William K. Koehler, Illinois State University

Six case studies, two violinists, two violists, and two cellists were carried out in order to make single subject comparisons. The most extreme cases were selected based on posttest performance scores on a composite performance measure. All subjects participated in four 75-minute sessions. During each treatment session, 16 performance measures were taken. A Grass four-channel myograph, analog to digital converter, computer, threshold beeper, sound pressure meter, electrodes, tape recorder and tape were used in data collection. Electrodes were placed on the trapezius, posterior deltoid, bicep, and the forearm flexor muscle groups of the right arm. Data were then integrated and rectified, yielding macro data in mV/s units. EMG potentials of muscle expenditure across the four sessions for each subject are presented below.

A breakdown of this advanced violinist's muscle expenditure for the spiccato bowing can be seen in Figure 1. The trapezius muscle accounts for the most muscle expenditure, and the remaining muscle groups function somewhat independently on the spiccato stroke. The posterior deltoid also functions independently from the trapezius. This trend was present across all sessions. An examination of mv/sec muscle expenditures reveals a decrease in bicep (-10%), and increases in trapezius (+23%), posterior deltoid (+7%), forearm flexor (+32%), and composite muscle expenditure (+15%) from pretest to posttest.

A breakdown of the advanced violinist's muscle expenditure for the sautillé bowing can be seen in Figure 2. Muscle expenditure is more equally distributed among the trapezius, posterior deltoid, bicep, and forearm flexor than on spiccato. This trend was modified from pretest to posttest. The posterior deltoid muscle accounted for the most muscle expenditure for three of the four sessions. After session two, posterior deltoid muscle expenditure decreased dramatically, while the trapezius increased. However, due to a decrease in trapezius muscle expenditure, increased integration among muscle groups from pretest to posttest resulted. An examination of mv/sec muscle expenditures reveals a considerable decrease of 35% in posterior deltoid, and increases in trapezius (+33%), bicep (+5%), and forearm flexor (+18%), and slight decrease of 1% in composite muscle expenditure from pretest to posttest.

A Novice Violinist

A breakdown of this subject's muscle expenditure for the spiccato bowing can be seen in Figure 3. Muscle expenditure by this subject is far from the expected model. It is to be expected that the trapezius must bear the weight of the whole arm, and the other muscle groups should function independently. In the novice violinist, excessive bicep muscle expenditure on the spiccato stroke is evident on the first two sessions. A physiological explanation for the inordinate bicep muscle expenditure could be the fact that the trapezius does not bear the weight of the bow arm and the lever at the elbow does not sufficiently contribute to applying weight into the string. Movement in the wrist and forearm with support from higher elbow placement was deemed necessary. Consequently, constant reinforcement for higher right elbow placement was in part responsible for a shift in dominant expenditure from bicep to posterior deltoid across sessions. An examination of mV/s muscle expenditures reveals the largest decrease of 1936% in bicep, a large increase of 420% in posterior deltoid, an increase of 61% in forearm flexor, and a slight decrease of 6% in trapezius from pretest to posttest. Further, the pretest to posttest decrease in bicep muscle expenditure was considerable. Results may reflect a lack of knowledge of results and an uncertainty in error detection and correction. It is apparent, that the less accomplished string player has a far larger range of EMG potential variation than does the accomplished string player. On spiccato, a large decrease of 374% in composite muscle expenditure from pre to post tests was evident.

The theoretically desirable breakdown of muscle expenditure for the sautillé bowing is absent in the novice violinist (see Figure 4). As is evident in the graphs of the accomplished cellist and the advanced violinist, muscle expenditure on the sautillé bowing should be more equally distributed among the trapezius, posterior deltoid, bicep, and forearm flexor than on spiccato. Once again, muscle expenditure by this subject is far from the expected model. It is to be expected that muscle expenditure on sautillé should be more equally distributed among the trapezius, posterior deltoid, bicep, and forearm flexor than on spiccato. This trend was modified from pretest to posttest. The posterior deltoid muscle accounted for the most muscle expenditure for three of the four sessions. After session 2, bicep muscle expenditure decreased dramatically; while posterior deltoid increased. However, due to a decrease in trapezius muscle expenditure, increased integration among muscle groups from pretest to posttest resulted.

