Unit motion analysis of the movement of children with cerebral palsy

Abstract

It is generally acknowledged that a child suffering from cerebral palsy shows many kinds of motor disorders. The auther introduces the novel term “unit motion” to describe the characteristics of motion in child and to analyze the essentials of crippled motion. Unit motion is the term applied to the simplest motion of human being which is a specific unit of one-way motion (stretching, bending, etc.), and covers the whole range of the trajectory of a part of joint (shoulder, elbow, wrist, etc.).The purpose of this study was to investigate unit motion in children with cerebral palsy: It was designed to examine the relationship between one motion part of the body and the other and to study a developmental tendency of crippled motion to find some characteristic of unit motion by means of factor analysis.The measure used in this study was the unit motion test, consisting of 72 items, which was devised by the author. A unit motion was to be evaluated from two aspects: motor ability and muscular tension. A six-point scale for motor ability was constructed, ranging from “very hard to move by one-self” (1 point) to “very smooth” (6 points). The grade in the test of muscular tension was also 6 points, ranging from “over tension” (1 point) to “adequate” (6 points).Subjects were 126 children, aged from 3 to 19 years old (70 males and 50 females).Based on the subject's score, the items were intercorrelated to form a 72×72 correlation matrix. A statistically significant correlation was found between (1) left and right parts; shoulder, arm, elbow, thigh, knee, (2) the upper and the lower limbs; shoulder, arm, elbow, trunk, hip, thigh, knee, (3) shoulder, arm and elbow, (4) trunk, hip, thigh and knee, (5) left (right) wrist and left (right) fingers, (6) left (right) ankle and left (right) toes. (7) Mouth, breast, tongue and neck were each correlated too. (8) Eyes had no significant parts.The Varimax method of factor analysis was applied to the correlation matrix based on 72 items, and three factors were extracted. The nature of these factors may be summarized as follows: Factor 1 is interpreted as the abilities of “Speech”. Factor 2 represents the abilities of “Body locomotion”. And the items loaded with Factor 3 are related to the abilities of “Manipulation”.Subjects were divided by motor and tension total scores in to a high ability group, a middle ability group and a low ability group. When applied to the subjects of each group, the factor score showed differences. It was found that Factor 2 was lower than other two factors for all groups: Body locomotion is more difficult than Speech or Manipulation.Tension scores showed a tendency to decrease with age: The more the age of a child increases, the more difficult the usage of muscular tension becomes.