title: Statistical Parametric Mapping (SPM) for alpha-based statistical analyses of multi-muscle EMG time-series.
abstract: Multi-muscle EMG time-series are highly correlated and time dependent yet traditional statistical analysis of scalars from an EMG time-series fails to account for such dependencies. This paper promotes the use of SPM vector-field analysis for the generalised analysis of EMG time-series. We reanalysed a publicly available dataset of Young versus Adult EMG gait data to contrast scalar and SPM vector-field analysis. Independent scalar analyses of EMG data between 35% and 45% stance phase showed no statistical differences between the Young and Adult groups. SPM vector-field analysis did however identify statistical differences within this time period. As scalar analysis failed to consider the multi-muscle and time dependence of the EMG time-series it exhibited Type II error. SPM vector-field analysis on the other hand accounts for both dependencies whilst tightly controlling for Type I and Type II error making it highly applicable to EMG data analysis. Additionally SPM vector-field analysis is generalizable to linear and non-linear parametric and non-parametric statistical models, allowing its use under constraints that are common to electromyography and kinesiology.
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, UK. Electronic address: m.a.robinson@ljmu.ac.uk.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Robinson
authors.affiliation: Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, UK.
authors.forename: Jos
authors.initials: J
authors.lastname: Vanrenterghem
authors.affiliation: Department of Bioengineering, Shinshu University, Japan.
authors.forename: Todd C
authors.initials: TC
authors.lastname: Pataky
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D002648:Child; D003627:Data Interpretation, Statistical; D004576:Electromyography / Q000379:methods*; D005684:Gait / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology*
keywords: Biomechanics; Experimental error; Multivariate statistics; Random field theory; Vector-field analysis