International Symposium on Performance Science
ISBN 978-2-9601378-0-4© The Author 2013, Published by the AEC
All rights reserved

Effect of daily piano practice on finger
kinematics and muscular load
Ayumi Nakamura1, Tatsushi Goda1, Noriko Nagata1, and Shinichi Furuya2
1 Graduate School of Science and Technology, Kwansei Gakuin University, Japan
2 Institute for Music Physiology and Musician's Medicine, Hanover

University of Music, Drama, and Media, Germany

The present study aimed at assessing impacts of daily piano practice onkinematics and muscular activity of finger movements while musicallynaïve individuals played the piano. Six participants were asked to play acertain melody with metronome with the non-dominant left hand. They
practiced fifty trials per day over four successive days. Time-varying joint
positions at the hand were recorded using a motion-capture system consisting of 13 high-speed cameras. Extrinsic finger muscular activities
were also recorded using a surface electromyography (EMG). The
amount of agonist-antagonist muscular co-activation was then computed. The joint angle averaged within each trial was also computed at
the MCP, PIP, and DIP joints for each of the fingers. With practicing, themean angle at the MCP joint became more flexed while the angles at thePIP and DIP joints became more extended. One-way repeated measures
ANOVA confirmed significant changes in the joint posture with daily
practice. The amount of co-activation of the finger flexor and extensor
muscles also displayed a decrease, which indicates a reduction in joint
stiffness. This study provided the first evidence demonstrating that daily
piano practice reorganizes hand posture in playing and economizes muscular work for stiffening joints.
Keywords: motor control; motor learning; electromyography; kinematics; motion capture

Successful tone production in piano playing requires muscular compensation
for the mechanical interaction between the fingertip and piano key. A previous study demonstrated that, while depressing a key, expert pianists configured more upstanding finger posture compared with novice piano players

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WWW.PERFORMANCESCIENCE.ORG(Furuya and Kinoshita 2008a). In addition, the pianists with superior skill
produced smaller finger joint torque elicited by the key-reaction force as wellas finger muscular torque (Furuya and Kinoshita 2008b). A simulation study
also identified mechanical efficiency of the upstanding finger posture in piano
keystrokes (Harding et al. 1993). It is therefore likely that pianists learned toconfigure upstanding finger posture during key-depression through practice.
However, there remain several confounding factors, such as the effect of explicit instruction of the optimal finger posture by piano teachers and geneticeffects. A longitudinal study is needed to directly assess whether extensive
piano practice yields organization of the upstanding finger posture in pianoplaying.
To test a hypothesis that piano practice reorganizes hand posture so as tominimize muscular effort, the present study addressed the effect of daily piano practice on finger posture and finger muscular activity while playing asimple melody. To investigate this provides insights into not only the neuraloptimization process of the organization of redundant motor systems, butalso into pathological mechanisms yielding repetitive strain injuries such as
tendonitis, carpal tunnel syndrome, and focal hand dystonia that have beenprevalent among pianists (Altenmuller and Jabusch 2009, Furuya et al.
2006).
METHOD
Participants
Twelve musically-naïve adult individuals (10 males and 2 females, M=22.4,
SD=1.2 years, all right-handed) participated in the present study.
Procedure
The experimental task was to play a certain melody with metronome (twostrokes per second) with the non-dominant left hand. They practiced fifty
trials per day over four successive days. The target loudness for the tone wasset to approximately 90 MIDI velocity during the task and was monitored by
an experimenter during each trial.
Data acquisition procedures and analysis
The experimental apparatus used was a digital piano with a touch response
action (P-250 YAMAHA Co.), a motion-capturing system consisting of 13
high-speed cameras (eight Eagle and five Hawk Eye, Mac3D system, MotionAnalysis Co.), and a two-channel electromyography (EMG) system (HaradaINTERNATIONAL SYMPOSIUM ON PERFORMANCE SCIENCE

