Between- and within-subject variance of motor variability metrics in females performing repetitive upper-extremity precision work

Sex-Specific Links in Motor and Sensory Adaptations to Repetitive Motion–Induced Fatigue

“…An overall mean angle was calculated to represent the average joint angle within each block of recording. Furthermore, a single coefficient of variation (CV) representing the cycle-to-cycle variability of joint angles was calculated by normalizing the pooled standard deviations of angular measures across different time points to the overall mean angle (Srinivasan, Rudolfsson, & Mathiassen, 2015).…”

“…In a procedure identical to that for shoulder and elbow angle and CV calculations, time curves for continuous relative phase were normalized to 100% of each forward movement's duration and were sampled at each 10% of the movement cycle (Srinivasan et al, 2015). An overall mean relative phase angle was computed to represent all forward movements for each 30-s block.…”

Intrinsic movement variability at work. How long is the path from motor control to design engineering?

“…Finally, mathematical tools such as Dynamic Time Warping (Muscillo et al, 2007), geometric invariants (De Schutter, 2009;De Schutter et al, 2011) and other pattern recognition tools can be used to measure similarity between several repetitions of a movement and to categorise them (Granata et al, 2015). A wide range of studies of motor variability have been conducted for different purposes, yet there is currently no consensus on the most relevant descriptors to use in one situation or another (Srinivasan et al, 2015b(Srinivasan et al, , 2015c. Indeed, movement variability may be difficult to comprehend since in a given condition some descriptors can indicate an increase in movement variability while others indicate a decrease (Srinivasan et al, 2015b).…”

“…Task repetitiveness could be cyclic or intermittent throughout the day. Movement variability is present during repetitive occupational work (Madeleine, 2010;Srinivasan et al, 2015c).…”

Effects of concurrent physical and cognitive demands on arm movement kinematics in a repetitive upper-extremity precision task

“…The following variables were computed for each movement cycle to describe the kinematic properties of shoulder elevation and elbow flexion movements (Srinivasan, Rudolfsson, & Mathiassen, 2015c): (1) Range of motion (ROM); (2) peak velocity (Peak Vel); (3) average velocity (Avg Vel); (4) time to peak velocity (Time PV); (5) area under the movement curve (Area); (6) average angle (Avg Ang); and (7) average phase (Avg Ph), where ''phase'' was used to quantify the relationship between joint angle and angular velocity, and computed as per (Hamill, van Emmerik, Heiderscheit, & Li, 1999). The overall means of these parameters across all movement cycles for each subject in each pipetting condition was used to describe the central tendencies of the kinematics properties of shoulder elevation and elbow flexion.…”