Proper posture means to sit upright and do not hunch your back.
Curve both your fingers on the piano keyboard.
From the back, the shoulders and arms look relaxed.
CAUTION: The photos below show postures that you must avoid.
Avoid sitting too far away from the piano with your arms stretched out.
Avoid sitting too near the piano with your elbows tucked backwards.
Avoid sitting with your feet crossed over each other. Keep both feet flat on the ground.
For students who are petite, a stool to support the legs is necessary to maintain balance.
Remember, good posture facilitates good performance.
Good performance means good music.