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Electronics Industry Ltd.). To collect positional data on anatomicallandmarks, spherical reflective markers (5 mm in diameter for the hand andkey and 9 mm in diameter for the wrist and elbow) were attached to 5
separate keys and on all joint centers of the right hand and arm (see Figure
1A, 1B). The joint angle averaged within a trial was also computed at the
metacarpo-phalangeal (MCP), proximal-phalangeal (PIP), and distalphalangeal (DIP) joints for each of the fingers. The amount of agonistantagonist muscular co-activation was then computed based on the methods
that we developed previously (Furuya et al. 2011).
Using the day as the independent variable, a one-way analysis of variance(ANOVA) with repeated measurements was performed for each of the dependent variables (joint angle and co-activation). We defined trials 1-5 as pre
5 trials and trials 46-50 as post 5 trials. Newman–Keuls post hoc tests were
performed where appropriate to correct for multiple comparisons. Statisticalsignificance was set at p<0.05.
RESULTS
Joint angles of the striking fingers
Figure 2 shows the mean joint angle at the MCP, PIP, and DIP joints of thestriking fingers (index, middle, ring, and little fingers) during keystrokes
across participants at practice. ANOVA confirmed a practice effect on theMCP joint at the index and middle fingers, on the PIP joint at the index,middle, and ring fingers, and on the DIP joint at the middle finger (Table 1),
which confirmed that the daily piano practice reorganized the hand posture in
piano playing.

A

B

Figure 1. (A) Experimental appearance. (B) Reflective markers for the motion-capturesystem and surface electromyography. (See full color version at www.performancescience.org.)

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Figure 2. Group means of changes in the mean angle of joints during the training session over the four successive days. The 1st, 2nd, 3rd, and 4th rows correspond to theindex, middle, ring, and little finger, respectively. 1st, 2nd, and 3rd columns correspondto the MCP, PIP, and DIP joint, respectively. A bar in grey and white indicates pre andpost 5 trials the mean angle of joints, respectively.

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Table 1. Results of 1-way ANOVA.
MCP | F7,35

PIP | F7,35

DIP | F7,35Index

2.86*5.11**

1.82

Middle6.60**

9.06**

4.12**

Ring

1.71

5.66**

1.70

Little

1.33

0.76

1.46

Note. *p=0.05, **p=0.01.

Figure 3. Group means of changes in the amount of agonist-antagonist muscular coactivation during the training session over the four successive days. A bar in grey andwhite indicates the amount of agonist-antagonist muscular co-activation of pre and post
5 trials. The value was normalized so that the pre-trials of each day became 100%.

Muscular Activity
Figure 3 illustrates the group mean of the co-activation of the finger flexorand extensor muscles over four training days. The amount of co-activation
also displayed a decrease with practice, which indicates reduction of finger
muscular stiffness. A paired t-test confirmed significant changes in the muscular load on the third (p=0.02) and fourth (p<0.001) days of practice.
DISCUSSION
We found that the mean joint angle was increased at the MCP joint of theindex and middle fingers. In addition, it decreased at the PIP joint of the index, middle, and ring fingers, and at the DIP joint of the middle finger. Furthermore, there was a significant decrease of the amount of muscular co-activation through the daily practice. These findings suggest that the practicereorganized the hand posture so as to make piano performance more effi-66

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cient. This idea is in agreement with previous findings that pianists with superior proficiency play more efficiently (Furuya and Kinoshita 2008b, Furuya
et al. 2011). The novelty of the present study is that the learning-dependent
economization of movements occurred even without explicit instructions withrespect to the optimal piano technique, suggesting spontaneous optimization
process of the nervous system (Osu et al. 2002).
Acknowledgments
We thank Professor Miwa at Kwansei Gakuin University for his contribution to datacollection and analysis.
Address for correspondence
Ayumi Nakamura, Graduate School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan; Email: nakamura@kwansei.ac.jp
References
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Furuya S. and Kinoshita H. (2008b). Organization of the upper limb movement for
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Altenmüller E. and Jabusch H. C. (2009). Focal hand dystonia in musicians: Phenomenology, etiology and psychological trigger factors. Journal of Hand Therapy, 22,pp. 144-155.
Furuya S., Nakahara H., Aoki T. et al. (2006). Prevalence and causal factors of playingrelated musculoskeletal disorders of the upper extremity and trunk among Japanese pianists and piano students. Medical Problems of Performing Artists, 21, pp.
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