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American Osteopathic Academy of Sports Medicine

29th Annual Clinical Conference • March 19-22, 2014 • Westin Tampa

Harbour Island Hotel • Tampa, Florida     

Snowmass, CO

  Hand Biomechanics of Skilled Pianists

and Preventive and Rehabilitative Strategy for Pain and Injury 

University of South Florida Sang-Hie Lee, PhD, EdD, MM

Collaborators: Angel Luciano, MD; Jeffrey Chodil, MM; Yun Lin, PhD candidate; Yu

Sun, PhD, This research was supported by USF Neuroscience Collaborative Grant

Order  of  Slides  

l Slides  #4  –  7          Introduction  l Slides  #8  –  12        Literature  l Slides  #13  –  36      Study  l Slides  #37  –  48      Cases  l Slides  #49  –  50  “Peanuts  play”  

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Skilled Pianists Hands

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Premises

l Skilled pianists’ hand dexterity involves precise finger-touch control and efficient bodily support to produce the desired tones.

l Pianists’ hand come in varied size and shape. l We developed hand measurement-- static

biometrics, dynamic range of motion, and motion capture and compared the hand data with performance data (MIDI).

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Questions l Are there differences in hand biomechanics among

different classification of pianists as results of their training?

l Are there relationships between hand biomechanics and performance quality?

l Are the relationships vary among the four groups? l Are there differences in performance quality among the

classifications? l Does sex influence biomechanics and performance, and

does it factor in the relationships between them?

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Demystifying Pianists’ Hands “Liszt hands were large.”

l Liszt’s had “deep-lying connective tissues between the fingers” which gave him superb finger independence (Kentner 1976).

“Accomplished pianists all have long fingers.”

l Busoni, Rachmaninoff, Rosenthal, and Saur had long fingers, while d’Albert, Reisnauer, Teresa Carreno, and Pachmann, had short ones (Kentner 1976).

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Otto  Ortmann  (1929,  1962,  1984)  

l  An adult pianist with a smaller hand and larger hand span (127°) had the pianistic advantage over a pianist with a large hand and smaller hand span (75°).

l  A child’s hand—generally featuring a small span between the thumb and index finger, high webs between fingers 2–3, 3–4, and 4–5, a small span between fingers 1 and 5, and a lesser range of movement at the wrist—is an example of a disadvantageous piano-playing hand.

l  A same-age child with all the opposing biomechanical features made more rapid progress, possibly attributable to the biomechanical advantage.

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Christoph Wagner (1988, 2006)

l Analyzed 238 pianists’ biomechanical data.

l Pianists’ left hand spans were significantly greater than the right hand.

l Ranges of both active movement --flexion of the metacarpophalangeal (MCP) joint, wrist abduction, and forearm pronosupination, and passive movements-- were greater in female than male.

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Lee study (1990)  

l Lee study of 13 skilled pianists concluded that wrist mobility in the ulnar direction and spans involving all fingers were factors relating to good piano performance.

¡ Chopin Etude Op.10 # 1 ¡ Cortot Exercises five-finger-scale with 4th

finger pressed down

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Consensus

l The consensus of these studies is that skilled piano techniques are influenced by flexible hand span and wrist joint mobility that enable efficient hand-arm coordination rather than by the size or shape of the hand and arm.

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Kinematics of Piano Playing (Jerde et al, 2006)  

•  Covariation of the Metacarpal and Proximal Interphalangeal Joints

•  Finger Individuation in Coordination of the Hand Motion

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Predictors l   Hand Size:

a) hand length b) hand width c) composite finger length.

l  Hand Mobility (span and ulnar deviation): a) composite finger span 1-3 b) composite finger span 2-4 c) composite finger span 3-5 d) composite finger span 1-5 e) ulnar deviation at the wrist

l  Weight variables: a) hand weight b) arm weight c) hand-arm weight ratio

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Dependent variables (Performance Variables)

l  Dynamic evenness (key velocity) l  Articulation (Key note-on to note-off timing)

evenness l  Tempo – consecutive notes-on timing (real time beats) l  Fourth finger-sustain in task #7 l  Error, defined by before and after touch and wrong

notes

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Pianists were Identified in four Classifications

l  Artists n=9 l  Graduate piano major students n=8 l  Undergraduate piano major students n=5 l  Injured pianists n=9

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Pianists l A total of 31 pianists l ages ranging from 18 to 50 l 16 male and 15 female l  9 artist-pianists who performed internationally l  8 graduate piano performance majors l  5 undergraduate piano majors l  9 trained pianists who were currently

experiencing pain or injury. l All were “skilled” (i.e., classically trained) pianists,

signed IRB Informed Consent Form.  16  

Measuring Hand

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Equipment: AvantGrand Piano: YAMAHA AvantGrand N3 version, hybrid piano with electronic speakers highlights

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Eight  piano  tasks  

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Statistical Analysis l  Nominal variables (sex and classification) are described as

frequencies with mean values ± SD and compared using X2 analysis or Fischer’s exact test as appropriate.

l  Hand biomechanics and performance variables are treated as ranked (described as medians and 25th-75th percentiles) and continuous measures.

l  Group medians for all continuous measures (hand biomechanics and performance variables) were compared between classifications using a Mann-Whitney U test or Kruskal-Wallis test.

l  Spearman rank correlation test was used to measure the strength of association between the predictors and the dependent variables.

l  Linear regression models were created in order to identify independent variables that predict changes in performance variables. P value ≤ 0.05 was considered statistically significant.

