Queensland State Archives posted a photo:
Isometrics in the office
Hamburg, – Ever since it has been proved that pains in the head and shoulders and signs of general tiredness can be caused by feeble muscles millions of people have taken to isometrics.
In the Federal Republic of Germany an estimated 70,000 office workers spend two to ten minutes a day doing isometric exercises.
Secretaries, for instance, can be seen pressing the flat of their hands against their typewriters and pressing their fingers together or their heads against their hands. Other isometric exercises, designed to keep unexercised muscles in trim, can be practised without onlookers noticing.
Description source:
The Canberra Times, 21 May 1969
View the original image at the Queensland State Archives:
Digital Image ID 2711