The rhythmic finger-fall in the left hand is important and affects our coordination with the right arm.
There are some bow-strokes (sautillé, three note chords) where it can help to focus on the action of the bow arm. Passages of up-bow staccato however can benefit from thinking primarily about the left hand and allowing the bow to follow along.
It is also a good general principle in our practice and problem-solving to switch our attention away from the side of the body that we are having difficulties with to the side of the body that we are not.
For instance if we are working on a difficult passage of double-stops or harmonics it can help to focus on our point of contact with the bow and resonance of sound. Or if we not happy with a passage of ricochet then we can focus our practice on the clarity and evenness of our left hand.
This excerpt is from Kreutzer Study No.4....