The movement skill abilities of fourteen children with autism were assessed on three movement tasks: the overhand throw, kick and horizontal jump. Skill level was assessed both quantitatively and qualitatively. Correlations were calculated to determine the relationship between these two measures on all skill items. / A Generalizability Analysis was conducted to determine the minimal conditions required to observe reliably the movement skills of children with autism. The conditions generalized in this study were observers and trials. / The results indicated that there was a significant relationship between quantitative and qualitative measures on the horizontal jump and the kick. A correlation of.37 was obtained for the overhand throw, but was not considered significant. Results of the generalizability analysis indicated that reliable results were obtained with one observer and one trial for all three skill items.

In order to grasp an object, the human nervous system must transform the intended hand displacement into control signals distributed to motor neurons and ultimately to muscles. The aim of this thesis is to describe the nature of the internal representations that the human motor system uses to perform reaching movements. / The aim of the first study was to provide a clear and simple way to test whether dynamical information is coded by the nervous system in an extrinsic, Cartesian, versus intrinsic, muscle- or joint-based, system of coordinates. As a means to determine the frame for reference used by the motor system, we examined how adaptation to externally applied forces transfers across different arm configurations. We trained subjects to make reaching movements while holding a robotic arm that applied forces proportional and perpendicular to the tangential velocity of the hand. While in the first trials hand paths were substantially deviated, subjects rapidly adapted to the new dynamic condition; they learned to compensate for the forces in order to restore the kinematics observed in the absence of load. Learning of the new dynamics transferred across movements performed in different regions of the workspace when the relation between joint displacements and experienced torques remained unchanged, rather than when the mapping between hand displacements and forces was preserved. This provided support to the idea that dynamics are encoded in muscle- or joint-based coordinates. / The results of the first study described a process of generalization that relies on the invariance of the mapping between torques and joint displacements. While this clearly points to an intrinsic coding of dynamics, it does not explain whether or how generalization over the workspace occurs when the pattern of torques changes with the configuration of the arm. In the second study, subjects learned a force field in which the forces acted always in the same direction relative to an external frame of reference, which defines a mapping between joint displacements and torques that varies with the configuration of the arm. Our idea was to test if in the absence of invariance in the pattern of torques, generalization would occur on the basis of the invariance in the direction of the forces represented in an extrinsic system of coordinates. (Abstract shortened by UMI.)

Motor planning was assessed by performance of 10 male children (age range 9-12 years) with ASD on a simple obstacle course of horizontal barriers. The primary measures of motor planning were acts of hesitation and hesitation time. These measures, along with executive functioning scores from the BRIEF, and measures of movement execution were correlated to assess the validity of this obstacle course. Results of these correlations supported the validity of the motor planning inferences from the performance of the obstacle course since motor planning correlated in the expected directions with the BRIEF scores and movement execution measures. Internal consistency (Cronbach's alpha) was sufficiently high to support the reliability of this obstacle course, with the item analysis providing direction for the most reliable barrier heights. Therefore, the use of this obstacle course task provides both valid inferences and reliable measures of motor planning, although further development is warranted.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1983. / Bibliography: leaves 252-259. / Microfiche. / xv, 259 leaves, bound ill. 29 cm

Thesis (MAppSc in Physiotherapy) -- University of South Australia, 1994

Thesis (MAppSc in Physiotherapy) -- University of South Australia, 1994

Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisor: Nancy Getchell, Dept. of Health, Nutrition, and Exercise Sciences. Includes bibliographical references.

Thesis (M.S.)--Indiana University, 2006. / Includes bibliographical references (leaves 38-41). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (M.S.)--Indiana University, 2006. / Includes bibliographical references (leaves 38-41).

Thesis (Ph. D.)--University of Adelaide, Dept. of Psychology, 1992. / Includes bibliographical references (leaves 208-219).