Seasonal Change in Countermovement Jump Performance in NCAA Women’s Golfers

Background of Study: The countermovement vertical jump (CMJ) task has been reported to have positive associations with golf-specific performance variables. Additionally, the CMJ is commonly used to assess neuromuscular fatigue in athletic populations. Objective: Thus, this investigation sought to examine the changes in CMJ performance throughout a competitive season in NCAA collegiate women’s golfers. Methods: Using a longitudinal study design, six collegiate women golfers completed three sessions (pre, mid, and post) of CMJ testing during the spring competition period. During each testing session, two successful jump trials were collected using a portable force platform sampling at 1000 Hz. During each trial, an arm swing was restricted by the use of a dowel placed across the upper back. A one-way repeated measures analysis of variance was used to determine if differences were present between testing sessions. Results: Propulsive net impulse significantly increased from pre to mid (p 0.05) and pre to post (p 0.05). No other variables showed a statistically significant change over the duration of the study, though moderate effect size increases were in countermovement depth from pre to mid-testing (0.73) and jump height from pre to post-testing (0.72). Conclusions: These findings support previous findings of an increase in vertical jump performance over the course of a season in collegiate golfers, though strategies for maximal performance may shift

Phase Specific Comparisons of High and Low Vertical Jump Performance In Collegiate Female Athletes

Introduction: Countermovement vertical jump testing has become a staple in athlete assessment protocols. As the popularity of jump testing has grown, a need and interest has also grown in identifying the factors that underpin high-level outputs. As jump height alone as a variable in evaluating vertical jump performance has been questioned in athletic populations, other variables such as the reactive strength index modified (RSIm) allow for not only evaluating the outcome, but the strategy used in obtaining that outcome. Purpose: Thus, the purpose of this investigation was to examine the differences in high and low vertical jump performances, as determined by the RSIm in female collegiate athletes. Methods: Thirty NCAA Division I female volleyball and basketball athletes performed countermovement vertical jump trials on a force platform. The sample was then broken into two groups as determined by median RSIm values. Independent sample t-test were then used to compare groups. Results: High RSIm group displayed greater jump heights (P \u3c 0.05). Additionally, the high performing group displayed lower eccentric duration times (P \u3c 0.05). No differences between groups were seen in kinetic variables. Conclusion: The high performing group displayed faster eccentric times which translated to lower values in time to take-off though not statistical significant. The higher RSIm values appear to be a result of both greater jump heights and reduced time to take off. Thus, focus being placed on the speed of the movement during training would be of benefit in improving RSIm values

Examination of Countermovement Jump Performance Changes in Collegiate Female Volleyball in Fatigued Conditions

The purpose of this investigation was to examine changes in countermovement vertical jump performance after a single sport-specific training session in a sample of collegiate female volleyball athletes. Eleven NCAA Division I volleyball athletes performed countermovement vertical jumps with and without an arm swing prior to and immediately after a sport-specific training session. Each participant completed two jumps in each condition using a portable force platform. Paired samples t-tests were performed within each jump condition. When using an arm swing, mean braking force was the only variable to display a statistically significant change (p p p < 0.05). Additionally, a single-subject analysis was performed across all eleven participants resulting in general trends seen in the no-arm-swing condition, whereas the arm-swing condition displayed inconsistent findings across participants

Positional Comparison of Jump Performance in NCAA Division I Female Volleyball Athletes

Background: The vertical jump task is a critical component of success in volleyball. Each position on the court has its own physical demands and has differing levels of vertical jump task demands. Objective: Thus, the objective of this investigation was to compare vertical jump performance between the two positional groups using the countermovement jump (CMJ) and squat jump (SJ). Methods: Using an observational cross-sectional study design, nineteen NCAA Division I female volleyball athletes participated in this investigation. Participants first performed three CMJ trials followed by 3 SJ trials on a force platform. Jump height, peak and mean net propulsive forces, and time to take off were calculated for both the CMJ and SJ. Reactive strength index modified and propulsive duration were additionally calculated for the CMJ and average RFD for the SJ. Independent sample t-tests were performed comparing positional groups on each variable of interest with Hedges g effect sizes additionally calculated. Results: No statistically significant differences (p 0.05) were found between any of the variables of interest in the CMJ though moderate effect sizes were seen in jump height (g =0.78). No statistically significant differences were present in the SJ though moderate effect sizes were seen in RFD (g = 0.65), mean propulsive force (g = 0.79) and peak propulsive force (g = 0.66). Discussion: As the vertical jump task is a critical task for high-level performance in both positions, and the no differences seen between groups, training programs should be designed to improve jump performance with special attention to the individual athletes’ needs rather than the specifics of the playing position

