Negative vs positive tilt?

[jamadagni]

I'm sorry if this question is noobish but I did search the forums and it still wasn't very clear to me:

This thread by Jacobolus and other posts of his and others here, here and here seem to indicate that negative tilt, where the part of the keyboard closer to the user is higher than the one far away is beneficial. For instance this keycap profile diagram:
But I am not able to understand how negative tilt is beneficial. I am inclined to think that if "higher" row keys are actually physically higher then it will be easier for fingers stretching forward to hit them, no? If I'm wrong please point out the flaw in my reasoning...

The tilt/tent kit provided by [url=https://www.indiegogo.com/projects/ergodox-ez-an-incredible-mechanical-keyboard]the ErgoDox EZ[/url]:
[img]https://images.indiegogo.com/file_attachments/1409329/files/20150423101014-tilt-tent-1.jpg">>
is shown to provide for positive tilt but probably that can be turned the other way around too, so that's not an indication either way.

But sculpted keyboards like Katy, Dactyl Cave and rsheldiii's cave seem to increase the height as we go to the "higher" rows i.e. digit/F rows. The Kinesis which is the inspiration for the above individual efforts, does seem to go down though, but it doesn't have a proper F row and I'm not sure how that would factor into the equation.

Finally, the point of DCS and other profiles seem to make it convenient for "higher" row keys to be hit by the fingers stretching upwards so it does seem that positive tilt is good as per my reasoning above?!

Totally confused here...

[kurplop]

So much has to do with your typing style. The goal is to keep your wrists from extending back. If the persons posture and height relative to the keyboard allows for a neutral wrist position regardless of the keyboard angle, your doing it right.

[Melvang]

The tilt you "should" have is dependent on a lot more than just what profile caps you have.  Also has to do with what angle your wrists sit at when at your keyboard.  This is also very dependent on the height of the keyboard in relation to your persons.  If your keyboard sits higher and your arms have to reach up, then a positive tilt is probably better, if your keyboard sits on your lap, then a negative tilt would be my guess.

Look at some old pics from offices back in the beam spring days.  Those keyboard have TONS of positive tilt, but they also sit very high in relation to the person typing.

[tp4tissue]

The truth is,   this really doesn't matter.

Because  the major RSI issues are far greater influenced by other things such as keyboard height,  table height, elbow height, wrist tilt, etc..