I have been playing for over 10 years but never had technical guidance on piano. Lately I have been trying to correct that. I have been working on getting my scales and runs more relaxed, homogeneous sounding, and fast.
For this I have been trying out a new approach, which involves more playing with the "elbow" rather than with the fingers. A good example of the movement is when you drop your fingers on a table surface, sequentially, like when acting impatient. This movement is guided by the hand, and the fingers just follow and control the hitting moment, but there is no effort coming from the fingers nor from the wrist. Also there is little to no finger-lifting motion, as the whole hand lifts for the next position.
When I translate this into piano, I try to keep the wrist relaxed and guide the downward movement from the shoulder/elbow. The main issue that I have with this is with the lateral movement, on getting the "thumb under" motion (this actually avoids the thumb-under motion, as it forces to rather jump to the next position), and get a smooth transition when I switch the hand position, as the downward movement often makes an accent if I am not careful.
So far this has drastically increased the velocity and lightness of my runs, but I would require a lot more time for perfecting this movement.
Is this a 'traditionally' correct approach? Or is there something that I am neglecting with this technique?