The purpose of this study was to develop predictive models relating isokinetic knee testing performance to anthropometric and demographic variables. The subjects were 134 healthy volunteers (70 female, 64 male) between the ages of 10 and 80 years. The investigators measured subjects' peak knee flexion and extension torque production at two angular velocities. Stepwise regression analyses were used to examine the relationship between each torque-dependent variable and the following potential predictor variables: age, sex, side of lower extremity dominance, height, weight, percentage of body fat, and thigh girth. The investigators generated two sets of models designed to predict preinjury knee strength. Clinicians can use one set of models by assessing predictor variables before or immediately following injury. The second set of models involves the assessment of predictor variables postinjury, excluding an assessment of percentage of body fat and thigh girth. The results indicated that peak knee torque production can be predicted with statistically significant accuracy (multiple R = .78-.87). The predictive models generated in this study can be used to establish muscle strength goals for patient rehabilitative programs.

The t test is used to test for differences in means or to test a criterion measure between two groups of scores. Whether an investigator designs a study where the subjects' scores from one group are independent of the scores in the other group (independent t test), the basic assumptions of the test are identical. Hence, the subjects' scores from each group are assumed to be normally distributed and the variance of the two groups of scores are assumed to be homogeneous. The basic differences between the independent t test and the correlated t test are in calculating the t statistic and the df and in the method in which subjects are assigned to each group. If an investigator uses the same subjects in each group, then the correlated t test must be used. If subjects are matched or paired by some related variable, such as age, height, or weight, then the correlated t test should be used. In all other cases, the independent t test would be appropriate.

The purpose of this study was to determine which set of selected kinematic variables affected the speed of visually impaired residential youth in the sprint run. The subjects were 27 students, 16 males and 11 females, between the ages of 9.4 and 16.4 years. Film data were collected during two trials of the 50-m dash. A Fortran computer program produced nine variables from these digitized data. A multiple regression analysis was performed on the variables using running speed as the dependent variable. Results of a correlation matrix yielded five variables with significant bivariate correlations to running speed. Results of a regression analysis indicated that the cycle length and hip joint range of motion had significant effects on running speed. Implications for an increase in sprinting speed include increasing stride length via the generation of greater hip extension during the drive phase and a greater hip flexion during the recovery phase of sprint running.

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This study examined the coefficients of restitution (e) of selected balls used in team sports for the visually impaired: beep baseball and goal ball. Specifically, a basketball was compared to two men's standard goal balls, and a softball was compared to three different types of beep baseballs. The e for all balls was calculated by dropping each ball five times from heights of 6 ft (1.83 m) and 19.25 ft (5.88 m). A Sony reel-to-reel videotape recorder was used to record rebound heights on a background scale for each ball dropped. Reliability tests of the procedures yielded correlation coefficients (r) of 0.996 and 0.998 for the 6 ft (1.83 m) and 19.25 ft (5.88 m) drops, respectively. Two two-factor analysis of variance (ANOVA) tests yielded significant differences across ball type and height of drop for the basketball and goal balls and for the softball and beep baseballs, respectively (p < 0.001). The es for the more recently developed beep baseballs are close to that of the standard softball, indicating a possible danger to visually impaired participants in beep baseball.