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Yamashita N, Sato D, Mishima T. Change-of-Direction Performance and Its Deficits in Relation to Countermovement-Jump Height and Phase-Specific Performance Among Female Athletes. Int J Sports Physiol Perform 2024:1-8. [PMID: 39191375 DOI: 10.1123/ijspp.2024-0006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 06/03/2024] [Accepted: 06/25/2024] [Indexed: 08/29/2024]
Abstract
PURPOSE Jump and linear sprint performances both correlate with pro-agility performance. However, correlation does not imply causation, and potential confounders may affect the correlation. Therefore, this study aimed to determine the relationship between change-of-direction (COD) performance and COD deficits (COD-D) in linear-sprint and countermovement-jump (CMJ) -related performance using multiple stepwise linear-regression models. METHODS The study included 42 female national-level intercollegiate athletes. The 10- and 20-m linear-sprint and pro-agility times, COD-D, CMJ height, and phase-specific force production and rate of force development during eccentric unloading, eccentric braking, and the concentric phases of CMJ were measured. Stepwise linear-regression analyses were used to predict the factors related to COD and COD-D. RESULTS CMJ height was the sole predictor in the 10-m pro-agility model (adjusted R2 = .234, P = .001). Modified Reactive Strength Index (standardized coefficient, -.710) and the lowest center-of-mass depth during the CMJ (standardized coefficient, .323) were predictors in the 20-m pro-agility model (adjusted R2 = .330, P < .001). For the 10- and 20-m COD-D models, the rate of force development at 30 and 60 milliseconds, respectively, during the concentric phase was the only predictor of performance (adjusted R2 = .183, P = .003 and .237, P = .001, respectively). CONCLUSIONS These results suggest that athletes should concentrate on improving their CMJ height, increasing their ability to lower their center of mass more deeply, and increasing their instantaneous force-production abilities immediately after the eccentric braking phase of CMJ to improve their COD performance.
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Affiliation(s)
- Naoyuki Yamashita
- Faculty of Arts and Sciences, Kyoto Institute of Technology, Kyoto, Japan
| | - Daisuke Sato
- Sports Science Center, Osaka University of Health and Sport Sciences, Senangun, Japan
| | - Takaaki Mishima
- School of Health and Sport Sciences, Osaka University of Health and Sport Sciences, Senangun, Japan
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Yamashita N, Sato D, Mishima T. Jump height ingenerated by countermovement and arm swing better correlates with proagility shuttle run tests but not with change of direction deficits in collegiate female athletes. J Sports Med Phys Fitness 2024; 64:749-757. [PMID: 38602034 DOI: 10.23736/s0022-4707.24.15691-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
BACKGROUND Jumping and linear sprinting performances show a moderate correlation with change of direction (COD) ability. However, the extent of these correlations remains unknown through statistical analysis. Thus, this study statistically compared correlation coefficients between COD, COD deficit (CODD), and jumping and linear sprint performances. METHODS National-level basketball (29) and baseball (18) intercollegiate female athletes performed 20-m linear sprint, proagility (5-10-5) test, squat jump (SJ), countermovement jump with (CMJarm) and without (CMJ) arm swing and modified reactive strength index (RSImod). Correlation analysis was used to assess factors correlated with COD performance and CODD; subsequently, correlation coefficient comparison test was used to determine better correlations with COD and CODD performance. RESULTS CMJ (r=-0.483) and CMJarm (r=-0.446) had stronger correlations with 10-m COD (both, P<0.018) than with 10-m linear sprint (r=0.431, P=0.002). For 20-m COD, RSImod, CMJ, and CMJarm (r=-0.491--0.543, P<0.001) better correlated with 20-m COD than with 20-m linear sprints (r=0.436, P=0.002), while RSI (both r=-0.317, P<0.030) and SJ (r=-0.359, r=-0.293, P=0.046) were weakly correlated with 10- and 20-m COD. The differences in correlation coefficients for RSImod, CMJ, and CMJarm were not significant in both 10- and 20-m COD. Ten-meter linear sprint performance only correlated with 10-m CODD, while no correlation was observed with 20-m CODD. CONCLUSIONS Stronger correlations of RSImod, CMJ, and CMJarm with 10-/20-m COD than with linear sprinting, RSI, and SJ suggest that training focused on improving countermovement and arm swings with jumping may enhance COD performance in female athletes.
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Affiliation(s)
- Naoyuki Yamashita
- Faculty of Arts and Sciences, Kyoto Institute of Technology, Kyoto, Japan
| | - Daisuke Sato
- Department of Sports Performance Assessment, Sports Science Center, Osaka University of Health and Sport Sciences, Senangun, Japan -
| | - Takaaki Mishima
- School of Health and Sport Sciences, Osaka University of Health and Sport Sciences, Senangun, Japan
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Alrashdi NZ, Motl RW, Lein DH, Aguiar EJ, Perumean-Chaney SE, Ryan MK, Ithurburn MP. Rehabilitation-Specific Predictors of Pain Intensity and Physical Activity Levels in Individuals With Acetabular Dysplasia 6 Months After Periacetabular Osteotomy. Scand J Med Sci Sports 2024; 34:e14711. [PMID: 39118426 DOI: 10.1111/sms.14711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 07/07/2024] [Accepted: 07/25/2024] [Indexed: 08/10/2024]
Abstract
INTRODUCTION Individuals with acetabular dysplasia often report hip joint instability, pain, and poor hip-related function. Periacetabular osteotomy (PAO) is a surgical procedure that aims to reposition the acetabulum to improve joint congruency and improve pain and function. We aimed to examine the influence of presurgery clinical measures on functional recovery following PAO and the associations among clinical outcomes after PAO. METHODS We screened 49 potential participants, 28 were enrolled, and 23 completed both study visits (pre-PAO and 6 months post-PAO). We evaluated dynamometer-measured hip and thigh strength, loading patterns during a squat and countermovement jump (CMJ), pain intensity, and device-measured physical activity (PA) levels (light, moderate-to-vigorous PA [MVPA], and daily steps). We used linear regression models to examine the influence of muscle strength (peak torque; limb symmetry index [LSI]) and loading patterns before PAO on pain intensity and PA levels in individuals 6 months following PAO. Additionally, we used Pearson correlation coefficient to examine cross-sectional associations among all variables 6 months following PAO. RESULTS Lower extremity muscle strength and loading patterns during the squat and CMJ before PAO did not predict pain intensity or device-measured PA levels in individuals 6 months following PAO (p > 0.05). Six months following PAO, higher knee extensor LSI was associated with higher time spent in MVPA (r = 0.56; p = 0.016), higher hip abductor LSI was associated with both lower pain (r = 0.50; p = 0.036) and higher involved limb loading during the squat task (r = 0.59; p = 0.010). Lastly, higher hip flexor LSI was associated with higher CMJ takeoff involved limb loading (r = 0.52; p = 0.021) and higher involved hip extensor strength was associated with higher CMJ landing involved limb loading (r = 0.56; p = 0.012). CONCLUSION Six months after PAO, higher hip and thigh muscle strength and strength symmetry were associated with lower pain, higher PA levels, and greater normalized limb loading during dynamic movement tasks.
