Organization of the upper limb movement for piano key-depression differs between expert pianists and novice players

The present study investigated the expert-novice difference in the organization of upper-limb movement for the key-depression on the piano. Kinematic and electromyographic recordings were made while experts (N = 7) and novices (N = 7) of classical-piano players performed a right hand octave keystroke to produce four different sound dynamics. The joint torque generated at the key-bottom moment (key-force torque) was also estimated. At all sound dynamics, the experts showed a larger finger attack angle, more flexed shoulder, wrist, and MP joints, more extended elbow joint, and smaller key-force torque at the MP joint than the novices. The level of co-activation in the finger flexor-extensor muscles during the period prior to the key-bottom moment was also lower for the experts. To attain the large attack angle by the experts, as the fingertip depressed the key to the bottom, their shoulder was actively flexed, the forearm was thrust forward, and the hand was rotated forward. The novices, on the other hand, actively extended their shoulder to move the forearm and hand downward to depress the key. These results confirmed a substantial difference in the key-depression movement organization between the experts and novices. These findings also suggest that experts use a synergistically organized multi-joint limb motion that allows them to minimize the biomechanical load and muscular effort to the distal muscles. The novices, on the other hand, tend to rely on a rudimentary synergy of joint motion developed through daily experience.