Communication Affichée: Poster Tour 1
Le 14/10/2021 de 11:00 à 11:30
Comparaison de 4 indices de fluidité du mouvement lors de la réalisation de mouvements de pointage au membre supérieur chez 32 sujets sains
Nicolas Bayle (Créteil, France), Mathieu Lempereur (Brest, France), Emilie Hutin (Créteil, France), Olivier Rémy-Néris (Brest, France), Jean-Michel Gracies (Créteil, France), Gwenaël Cornec (Brest, France)
Objective : Measurements of movement smoothness include the number of zero-crossings on acceleration profiles (N0C), the Log Dimensionless Jerk (LDLJ), the Normalized Averaged Rectified Jerk (NARJ) and the Spectral Arc Length (SPARC). We compared sensitivity to handedness and movement type of these four metrics in healthy subjects and explored correlations with kinematic parameters.
Material / Patients and Methods : Thirty-two healthy participants (age 63±16 y) underwent upper limb 3D motion analysis during two sets of three pointing movements on each side. Participants were seated, palm of the hand facing down on the table before movement onset; they performed forward-pointing movements (FPM) at self-selected speed to a target located ahead at 90% arm length at shoulder height, and backward pointing movements (BPM), back to the initial position, with and without a three-second pause between FPM and BPM. We collected kinematics (including trajectory, speed), N0C, SPARC, LDLJ and NARJ.
Results : LDLJ, NARJ and N0C found backward movements to be smoother while SPARC found forward movements to be smoother. No marker indicated differences across sides. Inter- and intra-subject coefficients of variation (CoV) were lowest for SPARC. LDLJ, NARJ and N0C were correlated with each other and with movement time, unlike SPARC.
Discussion - Conclusion : There are major differences between smoothness indices measured in the temporal domain (N0C, LDLJ, NARJ), which depend upon movement time, and the one measured in the frequency domain, the SPARC, which gave results opposite to the other markers when comparing backward and forward movements.
Keywords : Movement moothness
Disclosure of interest : None