Submovements Grow Larger, Fewer, and More Blended during Stroke Recovery

Abstract

Submovements are hypothesized building blocks of human movement, discrete ballistic movements of which more complex movements are composed. Using a novel algorithm, submovements were extracted from the point-to-point movements of 41 persons recovering from stroke. Analysis of the extracted submovements showed that, over the course of therapy, patients' submovements tended to increase in peak speed and duration. The number of submovements employed to produce a given movement decreased. The time between the peaks of adjacent submovements decreased for inpatients (those less than 1 month post-stroke), but not for outpatients (those greater than 12 months post-stroke) as a group. Submovements became more overlapped for all patients, but more markedly for inpatients. The strength and consistency with which it quantified patients' recovery indicates that analysis of submovement overlap might be a useful tool for measuring learning or other changes in motor behavior in future human movement studies.

Individual Premotor Drive Pulses, Not Time-Varying Synergies, Are the Units of Adjustment for Limb Trajectories Constructed in Spinal Cord

“…Kinematic strokes of specific features have been proposed as high-level or kinematic planning primitives (Viviani and Terzuolo, 1982;Hogan, 1984;Flash and Hogan, 1985;Sanger, 2000;Schaal et al, 2003;Sosnik et al, 2004;Flash and Hochner, 2005). Unit strokes or unimodal kinematic primitives, identified at the trajectory level, are used to examine adjustments and tracking (Burdet and Milner, 1998;Novak et al, 2002;Roitman et al, 2004;Fishbach et al, 2005Fishbach et al, , 2007, motor learning (Sosnik et al, 2004;Pasalar et al, 2005), and recovery of function (Doeringer and Hogan 1998;Krebs et al, 1999;Rohrer et al, 2004).…”

Motions or muscles? Some behavioral factors underlying robotic assistance of motor recovery

“…Using the scattershot algorithm, we extracted submovements from planar point-to-point reaching movements made with the hemiparetic arm by 41 patients recovering from stroke [55]. Fifteen were acute-stage inpatients who had suffered their first unilateral infarct less than 1 month before beginning the study, and twenty-six were chronic-stage outpatients between 12 and 54 months poststroke.…”

Reaching, Swinging, and Punching: Kinematic Change after Video Gaming Intervention in an Individual with Chronic Stroke

“…Thus the shoulder and wrist approximate a smooth motion with values of 5.3 and 5.0 respectively after the intervention. This is an indication of improved motor control since during motor recovery post stroke, motion typically becomes less fragmented and smoother [18]. The changes in golfing are especially striking since the participant played golf only 5% of his gaming time.…”

“…During motor recovery post stroke, movement typically becomes less fragmented and smoother [18]. While clinical measures assess whether change has occurred during recovery, kinematic analysis permits quantification of these changes.…”