Frequency of Left-Handed Children Age 7- 21 Years Old in Blora Central Java

Abstract

Left-handed is a natural behaviour in human populations. The frequency of left-hander seems highly variable in societies and always at a lower frequency compared with right-hander. The aim of this study is to determine the frequency of children age 7 to 21 years old in Blora, Central Java and to collect the data on their hand precision and power grip. The respondents were elementary students, junior high school students, high school students and undergraduate students (age 7-21 years old). Subjects were measured with Rife methods, power grip, and precision grip. Total frequency left-handed children were 5.2% in Blora. The frequency of left-hander in Blora have a similarity with the frequency of lefthander in Bogor, but the frequency of left-hander in Blora is lower when compared with the previous study in Padang. The result indicates that the frequency of left-hander grows smaller at older groups. Higher education, cultural, social pressure and environment influences suppress left-handed behaviour.