A physiological explanation for the inordinate bicep muscle expenditure could be the fact that the posterior deltoid does not bear the weight of the bow arm and the lever at the elbow does not sufficiently contribute to applying weight into the string. On high strings, the posterior deltoid seems to bear the weight of the arm since a single lever (at the elbow) is employed. Movement in the wrist and forearm with support from higher elbow placement was deemed necessary. Consequently, constant reinforcement for higher right elbow placement was in part responsible for a shift in dominant expenditure from bicep to posterior deltoid across sessions. An examination of the novice violinist's mV/s muscle expenditures reveals a 57% decrease in trapezius, a 1212% decrease in bicep, and a slight decrease in forearm flexor from pretest to posttest. As in the spiccato bowing, the novice violinist dramatically increased posterior deltoid expenditure in attempting to improve the stroke. On sautillé, the novice violinist increased posterior deltoid expenditure by 569%.

An examination of composite muscle expenditure on sautillé over trials for this subject showed a considerable decrease of 272% in muscle expenditure from pretest to posttest. The muscle groups should work together to accomplish the sautillé. The bicep acts oppositely from the forearm flexor. That is, as the forearm makes a movement to the right in executing the down bow, the elbow moves slightly to the left to prepare for the rebound (up bow). This "pumping" motion of the upper arm (accomplished by the bicep muscle and posterior deltoid) increased from pre- to post-test. The forearm and posterior deltoid should act independently to allow for the elasticity of the bow. It is this elasticity that enables the bow hair to barely leave the string, producing the desired off-the-string sound in fast passages. It the novice violinist, the elbow lever was not used to the degree necessary to execute the sautillé stroke effectively. The elbow was held too low to initiate an underhand forearm motion from the elbow.

This accomplished violist used a fixed arm with movement predominantly in the wrist to accomplish the spiccato and sautillé strokes. A breakdown of this subject's muscle expenditure for the spiccato bowing can be seen in Figure 5. The bicep muscle accounts for the most muscle expenditure, and the remaining muscle groups function somewhat independently on the spiccato stroke. This trend was present across all sessions. An examination of mv/sec muscle expenditures reveals decreases in bicep (-16%) and forearm flexor (-10%), and increases in trapezius (+79%) and posterior deltoid (+6%) from pretest to posttest. A 2% increase in composite muscle expenditure is evident from pretest to posttest.

A breakdown of the advanced violist's muscle expenditure for the sautillé bowing can be seen in Figure 6. Muscle expenditure is somewhat more equally distributed among the trapezius, posterior deltoid, bicep, and forearm flexor than on spiccato. This trend was modified from pretest to posttest. The bicep muscle accounted for the most muscle expenditure over all four sessions. After session 1, bicep muscle expenditure decreased dramatically. Due to the decrease in bicep muscle expenditure, increased integration among muscle groups from pretest to posttest resulted. An examination of mV/s muscle expenditures reveals a considerable decreases in bicep (-24%), forearm flexor (-36%), trapezius (-6%), and posterior deltoid (-22%) from pre- to post-test. A considerable decrease in composite muscle expenditure (-23%) from pretest to posttest is evident.

A Novice Violist

A breakdown of the novice violist's muscle expenditure for the spiccato bowing can be seen in Figure 7. Excessive trapezius muscle expenditure on the spiccato stroke is evident on the last two sessions. A physiological explanation for the inordinate trapezius muscle expenditure could be the fact that the shoulders are raised while playing and elbow does not sufficiently contribute to applying weight into the string. Movement in the wrist and forearm with support from higher elbow placement was deemed necessary. An examination of mV/s muscle expenditures reveals decreases in posterior deltoid (-9%), bicep -(3%), and increases in trapezius (+49%), and forearm flexor (+1%), from pretest to posttest. An increase of 15% in composite muscle expenditure was evident on spiccato from pre to post tests. It is again apparent, that the less accomplished string player has a far larger range of EMG potential variation than does the accomplished string player.

