Most slider buttons require the user to push with the thumb while pulling the knife in the direction of the cut. These opposing forces cause a certain amount of strain that can be avoided with a design like Ergo Pull, where the user pulls both the slider and the knife in the same direction.This may seem like a small adjustment, but the results are impressive, especially when considering cutting tasks repeated over long shifts where there is a potential for cumulative strain injuries. In testing done by United States Ergonomics (an independent third-party testing agent), Ergo Pull technology resulted in less forearm effort, upper arm effort, and hand muscle strain than the standard push-blade lever utility knife.