Abstract:

Background:
Motor learning includes the ability to plan and execute movement, skill acquisition, motor adaptation and decision making, that is, the ability to select the correct movement in the proper context. Within the motor control framework, skill acquisition depends on practice dependent reduction of performance errors. Objective: The research was conducted to study the effect of body-scaled information on reaching strategies for typically developing and hemiplegic children.

Design:
A cross-sectional study. Venue: The study began at June 2014 up to March 2015 and conducted at the faculty of physical therapy outpatient clinic, Cairo University. The study approved by the ethical committee.

Subjects:
Fifty typically developing children aged from four to six years old and twenty age-matched hemiplegic cerebral palsy children randomly selected were participated in the study.

Methods:
Children were instructed to reach and grasp different cube sizes represented in ten pairs. Assessment was divided into non-instructed trial and forced instructed trial. In each trial, every cube was reached and grasped three times, so a total of sixty trials were collected from each child. All reaching trials were recorded using two cameras placed on right and left sides of the child. The ratio between each cube size and the maximal distance between index finger and thumb was calculated to determine the critical ratio.

Results:
There was a statistically significant in the mean critical ratio between paretic (1.89) and non-paretic arms (1.36) in children with hemiplegia. Also, a statistically significant was found when the preferred arm in the typically developing group (1.32) compared with non-paretic one in hemiplegic children (1.89).

Conclusion:
The knowledge of critical ratio can be utilized to decrease the chance of trial and error of chosen objects in treatment sessions and hence proper practice and effective motor learning therapy can be achieved.

Keywords:

Reaching strategy, Hemiplegia, Children, Body scale, Learning.