Yes, it's true: the Germans killed the beam spring.
In
An overview of standards and guidelines for visual display terminals it is written,
The first recommendation, having the elbows at right angles and the forearms horizontal, was adopted in the German DIN standard. For this posture, the distance between the forearms and the upper side of the thigh is between 100 and 130 mm depending on operator body size. In order to allow sufficient leg room, the table top and keyboard combined cannot be thicker than about 100 mm. According to DIN 66234, the thickness of the keyboard, measured at the home row, must be limited to 30 mm.
Recent research has not added much to Lundervold's observations. However, a couple of studies have raised
questions about the appropriateness of the 90 degree elbow angle recommendation. Zipp et al (1980) measured EMG
in several muscles during a typing task. They observed that there is a flat minimum in electromyographic (EMG) activity for elbow angles between 90 and 75 degrees. Their results therefore support the idea that the forearm should slope upwards with an elbow angle less than 90 degrees.
The findings of Zipp and his co-workers are supported by those of Grandjean et al (1982), who found that typists generally prefer to elevate the forearms, that is, to decrease the elbow angle. The authors pointed out that the upper arms were usually not hanging down vertically but were slightly elevated both sagittalty and frontally
This seems to imply that the Germans were wrong to kill the beam spring, even under the reasonable assumption that people are too stupid to adjust their desk.
In
Standards factor: the emergence of ISO 9241 and some of its parts it is mentioned that “the U.S. voted to disapprove the DIS of ISO 9241-4, Keyboard requirements”, but not why.