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Affiliation(s)
- Naif Z Alrashdi
- Department of Physical Therapy and Health Rehabilitation, College of Applied Medical Sciences, Majmaah University, Majmaah, Kingdom of Saudi Arabia
| | - Robert W Motl
- Department of Kinesiology and Nutrition, University of Illinois Chicago, Chicago, Illinois, USA
| | - Donald H Lein
- Department of Physical Therapy, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Elroy J Aguiar
- Department of Kinesiology, The University of Alabama, Tuscaloosa, Alabama, USA
| | | | - Michael K Ryan
- Andrews Sports Medicine and Orthopaedic Center, Birmingham, Alabama, USA
- The American Sports Medicine Institute, Birmingham, Alabama, USA
- Prevea Health Orthopaedics and Sports Medicine, Green Bay, Wisconsin, USA
| | - Matthew P Ithurburn
- Department of Physical Therapy, University of Alabama at Birmingham, Birmingham, Alabama, USA
- The American Sports Medicine Institute, Birmingham, Alabama, USA
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Harry JR, Barker LA, Tinsley GM, Krzyszkowski J, Chowning LD, McMahon JJ, Lake J. Relationships among countermovement vertical jump performance metrics, strategy variables, and inter-limb asymmetry in females. Sports Biomech 2024; 23:1009-1027. [PMID: 33947320 DOI: 10.1080/14763141.2021.1908412] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 03/19/2021] [Indexed: 10/21/2022]
Abstract
Dependent variables commonly studied during countermovement vertical jump (CMVJ) tests largely stem from male-only studies despite females'distinct energy storage and reutilisation strategies. This could limit progress among females seeking increased CMVJ performance through targeted changes in certain variables. We explored relationships between CMVJ performance metrics (jump height, modified reactive strength index, jump power, and takeoff momentum) and (a) temporal and force application variables and (b) inter-limb force and yank (i.e., rate of force development) asymmetry in 31 recreationally active females. Participants performed eight CMVJs while ground reaction force (GRF) data were obtained. Pearson product-moment correlation coefficients assessed the strength and direction of the associations. Twenty-six significant relationships (r ≥ ±0.357; p < 0.05) were detected across the CMVJ performance variables. The significantly correlated variables were generally isolated to only one of the four performance metrics. Only the percentage of concentric phase inter-limb force asymmetry was significantly associated with CMVJ performance, specifically jump power and takeoff momentum. Coaches and physical performance professionals should be aware of popular strategy variables' association or lack of association with commonly studied performance metrics when seeking to understand or improve specific CMVJ jumping abilities in females.
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Affiliation(s)
- John R Harry
- Human Performance & Biomechanics Laboratory, Texas Tech University, Lubbock, TX, USA
| | - Leland A Barker
- Department of Exercise Science and Pre-Health Professions, Creighton University, Omaha, NE, USA
| | - Grant M Tinsley
- Energy Balance & Body Composition Laboratory, Texas Tech University, Lubbock, TX, USA
| | - John Krzyszkowski
- Human Performance & Biomechanics Laboratory, Texas Tech University, Lubbock, TX, USA
| | - Luke D Chowning
- Human Performance & Biomechanics Laboratory, Texas Tech University, Lubbock, TX, USA
| | - John J McMahon
- Directorate of Psychology and Sport, University of Salford, Salford, UK
| | - Jason Lake
- Chichester Institute of Sport, University of Chichester, West Sussex, UK
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
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Bright TE, Harry JR, Lake J, Mundy P, Theis N, Hughes JD. Methodological considerations in assessing countermovement jumps with handheld accentuated eccentric loading. Sports Biomech 2024:1-18. [PMID: 38990167 DOI: 10.1080/14763141.2024.2374884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 06/27/2024] [Indexed: 07/12/2024]
Abstract
This study aimed to compare the agreement between three-dimensional motion capture and vertical ground reaction force (vGRF) in identifying the point of dumbbell (DB) release during a countermovement jump with accentuated eccentric loading (CMJAEL), and to examine the influence of the vGRF analysis method on the reliability and magnitude of CMJAEL variables. Twenty participants (10 male, 10 female) completed five maximal effort CMJAEL at 20% and 30% of body mass (CMJAEL20 and CMJAEL30, respectively) using DBs. There was large variability between methods in both loading conditions, as indicated by the wide limits of agreement (CMJAEL20 = -0.22 to 0.07 s; CMJAEL30 = -0.29 to 0.14 s). Variables were calculated from the vGRF data, and compared between four methods (forward integration (FI), backward integration (BI), FI adjusted at bottom position (BP), FI adjusted at DB release point (DR)). Greater absolute reliability was observed for variables from DR (CV% ≤ 7.28) compared to BP (CV% ≤ 13.74), although relative reliability was superior following the BP method (ICC ≥ 0.781 vs ≥ 0.606, respectively). The vGRF method shows promise in pinpointing the DB release point when only force platforms are accessible, and a combination of FI and BI analyses is advised to understand CMJAEL dynamics.
