Preliminary Scale of Reference Values for Evaluating Reactive Strength Index-Modified in Male and Female NCAA Division I Athletes

Abstract

The purpose of this analysis was to construct a preliminary scale of reference values for reactive strength index-modified (RSImod). Countermovement jump data from 151 National Collegiate Athletic Association (NCAA) Division I collegiate athletes (male n = 76; female n = 75) were analyzed. Using percentiles, scales for both male and female samples were constructed. For further analysis, athletes were separated into four performance groups based on RSImod and comparisons of jump height (JH), and time to takeoff (TTT) were performed. RSImod values ranged from 0.208 to 0.704 and 0.135 to 0.553 in males and females, respectively. Males had greater RSImod (p < 0.001, d = 1.15) and JH (p < 0.001, d = 1.41) as compared to females. No statistically significant difference was observed for TTT between males and females (p = 0.909, d = 0.02). Only JH was found to be statistically different between all performance groups. For TTT no statistical differences were observed when comparing the top two and middle two groups for males and top two, bottom two, and middle two groups for females. Similarities in TTT between sexes and across performance groups suggests JH is a primary factor contributing to differences in RSImod. The results of this analysis provide practitioners with additional insight as well as a scale of reference values for evaluating RSImod scores in collegiate athletes.

The Influence of Countermovement Jump Protocol on Reactive Strength Index Modified and Flight Time: Contraction Time in Collegiate Basketball Players

“…The increase in the performance variables of RSI Mod FT , RSI Mod IMP , and FT:CT during the CMJ AS compared to the CMJ NAS, while lacking very large, or nearly perfect, correlations between jump performances indicates different information may be captured from the CMJ AS force-time signature not acquired from the CMJ NAS. Although much of the previous literature has used the CMJ NAS protocol to assess RSI Mod FT , RSI Mod IMP , and FT:CT [ 5 , 26 , 38 ], the present data suggests the inclusion of the CMJ AS protocol may identify alterations in maximal performance capacities. In addition, the CMJ AS may provide information independent from that obtained during the CMJ NAS and may relate more closely to the athlete’s expression of performance capabilities during the actual sporting event tasks, especially in sports incorporating a large vertical component.…”

“…In addition, the CMJ AS may provide information independent from that obtained during the CMJ NAS and may relate more closely to the athlete’s expression of performance capabilities during the actual sporting event tasks, especially in sports incorporating a large vertical component. Furthermore, recognizing differences in performance between the CMJ NAS and CMJ AS will be essential in developing and comparing reference RSI Mod and FT:CT values among various athletic populations [ 26 ].…”

“…Nevertheless, previous literature has yet to compare performance differences in RSI Mod and FT:CT between CMJ protocols, nor the relationship in performance within each variable between the CMJ NAS the CMJ AS. Understanding the relationship within each variable between protocols may aid coaches in determining which CMJ protocol to use for athlete assessment, while also providing context for practitioners when comparing an athlete’s performance profile characteristics with respect to normative data [ 26 ].…”

Maturation-, age-, and sex-specific anthropometric and physical fitness percentiles of German elite young athletes

“…The 20 th , 40 th , 50 th , 60 th , and 80 th percentiles were calculated. Due to the limited overall data pool of elite young athletes [ 31 ] and in accordance with other authors [ 32 , 33 ], anthropometric and physical fitness differences as well as percentile reference values were only calculated if 30 participants were available within a subgroup. All analyses were conducted using IBM SPSS Statistics for Windows, Version 26.0 (IBM Corp., Armonk, NY, USA).…”

The Effect of Height on Drop Jumps in Relation to Somatic Parameters and Landing Kinetics

“…These forceful movements guarantee optimal performance but in some cases, maximal performance in his/her sport. The most powerful movements such as the initiation of movement (start), short acceleration, quick deceleration, cutting maneuverer, and quick change of direction, as well as any type of jumping, require force production into the ground for any propulsion (forward, backward, side to side) [ 6 ]. In addition, when an athlete executes any type of jumping activities, they need to limit the impact of force during the landing phase.…”