Ground reaction force (GRF) data collected and synchronized with film data to determine peak GRF and calculate moments about ankle and knee during rope skipping. Two, five minute conditions were analyzed for 10 subjects. Condition 1 was set rate and style. Condition 2 was subjects' own rate and style. Means and standard deviations were reported for peak GRF, ankle and knee moments. One way ANOVAs reported no significant difference between conditions for variables measured. Efficiency and nature of well phased impacts during rope skipping may be determined by combination of GRF, similarities in magnitude and direction of joint moments, and sequencing of segmental movements. Technique and even distribution of force across articulations appear more important than magnitudes of force produced by given styles.

The present investigation was designed to examine the effects of the positive manipulation of information on self-efficacy and subsequent performance of 180 female subjects. High, moderate, and low self-efficacy subjects were randomly assigned to a treatment condition in a 3 x 4 x 3 (preexisting self-efficacy x efficacy information source x trials) factorial design. Information from the three efficacy sources of performance accomplishments, verbal persuasion, and vicarious experience was manipulated towards success after subjects completed a muscular leg endurance task. The results supported self-efficacy theory with high self-efficacy subjects extending their legs significantly longer than moderate and low self-efficacy subjects. However, subjects did not differentially [sic] respond to the manipulation of the efficacy information. Results are discussed in terms of efficacy as a mediator of performance on an endurance task as well as the lack of differential changes in efficacy based on the source from which that information is derived.

The purpose of this study was to investigate two different plyometric training techniques for increasing vertical jumping ability. Twenty-four female high school volleyball players were matched for height and weight and distributed equally among three groups. Each subject performed a vertical jump test, Margaria power test, Wingate bicycle test, and an isokinetic leg strength test prior to and following six weeks of training. Plyometric training significantly (p<.05) improved vertical jumping ability and some indices of leg strength and power. Weighted plyometrics did not enhance performance more than plyometrics alone. These data support the view that plyometric training with or without added weights enhances vertical jumping and leg power.