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Astronauts have complained of difficulty in grasping tools, hand fatigue, and hand/forearm pain during extravehicular activities. This study was conducted to examine hand grip performance with a bare hand and in a spacesuit glove at two different pressures, with three hand positions and two elbow positions. Sixteen subjects, selected from the suited-subject pool at the Johnson Space Center, gripped a hand dynamometer encased in a vacuum chamber designed to simulate the operating pressures in space. The results for the bare hand condition showed a significant effect for hand position and a significant elbow/hand interaction. The spacesuit glove at operating pressure was responsible for an average 42% grip strength decrement from the bare hand condition. A new procedure for determining hand size from projected hand surface area revealed that bare and gloved-hand grip strength was highly correlated with hand size, as were body weight, height, and forearm circumference. / M. S.

Thirty-two Virginia Tech varsity football players served as subjects to examine the effect of protective knee braces on agility and selected isokinetic strength, power, and endurance measures. Each subject performed the Semo agility test in each of three experimental conditions: braced with the Anderson knee stabler (B,An); braced with the Arco knee guard (Bâ Ar); and unbraced (Un). The order of agility tests was randomized. The subjects were than administered a Cybex knee extension/flexion test at 60 deg/sec and 300 deg/sec. Each subject performed the Cybex tests in each of the three experimental conditions (B-An, B-Ar, and Un). The order of Cybex tests was randomized. The test protocol consisted of three maximal repetitions at 60 deg/sec and 40 maximal repetitions at 300 deg/sec. The following isokinetic variables were recorded: (1) peak torque/body weight ratio of the quadriceps and hamstrings at 60 deg/sec and 300 deg/sec; (2) average range of motion for knee extension/flexion at 60 deg/sec and 300 deg/sec; (3) average power, torque acceleration energy, and endurance ratio of the quadriceps and hamstrings at 300 deg/sec. Repeated measures analysis of variance revealed no significant difference (p > .05) in agility test scores between the three experimental conditions. Repeated measures analysis of variance also revealed no significant difference (p > .05) in the isokinetic responses of subjects as they were tested within the three experimental conditions. The investigator concluded that protective knee braces had no effect on agility, isokinetic strength, power, and endurance. / Master of Science

The purpose of this study was to evaluate the relationships among field dependency levels, performance on a non-locomotor balancing task both sighted and blindforded, and the acquisition of a complex biplanar motor skill. The participants for this investigation were young (ages 9-17) female gymnasts (n = 17) who had all received at least one year of gymnastics training, and could perform the prerequisite skills required for this experiment. All subjects were given the embedded figures test (EFT) (Witkin, Oltman, Raskin, & Karp, 1971) and a sighted and a blindfolded task on a stabilometer. The subjects, having been taught with a non-visual teaching method, were then given 50 trials of the full twisting back flip (FULL) on the trampoline. The gymnasts were attached to an overhead spotting rig to insure their safety. A single factor model (field dependence-independence) with three levels (high, middle, and low) was used to examine the relationships among variables. An analysis of covariance (ANCOVA) was used to adjust posttest FULL scores to pretest scores and to assess the effects of field dependency levels on the FULL learning which:it:ook place. Multiple correlations were used to examine the relationships among EFT scores, stabilometer time in balance (TIB) and time in balance blindfolded (TIBB) scores, and pretest and posttest FULL scores. From the data analysis it was found that subjects' field dependency levels did not correlate significantly with their pretest or posttest FULL scores, or with the stabilometer measures. A significant relationship was found between pretest and posttest FULL scores (r = .837) and TIB and TIBB scores (r = .541). The following conclusions were drawn from the findings: (1) because of the lack of significant correlations between the FULL and either the EFT or the stabilometer task, the use of either of these measures as a predictor of the rate of learning of the FULL is not warranted; (2) of all the variables used in this investigation, subjects' pretest FULL scores are the best indicators of how rapidly they will learn the FULL, having been taught by the non-visual method. / M.S.