Strength changes of the quadriceps and alterations in vertical leap measurements after 6 weeks of training on the shuttle 2000

The purpose of this study was to determine if 6 weeks of training on the Shuttle 2000 (Contemporary Design, WA, USA) would change quadriceps strength or vertical leap measurements. Thirty university women were assigned randomly to one of two groups. The training group exercised for 6 weeks, with three sets of 15 repetitions of a horizontal squat against resistance. Pretests and posttests of vertical leap and quadriceps strength, measured eccentrically and concentrically on the Kin Com (Chattex Corp., Chattanooga, TN) at 60 and 180 deg/sec, were used for analysis. t Tests were used to determine significant differences between the two groups. Percent change was defined as [(posttest) − (pretest)/pretest] × 100. Results of the t test on the percent change in vertical leap showed a significant difference between the groups at p < 0.01. Moderate increases in quadriceps strength were found in the training group for each speed and type of contraction, but no statistically significant change was seen between the two groups at either speed or type of contraction. The improved performance could be related to enhanced neural activation/control.