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Affiliation(s)
- Thomas E Bright
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
- School of Sport, Exercise and Rehabilitation, Plymouth Marjon University, Plymouth, UK
| | - John R Harry
- Human Performance & Biomechanics Laboratory, Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, TX, USA
| | - Jason Lake
- Institute of Sport, Nursing, and Allied Health, University of Chichester, Chichester, UK
| | - Peter Mundy
- Research and Development, Hawkin Dynamics, Inc, Westbrook, ME, USA
| | - Nicola Theis
- School of Sport and Exercise, University of Gloucestershire, Gloucester, UK
| | - Jonathan D Hughes
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
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Shinchi K, Yamashita D, Yamagishi T, Aoki K, Miyamoto N. Relationship between jump height and lower limb joint kinetics and kinematics during countermovement jump in elite male athletes. Sports Biomech 2024:1-12. [PMID: 38742268 DOI: 10.1080/14763141.2024.2351212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 04/25/2024] [Indexed: 05/16/2024]
Abstract
This study aims to identify the relationship between jump height and the kinetic and kinematic parameters of the hip, knee, and ankle joints during countermovement jump (CMJ) in elite male athletes. Sixty-six elite male athletes from various sports (strength and power, winter downhill, combat, ball game, and aquatic) performed maximal effort CMJs with hands and arms crossed against their chests on force platforms. Jumping motion in the sagittal plane was recorded using video analysis and the peak torque, power, and angular velocity of the right hip, knee, and ankle joints were calculated during the propulsive phase. Correlations between the CMJ height and kinetic and kinematic parameters were investigated using Pearson's product-moment coefficient (r) and Spearman's rank correlation coefficient (ρ). CMJ height was highly correlated with peak hip power (ρ = 0.686, p < 0.001) and peak knee angular velocity (r = 0.517, p < 0.001), and moderately correlated with peak hip angular velocity (r = 0.438, p < 0.001) and peak hip torque (r = 0.398, p = 0.001). These results indicate that notable hip torque and power can contribute to increased angular velocity in both the knee and hip joints, ultimately increasing the CMJ height in elite male athletes.
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Affiliation(s)
- Kotaro Shinchi
- Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
- Department of Sport Medicine and Research, Japan Institute of Sports Sciences, Tokyo, Japan
| | - Daichi Yamashita
- Department of Sport Medicine and Research, Japan Institute of Sports Sciences, Tokyo, Japan
- Department of Sport Science and Research, Japan Institute of Sports Sciences, Tokyo, Japan
| | - Takaki Yamagishi
- Department of Sport Science and Research, Japan Institute of Sports Sciences, Tokyo, Japan
| | - Kazuhiro Aoki
- Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
| | - Naokazu Miyamoto
- Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
- Department of Sport Science and Research, Japan Institute of Sports Sciences, Tokyo, Japan
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Harry JR, Simms A, Hite M. Establishing Phase Definitions for Jump and Drop Landings and an Exploratory Assessment of Performance-Related Metrics to Monitor During Testing. J Strength Cond Res 2024; 38:e62-e71. [PMID: 38090985 DOI: 10.1519/jsc.0000000000004700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
ABSTRACT Harry, JR, Simms, A, and Hite, M. Establishing phase definitions for jump and drop landings and an exploratory assessment of performance-related metrics to monitor during testing. J Strength Cond Res 38(2): e62-e71, 2024-Landing is a common task performed in research, physical training, and competitive sporting scenarios. However, few have attempted to explore landing mechanics beyond its hypothesized link to injury potential, which ignores the key performance qualities that contribute to performance, or how quickly a landing can be completed. This is because a lack of (a) established landing phases from which important performance and injury risk metrics can be extracted and (b) metrics known to have a correlation with performance. As such, this article had 2 purposes. The first purpose was to use force platform data to identify easily extractable and understandable landing phases that contain metrics linked to both task performance and overuse injury potential. The second purpose was to explore performance-related metrics to monitor during testing. Both purposes were pursued using force platform data for the landing portion of 270 jump-landing trials performed by a sample of 14 NCAA Division 1 men's basketball players (1.98 ± 0.07 m; 94.73 ± 8.01 kg). The proposed phases can separate both jump-landing and drop-landing tasks into loading, attenuation, and control phases that consider the way vertical ground reaction force (GRF) is purposefully manipulated by the athlete, which current phase definitions fail to consider. For the second purpose, Pearson's correlation coefficients, the corresponding statistical probabilities ( α = 0.05), and a standardized strength interpretation scale for correlation coefficients (0 < trivial ≤ 0.1 < small ≤ 0.3 < moderate ≤ 0.5 < large ≤ 0.7 < very large) were used for both the group average (i.e., all individual averages pooled together) and individual data (i.e., each individual's trials pooled together). Results revealed that landing time, attenuation phase time, average vertical GRF during landing, average vertical GRF during the attenuation phase, average vertical GRF during the control phase, vertical GRF attenuation rate, and the amortization GRF (i.e., GRF at zero velocity) significantly correlated with landing performance, defined as the ratio of landing height and landing time ( R ≥ ± 0.58; p < 0.05), such that favorable changes in those metrics were associated with better performance. This work provides practitioners with 2 abilities. First, practitioners currently assess jump capacity using jump-landing tests (e.g., countermovement jump) with an analysis strategy that makes use of landing data. Second, this work provides preliminary data to guide others when initially exploring landing test results before identifying metrics chosen for their own analysis.
