Helen M. Eckert

Balance and stability.

An examination of balance and stability indicates that the functional aspects of stability may mediate against optimal balance development.

Stabilometer Performance of Educable Mentally Retarded and Normal Children.

Abstract Five trials on the stabilometer were administered to 274 EMR children ages 6 to 13 years and 151 normal children ages 6 to 9 years. Older EMR boys and girls had slightly more board movement than younger EMR children whereas there was a tendency for board movement to decrease with age for the normal children. There were no appreciable sex differences between the EMR and the normal age groupings with the exception that board movement of the young EMR boys was significantly less than that of the young and old EMR girls. Normal children had significantly less board movements than EMR children at all age levels. There was some decrease in relative intra-individual variability with increasing age for both EMR and normal children but normal children were more efficient in early learning than EMR children.

Angular Velocity and Range of Motion in the Vertical and Standing Broad Jumps

Abstract Cinematographic records were taken of the vertical and standing broad jumps, and strength measurements made of the isometric extensor strength of the hip, knee, and ankle joints for eighteen men and eleven women. A comparison of range of motion of joint actions and maximal angular velocities for men and women indicated distinct time-force coordinations of the various joint actions in the performance of the vertical and standing broad jumps. No general relationship nor pattern of relationships was found between isometric extensor strength and maximal angular velocity.

Linear Relationships of Isometric Strength to Propulsive Force, Angular Velocity, and Angular Acceleration in the Standing Broad Jump

Abstract The cinematographic records of ten boys at 8, 10, and 12 years of age were used to calculate the propulsive force of the body as a whole and the angular velocity and angular acceleration of the hip, knee, and ankle joints during the performance of the standing broad jump. The propulsive force was correlated with the isometric strength measures of the lower limbs and with the distance jumped. These relationships were not significant although those between propulsive force and measured strength tended to approach significance at 10 and 12 years of age. The calculated angular measures were correlated with the isometric extensor strength of the muscles of the respective joints. There was no relationship between the calculated angular measures and isometric extensor strength at the knee and ankle joints. The relationships of isometric extensor strength to the maximal angular velocity and to the angular velocity at the point of maximal acceleration were fairly high at the hip joint. They ranged from .5...

Reliability of Reaction Time

Various statistical models for assessing the reliability of repeated measures of reaction time are compared. The results indicate that the intraclass correlation for scores is appropriate for assessing reliability of an individuals performance during repeated measures, whereas the intraclass correlation for means or the odd-even product-moment correlation represents the reliability of the mean performance of the individual with respect to the group.

The Effect of Added Weights on Joint Actions in the Vertical Jump

Abstract Cinematographic records were taken of 17 males during the performance of the vertical jump under four conditions of weighting; namely: no additional weight, and additions of 6, 12, and 18 pounds. Decreases in maximal angular velocity and increases in range of motion and time of the joint actions of the hip, knee, and ankle were noted with increasing amounts of weight. Significant decreases were obtained in the V/t ratio at the hip and knee joints with increasing amounts of weight. If one assumes a constant available force, these adjustments are consistent with an increase in mass (weight) according to the formula F = m V/t.

Relationship between Strength and Work Load in Push-Ups

Fifteen well-conditioned college women, who had been thoroughly trained in the correct technique for womens push-ups, were tested for maximal pushing strength in two positions and for the number o...

Learning Curves for Delayed Static and Dynamic Visual Feedback.

Abstract Sixty subjects were randomly assigned to 20 initial trials of blind maze tracing under conditions of delayed static or dynamic visual feedback and completed the alternate condition during the second series of 20 trials one week later. The amount of delay (10 sec.) was the same for all trials, and the maze remained the same for all trials. For static visual feedback, subjects were allowed to view their previously completed tracing for 10 sec., whereas for dynamic feedback they saw a replay of their taped action in tracing the maze. Significant learning occurred over the two series of trials for both groups of subjects and within each feedback condition for Group B. There was no significant difference between the two feedback conditions.

Factorial Analyses of Perceptual Motor and Reading Skills.

Abstract Similar-eye-hand coordination tasks were administered to 22 boys and 27 girls at ages 3 and 4 yr and to 33 boys and 28 girls in grades 1 and 2. In addition, the Gates Primary Reading test was administered to the latter age level. There was no consistent factor patterning over age levels or for the sexes with the exception of the reading skills factor which was consistent for both sexes for the reading variables but also had an additional loading of the catch for boys and of the pursuit rotor for the girls.

Statistical models for inter- and intraindividual variability

Abstract Data were collected on 60 subjects using a two-treatment, repeated measure design for a blind tracing task and analyzed using various statistical models. The results indicated that appropriate models for estimating the intraindividual response variability included the standard deviation of all trials for each subject, the average of each individuals standard deviation, the adjacent trials correlation coefficient model for repeated trials, and the intraclass reliability for obtained scores model for ANOVA designs. The latter model provides a single score estimate of variability which may be used in interstudy comparisons.