Arm as Basis for Hand-exertion

Question: Should the hand and forearm be used as a basis for hand-exertion during piano playing?
The hand and forearm are important parts of the body involved in piano playing, but they should not be the sole basis for hand exertion. Piano playing involves a complex interplay of different muscles and joints throughout the body, including the fingers, wrists, elbows, shoulders, and even the back and legs.
While the hand and forearm do play a significant role in controlling the movement and force of the fingers on the keys, it is important to maintain a relaxed and balanced posture throughout the entire body to prevent strain or injury. This means using the larger muscles in the back and shoulders to support the weight of the arms and hands, and engaging the core muscles to maintain stability and control.
Additionally, piano playing should not be limited to the use of only one type of touch or technique. Different styles and genres of music require a variety of techniques, including legato, staccato, chordal playing, and more. This requires a flexible and adaptable approach to playing, using a combination of different muscle groups and movements to achieve the desired sound and expression.
In summary, while the hand and forearm are important components of piano playing, they should not be relied upon exclusively. A well-rounded approach to playing that incorporates the entire body and a variety of techniques is essential for achieving optimal performance and preventing injury.

The basis for this hand-exertion, must be provided by the arm (forearm and upper-arm) itself, in one of the six forms to be described in the next module. Thus we see that the playing apparatus roughly consists of four components of four living levers:

1. Finger
2. Hand
3. Forearm, and
4. Upper-arm

We must now consider all these four components or elements of touch in further detail. The fulcrum for the finger is the first phalanx and metacarpal bone.
The phalanges or finger bones are fourteen in number three for each finger, and two for the thumb.

I am often asked to give advice on how to play a passage faster. This is almost impossible to diagnose over text, without seeing the person interact with that particular motion involved with the generation of sound. The short answer is that there could be many factors preventing the obtainment of speed, including stretching, twisting, or last minute adjustments and inefficient movements. The body may not be in the correct position, the arm might be a few centimeters from where it needs to be. As it happens, the tools for playing faster are also the tools for an optimal technique. Go for skill and speed will be a by-product.
A common assumption is that fingering is the magic bullet to instant speed. While fingering is critical, fingering alone is not enough to make the passage flawless. It is the combination of logical and comfortable fingering with the relevant choreography of the

1. "in and out" movements,
2. walking hand and arm adjustments,
3. shaping,
4. grouping

that make a good fingering work.
Without the understanding of the accompanying movements and how much of each to apply, the best and optimal fingering could potentially not make much sense.