The ability to play repeated up or down bows at the heel of the bow is tested throughout the Ševčík variations.
Like Variation 3, the bowstroke for both the up bows and the down bows is a collé stroke that requires an active movement of the hand and fingers.
For the down bows the bow plays the note, leaves the string and while in the air, the fingers and hand re-curve ready for the next down-bow stroke, thus completing the circular shape.
This is reversed for the up bow.
As with all the Ševčík variations look for the long musical line and avoid emphasising the beginning of every bar. For instance the first 4 bars of variation 4 can be seen as a classic question and answer phrase, with bars 1 – 2 as the question and bars 3 – 4 as the answer.
Use the side of the hair so that you have a thinner edge with which to contact the string.