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Affiliation(s)
- John R Harry
- Human Performance & Biomechanics Laboratory, Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, TX
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Fong HB, Nelson AK, McGhee D, Ford KR, Powell DW. Increasing Breast Support is Associated With a Distal-to-Proximal Redistribution of Joint Negative Work During a Double-Limb Landing Task. J Appl Biomech 2024; 40:14-20. [PMID: 37917960 DOI: 10.1123/jab.2022-0244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 07/28/2023] [Accepted: 08/21/2023] [Indexed: 11/04/2023]
Abstract
Female athletes exhibit greater rates of anterior cruciate ligament injury compared with male athletes. Biomechanical factors are suggested to contribute to sex differences in injury rates. No previous investigation has evaluated the role of breast support on landing biomechanics. This study investigates the effect of breast support on joint negative work and joint contributions to total negative work during landing. Thirty-five female athletes performed 5 landing trials in 3 breast support conditions. Lower-extremity joint negative work and relative joint contributions to total negative work were calculated. Univariate analyses of variance were used to determine the effect of breast support on negative joint work values. Increasing levels of breast support were associated with lower ankle negative work (P < .001) and ankle relative contributions (P < .001) and increases in hip negative work (P = .008) and hip relative contributions (P < .001). No changes were observed in total negative work (P = .759), knee negative work (P = .059), or knee contributions to negative work (P = .094). These data demonstrate that the level of breast support affects lower-extremity biomechanics. The distal-to-proximal shift in negative joint work and relative joint contributions may be indicative of a more protective landing strategy for anterior cruciate ligament injuries.
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Affiliation(s)
- Hailey B Fong
- Musculoskeletal Analysis Laboratory, College of Health Studies, The University of Memphis, Memphis, TN, USA
| | - Alexis K Nelson
- Musculoskeletal Analysis Laboratory, College of Health Studies, The University of Memphis, Memphis, TN, USA
| | - Deirdre McGhee
- Biomechanics Research Laboratory, School of Medicine, Faculty of Science, Medicine & Health, University of Wollongong, Wollongong, NSW, Australia
| | - Kevin R Ford
- Biomechanics and Physiology Laboratory, High Point University, High Point, NC, USA
| | - Douglas W Powell
- Musculoskeletal Analysis Laboratory, College of Health Studies, The University of Memphis, Memphis, TN, USA
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Rites AA, Merino-Muñoz P, Ribeiro F, Miarka B, Salermo V, Gomes DV, Brito CJ, Aedo-Muñoz E. Effects of peppermint oil inhalation on vertical jump performance in elite young professional soccer players: A double-blinded randomized crossover study. Heliyon 2024; 10:e24360. [PMID: 38293549 PMCID: PMC10826725 DOI: 10.1016/j.heliyon.2024.e24360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 01/06/2024] [Accepted: 01/08/2024] [Indexed: 02/01/2024] Open
Abstract
Aims To evaluate peppermint essential oil (PEO) inhalation's effect on young soccer athletes' motor performance. Methods A randomized crossover design was used to test the effect of the PEO. Eleven U-17 soccer players were evaluated into two conditions (PEO and Placebo - PLA). The players were tested in squat jump and countermovement jump and inhaled PEO or PLA and 10 min later performed the physical tests again. A mixed ANOVA was performed to test the hypotheses. Results Main effects were found for the time in jumping height in the CMJ (p = 0.037). No main and interaction effects were found in the SJ variables. Conclusion From the results, decrease CMJ performance acutely, both conditions presented decrease in JH, but based in effect size, PLA decrease is higher (more sample size for corroborate this) possibly due to improvements in the eccentric yielding sub-phase, where mentioned phase could be reflecting neural changes (required experimental verification). The PEO could be the interest in trainers for use before of match or in the half-time for minimize the decreased of physical performance by the rest.
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Affiliation(s)
- Alex Ambrosio Rites
- Postgraduate Program in Physical Education. Federal University of Rio de Janeiro, Brazil
- Fluminense Football Club, Brazil
| | - Pablo Merino-Muñoz
- Núcleo de investigación en ciencias de la motricidad humana, Universidad Adventista de Chile, Chile
- Escuela de Ciencias de la Actividad Física, el Deporte y la Salud, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Chile
| | | | - Bianca Miarka
- Postgraduate Program in Physical Education. Federal University of Rio de Janeiro, Brazil
| | - Veronica Salermo
- Postgraduate Program in Physical Education. Federal University of Rio de Janeiro, Brazil
| | - Diego Viana Gomes
- Postgraduate Program in Physical Education. Federal University of Rio de Janeiro, Brazil
| | - Ciro José Brito
- Escuela de Ciencias de la Actividad Física, el Deporte y la Salud, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Chile
| | - Esteban Aedo-Muñoz
- Escuela de Ciencias de la Actividad Física, el Deporte y la Salud, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Chile
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Smolarek T, Haff GG, Poon WCK, Nagatani T, Barley OR, Guppy SN. Dynamic and Isometric Force-Time Curve Characteristics Influencing Change of Direction Performance of State-Level Netball Players. J Strength Cond Res 2023; 37:2397-2404. [PMID: 37815246 DOI: 10.1519/jsc.0000000000004616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
ABSTRACT Smolarek, T, Haff, GG, Poon, WCK, Nagatani, T, Barley, OR, and Guppy, SN. Dynamic and isometric force-time curve characteristics influencing change of direction performance of state-level netball players. J Strength Cond Res 37(12): 2397-2404, 2023-Although multiple lower-body strength capacities are required to change direction rapidly, there is limited knowledge about the relative importance of these factors. Therefore, the purpose of this study was to assess the relationship between dynamic and isometric lower-body strength capacities and change of direction (COD) time in state-league netball players. Seventeen female athletes completed maximal isometric midthigh pull (IMTP), countermovement jump (CMJ), and modified 5-0-5 COD tests. Pearson's product moment correlations were used to determine the relationship between COD time and several IMTP and CMJ force-time curve characteristics. To assess the level of contribution of each force-time curve characteristic to COD time, multivariate-linear stepwise regression analyses were performed. A significant moderate correlation was noted between net relative peak force (PF) during the IMTP and COD time ( r = 0.488, p = 0.047), accounting for 23.8% of the variance in COD time. Moreover, concentric relative impulse during the CMJ was strongly correlated with COD time ( r = 0.718; p = 0.001), explaining 81.9% of the variance in COD time when combined with net relative braking PF in a stepwise regression. Based on these findings, female netball players who display higher concentric and isometric strength, as well as the ability to express higher impulses during the concentric phase of the CMJ, are likely to perform CODs faster. This may occur because COD requires the generation of greater propulsive forces, as well as reduced braking and contact times, along with greater isometric strength enabling effective repositioning of center of mass during COD tasks.
