The walking arm is the up and down movement of the forearm combined with the lateral motion of that same limb.
It is described as an almost invisible down-up motion of the forearm with every key that is played, for it assists in removing the burden from the fingers.
The walking arm must be used with great skill and must involve the forearm only, without involving the upper arm.
This movement contains a resemblance to actual walking.
For example, when the person bends the knee in walking, the foot lifts and moves the person's body to balance over the next step.
Movement across is made by an up-down movement which in turn creates a lateral movement.
The forearm and finger work together on this same principle.
In this way, the forearm is responsive to the needs of the finger, for it will adjust upwards for the finger to move off the key and there will be a slight lift of the arm with the lift of the fingers. These adjustments of the arm up and down to black and white keys make the keyboard feel as if there is no difference in sensation between black and white keys.
Rebound, Synchronization, and Sympathetic Movement
The up and down movement of the forearm combined with the lateral motion of the forearm generates momentum,
which enables the forearm rotation to complete its movement.
p is the symbol used to designate momentum.
momentum= (mass)(velocity)
This synchronization of the fingers and the forearm is in the technique of every fine pianist.
The rebound of the key will assist in playing and is the sympathetic movement of the forearm downward as the finger plays the key and the response upward as the next finger prepares to play. This rebound upward gives a perfect lift in preparation for the next key that is played.
The player should stay as close to the keys as possible, so that the movement is undetectable except as a slight movement .
1) up and down and 2) across
There is no efficient movement across the keyboard without the use of the walking arm.
The playing of the piano involves
vertical
as well as horizontal movement
(down, up, and across) . It is to be noted that, the motion in one direction must not in any way restrict the motion in the other.
This can be avoided by not instigating the next action until each key is completed.
Vertical Action
Vertical action should feel vertical and the timing must be distinct and separate.
The play to the next key must not be made until the first key is completed or else tension will result.
The fingertip should hold on to the bottom of the key and not release it until all action is completed. The act of reaching or expanding begins when the action of playing a finger is over.
Each key has a down-up motion and this sympathetic vibration must occur for each finger. It is perhaps most obvious in large skips when a big swing up and across is needed. When the walking arm is working together with the forearm rotation, the rebound factor is intrinsic and feels natural.
The walking arm element helps to achieve skips in legato which are the so-called un-stretchable distances.
