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

The purpose of the present investigation was to evaluate differences in Reactive Strength Index Modified (RSIMod) and Flight Time to Contraction Time Ratio (FT:CT) during the countermovement jump (CMJ) performed without the arm swing (CMJNAS) compared to the CMJ with the arm swing (CMJAS), while exploring the relationship within each variable between jump protocols. A secondary purpose sought to explore the relationship between RSIMod and FT:CT during both jump protocols. Twenty-two collegiate basketball players performed both three CMJNAS and three CMJAS on a force plate, during two separate testing sessions. RSIMod was calculated by the flight-time (RSIModFT) and impulse-momentum methods (RSIModIMP). CMJ variables were significantly greater during the CMJAS compared to CMJNAS (p < 0.001). There were large to very large correlations within each variable between the CMJAS and CMJNAS. There were significant positive correlations among RSIModFT, RSIModIMP, and FT:CT during both the CMJAS (r ≥ 0.864, p < 0.001) and CMJNAS (r ≥ 0.960, p < 0.001). These findings identify an increase in RSIMod or FT:CT during the CMJAS, that may provide independent information from the CMJNAS. In addition, either RSIMod or FT:CT may be utilized to monitor changes in performance, but simultaneous inclusion may be unnecessary.

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Countermovement Jump Inter-Limb Asymmetries in Collegiate Basketball Players

Sports ◽

10.3390/sports7050103 ◽

2019 ◽

Vol 7 (5) ◽

pp. 103 ◽

Cited By ~ 2

Author(s):

Aaron Heishman ◽

Bryce Daub ◽

Ryan Miller ◽

Brady Brown ◽

Eduardo Freitas ◽

...

Keyword(s):

Injury Risk ◽

Force Plate ◽

Return To Play ◽

Countermovement Jump ◽

Basketball Players ◽

Arm Swing ◽

Force Development ◽

Collegiate Basketball ◽

Limb Asymmetry ◽

Absolute Reliability

The purpose of the present study was to establish the intrasession and intersession reliability of variables obtained from a force plate that was used to quantitate lower extremity inter-limb asymmetry during the bilateral countermovement jump (CMJ). Secondarily, a comparison was performed to determine the influence of the jump protocol CMJ with or without an arm swing (CMJ AS and CMJ NAS, respectively) on inter-limb asymmetries. Twenty-two collegiate basketball players performed three CMJ AS and three CMJ NAS on dual force platforms during two separate testing sessions. A majority of variables met the acceptable criterion of intersession and intrasession relative reliability (ICC > 0.700), while fewer than half met standards established for absolute reliability (CV < 10%). CMJ protocol appeared to influence asymmetries; Concentric Impulse-100 ms, Eccentric Braking Rate of Force Development, Eccentric Deceleration, and Force at Zero velocity were significantly different between jumping conditions (CMJAS versus CMJ NAS; p < 0.05). The present data establish the reliability and smallest worthwhile change of inter-limb asymmetries during the CMJ, while also identifying the influence of CMJ protocol on inter-limb asymmetries, which can be useful to practitioners and clinicians in order to effectively monitor changes associated with performance, injury risk, and return-to-play strategies.

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Biomechanical Analysis of the Jump Shot in Basketball

Journal of Human Kinetics ◽

10.2478/hukin-2014-0062 ◽

2014 ◽

Vol 42 (1) ◽

pp. 73-79 ◽

Cited By ~ 12

Author(s):

Artur Struzik ◽

Bogdan Pietraszewski ◽

Jerzy Zawadzki

Keyword(s):

Peak Power ◽

High Performance ◽

Force Plate ◽

Lower Limbs ◽

Biomechanical Analysis ◽

Countermovement Jump ◽

Mean Power ◽

Basketball Players ◽

Arm Swing ◽

High Level

Abstract Basketball players usually score points during the game using the jump shot. For this reason, the jump shot is considered to be the most important element of technique in basketball and requires a high level of performance. The aim of this study was to compare the biomechanical characteristics of the lower limbs during a jump shot without the ball and a countermovement jump without an arm swing. The differences between variables provide information about the potential that an athlete can utilise during a game when performing a jump shot. The study was conducted among 20 second-league basketball players by means of a Kistler force plate and the BTS SMART system for motion analysis. The variables measured included the take-off time, mean power, peak power, relative mean power, jump height, maximum landing force and calculated impact ratio. Surprisingly, more advantageous variables were found for the jump shot. This finding suggests a very high performance level in the jump shot in the studied group and a maximum utilisation of their motor abilities. Both types of jumps were characterised by high mean and peak power values and average heights. The high forces at landing, which result in considerable impact ratios, may have prompted the studied group to land softly. Use of the countermovement jump without an arm swing is recommended to assess and predict the progression of player’s jumping ability

