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The purpose of this study was to measure the difference in a loaded versus unloaded vertical jump on jump height and muscle activation. It was hypothesized that the loaded vertical jump would have a significant increase in comparison to the unloaded vertical jump due to the stimulus that the resistance band would apply. The muscle focused on in this study was the Gastrocnemius. The gastrocnemius is known to aid in knee flexion during the loading phase (phase one) and assist in plantar flexion at the talocrural joint in the jumping phase (phase two). 8 healthy young athletes (female = 3) were recruited for this study. The protocol for this study consisted of a five-exercise warm-up, then would perform a vertical jump for the first comparison. After five minutes of rest, the participant would then perform a loaded squat with a resistant band and immediately perform a vertical jump for the second comparison. The process was repeated such that each subject performed two trials of both the loaded and unloaded jumps. All jumps were performed on a Just Jump Mat ® which reported jump height in inches. Electromyography (EMG) was recorded in the gastrocnemius muscle with Delsys Trigno wireless sensors. The root mean square of the EMG signal was computed. A paired sample T-test was used to compare the average peak EMG signal and height of both vertical jumps. We determined from the p-value of the vertical jump (p=.103), and the p-value of the EMG (p=.474) that there was no significant difference between the two jumps because the value of each was greater than .05. In conclusion, for both the unloaded and loaded vertical jump there was no significant difference reported. This study would be best applied to athletic individuals who compete in some sort of power-type sport. The limitations we had in this study were the small number of participants gathered for the study (n=8), The height of the participant which would impact the total resistance of the band, the amount of resistance, and the lack of experience of the individuals performing the loaded squat. Reasoning for why this study didn’t work could be due to the limiting factor that the participant in the study had little to no experience in performing a squat with a loaded resistance such as the resistance band. Future studies should provide familiarization trials and normalize the length of the resistance band.

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