(06) KINETIC AND KINEMATIC ASPECTS OF THE VERTICAL JUMP RELATED TO OVERREACHING: A SYSTEMATIC REVIEW

Saturday, July 15, 2023

9:45 AM – 10:00 AM East Coast USA Time

Location: Milano I-II

Podium Presenter(s)

Jeremy A. Ross, M.Ed., CSCS, CPSS

Assistant Professor
University of Kentucky Sports Medicine Research Institute
Wilmington, North Carolina, United States

Author(s)

BL

Brian Leary

Assistant Professor
West Virginia University
Morgantown, West Virginia, United States
JJ

Jacob Jelmini

Doctoral Candidate
University of Kentucky
Lexington, Kentucky, United States
MH

Matthew Hoch

Associate Professor
University of Kentucky
Lexington, Kentucky, United States
Nicholas Heebner, PhD, ATC

Associate Professor
University of Kentucky
Lexington, Kentucky, United States

Abstract Details: Overreaching, or training to a point of degraded performance with the goal of supercompensation, is a viable training strategy for athletic improvement; however, this type of heightened training carries risks including non-functional overreaching and potentially the overtraining syndrome. Jump testing is commonly used by coaches to identify overreaching, but coaches are often uncertain which kinetic and kinematic jump variables best inform on an athlete’s training status.

Purpose: A systematic review was conducted to identify jumping kinetic and kinematic variables in athletes associated with an overtrained or overreached state.

Methods: An electronic literature search was conducted using PubMed and EBSCOHost querying the databases CINAHL and Sport Discus. Key words and Mesh terms (PubMed) were identified and used to search for studies that described neuromuscular fatigue or overreaching and jumping in the Title or Abstract. Manuscripts were included if they 1) monitored overreaching related to an exercise or sport stimulus lasting ≥3 weeks, 2) studied healthy, adult athletes at National Level or above, and 3) included an unloaded vertical jump test. Manuscripts were excluded if they 1) were not peer-reviewed original research, 2) did not report measured kinetic/kinematic variables, 3) reported outcome variables for supercompensation only, 4) did not include sufficient data to calculate effect sizes (ES) and confidence intervals (95%CI), 5) were not available in English. ES and 95%CI were extracted or calculated from reported standard deviation/standard error. A modified 14-item Downs and Black checklist was used to assess risk of bias.

Results: Fourteen manuscripts met inclusion/exclusion criteria. A PRISMA Diagram of search results is included as Figure 1. Most studies had a low (71.4%) or moderate (21.4%) risk of bias. 29 unique outcome measures were reported with 11 reported in multiple studies. The most reported measures were the ratio of flight time to contraction time (FT:CT, 15 ES reported), jump height (12 ES), mean power (7 ES), peak power (7 ES), mean velocity (5 ES) and peak force (PF, 5 ES). FT:CT and PF demonstrated the most consistent negative changes with exposure.

Conclusions: JH alone is insufficient to identify chronic neuromuscular fatigue. The strongest evidence suggests that FT:CT and PF may prove useful to identify overreaching. More research is warranted to further clarify these results. PRACTICAL APPLICATIONS: Coaches should consider peak force and measurements related to jumping strategy combined with jump height (such as FT:CT or reactive strength index modified) in conjunction with environmental, individual and sport factors to inform on athlete training status. More research in highly trained athletes is warranted to identify the sensitivity and specificity of these variables and/or to identify additional variables (such eccentric force production variables) related to athlete overreaching.

Acknowledgements:

No funding sources to disclose