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Reliability of and Relationship between Flight Time to Contraction Time Ratio and Reactive Strength Index Modified

Sports ◽

10.3390/sports6030081 ◽

2018 ◽

Vol 6 (3) ◽

pp. 81 ◽

Cited By ~ 8

Author(s):

John McMahon ◽

Jason Lake ◽

Paul Comfort

Keyword(s):

Positive Relationship ◽

Neuromuscular Function ◽

Flight Time ◽

Contraction Time ◽

Robust Methods ◽

Strength Index ◽

Countermovement Jump ◽

Force Time ◽

Method R ◽

Absolute Reliability

Countermovement jump (CMJ) force-time testing is commonly used to monitor seasonal alterations in athletes’ CMJ strategy (to infer alterations in neuromuscular function). The flight time to contraction time (FT:CT) ratio and reactive strength index modified (RSImod) are considered to be two primary CMJ variables of interest. Due to similar calculations, it is likely that the FT:CT ratio and RSImod share similar reliability and an almost perfect relationship. Consequently, there may be no requirement to include both variables in CMJ monitoring reports. This study aimed to investigate this by recruiting twenty-five males to perform three CMJs on a force platform across two sessions that were separated by one week. The FT:CT ratio and two calculations of RSImod (based on the jump height from either flight time or take-off velocity) were then calculated using robust methods. The between-day reliability was good-excellent for all of the variables (95% confidence interval range of the coefficient of variation = 2.02–9.22%) with no significant between-day differences noted (p ≥ 0.231). There was an almost perfect positive relationship between the FT:CT ratio and RSImod regardless of the calculation method (r = 0.944–0.947, p < 0.001). As the FT:CT ratio and RSImod yield similar absolute reliability and share 90% of common variance, there is little reason to include both variables in CMJ monitoring reports.

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Countermovement Jump Reliability Performed With and Without an Arm Swing in NCAA Division 1 Intercollegiate Basketball Players

The Journal of Strength and Conditioning Research ◽

10.1519/jsc.0000000000002812 ◽

2020 ◽

Vol 34 (2) ◽

pp. 546-558 ◽

Cited By ~ 8

Author(s):

Aaron D. Heishman ◽

Bryce D. Daub ◽

Ryan M. Miller ◽

Eduardo D.S. Freitas ◽

Brett A. Frantz ◽

...

Keyword(s):

Countermovement Jump ◽

Basketball Players ◽

Arm Swing ◽

Division 1

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Countermovement Jump Reliability when Performed With and Without an Arm Swing in NCAA Division 1 Basketball Players

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000538208.39002.8d ◽

2018 ◽

Vol 50 (5S) ◽

pp. 669

Author(s):

Aaron D. Heishman ◽

Ryan M. Miller ◽

Eduardo D.S. Freitas ◽

Japneet Kaur ◽

Bianca A.R. Galletti ◽

...

Keyword(s):

Countermovement Jump ◽

Basketball Players ◽

Arm Swing ◽

Division 1

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Reliability and Differences of Jump Kinetics Related to Different Load in College Male Athletes

Athens Journal of Sports ◽

10.30958/ajspo.8-4-3 ◽

2021 ◽

Vol 8 (4) ◽

pp. 261-270

Author(s):

Chia-Hung Chuang ◽

Ching-Hung Lin ◽

Cheng-Wen Wu ◽

Kuo-Chuan Lin

Keyword(s):

Repeated Measures ◽

Force Plate ◽

Eccentric Contraction ◽

Countermovement Jump ◽

Male Athletes ◽

Arm Swing ◽

Repetition Maximum ◽

College Male ◽

Contraction Duration ◽

Post Hoc

The purpose of this study was to explore reliability and differences of jump kinetics related to different training load in college male athletes. The subjects were required to perform countermovement jump (CMJ) and loaded countermovement jump (LCMJ-0%, LCMJ-20% and LCMJ-80% of one-repetition maximum squat) three times for each load which were recorded by a force plate. One-way repeated measures ANOVA and the LSD post hoc method were employed to evaluate the results. The results reveled that jump kinetics-related parameters increased/decreased by the load. Compared with the loading jumps, the CMJ incorporate with an arm swing directly led to an increase in eccentric contraction duration during jumping. Most of the jump mechanical parameters under substantially different load conditions fall within the good to excellent reliability. It appears that the CMJ and CMJ with extra load were reliable in explore the kinetics related parameters. Keywords: countermovement jump, one-repetition maximum, arm swing, eccentric contraction

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Does Footwear Influence Countermovement Jump Parameters Used To Monitor Performance In Collegiate Basketball Players?

