Mark Kruger, Mark Lammers, Lela June Stoner, and Richard Fuller, Gustavus Adolphus College; Debra Allyn, Iowa State University

In the last several decades the field of biomechanics has produced an important body of information that has enhanced performance in athletics and many other areas of human locomotion. These techniques are available to the researcher who is interested in body movement as it pertains to music performance. Through the use of techniques such as electromyography, electrogoniometry, videography as well as other procedures, information can be obtained that has implications for improved instrument and voice instruction.

Biomechanical research techniques were used to study the right arm of trombone players during musical performance. Wrist and elbow motion, slide acceleration and speed, and the muscle activity of 66 trombone players were examined. Professional performance was compared to that of novices. Although there is similarity in activity among players, professionals move the slide faster, more efficiently, and use less elbow angle to reach the far positions. Individual variability is greatest in the wrist. The researchers believe that this study and examination of musical performance can contribute to an increased understanding of expertise and improved pedagogy.

Instrumental and vocal teachers teach as they have been taught, passing on their pedagogical ideas and experience through what can be called an oral tradition. Improvements in teaching have been made through the examination of the oral tradition as new theories and teaching techniques are produced. However, there are scientific methods now available that can be used to test theories of instruction and assumptions about the techniques required for successful performance.

A team of researchers at Gustavus Adolphus College in Saint Peter, Minnesota is exploring ways in which scientific observation can be used to advance musical pedagogy. The team consists of a psychologist, a physicist, a musician and two kinesiologists. The evolution of the team came as a result of work done by the musician, the psychologist and one of the kinesiologists over a period of years which has focused on the right arm of trombone players. In 1993 the team was expanded when they were awarded a National Science Foundation Grant to continue the study.

The approach has been to study the pedagogical literature such as the published lesson material, magazine articles, and treatises by musician-authors such as Fink (1970), Kleinhammer (1963) and others. From that investigation a hypothesis was created regarding a proper pedagogy for teaching about the right arm of trombone players which could then be tested using scientific methods and means. Each of the studies reported here focused upon the differences between expert (professional) and novice (student) trombonists in order to increase understanding of motor performance skills and the manipulation of the trombone slide.

Three studies have been conducted on the right arm of trombone players. The first, involving 14 trombonists, was done in 1981 and reported in 1983 (Lammers, 1983). Seven of the subjects were professional players and seven were college student performers. Electromyography (EMG) and electrogoniometry (ELGON) were used in that first study. The muscles studied using EMG were the biceps and triceps of the upper arm and the extensor and carpi radials of the forearm. The electrogoniometers used were single plane instruments that measured flexion and hyperextension of the wrist and the angle of the elbow. Because the findings in the first study involving the electrogoniometer at the wrist were inconclusive, a second study was done at the Mayo Clinic in Rochester, Minnesota in 1987 (Lammers & Kruger, 1991). An orbital electrogoniometer was used to measure both hyperextension-flexion and abduction-adduction of the wrist. Ten student trombone players were the subjects. The third study involved ELGON, videography (both fast and slow speed) and a range finder called sonic ranger. Forty-two subjects were studied ranging from sixth graders to professional trombonists. Data was taken at the University of Minnesota and at Gustavus Adolphus College.

With the procedures followed in the three studies, the researchers have been able to: 1) calculate the angle of the elbow used in each of the seven positions of the trombone slide, 2) calculate the amount of time used to move from one position to another, 3) calculate the amount of time the slide is held in each position, 4) calculate the angle of flexion - hyperextension as well as abduction - adduction of the wrist, 5) calculate the acceleration and speed of the slide, and 6) make anecdotal observations.

The forty-two subjects in the third study were recruited in three groups: beginning players who had played for less than three years, college students, and adult amateur and professional performers. Each subject was asked to sign a consent form after being fully informed about the study. Subjects played their own instruments and were given a short period of time to warm up before their performance was recorded. All subjects were paid for their participation.

Upon entering the data-gathering area, each subject was asked to fill out a questionnaire that requested the following information: age, number of years playing the trombone, number of hours per week spent playing the trombone and the style of music they most frequently performed. They were also asked to classify themselves as a student, an amateur or a professional. Each player’s upper (shoulder to elbow) and lower (elbow to wrist) arm were measured. The means for age, hours of performance per week and length of the upper and lower arm in centimeters are found in Table 1.