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Affiliation(s)
- Tinka Smolarek
- Institute of Sport and Exercise Sciences, University of Münster, Münster, Germany
| | - G Gregory Haff
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia; and
- Directorate of Psychology and Sport, University of Salford, Salford, United Kingdom
| | - Wayne C K Poon
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia; and
| | - Tsuyoshi Nagatani
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia; and
| | - Oliver R Barley
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia; and
| | - Stuart N Guppy
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia; and
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Nishiumi D, Yamaguchi S, Kurokawa T, Wakamiya K, Hirose N. Force-Velocity Profiling During the Braking Phase of Countermovement Jump: Relationship to Eccentric Strength and Validity of the 2-Point Method. J Strength Cond Res 2023; 37:2141-2148. [PMID: 37883394 DOI: 10.1519/jsc.0000000000004544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
ABSTRACT Nishiumi, D, Yamaguchi, S, Kurokawa, T, Wakamiya, K, and Hirose, N. Force-velocity profiling during the braking phase of countermovement jump: Relationship to eccentric strength and validity of the 2-point method. J Strength Cond Res 37(11): 2141-2148, 2023-The aims of this study were threefold: to investigate the force-velocity profile during the braking phase (bFVP) of the countermovement jump (CMJ) and its relationship with other performance indicators, and whether it could be measured using the two-point method. Sixteen trained men performed 6 different loaded CMJs (0%, 32 kg, 60, 80, 100, and 120% body mass), and eccentric strength measurements were determined. Scatter plots were created using the mean force and velocity during the braking phase of each loaded CMJ. The corrected Akaike's information criterion (AICc) was calculated by fitting linear, quadratic, and cubic regression equations to the bFVP and compared using the 1-way analysis of variance and Bonferroni's post hoc tests. A correlation analysis was performed between the bFVP and other performance indicators. A bias assessment was performed to validate the 2-point method of the bFVP. The significance level was set at p < 0.05. The AICc in the linear regression equation was significantly lower (p < 0.05) than those in the other regression equations. Significant correlations were found between the slope and theoretical maximum force of the bFVP obtained from the linear regression equation and eccentric 1 repetition maximum. The acceptable condition for bias was met by 0-120%. The bFVP is likely to have a linear relationship and can be associated with eccentric strength. Furthermore, the 2-point method in bFVP has validity.
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Affiliation(s)
- Daichi Nishiumi
- Graduate School of Sport Sciences, Waseda University, Saitama, Japan
| | - Shota Yamaguchi
- Institute of Physical Education, Keio University, Kanagawa, Japan; and
| | - Takanori Kurokawa
- Graduate School of Sport Sciences, Waseda University, Saitama, Japan
| | - Kazuki Wakamiya
- Graduate School of Sport Sciences, Waseda University, Saitama, Japan
| | - Norikazu Hirose
- Faculty of Sport Sciences, Waseda University, Saitama, Japan
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12
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Nishioka T, Okada J. Ballistic Exercise Versus Heavy Resistance Exercise Protocols: Which Resistance Priming Is More Effective for Improving Neuromuscular Performance on the Following Day? J Strength Cond Res 2023; 37:1939-1946. [PMID: 36930886 PMCID: PMC10510827 DOI: 10.1519/jsc.0000000000004512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Abstract
ABSTRACT Nishioka, T and Okada, J. Ballistic exercise versus heavy resistance exercise protocols: which resistance priming is more effective for improving neuromuscular performance on the following day? J Strength Cond Res 37(10): 1939-1946, 2023-This study aimed to determine whether ballistic exercise priming (BEP) or heavy resistance priming (HRP) is more effective for improving ballistic performance after 24 hours. Ten resistance-trained men performed BEP and HRP conditions 72-144 hours apart in a randomized and counterbalanced order. Jumping performance was assessed before and 24 hours after the BEP and HRP sessions using 0 and 40% one-repetition maximum (1RM) squat jump (SJ), 0 and 40% 1RM countermovement jump (CMJ), and drop jump (DJ) reactive strength index (RSI). Statistical significance was accepted at p ≤ 0.05. In the BEP condition, 0% 1RM CMJ height (+3.62%) as well as theoretical maximum velocity (+5.14%) and theoretical maximum power (+2.55%) obtained from CMJ 24 hours after the priming session were significantly greater than those at the baseline ( p ≤ 0.05), but 0% 1RM SJ height and DJ RSI ( p > 0.05) were not greater than those at the baseline. In the HRP condition, the jump performances were not improved ( p > 0.05). The percentage change in 0% 1RM CMJ height in the BEP condition was significantly greater than that seen in the HRP condition ( p = 0.015) but did not differ for 0% 1RM SJ height and DJ RSI ( p > 0.05). These results suggest that the BEP is more effective than HRP in improving CMJ performance after 24 hours. Therefore, practitioners should consider prescribing resistance priming using low-load ballistic exercises rather than high-load traditional exercises when planning to enhance athlete performance on the following day.
