Comparison of Two Piano Playing Methods Using Motion Capture

Proceedings of the ASME 2010 Summer Bioengineering Conference SBC2010 June 16-19, 2010, Naples, Florida, USA

SBC2010-19 COMPARISON OF TWO PIANO PLAYING METHODS USING MOTION CAPTURE

Jace D. Kelley*, Heather D. Benoit*, Joel D. White*, Jane Abbott-Kirk**, Brian A. Garner*, and Carolyn P. Skurla* * Department of Mechanical Engineering Baylor University Waco, TX 76798 United States of America

** Department of Keyboard Studies - Music Baylor University Waco, TX 76798 United States of America

A motion capture study was performed to quantify differences between two piano playing methods. Reflective markers were placed on the hands, arms, and torsos of 10 pianists. Cameras positioned around the pianist captured and recorded the motion of the markers for post-processing analysis.

playing the piano. The second specific aim was to identify what areas of the upper body experienced the greatest differences between the two groups. Application The study results in the collection of quantitative data that may aid researchers, instructors, and musicians who are concerned about the susceptibility of pianists to RSI.

INTRODUCTION

METHODS

Many musicians suffer from tendinitis, carpal tunnel syndrome, and other chronic pain syndromes due to repetitive strain injury (RSI) [1]. Training methods and playing techniques, such as the Taubman approach, have been developed to help reduce the risk of these injuries and aid rehabilitation. The Taubman approach is designed to reduce stress on the pianist’s forearms, hands, and fingers by limiting the amplitudes of each joint’s movements. The purpose of the proposed study was to compare differences between the motions of conventionallytrained pianists vs. those trained with the Taubman approach. The hypothesis was that there would be a significant difference in amplitudes of joint motion between the two groups of pianists. Prior Research Approx. 50-80% of musicians experience musculoskeletal problems, with the risks being the greatest for string and keyboard players [2]. Long hours of practice and performance combined with incorrect posture or improper technique can lead to professionally limiting RSI [2-3]. Early, accurate diagnosis and intervention are very important [4]. The primary treatment for RSI is early education and implementation of healthy lifestyle habits both to prevent RSI [4] and to retrain musicians with RSI. No previous study comparing and quantifying motion between the Taubman approach and conventional methods has been found. Previously, motion capture with a video-based marker detection system was used to study pianists playing an octave and a chord, but the investigators were only interested in the abduction angle of the thumb and small finger [5]. Specific Aims We used a video-based marker detection system to analyze motion of the pianists’ fingers, hands, arms, neck and back. The first specific aim was to determine whether there was a quantifiable difference in motion between the two methods of

Marker Placement Markers were placed on the right hand, right arm, and torso of each pianist. A marker was placed on both the metacarpophalangeal joint and the proximal interphalangeal joint of each finger. Two markers were placed on the right wrist as on the dorsum of the hand. Markers were placed on the right elbow, right shoulder, the sternum, C7 spinal process, and two other locations on the spine (See Figure 1).

ABSTRACT

Figure 1: Body Marker Arrangement Camera Arrangement Four digital video cameras, all pointing toward the middle of the keyboard, were arranged as shown in Figure 2. Cameras 1 and 4 tracked the movement of the hand, wrist, elbow, and sternum. Cameras 2 and 3 tracked the markers on the shoulder and back.

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performed to capture shoulder and back motion and to analyze each musical piece separately.

Piano

Position: Arm Elevation Angle 90 80 70

Camera 1 Angle (deg)

60

Camera 4

50 40 30

Stool 20 10 0 Subj2

Subj4

Subj9

Subj5

Taubman

Camera 3

Subj7

Subj10

Traditional

Figure 3: Average ± standard deviation of forearm elevation angle for six subjects.

Camera 2

Position: Pronation

Figure 2: Camera Arrangement (Top View) 100 90

Space Calibration Two calibration objects were used. One was used to calibrate the space over the keyboard, which contained the players’ hands and forearms. The other was used to calibrate the area in which the subject was seated. Procedure Volunteers provided informed consent after reading the IRB-approved study protocol. Five subjects were in each group. After placement of markers, the pianists played three short pieces of music using their normal piano-playing technique. Each piece of music was repeated 3 times. Simi Motion, Version 7.3 (Simi Reality Motion Systems GmbH, Unterschleissheim, Germany) was used to track the threedimensional motion of the markers. Initial data analysis of this pilot study focused on position, velocity, and acceleration data for elbow angle, forearm elevation, pronation of the hand, wrist angle (i.e., perpendicular to the forearm), and wrist deviation angle (i.e., angle in plane with the forearm). The resulting data was used to compare the motion of each subject and to compare the traditional method vs. the Taubman approach. ANOVA statistical analysis was performed using SAS 9.2 (SAS Institute, Cary, NC).

80

Angle (deg)

70 60 50 40 30 20 10 0 Subj2

Subj4 Taubman

Subj9

Subj5

Subj7

Subj10

Traditional

Figure 4: Average ± standard deviation of hand pronation angle for six subjects.

REFERENCES [1] Parlitz, D., and Perschel, T., 1998, “Assessment of dynamic finger forces in pianists: Effects of training and expertise,” J Biomech,31,pp.1063-67. [2] Hansen, P.A. and Reed, K., 2006, “Common Musculoskeletal Problems in the Performing Artist,” Phys Med Rehabil Clin N Am,17,pp.798-801. [3] Leijnse, J.N.A., 1997, “Anatomical Factors Predisposing to Focal Dystonia in the Musician’s Hand,” J Biomech,30,pp. 659-69. [4] Schafer-Crane, G.A., 2006, “Repetitive Stress and Strain Injuries: Preventive Exercises for the Musician,” Phys Med Rehabil Clin N Am,17,pp.827-42. [5] Sakai, N., and Liu, M., 2006, “Hand Span and Digital Motion on the Keyboard: Concerns of Overuse Syndrome in Musicians,” J Hand Surg,31,pp.830-35.

RESULTS Four subjects, two from the Taubman group and two from the traditional group were rejected for technical reasons related to collection and tracking of the video data. Wrist angle could not be tracked for one of the remaining Taubman subjects because the marker on the dorsum of the hand was missing. There was no measure that was statistically significantly different between the groups.

DISCUSSION Although the results were not significantly different between the two groups, there was an interesting trend with regard to the position plots (See Figures 3 & 4). The standard deviations for the traditionally-trained subjects tended to be greater than those of the Taubman-trained subjects, which may indicate that the Taubman students displayed smaller amplitudes in their motions. Statistically significant results may be obtained in the future with a larger sample size. Future data analysis will be

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