As is evident in the graphs of the accomplished cellist and the advanced violinist, muscle expenditure on the sautillé bowing should be more equally distributed among the trapezius, posterior deltoid, bicep, and forearm flexor than on spiccato. Muscle expenditure by this subject is far from the expected model (see Figure 8). An examination of the novice violist's mV/s muscle expenditures reveals a 10% decrease in posterior deltoid, a slight decrease of 5% in forearm flexor, and a 10% increase in bicep from pretest to posttest. As in the spiccato bowing, the novice violist dramatically increased trapezius expenditure in attempting to improve the stroke. On sautillé, the novice violinist increased trapezius expenditure by 48%. An examination of composite muscle expenditure on sautillé over trials for this subject showed a slight increase of 16% in muscle expenditure from pretest to posttest (see Figure 8).

An Accomplished Cellist

A breakdown of this subject's muscle expenditure for the spiccato bowing can be seen in Figure 9. The trapezius muscle accounts for the most muscle expenditure, and the remaining muscle groups can be seen as functioning independently on the spiccato stroke. The posterior deltoid is also independent from the trapezius. This trend was present across all sessions. An examination of mV/s muscle expenditures reveals decreases in trapezius (-26%), and forearm flexor (-4%), and increases in posterior deltoid(+17%), and bicep (+4%) from pretest to posttest (see Figure 9). A 16% decrease in composite muscle expenditure is evident from pretest to posttest.

Muscle expenditure for the sautillé bowing can be seen in Figure 10. On the sautillé bowing, muscle expenditure is more distributed among the trapezius, posterior deltoid, bicep, and forearm flexor than on spiccato. This trend was present across all sessions. However, due to a decrease in trapezius muscle expenditure, increased integration among muscle groups from pretest to posttest resulted. An examination of mV/s muscle expenditures reveals a considerable decrease of 25% in trapezius, increases in posterior deltoid (+19%), bicep (+26%), and forearm flexor (+3%), and a slight decrease in composite muscle expenditure (-3%) from pretest to posttest.

A Novice Cellist

A breakdown of the novice cellist's muscle expenditure for the spiccato bowing can be seen in Figure 11. The trapezius muscle accounts for the most muscle expenditure, and the remaining muscle groups function independently on the spiccato stroke. This trend was also encountered in the accomplished cellist. However, the trapezius muscle expenditure of the novice cellist is 309% greater than that of the accomplished cellist on the posttest. The posterior deltoid also acts independently from the trapezius. This trend was present across all sessions. An examination of mV/s muscle expenditures revealed decreases in trapezius (-15%), and posterior deltoid (-5%), and increases in forearm flexor (+21%), and bicep (+21%), from pretest to posttest. A 12% decrease in composite muscle expenditure is evident from pretest to posttest. Composite muscle expenditure on spiccato of the novice cellist is 224% greater than that of the accomplished cellist on the posttest.

A breakdown of the novice cellist's muscle expenditure for the sautillé bowing can be seen in Figure 12. In the novice cellist, the trapezius muscle accounts for the most muscle expenditure, and the remaining muscle groups function independently as on the spiccato stroke. The trapezius muscle expenditure of the novice cellist is 289% greater than that of the accomplished cellist on the posttest. In the novice cellist, the posterior deltoid appears to be independent of the trapezius. This trend was present across all sessions. An examination of mV/s muscle expenditures revealed a decrease in trapezius(-16%), and increases in posterior deltoid (+8%), forearm flexor (+39%), and bicep (+33%), and a slight decrease in muscle expenditure (9%) from pretest to posttest. Composite muscle expenditure on sautillé of the novice cellist is 26% greater than that of the accomplished cellist on the posttest.