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Affiliation(s)
- Takuya Nishioka
- Graduate School of Sport Sciences, Waseda University, Saitama, Japan; and
| | - Junichi Okada
- Faculty of Sport Sciences, Waseda University, Saitama, Japan
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13
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Shi L, Ye X, Han D, Yang C, Tu Y. Acute Effects of Back Squat Combined with Different Elastic Band Resistance on Vertical Jump Performance in Collegiate Basketball Players. J Sports Sci Med 2023; 22:502-511. [PMID: 37711720 PMCID: PMC10499146 DOI: 10.52082/jssm.2023.502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/10/2023] [Indexed: 09/16/2023]
Abstract
The purpose of this study was to compare the acute effects of back squat exercise with or without elastic band on countermovement jump performance. Thirteen collegiate male basketball players (age: 20.5 ± 0.9 years; height: 188.5 ± 8.5 cm; body mass: 82.8 ± 12.9 kg) completed 5 familiarization and 4 experimental sessions separated by at least 48 hours. In the experimental sessions, the order of the conditions was randomized so that the participants performed 1 set of 3 repetitions of barbell back squat at 85% of their one-repetition maximum (1-RM), 1 set of 3 repetitions of back squat at 85% 1-RM with 20% variable resistance training (VRT), 30%VRT, or 40%VRT of the total load coming from the elastic band. Countermovement jump performance was assessed before (baseline), 30 seconds, 3 minutes, 6 minutes, and 9 minutes following each condition. Jump height, rate of force development, peak power, and vastus lateralis, vastus medialis, and medial gastrocnemius electromyography data were collected. Compared with the baseline, 30%VRT significantly improved jump height at 3 minutes post-exercise by 1.3 cm (P < 0.001) and 6 minutes post-exercise by 1.2 cm (P = 0.005); 40%VRT significantly improved jump height from 30 seconds up to the 9th minute (1.2 to 1.9 cm, P ≤ 0.036). The superior jump height was also accompanied by improved kinetic and electromyography data. No significant changes were observed in the barbell back squat and 20%VRT conditions. In conclusion, back squat at 85% 1-RM with 40% elastic band resistance led to superior vertical jump performance with an optimal time window of 3 minutes.
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Affiliation(s)
- Lin Shi
- Center for Post-doctoral Studies of Sport Science, Chengdu Sport University, Chengdu, China
- School of Physical Education, Chengdu Sport University, Chengdu, China
- School of Elite Sport, Shanghai University of Sport, Shanghai, China
| | - Xin Ye
- Department of Rehabilitation Sciences, University of Hartford, West Hartford, USA
| | - Dong Han
- School of Elite Sport, Shanghai University of Sport, Shanghai, China
| | - Chengbo Yang
- School of Sport Training, Chengdu Sport University, Chengdu, China
| | - Yanhao Tu
- School of Physical Education, Chengdu Sport University, Chengdu, China
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14
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Nishiumi D, Nishioka T, Saito H, Kurokawa T, Hirose N. Associations of eccentric force variables during jumping and eccentric lower-limb strength with vertical jump performance: A systematic review. PLoS One 2023; 18:e0289631. [PMID: 37535669 PMCID: PMC10399862 DOI: 10.1371/journal.pone.0289631] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 07/24/2023] [Indexed: 08/05/2023] Open
Abstract
The purpose of this systematic review was to summarize the associations of eccentric force variables during jumping and eccentric lower-limb strength with vertical jump performance. A literature search was conducted in September 2022 using PubMed, Web of Science, and Scopus. Thirteen cross-sectional studies investigating the relationship between eccentric force and strength variables, such as force, rate of force development (RFD), power, time, and velocity, and vertical jump performance, including the jump height, reactive strength index (RSI), and reactive strength index-modified (RSImod), were included in this systematic review. As eccentric strength, variables during the unloading-to-braking phase of countermovement jump (CMJ) (force, RFD, etc.) and the eccentric force of the squat movement and knee joint were included. The CMJ height, RSImod, and drop jump RSI were included to analyze the vertical jump performance. The modified form of the Downs and Black checklist was used to evaluate quality. Associations between the force and RFD during the descending phase of the CMJ and jump height were observed in some studies but not in others, with differences between the studies. Some studies reported associations between the force and/or RFD during the descending phase of the CMJ and RSImod of the CMJ, with no differences among their results. In addition, there are associations of the eccentric forces during squatting and knee extension with the CMJ and the drop jump heights and RSI of the drop jump. The eccentric force variables in the CMJ and RSImod are related; however, their relationship with jump height remains unclear. Furthermore, improved eccentric muscle strength may contribute to vertical jump height because of the associations of the eccentric strength during knee extension and squatting with jump height.
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Affiliation(s)
- Daichi Nishiumi
- Graduate School of Sport Sciences, Waseda University, Saitama, Japan
| | - Takuya Nishioka
- Institute of Physical Education, Keio University, Hiyoshi, Yokohama, Japan
| | - Hiromi Saito
- Graduate School of Sport Sciences, Waseda University, Saitama, Japan
| | - Takanori Kurokawa
- Graduate School of Sport Sciences, Waseda University, Saitama, Japan
| | - Norikazu Hirose
- Faculty of Sport Sciences, Waseda University, Saitama, Japan
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15
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Krzyszkowski J, Chowning LD, Harry JR. Phase-Specific Verbal Cue Effects on Countermovement Jump Performance. J Strength Cond Res 2022; 36:3352-3358. [PMID: 34533485 DOI: 10.1519/jsc.0000000000004136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
ABSTRACT Krzyszkowski, J, Chowning, LD, and Harry, JR. Phase-Specific Verbal Cue Effects on Countermovement Jump Performance. J Strength Cond Res 36(12): 3352-3358, 2022-The aim of this study was to determine whether countermovement vertical jump (CMVJ) phase-specific cues can improve jump performance and phase-specific force-time characteristics. Twenty-nine subjects (14 males and 15 females) performed 15 total CMVJ trials (5 per condition) while being provided with a control and phase-specific (unloading phase and eccentric braking phases) foci of attention. Jump height, reactive strength index-modified, countermovement depth, time-to-takeoff, and CMVJ subphase force-time characteristics were compared between each phase-specific verbal cues and the control condition using paired samples t-tests ( α = 0.05) and Cohen's d effect sizes ( d ; large >1.2). Female ( d = 0.242; p = 0.012) and male ( d = 1.96; p = 0.047) subjects achieved greater jump heights in the control condition compared with the unloading phase condition. Females demonstrated a faster unloading phase, less unloading force, greater unloading yank, and greater braking force during the unloading condition, as well as greater eccentric braking force during the eccentric braking condition compared with the control condition ( p ≤ 0.014; d ≥ 0.242). Males exhibited less body mass unloading, greater unloading yank, faster eccentric braking time, greater eccentric braking force, and greater eccentric braking yank for both the unloading and eccentric braking conditions compared with the control condition ( p ≤ 0.047; d ≥ 0.196). Collectively, these results suggest that phase-specific foci of attention do not acutely improve jump performance but can enhance phase-specific force-time characteristics in recreationally active individuals. Specifically, practitioners should consider using an eccentric braking phase instruction for individuals need to improve eccentric braking force generation.
