ABSTRACT
A study was designed in order to determine the patterns and interdependence existing between characteristics of discrimination of force and exerted force in preschool childhood. A total of 28 to 30 preschool children aged approximately 5 to 6 years volunteered to be subjects for each motion, and they discriminated forces in grip, elbow flexion and extension motions. Lower threshold (LT), upper threshold (UT) and interval of uncertainty (IU) were selected as variables representing the characteristic of discrimination of force. Prior to the main examina-tion, unpaired t-test revealed no sex differences in LT, UT and IU for any motions. Therefore, the data derived from boys and girls was pooled for subsequent analysis. The patterns of relationships between variables and exerted force, which was expressed as the percentage of maximal voluntary contraction, generally indicated nonlinear rather than linear combinations, as a result of analysis by simple regression and 2 nd to 5 th degree polynomials. In addition, the interdependency of the relationships was estimated for grip (36.6-44.2%), elbow flexion (26.1-46.8%), and elbow extension (28.1-37.6%) using coefficients of determination in second degree polynomials. Individual differences in the subjects seemed to affect the interdepend-ency during preschool childhood.
