Lateral motion vs. Finger stretching

[palmtree]

Hey all, I'm struggling with the following question: is it better to prioritize on moving the wrists/hands laterally across the keyboard, thus bringing the fingers directly over the keys they are going to hit (or at least closer), or rather to stretch the fingers horizontally and keep the wrist/hands more immobile?

For context, I'm playing a piece where, in the left hand, I hit a C followed by A and C' together; then C followed by Bb and C' together. My hands are big enough to stretch the distance and hit Bb and C' while keeping my 5th finger on the C to prepare for when I hit that note again... but if I do this motion too many times my fingers and hand begin to feel rather uncomfortable. It's not painful, but I can tell it's getting there.

Are there stretches and/or flexibility exercises for me to work on being able to stretch the distance comfortably, or would it be better to move my wrist across the keyboard and not worry about trying to stretch?

Thank you all for your time, and I hope this made sense!

[brogers70]

I think that it's a good idea to minimize the amount of time your hand is in an extended position. I would not think it a good idea to hold your hand in an octave span simply in order to avoid moving the hand laterally - that sounds like a sure way to induce unnecessary tension. Sometimes you have no choice, but when you can, let the hand relax into a non-extended position.

[ego0720]

Lateral movements is my vote. Avoid stretching the hand.  I would identify this as the Taubman approach.

There is no healthy way to stretch for the purposes of expanding the hands octave reach. But you can pull the fingers vertically backwards at the knuckles and wrist the opposite direction to give it range for general hand-finger suppleness. These unrelated to the original question.

[quantum]

In passages that suggest constant and repetitive abduction-adduction, a stretched hand is preferable.  Repetitive back and forth of abduction and adduction is a fatigue point, and maintaining a stretched hand requires less workload and causes less fatigue.  Example:  LH waltz pattern of bass note, chord, chord.  Chopin Op 18, and similar. 

In passages that do not require the maintenance of a specific hand shape, or where it is impractical to do so, the lateral and flexible movement from the wrist is preferred.  Broken chords tend to do better with involvement of the wrist, as opposed to a static stretch.  Example: broken chords that span intervals larger than an octave.  LH of Chopin Fantasie Impromptu, LH of Op 27/1.

Whichever technique is better suited to the passage, maintaining an open hand and flexible palm is essential.  Closed or small shaped hand positions carry more danger of inducing unwanted tension in the playing mechanism.  Of course there are instances where closed hand shapes are needed, but an open hand is far preferable.