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Affiliation(s)
- John Krzyszkowski
- Human Performance & Biomechanics Laboratory, Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, Texas
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16
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Nishioka T, Okada J. Associations of maximum and reactive strength indicators with force-velocity profiles obtained from squat jump and countermovement jump. PLoS One 2022; 17:e0276681. [PMID: 36269787 PMCID: PMC9586393 DOI: 10.1371/journal.pone.0276681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
Abstract
Understanding the properties associated with the vertical force–velocity (F–v) profiles is important for maximizing jump performance. The purpose of this study was to evaluate the associations of maximum and reactive strength indicators with the F–v profiles obtained from squat jump (SJ) and countermovement jump (CMJ). On the first day, 20 resistance-trained men underwent measurements for half squat (HSQ) one-repetition maximum (1RM). On the second day, jump performances were measured to calculate the drop jump (DJ) reactive strength index (RSI) and the parameters of F–v profiles (theoretical maximum force [F0], velocity [V0], power [Pmax], and slope of the linear F–v relationship [SFv]) obtained from SJ and CMJ. The DJ RSI was not significantly correlated with any parameter of the vertical F–v profiles, whereas the relative HSQ 1RM was significantly correlated with the SJ F0 (r = 0.508, p = 0.022), CMJ F0 (r = 0.499, p = 0.025), SJ SFv (r = −0.457, p = 0.043), and CMJ Pmax (r = 0.493, p = 0.027). These results suggest that maximum strength is a more important indicator than reactive strength in improving vertical F–v profiles. Furthermore, the importance of maximum strength may vary depending on whether the practitioner wants to maximize the performance of SJ or CMJ.
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Affiliation(s)
- Takuya Nishioka
- Graduate School of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
- * E-mail:
| | - Junichi Okada
- Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
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17
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Fleeton JRM, Sanders RH, Fornusek C. Impact of maximal strength training on countermovement jump phase characteristics in athletes with cerebral palsy. J Sports Sci 2022; 40:2118-2127. [PMID: 36273245 DOI: 10.1080/02640414.2022.2137303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Analysis of the countermovement jump (CMJ) force-time curve phases provides insight into athlete neuromuscular function and methods by which jump height improves in response to training. A CMJ phase analysis and the dynamic strength index (DSI) have yet to be explored in athletes with cerebral palsy (CP). This study aimed to address this knowledge gap. Eleven state- to international-level athletes with CP completed a pre-post maximal strength training intervention with waitlist control. CMJ was assessed via force plate pre/post baseline and after the 12-week intervention. Following the intervention, CMJ height, takeoff velocity, and concentric phase peak and mean force, impulse and mean acceleration improved significantly (p = 0.006-0.001). No changes were observed in any eccentric braking phase variable (p = 0.79-0.13), while DSI lowered (p = 0.03). In athletes with CP, strength training increased CMJ concentric phase peak and mean force and impulse, increasing velocity and acceleration and therefore jump height. DSI lowered due to moderate and small increases in isometric mid-thigh pull and CMJ peak force, respectively. Unlike in non-disabled athletes, strength training did not alter any eccentric phase variable; therefore, other modalities may be required to further optimize jumping performance in athletes with CP.
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Affiliation(s)
- Jennifer R M Fleeton
- The University of Sydney School of Health Sciences, Discipline of Exercise and Sport Science, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
| | - Ross H Sanders
- The University of Sydney School of Health Sciences, Discipline of Exercise and Sport Science, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
| | - Ché Fornusek
- The University of Sydney School of Health Sciences, Discipline of Exercise and Sport Science, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia
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18
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Harry JR, Krzyszkowski J, Harris K, Chowning L, Mackey E, Bishop C, Barker LA. Momentum-Based Load Prescriptions: Applications to Jump Squat Training. J Strength Cond Res 2022; 36:2657-2662. [PMID: 35916892 DOI: 10.1519/jsc.0000000000004294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2023]
Abstract
ABSTRACT Harry, JR, Krzyszkowski, J, Harris, K, Chowning, L, Mackey, E, Bishop, C, and Barker, LA. Momentum-based load prescriptions: Applications to jump squat training. J Strength Cond Res 36(9): 2657-2662, 2022-Velocity-based training is often applied to ballistic exercises, like the barbell jump squat, to improve vertical jump performance. However, determining the ideal training load based on velocity data remains difficult because load prescriptions tend to be limited to subjective velocity loss thresholds, velocity ranges, or both. Using data from jump squats performed with 0, 15, 30, 45, and 60% of the 1-repetition maximum squat, we explored subjective and objective methods to determine the ideal training load. Specifically, we explored takeoff velocity and a related metric only recently discussed in the literature, system momentum (i.e., takeoff velocity multiplied by the mass of the athlete-load system). At the group level, an ideal training load could not be revealed objectively using takeoff velocity. With individual subjects, the process remained challenging using takeoff velocity. Conversely, an ideal training load could be revealed easily and objectively using system momentum at the group average and individual subject levels. System momentum at takeoff is well-suited to assist practitioners seeking to identify appropriate training loads for jump squat training and potentially other ballistic exercises. We suggest a pivot from velocity to system momentum when seeking to objectively establish training loads for the jump squat and related exercises.
