Variability of Electromyographic and Kinematic Measurement in Dance Medicine and Science Research

Abstract

Electromyographic and kinematic measurements can yield useful information about the neuromusculoskeletal processes and outcomes of dance performance. Human motor responses are versatile and adaptive. No two performances of a dance movement are precisely the same, not even for the most proficient dancer. To realize the usefulness of EMC and kinematic analysis in dance, performance variability, a natural consequence of the versatility of human motor responses, must be dealt with. At first glance the overwhelming variability seen in existing EMC and kinematic research in dance medicine and science might appear to be a stumbling block to progress. Viewed another way, this same variability can be seen as a useful ally. This paper reviews intra-subject variability, learning, and inter-subject differences in EMC and kinematic work in existing dance research. Evidence is presented that supports the use of variability data as a measure of performance and learning to distinguish experts from novices or to track training changes. Variability in EMC and kinematic data recorded continuously throughout a movement event will be used to examine the temporal relationships between neural and musculoskeletal patterns in dance performance. A case is made for analysis of variability in future investigations of tenets central to dance training such as “core support” and “whole body connectedness.” Throughout, recommendations are made for conventions useful for data collection, handling, and analysis. The ultimate goal is to facilitate comparisons between research reports and development of normative data sets as reference points for discussion of training, performance, clinical practice, and research.