A folder with good ergonomics can prevent your hand from sliding, take a look at a Spyderco Native, for example.
I must confess that I had a folder very similar to that, maybe with a slightly different blade but definitely the same handle (OK, I was around 16 years old and wanted something "stronger" than my SAK, definitely it was not a good choice...).
That folder was really heavy and impractical, I only used the guard to spin it around my index finger (like a cowboy's gun, go figure...), fortunately it was soon condemned to oblivion and I threw it away (literally) as soon as I was able to buy a nicer folder (a Steiner, a mixture of Buck 110 and Puma, defintely and improvement).
Nevertheless, that picture brought memories to me.
Jaime Orozco.