A “sliding” latch: due to this instrument’s size, the patient has to have a fine grip using the first three fingers. Also they must associate a small movement in the vertical plane to free the latch and move it along the horizontal plane. The patient can also be asked to do this task without using the visual channel, which means that they must rely on tactile-kinaesthetic information.
A “turning” handle: in this case the grip involves control with the thumb and side of the second finger. A supination and pronation rotating force is required to turn the handle.