Measuring multi-joint stiffness during single movements: numerical validation of a novel time-frequency approach.

ABSTRACT: This study presents and validates a Time-Frequency technique for measuring 2-dimensional multijoint arm stiffness throughout a single planar movement as well as during static posture. It is proposed as an alternative to current regressive methods which require numerous repetitions to obtain average stiffness on a small segment of the hand trajectory. The method is based on the analysis of the reassigned spectrogram of the arm's response to impulsive perturbations and can estimate arm stiffness on a trial-by-trial basis. Analytic and empirical methods are first derived and tested through modal analysis on synthetic data. The technique's accuracy and robustness are assessed by modeling the estimation of stiffness time profiles changing at different rates and affected by different noise level

SUBMITTER: Piovesan D 

PROVIDER: S-EPMC3309009 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature