The phase-plane coordination measure (Hamill et al. 2000): each joint angle is
mapped to a phase angle from its (normalised) phase portrait, and the
continuous relative phase is their difference through the movement. Its mean
absolute value (MARP) summarises whether the joints move more in-phase (near
0) or out-of-phase (near 180).
Usage
continuousRelativePhase(angle1, angle2, normalize = TRUE)
Arguments
- angle1, angle2
Numeric joint-angle time series of equal length, one
movement cycle (typically time-normalised); angle1 is the reference
(e.g. proximal) joint.
- normalize
Normalise the phase portrait (recommended; corrects for
amplitude differences).
Value
a crp_result list: crp (degrees, wrapped to +/-180), phase1,
phase2 (phase angles, degrees) and marp (mean absolute relative phase).
References
Hamill J, et al. (2000) Clin Biomech 15:S31-S39.
Examples
t <- seq(0, 2 * pi, length.out = 101)
continuousRelativePhase(sin(t), sin(t))$marp # in-phase ~ 0
#> [1] 0