Degree Type


Date of Award


Degree Name

Doctor of Philosophy


Human Development and Family Studies

First Advisor

Jacques Lempers


Eight individuals with Down syndrome practiced performing 100 elbow movements over one distance (36°), under the instruction to move "as fast as possible." The subjects were also pretested and posttested performing elbow flexion movements over four distances (18°, 36°, 54°, and 72°) "as fast as possible", and at a "comfortable speed" over 36°. For two of these distances (18° and 36°), the movements were also performed from a second starting position. They improved their motor performance between training sessions (110 movements), as measured by the kinematic and EMG parameters. This improvement performance was described by a logarithmic function. With training the subjects increased the intensity with which they activated their motoneuron pools, decreased the antagonist onset latency, and improved the peak velocity by 67%. This remarkable improvement was obtained without an increase in variability, which was already very low at the beginning of the training;The subjects were also able to transfer their performance improvement to the non-trained distances and to the different starting position. Subjects decreased their movement time by proportionally decreasing both the acceleration and deceleration time. This study supports the idea that subjects with Down syndrome can use patterns of muscle activation that are qualitatively indistinguishable from those employed by individuals without neurological impairment. With appropriate training, individuals with Down syndrome can achieve high levels of motor performance.



Digital Repository @ Iowa State University,

Copyright Owner

Gil Lúcio Almeida



Proquest ID


File Format


File Size

171 pages