Selecting Metrics That Matter: Comparing the Use of the Countermovement Jump for Performance Profiling, Neuromuscular Fatigue Monitoring, and Injury Rehabilitation Testing

Abstract

The countermovement jump (CMJ) is one of the most used performance assessments in strength and conditioning. Although numerous studies discuss the usability of different metrics in this test, this is often performed within the context of a specific aim. However, to our knowledge, no information currently exists providing practitioners with some over-arching recommendations on which metrics to choose when the purpose of using the test differs. This article discusses how the metrics selected to monitor during CMJ testing may differ when aiming to use it as a proxy for athletic performance, as part of neuromuscular fatigue monitoring, or as part of a test battery for return to performance in injured athletes.

Mixed Training Programs Applied to Young Soccer Players: Effects on Speed-Power Abilities

“…Regarding COD ability, no significant pre-post intervention changes were found in any group, which suggests that both MULTI and TRAD programs were unable to improve COD velocity and efficiency (i. e., COD deficit). Nevertheless, the individual analysis based on the target score [36] revealed a greater number of meaningful changes in zig-zag performance (in relative terms) in the MULTI protocol. Superior velocities (i. e., greater than the target score) were found for more than half of the players in this group (55 %) post-training, whereas only a third (33 %) of the players in the TRAD displayed faster performances at post-training.…”

“…Absolute and relative reliability of test scores were established using the coefficient of variation (CV) and a two-way random intraclass correlation coefficient (ICC), respectively. Individual CV values were computed and used to set "target scores" for post-measurements and examine whether variations in speed-power parameters were greater than their natural variability estimated at baseline (i. e., pre-tests) [36], thus providing an indication of whether a "true change" occurred for each soccer player. Additionally, to determine the magnitude of pre-and post-training differences between groups, effect sizes (ES) were calculated and interpreted using the thresholds proposed by Rhea [37] for highly trained subjects, as follows: < 0.25, 0.25-0.50, 0.50-1.00, and > 1.00 for trivial, small, moderate, and large, respectively.…”

Development and Reliability of Countermovement Jump Performance in Youth Athletes at Pre-, Circa- and Post-Peak Height Velocity

“…The countermovement jump (CMJ) is frequently used to assess and monitor lower body neuromuscular function due to its ease of implementation and the low risk of injury it offers (5). From a developmental International Journal of Strength and Conditioning.…”

“…An awareness of this developmental phenomenon is important as it is recommended that training volumeloads are modified to avoid excessive stress and to facilitate the re-learning of previously acquired skills and movement patterns (20). Despite previous research highlighting these patterns of development during growth and maturation, monitoring JH alone is limited as it does not describe jump strategy (1,5). Therefore, expanding analyses to include braking ("eccentric") and propulsion ("concentric") phase variables has been recommended to simultaneously monitor jump strategy as well as outcome (5,6,17).…”

“…Despite previous research highlighting these patterns of development during growth and maturation, monitoring JH alone is limited as it does not describe jump strategy (1,5). Therefore, expanding analyses to include braking ("eccentric") and propulsion ("concentric") phase variables has been recommended to simultaneously monitor jump strategy as well as outcome (5,6,17).…”