Neuro-mechanical aspects of playing-related mobility disorders in orchestra violinists and upper strings players: a review

Muscle fatigue during assisted violin performance

Muscle fatigue is a primary risk factor in developing musculoskeletal disorders, which affect up to 93% musicians, especially violinists. Devices providing dynamic assistive support (DAS) to the violin-holding arm can lessen fatigue. The objective was to assess DAS effects on electromyography median frequency and joint kinematics during a fatiguing violin-playing task. Fifteen university-level and professional violinists were equipped with electromyography sensors and reflective markers to record upper-body muscle activity and kinematics. They played G scales with and without DAS until exhaustion. Paired t-tests assessed DAS effects on delta (final-initial) electromyography median frequencies and joint kinematics. DAS prevented the median frequency decrease of left supraspinatus, superior trapezius, and right medial deltoid, and increases in trunk rotation, left-wrist abduction, and right arm-elevation plane. DAS effects on kinematics were marginal due to retention of musical performance despite fatigue. However, DAS reduced fatigue of several muscles, which is promising for injury prevention.Practitioner summary: Violinists are greatly affected by musculoskeletal disorders. Effects of a mobility assistive device on muscle fatigue during violin playing was investigated. The assistive technology slowed down the development of fatigue for three neck/shoulder muscles, making assisted musical performance a promising avenue to prevent violinists' injuries.

The effects of an ergonomic chinrest among professional violin players. A biomechanical investigation in a randomised crossover design

This study aimed to compare violinists' upper body kinematics and muscle activity while playing with different supportive equipment: their usual chinrest (UC) or an ergonomic chinrest (EC), each mounted on the violin. Three-dimensional motion capture and electromyographic data were acquired from the upper body while 38 pain-free professional violinists performed an excerpt of a music piece. There were only minor differences between the two set-ups tested. The EC resulted in less left rotation of the head (3.3°), slightly more neck extension (1.3°) and less muscle activity (0.5-1.0 %MVE). However, the overall high static muscle activity (4-10 %MVE across all muscles) was maintained using EC. For both setups, the head posture was left-rotated >15°, ≤6° flexed and left-bent 90% of the time. The EC did not produce a substantial difference in biomechanical load. Instead, future studies may focus on aspects other than chinrest design to lower the static workload demands.

Different Music Training Modulates Theta Brain Oscillations Associated with Executive Function

Different music training involves different hand coordination levels and may have a significant influence on brain oscillation for the executive function. However, few research has focused on the plasticity of executive function and the brain oscillation modulated by different musical instrument training modules. In this study, we recruited 18 string musicians, 20 pianists, and 19 non-musicians to perform a bimanual key pressing task during EEG recording. Behavioral results revealed that pianists have the highest accuracy and the shortest response time, followed by string musicians and non-musicians (p < 0.05). Time-frequency analyses of EEG revealed that pianists generated significantly greater theta power than the other groups from 500 ms to 800 ms post-stimulus in mid-central, frontal brain areas, and motor control areas. Functional connectivity analyses found that the pianists showed significantly greater connectivity in the frontal-parietal area in theta band based on phase-locking value analysis, which suggests that piano training improves executive function and enhances the connectivity between prefrontal and mid-central regions. These findings contribute to a better understanding of the effects of different music training on executive function.

Raynaud's phenomenon in a drummer player: Microvascular disorder and nailfold video capillaroscopic findings

Drummers are usually exposed to intensive physical stress and occupational diseases that have been only partially investigated. The majority of studies focus on musculoskeletal problems while microvascular abnormalities have been less considered. We report on a case of a 19-year-old drummer affected by Raynaud's phenomenon. The patient underwent nailfold video capillaroscopy that showed a non-specific pattern, with granular flow, dyshomogeneous capillary morphology, increased efferent/afferent loop ratio and many enlarged capillaries. The continuous exposition to vibration in drummers could determinate microvascular abnormalities with related cold induced disorders and Raynaud's phenomenon. Nailfold video capillaroscopy is a tool that allows to detect the alterations of the microcirculation and to carry out the follow-up of the patients with low cost, non-invasiveness, repeatability, high sensibility and specificity.

How Do Violinists Adapt to Dynamic Assistive Support? A Study Focusing on Kinematics, Muscle Activity, and Musical Performance

OBJECTIVE

Assessing violinists' motor and musical performance adaptations to dynamic assistive support (DAS) provided by a passive device, using a force-field adaptation paradigm.

BACKGROUND

Up to 93% of instrumentalists are affected by musculoskeletal injuries and particularly violinists. The repetitive nature of their work may lead to muscle fatigue, an injury risk factor. DAS has been used in occupational settings to minimize muscle activations and limit fatigue accumulation. DAS may however affect motor and musical performance.

METHOD

Fifteen expert violinists were equipped with reflective markers and surface and intramuscular electromyography (EMG) sensors. Movements, muscle activations, and sound were recorded while participants completed three experimental conditions for which they continuously played a 13-s musical excerpt: Control (no DAS), Adaptation (DAS), and Washout (no DAS). DAS was applied at the left elbow (violin-holding side). Conditions were repeated 1 week later. Participants later listened to their own audio recordings playing with and without DAS and blindly assessed their performances. Linear mixed models were used to compare DAS and no-DAS conditions' kinematic, EMG, and musical performance data.

RESULTS

DAS perturbed user kinematics but reduced mean activations of left medial deltoid and superior trapezius. Joint kinematic and muscle activation patterns between DAS and no DAS conditions however remained similar. Musical performance was unchanged with DAS.

CONCLUSION

Though DAS modified violinists' upper-limb configurations, resulting kinematics were not detrimental to musical performance. Reduced muscle activations with DAS could contribute to lessening muscle fatigue.

APPLICATION

Although its effect on muscle fatigue should be further investigated, DAS might be useful in preventing violinists' injuries.

Vibration Exposure and Transmissibility on Dentist's Anatomy: A Study of Micro Motors and Air-Turbines

The use of dental hand pieces endanger dentists to vibration exposure as they are subjected to very high amplitude and vibration frequency. This paper has envisaged a comparative analysis of vibration amplitudes and transmissibility during idling and drilling with micro motor (MM) and air-turbine (AT) hand pieces. The study aims to identify the mean difference in vibration amplitudes during idling, explore different grasp forces while drilling with irrigant injection by the dentist, and various vibration transmission of these hand pieces. The study utilized 22 separate frequency resonances on two new and eight used MMs and two new and eight used ATs of different brands by observing the investigator at 16 different dentist clinics. The study adopted a descriptive research design with non–probability sampling techniques for selecting dentists and hand pieces. Statistical methods like Levene Test of Homogeneity, Welch ANOVA, independent t-test, and Games–Howell test were utilized with SPSS version 22 and MS-Excel. The results reveal that vibration amplitudes and vibration transmissibility when measured at position 2 are higher than in another position 1. Vibrations during idling for used MMs are more than AT hand pieces, and the used MM (MUD) and used AT (AUA) hand pieces differ due to their obsolescence and over-usage. Vibration amplitudes increase every time with the tightening of grasping of the hand piece. Vibration amplitudes for each grasping style of MM hand piece differ from all other grasping styles of AT hand pieces. Routine exposure to consistent vibrations has ill physical, mental, and psychological effects on dentists. The used hand pieces more hazardous as compared to newer ones. The study suggests that these hand pieces must be replaced periodically, sufficient to break between two operations, especially after every hand piece usage. Hence, the present research work can be further extended by creating some control groups among dentists and then studying the vibration amplitude exposure of various dental hand pieces and subsequent transmissibility to their body parts.