Effects of a 6-Week Depth Jump Training Program on Balance Performance and Vertical Jump Height in Varsity Female Athletes

Introduction

Methods

References

DiscussionPurpose

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Plyometrics training is often used to improve strength and power (Behm & Sanchez, 2013). Specifically, plyometrics have been shown to be an effective training method for sprint-type activities (Behm, Wahl, Button, & Power, 2005). In addition to an increase in strength and power, an athlete’s vertical jump height is also improvied (Gerhi, Ricard, Kleiner, & Kirkendall, 1998; Flanagan, Ebben, & Jensen, 2008). Depth jumps also mimic sport like activity enhancing the specificity of the training (Gerhi et al., 1998), suggesting they can improve an athlete’s performance in competition.

Balance performance, often measured by centre of pressure, is an aspect of training that is often overlooked. Centre of pressure measures the ground reaction forces distributed throughout the foot while attempting to maintain balance (Hrysomallis, 2011). Minimal deviation in the athlete’s foot when balancing is an indicator of good balance. Although often overlooked, balance is required in sports as well as everyday activities so it can be suggested that an improvement in balance will transfer to an improvement in daily tasks as well as their sport. Twist, Gleeson, and Eston (2008) suggest that efficiency of movement is increased with adequate posture stability, therefore an increase in balance performance can also result in the exertion of greater forces in an unstable environment present in most sports (Behm & Sanchez, 2013).

Participants: 21 female varsity athletes from St. Francis Xavier University hockey and soccer teams consented to participate in this study. Each team was randomly divided into two groups: control or experimental group.Instrumentation: PasPort 2-Axis Force Platform Model No. PS-2142 (Figure 1) was used to measure the normal force throughout the maximal vertical jump and the lateral deviation of the the athlete’s balance during the one leg stance test.

Figure 1: PasPort 2-Axis Force Platform Model No. PS-2142

Stephanie Venedam, Jeff Vossen, & Dr. Angie Kolen Department of Human Kinetics

The purpose of this study was to determine if a 6-week depth jump training program increased balance performance and vertical jump height in female varsity athletes.

Results

Procedure: Subjects in the experimental group were instructed to adhere to a 6-week depth jump training program consisting of two sessions a week. This program consisted of one familiarization week of two sets of eight repetitions and five weeks of three sets of ten repetitions. These depth jumps (Figure 2) were performed off a 40 cm box. Pre-testing and post-testing was performed by both the experimental and control group. This consisted of two maximal vertical jumps of which the highest jump was recorded as well as a one leg stance test (Figure 2) that lasted up to three minutes performed on both the right and left foot.

Behm, D. G., & Sanchez, J. C. C. (2013). Instability resistance training across the exercise continuum. Sports Health: A Multidisciplinary Approach, 5(6), 500-503. Behm, D. G., Wahl, M. J., Button, D. C., Power, K. E., & Anderson, K. G. (2005). Relationship between hockey skating speed and selected performance measures. Journal of Strength & Conditioning Research, 19(2), 326-331.Fatouros, I. G., Jamurtas, A. Z., Leontsini, D., Taxildaris, K., Aggelousis, N., Kostopoulos, N., & Buckenmeyer, P. (2000). Evaluation of plyometric exercise training, weight training, and their combination on vertical jumping performance and leg strength. The Journal of Strength & Conditioning Research, 14(4), 470. Flanagan, E. P., Ebben, W. P., & Jensen, R. L. (2008). Reliability to the reactive strength index and time to stabilization during depth jumps. Journal of Strength & Conditioning Research, 22(5), 1677-1682.Gehri, D. J., Ricard, M. D., Kleiner, D. M., & Kirkendall, D. T. (1998). A comparison of plyometric training and techniques for improving vertical jump ability and energy production. Journal of Strength & Conditioning Research, 12(2), 85-89.Hrysomallis, C. (2011). Balance ability and athletic performance. Sports Medicine, 41(3), 221-232.Twist, C., Gleeson, N., & Eston, R. (2008). The effects of plyometric exercise on unilateral balance performance. Journal of Sports Sciences, 26(10), 1073-1080.Vescovi, J. D., Canavan, P. K., & Hasson, S. (2008). Effects of a plyometric program on vertical landing force and jumping performance in college women. Physical Therapy in Sport, 9(4), 185-192.

The 6-week depth jump training program did not significantly improve balance performance or vertical jump height in varsity female athletes.

The lack of improvement in vertical jump height found in this study (p = 0.974) is contradictory to previous literature (Fatouros et al., 2000; Flanagan et al., 2008). The lack of a significant increase in power may be attributed to the lack of individuality of the depth jumps as the box height was consistent throughout the study and for each participant. Several participants increases their vertical jump height while others showed minimal to no improvement. Subjects whose vertical jump height increased can be assumed to have had sufficient stimulus to improve their vertical jump height.

Balance performance results were also inconsistent with previous literature (Behm & Sanchez, 2013; Hrysomallis, 2011) with no improvement found in left and right foot lateral deviation. The left foot had significantly improved as noted by a decrease in left foot balance (p = 0.027) while the right foot lateral deviation showed no significant changes (p = 0.880). The lack of significant improvement in balance and power could be attributed to the length of the training program. A longer training program could have introduced a greater muscle stimulus, which could translate to more noticeable improvements. There was also minimal lateral deviation at pre-testing of our athletes. The high baseline values at pre-testing suggested a ceiling effect and minimal opportunity for significant improvements.

Future studies could examine a different population such as an older population or an average healthy population with a lower baseline fitness level. A longer training program could also be implemented and would be consistent with previous research which found significant improvements with a training program of 10 to 12 weeks (Fatouros et al., 2000).

Graph 1: Percentage of Practice Time Spent in MVPA

Graph 2: Percentage of Game Time Spent in MVPA

Table 1. Balance performance for pre and post-testing data collection.

Table 2. Summary of vertical jump height in pre and post-testing data collection.

Figure 2. Depth Jump Exercise

Figure 3. One Leg Stance Test performed during pre-testing