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 < 0.05). In the no-arm-swing condition, mean propulsive force, propulsive net impulse, jump height and reactive strength index modified all statistically increased (p < 0.05). Time to takeoff was statistically reduced (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.

Donahue, PT, Peel, SA, Rush, M, McInnis, AK, Littlefield, T, Calci, C, and Brutofsky, T. Examining countermovement jump strategies between women’s NCAA Division I sports. J Strength Cond Res 37(10): 2052–2057, 2023—The purpose of this study was to examine countermovement vertical jump performance among female athletes who rely heavily on vertical jump performance within their given sport. Forty-five female athletes representing 3 teams (basketball, volleyball, and beach volleyball) competing at the NCAA Division I level completed 2 maximal effort countermovement jumps (CMJ) using a portable force platform. A 1-way analysis of variance was used to compare groups across each variable. Statistically significant differences were found between the groups regarding propulsive duration and time to takeoff with basketball showing the shortest time and beach volleyball having the longest times (p < 0.05). In addition, differences were seen in countermovement depth and mean propulsive force between the groups with basketball displaying the smallest countermovement and highest force (p < 0.05). No differences were seen in jump height and reactive strength index modified. Greater force and shorter durations in basketball athletes versus the low force and long durations in the beach volleyball athletes suggest that sporting backgrounds play a large role in how the CMJ is performed. This information can aid strength and conditioning practitioners in the design of training programs that are sport specific to the strategies used by the athlete.

The countermovement jump (CMJ) is commonly used to assess both acute neuromuscular performance as well as adaptions to periods of training. Two methodologies are typically employed when performing the CMJ assessment. The first allows for the use of an arm swing (AS) to add a level of sport-specificity to the testing. The second restricts the movement of the arms (NAS) to allow for an assessment of the musculature of only the lower body. Thus, the purpose of this investigation was to examine differences in jump strategy between the two methodologies. Twenty-five female Division I collegiate athletes (volleyball = 13, beach volleyball = 12) participated in this investigation. Participants performed two CMJ in both the AS and NAS conditions. A paired samples t-test was used to evaluate differences in jump performance and jump strategy variables. During the braking phase of the CMJ statistical higher force values (p < 0.01) were seen in the NAS condition while longer phase durations were present in the AS condition (p < 0.001). No difference was seen in braking net impulse. During the propulsive phase statistically greater duration was seen in the AS condition (p < 0.001) leading to a greater propulsive net impulse (p < 0.001). The AS condition also displayed greater jump heights, countermovement depth and time to take off durations (p < 0.001) with no differences in reactive strength index modified. When performing CMJ assessments practitioners should consider which methodology they use carefully as the NAS assessment used a more force driven strategy while the AS used a time driven strategy.

Article: Association of anthropometrics and physical performance measures to golf-specific variables in collegiate male golfers - The Journal of Sports Medicine and Physical Fitness 2021 May;61(5):693-8 - Minerva Medica - Journals

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.

Article: Impact of aute caffeine ingestion on isometric squat and vertical jump performance - The Journal of Sports Medicine and Physical Fitness 2021 Dec 09 - Minerva Medica - Journals