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Hand  Biomechanics  Differences  by  Sex  Table 1. Hand Biomechanics Differences by Sex

Hand length .0001 * Finger length .0011 * Hand width .0001 * Finger span 1-3 .0141 * Finger span 1-5 .0451 * Finger span 2-4 .7111 Finger span 3-5 .3181 Hand weight .0031 * Arm weight .0001 * Hand/arm weight ratio .2241

There were no significant Hand Biomechanics Differencdes by Pianist Classification

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 Performance differences among pianist groups Three performance variables were found significantly different among the groups: l Articulation (duration from note-on to note off in legato

exercises in ms (p=0.026) l Playing speed (timing of consecutive notes-on in legato

in ms (p=0.019) l Playing speed (timing of consecutive notes-on in staccato

playing in ms (p=0.008)

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Evenness of Articulation and Tempo (Performance differences among pianist groups continued)

 a)  Evenness of articulation (SD note-on to note-off) in playing all legato exercises, artists and graduate students were not significantly different (p=0.96), while undergraduate and injured pianists showed significant differences (p=0.007 and p=0.05 respectively) from the previous two groups.

b)  Evenness of tempo (SD consecutive notes-on) in all legato playing also showed significant differences between artist and graduate pianists and undergraduate and injured pianists (p=0.02 and p=0.02 respectively).

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Evenness of Articulation and Tempo(continued)  

c)  Evenness of tempo (SD consecutive notes-on) in all staccato playing showed significant differences among all four groups of pianists (comparison within groups all with p values less than 0.05).

d)  No significant differences were found in key velocity (legato p=0.231, staccato p=0.466) or error (p=0.308) performance variables.

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Performance  Differences  (Evenness  of  Articulation  and  Tempo)  among  groups  

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Correlations between performance variables and hand biomechanics: The fourth-finger sustain in playing Piano Task #7 and Hand

Fourth-finger sustain ¡ hand length .47 p=.012* ¡ hand width .387 p=.032* ¡ finger length .477 p=.007* ¡ finger span 1 to 3 .448 p=.011*

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Evenness of velocity (dynamic control) and Hand: Correlations between performance variables and hand biomechanics continued

l Significant positive correlations between the composite (all 8 tasks) evenness of velocity in legato playing and hand width and finger span fingers 1 to 5

l Significant positive correlations between the composite (all 8 tasks) evenness of velocity in staccato playing with hand width and finger span fingers 1 to 5, but also finger spans 1-3, 2-4, and 3-5

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Evenness of velocity in legato playing and Hand

Evenness of Velocity ¡ Hand width .37 p=.042* ¡ Finger span 1-5 .39 p=.028*

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Evenness of velocity in staccato playing and Hand  

Evenness of Velocity ¡ Hand width .422 p=.042* ¡ Finger span 1-5 .539 p=.0001* ¡ Finger span 1-3 .459 p=.009* ¡ Finger span 2-4 .48 p=.006* ¡ Finger span 3-5 .483 p=.006*

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Positive Correlations between Hand Biomechanics and Performance Variables

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Prediction Model—Linear Regression

l For every 1 cm increase in finger span of fingers 1 to 5, the percentage of correct notes increased by 6% (B=0.057, p=0.037) and the percentage of fourth-finger sustain decreased by 10% (B=-0.103, p=0.003).

l For every 1 cm increased in finger span of fingers 1 to 3, the percentage of fourth-finger sustain was increase by 6% (B=0.059, p=0.005).

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Predictor  Model  Table  

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Summary  

l Sex Differences: hand sizes are significantly different between male and female except finger spans 2-4. 3-5. and ulnar deviation– this is consistent with the previous three studies.

l Pianists Classification: hand size factors show no difference among the pianists classes.

l Pianist classification does not show difference in key velocity control (loudness) or error rate.

l Pianist classification does show differences in evenness control in articulation and tempo.

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Summary  continued  

l Performance of task #7: hand length, hand width, finger lengths, finger span 1-3 were correlated with fourth-finger sustain.

l Key velocity evenness in legato playing: hand width and finger span fingers 1-5 were correlated with evenness of key velocity.

l Key velocity evenness in staccato playing: finger spans, 1-3, 2-4, and 3-5 were also positively correlated.

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Summary  continued  

l  Finger spans 1-3 and 1-5 predicted two performance variables: ¡  Wide finger span 1-5 seem to allow pianists to find

correct notes easily. ¡ The same wide finger span 1-5 seem to hinder the

fourth-finger sustain, while finger span 1-3 seem to help fourth finger sustain in (#7).

¡ We will look at motion capture data to understand these regression results better.

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Statistical  method  l Small number purposive sampling l Our variables meet the required assumption for

of non-parametric Mann Whitney U8 and Kruskal-Wallis9 Tests as alternatives to T-test or ANOVA.

l Power of large number l Intensive nature & multiple individualized

measurements limit the number in the study. l Cumulative data 36  

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Implications  

l Pianists’  biomechanical  profiles  is  useful  for      

¡   Efficient  playing      ¡   Injury  preventive  pedagogy    ¡   Rehabilitation  strategies  

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Gary Graffman & Leon Fleisher

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Student 1

l Small 2-4 finger span (2.8 inches)

l Finger weakness contributed to injury

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Injured Pianists Examples

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Student 8

l Short fifth finger

Adult  piano  student  

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Artist 6

l Large hand/arm weight ratio l Hand weight: 52 oz. l Arm weight: 87 oz. l Ratio: 0.60

Model  artist  pianist  

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Jazz  performer  

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College  piano  instructor  

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College  piano  instructor  

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Healthy  artist  pianist  

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“Playing”-­‐-­‐posture  matters!!!  

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Speaking of postureèfocal dystonia???