Figure 4
From: Control of multi-joint arm movements for the manipulation of touch in keystroke by expert pianists
The time-history curves of net joint acceleration (ACC in red) and its six components at the shoulder, elbow, wrist, and finger joints, and key and hand vertical position at the forte loudness level when one representative pianist were striking the key with the pressed (left panel) and struck (right panel) touches. MUSs, MUSe, MUSw, MUSf, VEL, and REA corresponded to joint acceleration attributed to shoulder MUS (violet), elbow MUS (right blue), wrist MUS (right green), finger MUS (navy blue), VEL (ocher), and REA (grey), respectively. The curves represent the average of 30 keystrokes. The dotted vertical lines indicate the moments of finger-key contact (a) and lowest key position (b).