When people are talking about the best ergonomic mouse, we frequently hear remarks about the so called “Handshake” position, alleged to be the most natural and relaxed. This statement is then substantiated by means of a picture or video in which a skeleton is used.
To our judgment this is an aberration, for, we as human beings can only act and do as we do because of physical functions for which we need muscles, tendons, blood, arteries, veins, nerves etc. By leaving out these higly significant elements of the acting human body, one gets a most unrealistic if not ridiculous impression.
Continuing Ergonomic Research
At both Erasmus (Rotterdam, Netherlands) and Hasselt (Belgium) University Medical Centers, highly educated researchers continue to study the human body, based on corpses, to simulate the situation in a working environment. This has also taken place for the position of forearm and hand while operating a computer mouse.
The first point to be made is that there is a fibrous sheet (membrane) which connects the 2 bones (Ulna and Radius) of the forearm. Rotating the forearm like when you put your hand on the desktop has a significant effect on this membrane. Next to this phenomenon one should not forget that a number of muscles which control the fingers are connected to this membrane.
In studies, the behaviour of this membrane has been looked at to establish the effects of for example a position like the “handshake”.
Truly neutral hand position on an ergonomic mouse is not vertical but slanted
Recent research by Professor K.J. van Zwieten and his team of the University of Hasselt (Belgium), demonstrated that the Handshake position results in a maximally taut membrane between the 2 bones, Ulna and Radius. Therefore the need to grip and pinch a mouse in a Handshake position, for example with a vertical mouse results in unnecessary strains in the already taut membrane. This could possibly result in physical complaints. In two publications, the resesarchers have stated that the use of a vertical PC-mouse in Handshake positions should therefore be re-evaluated.(see publication 1 and publication 2)
The studies with regard to the design of the computer mouse by Professor Han Ming Chen of National Taiwan University and Professor Snijders of Erasamus University Medical Center are of significant interest.
Erasmus University has already shown that the ElectroMyoGram (EMG) measurements of a vertical mouse show a continuous activity without any moment of rest, just like a standard computer mouse.
This, among others, is the result of the reaction force of the thumb with respect to the fingers, not only due to holding the mouse (gripping and pinching) but even more when switching.
By means of EMG measurements it is shown that a slightly slanted mouse body (like the HandShoe Mouse) prevents the above mentioned unnecessary tensions.
One must therefore assume that the truly neutral hand position on an ergonomic mouse is not vertical but slanted.