What do necklaces, eyeliner pencils, rubber bands, and 3D scanners have in common? They are all used in the process of collecting anthropometric data! In this article, we’ll go over some of the common – and uncommon – tools we use every day.
The first tool on our list is the anthropometer.
Anthropometer: The Versatile Judge of All Things Linear
Consisting of four interconnecting metal tubes with a movable slide, the
anthropometer is most suitable for measuring linear dimensions of human bodies, such as heights from the floor, or from a sitting surface.
The tool’s four tubes are engraved in millimeter intervals, and the user can easily read the numerical value through a window in the slide while measuring a study participant. There’s a separate engraved scale on the other side with the zero at the opposite end. When used in that way, this versatile instrument is a beam caliper and can be used to measure body lengths, breadths, and depths.
Invented by Swiss anthropologist Rudolf Martin, the anthropometer comes in four sections for a reason. Martin and the early anthropologists often collected data in remote locations, so portability was as important for the pioneers as it is for us. Since we often collect data around the United States and the world, at our customers’ location, or at truck shows, or on a ferry, or under a stairway (!), that portability is important for us, too. And we can happily report that the anthropometer fits nicely in an overhead compartment.
Calipers: Going the Distance
Smaller calipers, whether spreading or sliding, are devices used to measure the distance between two opposite sides of a particular object, as does the larger beam caliper. In the case of the smaller calipers, they are used to measure the length, breadth, or depth of smaller body parts, such as the fingers, the hand, the face, nose or ears. You may have seen the other specialized caliper at a gym or fitness center. The skinfold caliper measures the thickness of a piece of skin that’s pinched between the fingers. It’s useful in estimating the amount of body fat a person is carrying.
Anthropometric calipers such as these are specifically designed for measuring living humans. As a result, they have rounded tips and flat blades, unlike the very sharp industrial calipers that have similar functions but can be very pointy. We don’t want to hurt our participants!
Hurray for applied design!
Flexible Measuring Tape — Everyone’s Trusty Sidekick
Whether you sew, work in construction, or just like to do arts and crafts alone or with the kiddos, odds are you’ve used a flexible measuring tape.
The ancient Romans were the first to use a measuring device that consisted of leather strips with markings, but it wasn’t until 1864 that William H. Bangs secured a patent for the first spring-return pocket tape measure in the United States.
Consisting of a graduated strip made of plastic, fiberglass, metal, or even cloth, these tapes are among the most common measuring tools. But even the lowly tape comes in a variety of configurations for specific applications. That is the case with a tape measure often used in anthropometry. In fact, our preferred tape was developed for use in forestry – to measure the diameter of trees, determining when they are ready to cut. That’s not our use, obviously, but we appreciate the flexibility of the steel ribbon, its ease of cleaning (for participant hygiene) and the 8 cm leader below the zero marks, so we can get a good grip on the tape while measuring.
Needless to say, it’s an impressive tool for both its simplicity and versatility.
Capturing the 3D Surface: Beyond The Extremities
The tools described above all measure the body in just one or two dimensions. Sometimes it’s useful to capture the size and shape of the body in three dimensions. Older technology, such as the manual headboard or the automated headboard developed for the 1988 US Army anthropometric survey collected the locations of specific points or landmarks in three-dimensional space. We have also used a coordinate measuring machine to locate individual points on a person, or on a person sitting in a vehicle.
An even more comprehensive approach is to capture a 3-D image of a standing or seated person. An older technology for that purpose was stereophotogrammetry (seen above). The image appeared to be in three dimensions when it was viewed with special glasses or a viewer – much like the stereopticon from the early 20th century, or more recent 3D movies at the multiplex.
Now when we need a 3D image, we use scanners of various types. There are specialized 3D scanners that capture the head, the hand, the foot, the ear, and the whole body.
It is tempting to think of the technological progression from the Roman leather tapes to 3D scanners as a straight-line path from old to new. But there is considerable overlap along the way. We view 3D scans as complementary to our traditional body measurements with tapes and calipers. 3D scans capture the shape and contours of a body (or its parts) in ways that are different from the sort of information captured by traditional tools
All of our tools – from the oldest to the newest – are important in creating databases that meet the needs of today’s designers and those of tomorrow. We’re ready to embrace the next new tool that will help us improve the services that we can offer to our clients.
P.S. Those pencils, rubber bands and necklaces mentioned in the first line are used to locate landmarks prior to measuring. They increase accuracy and repeatability!