The subjects were asked to wear dark clothing so that florescent dots placed on the right arm could be used to record movement of the trunk, shoulder, elbow, wrist, and trombone slide. A special sleeve was designed to hold two light-weight electrogoniometers (made by Penny and Giles) on the wrist and elbow. A computer based data acquisition system was used to digitize and record movement sensed by the electrogoniometers attached to each participant’s wrist and elbow (75 samples/s). A paper cone was attached with Velcro to the end of each participant’s trombone slide. A second computer based data acquisition system was used to digitize distance and velocity data produced by the ultrasonic range finder (35 samples/s). After each of the pieces of equipment was calibrated and tested, a standard VHS video camera was started and the subjects proceeded to perform the assigned tasks. The VHS camera provided a record of each data collection session and an audio recording of musical performance.

Each subject was asked to perform the Bb scale in three tempos. Subjects were then asked to perform a second exercise. This exercise was constructed to make use of the entire slide and was also performed in three tempos. Starting in first-position "F", the exercise consisted of two notes played on each note descending chromatically to each position from one through seven. This exercise was also used in two earlier studies and makes comparisons across studies possible. The third exercise was a composition comprised of the 42 possible movements of the trombone slide randomly ordered. Finally subjects were also asked to perform two musical excerpts. The first musical performance task was "Sento nel core" by Stefano Donaudy published by G. Schirmer, New York, 1972 and the second was "Minuet alternat" from Sonata VI by Johann Ernst Galliard published by G. Schirmer, New York, 1963.

The quality of musical performance on each of the exercises performed by all of the trombone players was assessed by unbiased judges. In addition, judges recorded the number of audible errors and the predominant position of the elbow and hand in each exercise. Professionals on average made one fifth of the audible errors made by students. The rated quality of musical performance was twice as high for professionals as it was for student musicians who scored slightly ahead of the adult amateurs. Though these findings are not surprising, they do confirm that groups differed in their level of expertise.

Two findings stand out in the data recorded with the electrogoniometers. The elbow measurements reinforce earlier research and indicate that professionals use less elbow angle for positions two through seven than do students. Data from the wrist indicates that the more skilled players use more wrist action than do less skilled performers. However, there seems to be individual variation from player to player in the use of the wrist that reflects stylistic differences in the way the slide is held.

The data collected with the ultrasonic range finder indicates that professionals move the slide faster than the other players and thus are in position longer. This probably aids tone quality and intonation. One of the side observations made with the data provided by the sonic ranger is that musicians move the slide only as fast as they think they must, not ‘as fast as possible’ as taught by many trombone teachers. (See Figure 1.)

High-speed videography tracked the motion of the shoulder, elbow, wrist and trombone slide. However, data from this part of the study has not been fully analyzed. What has been done verifies the data collected with the sonic ranger and the electrogoniometers. The researchers will report more fully on this area of study in later publications.

This series of studies has shown that the use of biomechanical techniques in studying music performance is a useful and important way to enhance the oral tradition of teaching instruments and voice. The work of Tulchinsky and Riolo (1994), Winold, Thelen, & Ulrich (1994) and others provides additional support for the utility of examining performance with biomechanical techniques. The findings reported above should have an influence upon the trombone teacher in the way s/he approaches the student’s right arm which, heretofore, was largely ignored in the literature. The researchers will continue to analyze the data collected in the latest study. A process that will take several more years. However, much of what is important is now known and documented. Those important points are: (a) Professional trombonist use less muscle activity than do students and amateurs, (b) Professional trombonists use less elbow angle in positions two through seven than do their student counter parts, and (c) All players use as much speed as necessary to get to the next position, but the professionals get there faster.

A bibliography (Lammers, Kruger, Stoner & Nechanicky, 1996) has been compiled by the researchers to assist persons interested in learning more about what has been done in this field and the techniques and equipment used in that study. Pedagogists have the opportunity, through biomechanical methods, to reinforce or enhance instructional theories.

The results of our observations lead the researchers to suggest to teachers of the trombone three findings for their consideration. The first finding to consider is the elbow angle. The literature reports little about the elbow to the student of trombone playing, yet the findings here indicate that the more successful player uses less elbow angle for all slide positions but first position. Many of the professional players create less elbow angle by holding their instrument slightly to the right side of their body.

The second finding that may be of interest to pedagogists is the speed and acceleration of the slide. Even though the researchers found that all trombonists have great variability in this area, professionals do move the slide faster, so teachers should encourage younger players to move the slide faster at all tempos.

The third finding made by means of the sonic ranger and verified visually is that better players hold the instrument without extra movement of the slide from side to side or up and down. Good players have control of the instrument in relation to the body as well as to the manipulation of the slide.