The universal system of finger numbering applies to both hands: 1 is the thumb, 2 is the index finger, 3 is the middle, 4 is the ring finger, and 5 is the pinky. Although the numbering is identical, the actual fingering patterns used in scale playing are mirrored between the hands, so the right hand's thumb-under occurs at different points than the left hand's. The technique of passing the thumb underneath fingers 2, 3, or 4 to continue a scale smoothly is known as thumb under; it should be executed with a relaxed hand and minimal wrist rotation to maintain an even, legato sound.
Finger 4, the ring finger, is often considered the weakest because it shares tendons with the middle and pinky fingers, giving it less independence than the others. Pianists commonly practice exercises such as those by Hanon and Czerny specifically to build strength and independence in fingers 4 and 5. While finger 4 is naturally weaker, careful, focused practice can develop its articulation substantially.
Correct hand position is essential for tone production and injury prevention. The fingers should be gently curved as if holding a small ball, with the knuckles forming the highest point of the hand. The wrist should be level with the forearm, neither drooping down nor raised up, and the fingertips (not the pads) should make contact with the keys. A tense wrist leads to fatigue, pain, and an increased risk of injury such as tendinitis or carpal tunnel syndrome; a relaxed, flexible wrist enables better tone production, smoother passages, and greater dynamic control.
Bench height and seating position are equally important. The bench should be adjusted so that the forearms are roughly parallel to the floor when the hands rest on the keys. Pianists should sit on the front half of the bench, feet flat on the floor, at a distance that allows the elbows to be slightly in front of the body. Both feet should remain flat on the floor in front of the pedals, with the right foot near the sustain pedal and the left foot near the soft pedal. Good posture allows free arm movement and proper weight transfer into the keys. Sitting upright with a slight forward lean, shoulders relaxed and down, and arms hanging naturally ensures that the entire upper body can contribute to playing without restriction.