Basic study on trajectories of reaching movements in children with learning disabilities

Abstract

--A number of children with learning disabilities (LD) are not good at visuomotor control. In this study, we analyzed hand trajectories and joint angles during reaching movement tasks under rotated visual feedback in subjects with and without LD. The error in ballistic movement was determined by measuring the angle between the direction in which the subject started to reach out and the direction of the target (error angle), and the error in corrective movement was determined by the measuring the area between the trajectory and a straight line drawn between the starting point and the end point (error area). In the initial movement when the visual field had been rotated 30 deg, error angles were about -30 deg in both the LD and normal groups; however, the error area was 2.9 cm 2 greater in the LD group than in the normal group. On the other hand, joint paths of the shoulder in reaching the same target tended to change in the LD group. These results suggested that the LD subjects had worse skills in corrective movement than did the normal subjects and that adaptation by the LD subjects occurred more slowly than that by the normal subjects.

Linking brain stroke risk factors to human movement features for the development of preventive tools

“…It examines the capacity of the subject to react as quickly as possible to a visual stimulus. It is also based on the various forms of reaching tests (e.g., Levin, 1996 ; Lum et al, 1999 ; Minegishi and Takahashi, 2001 ; Prablanc et al, 2003 ; Wagner et al, 2008 ) since, contrarily to usual implementations of reaction time tests, which often only request pressing a button, we are interested by the kinematic of the whole movement of the upper-limb, from the starting point to the targeted zone.…”

A Globally Optimal Estimator for the Delta-Lognormal Modeling of Fast Reaching Movements

“…This is probably why fast reaching movements are so widely scrutinized in scientific publications involving human motion. This kind of elementary motion is the focus of interest in various fields, such as handwriting generation, where it is defined as a basic stroke [3], [4], [6], [7]; psychophysics, where it is used to study the speed-accuracy tradeoff [8]- [11] and other characteristics of movements [12]; rehabilitation, where it is often used, sometimes in conjunction with grasping, to develop robot-assisted therapy [13], [14], for therapy performance assessment [15] and for brain-machine interface design [16]- [18]; medicine, for the study of diseases like anarchic hand syndrome [19], mechanical low back pain [20], and Huntington's disease [21]; and in other fields, such as anthropomorphic robotics [22]- [24], fundamental neuroscience [25]- [31], education [32], and virtual human animation [33]. Of course, these are just some examples of the widespread use of reaching movements, and an comprehensive review would be required to provide a more complete list.…”