Humanscale stretch back to Henry Dreyfuss & Associates (HDA), the legendary industrial design firm responsible for shaping some of the most iconic objects of the twentieth century, including the classic Honeywell round thermostat and Bell’s ubiquitous tabletop telephone. The firm’s founder, Henry Dreyfuss, was an early and passionate champion of ergonomic design, steering his studio to approach the practice almost like an exact science. Under his guidance, the firm operated under the strict philosophy that form must always follow function, and function must follow data—specifically, lots and lots of reliable human data.
In the early decades of industrial design, no product was ever put into production without first consulting a comprehensive laundry list of bodily statistics. Designers needed concrete numbers for average human height, reach, arm span, sitting hip width, and the natural viewing angle from a standard office desk. Yet gathering those statistics was often a monumental hurdle.
"The big problem back then was that data wasn’t necessarily in a nice, easily usable form," recalls Bill Crookes, who worked at HDA from the early 1970s until the firm closed its doors in the early 2000s.
While physical data certainly existed, it was scattered and piecemeal. If an industrial designer wanted to know the precise dimensions and proportions of the average North American man’s leg, they had to dig through historical military records. If they wanted to understand the maximum decibel level comfortable to the human ear, they had to track down specialized statistics published by government agencies like the Environmental Protection Agency. Recognizing this massive inefficiency, one of HDA’s key partners, Niels Diffrient, became determined to consolidate all of this fragmented ergonomic data into a single, cohesive, and easily portable tool that working designers could take directly with them into the field.
Diffrient and his collaborative team, which included Crookes, spent years tediously gathering, verifying, and organizing human engineering data from every available credible source. Through their rigorous research, they learned hyper-specific details about the physical world, such as the fact that the average height of a fedora hat was precisely two inches—a seemingly minor detail that suddenly became crucial when taking door frame measurements into architectural consideration. They combed through official demographic sources for reliable information on the physical stature of wheelchair-bound men and women. They measured the subtle differences in gripping posture when a human hand wraps around a cylinder, a ball, or a pencil, and then meticulously organized all of this vast information onto Humanscale’s themed, rotating disks.
"They laid out every little bit of info on these tools by hand with a square triangle and a compass on a drafting table," explains Nathan Ritter, a design researcher at IA Collaborative.
The visual execution of the tool was just as impressive as the research behind it. Detailed illustrations on the front and back of the disks depicted human bodies and specific anatomical parts in various positions, accompanied by sharp arrows annotating dozens of distinct measurement points. Simply rotating the physical disks allowed a designer to filter the massive data sets instantly, revealing information specifically tailored to women, men, and children across their various statistical percentiles.
Upon its release, Humanscale was widely celebrated as a masterpiece of information design. Today, it is regarded by design historians as one of the very first interactive data visualizations. Although the physical disks have largely been superseded in modern corporate studios by technologically advanced tools—such as proprietary digital ergonomics databases that major design firms pay thousands of dollars to license—the philosophy behind Humanscale remains deeply foundational.
For the team at IA Collaborative, allowing the Humanscale disks to fade permanently into obscurity felt like an avoidable tragedy and a missed opportunity for the broader design community.
"They’re still just as relevant today as when they were just launched," Ritter notes.
The studio’s initial phase involves reissuing the original physical disks and accompanying books, but their long-term vision extends even further. Eventually, the team plans to digitize the rich archive of information, developing a modern interactive interface for the data that can be accessed seamlessly by today’s digital-first creators.
The driving motivation behind the reissue is a belief that most modern creators could benefit significantly from a tangible, straightforward tool to ensure their designs remain anchored to the actual physical needs of the people who will use them. In an era where digital tools allow designers to work entirely within virtual environments, losing touch with the physical realities of the human body remains an easy trap to fall into.
"You can design anything in a vacuum," Westra concludes. "Pero if you’re not considering the people who are going to use it, they’re not going to have a great experience."