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000759572.88715.fd ◽

2021 ◽

Vol 53 (8S) ◽

pp. 42-43

Author(s):

Keldon Peak ◽

Aaron Heishman ◽

Bryce Daub ◽

Ryan Miller ◽

Eduardo Freitas ◽

...

Keyword(s):

Countermovement Jump ◽

Basketball Players ◽

Collegiate Basketball

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Does Footwear Influence Countermovement Jump Parameters Used to Assess Performance in Collegiate Basketball Players?

International Journal of Kinesiology and Sports Science ◽

10.7575/aiac.ijkss.v.9n.2p.14 ◽

2021 ◽

Vol 9 (2) ◽

pp. 14

Author(s):

Aaron D. Heishman ◽

Keldon M. Peak ◽

Bryce D. Daub ◽

Ryan M. Miller ◽

Eduardo D.S. Freitas

Keyword(s):

Repeated Measures ◽

Performance Outcomes ◽

Performance Assessments ◽

Countermovement Jump ◽

Mean Power ◽

Basketball Players ◽

Short And Long Term ◽

Collegiate Basketball ◽

Testing Protocols

Background: The countermovement jump (CMJ) is used to monitor short- and long-term changes in neuromuscular performance, where practically relevant alteration may be subtle, requiring detailed and consistent testing protocols to limit error and allow detection of meaningful change. Collegiate basketball players often wear different types of footwear depending upon the training activity, potentially influencing CMJ performance outcomes. Objective: This study evaluated the influence of footwear on key CMJ variables used for routine performance assessments in a cohort of 11 NCAA women’s collegiate basketball players. Method: In a cross-over repeated measures study design, players performed three CMJs in Basketball-, Training-(Trainers), and Olympic Weightlifting (WL) shoes, in a randomized order during one testing session. One-way repeated measures analyses of variance (p ≤ .05) and effect sizes (Cohen’s d) were used to discern differences in CMJ variables among shoe conditions. Results: WL demonstrated greater Eccentric Mean Force (p ≤ .014, d ≥ 0.03) and lower Flight Time:Contraction Time (p ≤ .029, d ≥ 0.31), Jump Height (p ≤ .040, d ≥ 0.32), and Reactive Strength Index-Modified (p ≤ .032, d ≥ 0.40) than both Basketball and Trainers. Additionally, WL exhibited lower Concentric Mean Force (p = .018, d = 0.19), Concentric Mean Power (p = .008, d = 0.29), Eccentric Peak Force (p = .050, d = 0.19), and Flight Time (p = .036, d = 0.31) compared to Trainer. No significant differences and only trivial effects appeared between Basketball and Trainers (p > 0.05, d < 0.1). Conclusion: These findings suggest footwear significantly influences CMJ performance. WL shoes appear to negatively impact CMJ performance; however, Basketball and Trainers appear to exert negligible effects that should allow clinicians and practitioners to feel confident about measurement and data quality when performing short- and long-term CMJ measurements in either Basketball or Trainers.

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The Influence of Leader Behaviors, Coach Attributes, and Institutional Variables on Performance and Satisfaction of Collegiate Basketball Teams

Journal of Sport Psychology ◽

10.1123/jsp.8.4.332 ◽

1986 ◽

Vol 8 (4) ◽

pp. 332-346 ◽

Cited By ~ 74

Author(s):

Maureen R. Weiss ◽

Warren D. Friedrichs

Keyword(s):

Team Performance ◽

Leader Behaviors ◽

Basketball Players ◽

Institutional Variables ◽

Team Outcomes ◽

Athlete Satisfaction ◽

Collegiate Basketball ◽

Rewarding Behavior ◽

Relationship Of ◽

The Relationship

Based on Chelladurai and Carron's (1978) multidimensional theory of leadership, this study examined the relationship of leader behaviors, coach attributes, and institutional variables to team performance and athlete satisfaction. Collegiate basketball players (n = 251) representing 23 NAIA teams assessed their coach's leader behaviors and also indicated their satisfaction with various facets of their athletic experience. Regression analyses revealed that neither institutional nor coach attribute variables were significantly related to team performance or satisfaction. Leader behaviors, however, were found to be significantly related to these team outcomes. Analyses with individual satisfaction scores revealed that size of school, coach attributes, and leader behaviors were predictive of athlete satisfaction. Coaches who engaged in more frequent rewarding behavior, social support behavior, and a democratic style of decision-making produced more satisfied athletes. Moreover, younger coaches and those with better previous win/loss records were related to higher levels of athlete satisfaction.

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