title: Analysis of characterizing phases on waveform: an application to vertical jumps.
abstract: The aim of this study is to propose a novel data analysis approach, an analysis of characterizing phases (ACP), that detects and examines phases of variance within a sample of curves utilizing the time, magnitude, and magnitude-time domains; and to compare the findings of ACP to discrete point analysis in identifying performance-related factors in vertical jumps. Twenty-five vertical jumps were analyzed. Discrete point analysis identified the initial-to-maximum rate of force development (P=.006) and the time from initial-to-maximum force (P=.047) as performance-related factors. However, due to intersubject variability in the shape of the force curves (ie, non-, uni- and bimodal nature), these variables were judged to be functionally erroneous. In contrast, ACP identified the ability to apply forces for longer (P<.038), generate higher forces (P<.027), and produce a greater rate of force development (P<.003) as performance-related factors. Analysis of characterizing phases showed advantages over discrete point analysis in identifying performance-related factors because it (i) analyses only related phases, (ii) analyses the whole data set, (iii) can identify performance-related factors that occur solely as a phase, (iv) identifies the specific phase over which differences occur, and (v) analyses the time, magnitude and combined magnitude-time domains.
authors.affiliation: Applied Sports Performance Research, School of Health and Human Performance, Dublin City University, Dublin; with CLARITY: Centre for Sensor Web Technologies; and with Sports Surgery Clinic, Santry Demesne, Dublin, Ireland.
authors.forename: Chris
authors.initials: C
authors.lastname: Richter
authors.forename: Noel E
authors.initials: NE
authors.lastname: O'Connor
authors.forename: Brendan
authors.initials: B
authors.lastname: Marshall
authors.forename: Kieran
authors.initials: K
authors.lastname: Moran
mesh_terms: D054874:Athletic Performance; D001696:Biomechanical Phenomena; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013647:Task Performance and Analysis; D055815:Young Adult