Multidimensional signal analysis (MSA) involves the coordination and correlation of data gathered by multiple analytic techniques. For complex biosystems, MSA provides a means to investigate better aspects of the system that cannot be understood easily using a single method. This is
clearly the case for repetitive use injuries, also commonly referred to as overuse syndrome. Injuries from overuse syndrome are the result of deliberate physical behaviors. They typically are investigated through injury-site examinations, statistical or epidemiologic studies, and observation
of the behaviors associated with the injury. Diverse methods often must be used to evaluate a patient because individually they provide only partial information relating to the etiology. The use of MSA permits the integration of multiple observational perspectives, generally creating a more
holistic view. Using MSA, accurate external description of the movements thought to cause injury can be linked with internal physiologic conditions. Because physical work causes observed damage in overuse syndrome patients, a full examination of internal loading and muscle activity provides
one possibility for understanding the evolutionary nature of these pathologies. Kinematic description, internal load analysis, electromyography, and biomechanical modeling are complementary methods used for MSA in this study. In the current study, a nine-camera ViCON v8i system was used to
capture three-dimensional body kinematics as input for inverse dynamic modeling. Electromyography (Noraxon; 8-channel, wireless) was measured and synchronized to the model, permitting the correlation of joint moments and selected muscle activity. Results reveal clear relationships between
muscle activity and physiologic loading for a variety of bowing speeds, strong interaction among muscles and groups of muscles, and changes in motor control at varying speeds. Additionally, load levels and work patterns are quantitatively established, and evidence is found to support a three-phase
division of motor control based on speed: (1) increasing physical effort, (2) optimization, and (3) approaching physiologic limits. Combined with previous kinematic, kinetic, and statistical studies, the current study illuminates the relative risks of static versus dynamic loading, and provides
perspective on the working patterns of muscles throughout the kinematic chain of the arms and torso during violin performance. Most importantly, this study begins the process of establishing MSA as a means of gleaning a greater overall view from the separate observational perspectives provided
by multiple assessment methods used to examine performing artists’ injuries. This is the first such study for violin performance; an activity highly correlated with overuse syndrome.
Directional hypercomplex wavelets for multidimensional signal analysis and processing
