Sometimes when we practice something a million times and it is always uncomfortable, it is difficult to get that feeling out of the mind, and to start over. I recommend not playing Hanon for the time being, but concentrating on pieces which emphasize flexibility, cantabile tones, and polyphony in the Left Hand, for instance Bach preludes and fugues, or two-part inventions. Rediscover thoroughly the suppleness of the Left Hand, and erase from your mind entirely, the negative sensations you have experienced!
Walter Ramsey