COMPARISON OF INSTABILITY DEVICES ON MEASURES OF SINGLE LIMB POSTURE SWAY PARAMETERS

BACKGROUND: Single limb balance training is an integral part of both the prevention and rehabilitation process of lower extremity injuries. Practitioners use instability devices to provide a progressive overload to an individual during single limb balance training sessions. Previous investigations have shown that when using instability devices differences may or may not exist in postural sway parameters during use depending on the specific devices being assessed. Thus, this investigation sought to examine differences between a commonly used foam pad and a novel instability device (block) in measures of postural sway. METHODS: 22 healthy individuals with no history of lower extremity injury and neurological disorders participated in this investigation (age 21.66 ± 0.74 years, height 167.07 ± 10.74 cm, body 67.76 ± 13.45 kg). Participants performed three conditions of single limb static balance on a force platform sampling at 120 Hz. Each condition contained three 20 second trials separated by thirty seconds. The mean center of pressure (CoP) values of the three trials in each condition were then compared using a within-subjects repeated measures analysis of variance. RESULTS: Statistically significant differences were seen in sway area between conditions (f(2,42) = 5.28, p = 0.009), with the control (9.64 ± 4.53 cm) being significantly lower than both the foam pad (13.05 cm ± 4.25 cm) and block (12.33 ± 3.37 cm). Statistically significant differences were seen in CoP path length between conditions (f(2,42) = 5.52, p = 0.007), with the control (67.51 ± 9.49 cm) being significantly lower than both the foam pad (74.36 cm ± 9.76 cm) and block (76.38 ± 14.84 cm). Maximal medial-lateral CoP displacements were significantly different between conditions (f(2,42) = 6.24, p = 0.004). Lower displacements were seen in the control (1.39 ± 0.20 cm), which was statistically different from both foam pad (1.59 ± 0.24 cm) and block (1.53 ± 0.25 cm). Maximal anterior-posterior CoP displacements were not significantly different between conditions (f(2,42) = 1.50, p = 0.23). CONCLUSIONS: This investigation provides supporting evidence that different instability devices may provide similar changes in postural sway parameters in comparison to control conditions. The novel block instability device used in this investigation may be used in a similar fashion to the traditional foam pad in both prevention and rehabilitation settings based on no differences being found between the two devices

COMPARISON OF REACTIVE STRENGTH INDEX MODIFIED ACROSS DIVISION I FEMALE SPORTS

BACKGROUND: The countermovement jump (CMJ) is an exercise commonly used to monitor an individual’s neuromuscular abilities. Previous investigations have compared vertical jumping abilities across sports using the reactive strength index modified (RSImod). RSImod is the ratio of jump height and time to take off during the CMJ task. These investigations have revealed that differences in RSImod have been primarily a result of differences in jump height as time to take off were not different from each other. However, these comparisons have been conducted in sports that have different levels of exposure to the vertical jump task during the sport itself. Thus, the purpose of this investigation was to examine RSImod values across three women\u27s sports that have limited vertical jump exposures. METHODS: 54 collegiate female athletes from three sports (soccer = 29, softball = 15, and golf = 11) participated in this investigation. Data was collected from preseason CMJ testing for each sport as part of their athlete monitoring program. Prior to completing testing, each participant completed a standardized dynamic warm up. Each participant completed three maximal effort trials. Each trial was separated by thirty seconds. All trials were performed on the same portable force platform sampling at 1000 Hz. The mean of the three trials was calculated for each variable. A one-way analysis of variance was performed for each variable of interest. RESULTS: Statistically significant differences were seen in RSImod (f(2,54) = 4.30, p = 0.02), with golf (RSImod = 0.22 ± 0.04) being significantly lower than both soccer (RSImod = 0.30 ± 0.07) and softball (RSImod = 0.32 ± 0.13). Similarly, jump height displayed statistically significant differences between groups (f(2,54) = 8.08, p \u3c 0.001). Golf had the lowest jump height (0.20 ± 0.02 m), which was statistically different from both soccer (0.25 ± 0.04 m) and softball (0.25 ± 0.04 m). No statistical differences were seen in time to take off (f(2,54) = 0.29, p = 0.75) and countermovement depth (f(2,54) = 0.84, p = 0.44) between the groups. CONCLUSIONS: This investigation provides support for previous findings regarding differences between sports with both RSImod and jump height. As temporal variables such as time to take off show no significant differences between sports, this suggests that differences in jump performance are driven by force production capacities between sports