November 1917: prosthetic arms for war casualties

It seems appropriate, as we’re in Remembrance Week, to take a look at the Engineer’s coverage of one of the most distressing aspects of the First World War from an engineer’s point of view: the design and production of prosthetic limbs for those wounded in action.

This article, written by Edward Hobbs, a prosthetics designer, describes the function of an articulated arm to replace a limb which had been amputated at the shoulder. held on by cross-straps and a waist belt, the arm contained an arrangement of levers, bearings and cables which allowed the user to move the forearm and flex the hand using the remaining shoulder muscles. This allowed the user to lift weights up to about 2lb; enough to handle a full glass of ‘liquid refreshment’ (probably about a pint, we’d imagine) or raise his hat.

‘For many years it had been considered absolutely impossible to do anything for a man who had lost his arm at the shoulder,’ Hobbs said, ‘whereas the Hobbs hand can be raised or lowered at the shoulder, flexed and extended, the wrist twisted and the hand clasped at will — without any assistance from the sound hand.’

The arm came with interchangeable hands for a variety of different uses, with the ‘full clasping hand’ deemed the most popular and versatile. ‘With that hand a man can with a little training rapidly become fully proficient as a mechanical draftsman, or clerk; can handle his knife, fork and spoon; tie his necktie or his bootlaces, light his cigarette, play cards or billiards, and a thousand or one things besides,’ Hobbs claimed.