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Affiliation(s)
- John R Harry
- Human Performance and Biomechanics Laboratory, Texas Tech University, Lubbock, Texas
| | - John Krzyszkowski
- Human Performance and Biomechanics Laboratory, Texas Tech University, Lubbock, Texas
| | - Katie Harris
- Human Performance and Biomechanics Laboratory, Texas Tech University, Lubbock, Texas
| | - Luke Chowning
- Human Performance and Biomechanics Laboratory, Texas Tech University, Lubbock, Texas
| | - Ethan Mackey
- Human Performance and Biomechanics Laboratory, Texas Tech University, Lubbock, Texas
| | - Chris Bishop
- Faculty of Science and Technology, London Sport Institute, Middlesex University, London, United Kingdom ; and
| | - Leland A Barker
- Department of Exercise Science and Pre-Health Professions, Creighton University, Omaha, Nebraska
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19
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Santos-Mariano AC, Cristina-Souza G, Santos PS, Domingos PR, De-Oliveira P, Bertuzzi R, Rodacki C, Lima-Silva AE. Caffeine intake increases countermovement jump performance in well-trained high jumpers. PHARMANUTRITION 2022. [DOI: 10.1016/j.phanu.2022.100305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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20
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Krzyszkowski J, Chowning LD, Harry JR. Phase-Specific Predictors of Countermovement Jump Performance That Distinguish Good From Poor Jumpers. J Strength Cond Res 2022; 36:1257-1263. [PMID: 32412965 DOI: 10.1519/jsc.0000000000003645] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2023]
Abstract
ABSTRACT Krzyszkowski, J, Chowning, LD, and Harry, JR. Phase-specific predictors of countermovement jump performance that distinguish good from poor jumpers. J Strength Cond Res 36(5): 1257-1263, 2022-The modified-reactive strength index (RSImod) is commonly examined during the countermovement vertical jump (CMJ) to assess neuromuscular characteristics (i.e., explosiveness, fatigue, adaptation, etc.) of an athlete. However, both phase-specific variables explaining RSImod and corresponding differences between good and poor jumpers are not well understood in trained populations. This study sought to (a) identify predictors of RSImod during the CMJ based on phase-specific temporal and rate of force development (RFD) variables, and (b) identify differences in those predictors between performers with high and low RSImod performances from a sample of collegiate male basketball players (n = 22; 20 ± 2 years; 1.99 ± 0.06 month; 93.8 ± 7.5 kg). Subjects performed 3 maximal effort CMJ trials while ground reaction force data was recorded using 2 force platforms. Phase-specific temporal and RFD variables were calculated and entered into separate stepwise regression models using backward elimination to identify predictors RSImod. Individuals were then categorized into high (n = 11; RSImod = 0.68 ± 0.10) and low (n = 11; RSImod = 0.48 ± 0.04) RSImod groups according to the overall median RSImod (RSImod = 0.55). Independent t-tests (α = 0.05) were conducted and supplemented by Cohen's d effect sizes (d ≥ 1.2, large) to compare groups relative to significant predictors identified by the linear regression models and related variables. The temporal regression model (R2 = 0.530) retained unloading time and concentric time, whereas the RFD regression model (R2 = 0.429) retained unloading RFD and braking RFD. The high RSImod group exhibited significantly greater RSImod scores (d = 2.51, p < 0.001) and jump heights (d = 1.58, p < 0.001), shorter times to takeoff (d = 1.27, p = 0.007) and concentric times (d = 1.51, p = 0.002), and a greater braking RFD (d = 1.41, p = 0.005) than the low RSImod group. Individuals targeting enhanced CMJ performance may consider exploring strategies or interventions to develop quicker unloading and concentric phases and increasing eccentric RFD abilities.
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Affiliation(s)
- John Krzyszkowski
- Human Performance & Biomechanics Laboratory, Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, Texas
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21
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An Assessment of the Hopping Strategy and Inter-Limb Asymmetry during the Triple Hop Test: A Test–Retest Pilot Study. Symmetry (Basel) 2021. [DOI: 10.3390/sym13101890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The aims of the present study are to: (1) determine within- and between-session reliability of multiple metrics obtained during the triple hop test; and (2) determine any systematic bias in both the test and inter-limb asymmetry scores for these metrics. Thirteen male young American football athletes performed three trials of a triple hop test on each leg on two separate occasions. In addition to the total distance hopped, manual detection of touch down and toe-off were calculated via video analysis, enabling flight time (for each hop), ground contact time (GCT), reactive strength index (RSI), and leg stiffness (between hops) to be calculated. Results showed all coefficient of variation (CV) values were ≤ 10.67% and intraclass correlation coefficients (ICC) ranged from moderate to excellent (0.53–0.95) in both test sessions. Intrarater reliability showed excellent reliability for all metrics (CV ≤ 3.60%, ICC ≥ 0.97). No systematic bias was evident between test sessions for raw test scores (g = −0.34 to 0.32) or the magnitude of asymmetry (g = −0.19 to 0.43). However, ‘real’ changes in asymmetry (i.e., greater than the CV in session 1) were evident on an individual level for all metrics. For the direction of asymmetry, kappa coefficients revealed poor-to-fair levels of agreement between test sessions for all metrics (K = −0.10 to 0.39), with the exception of the first hop (K = 0.69). These data show that, given the inherent limitations of distance jumped in the triple hop test, practitioners can confidently gather a range of reliable data when computed manually, provided sufficient test familiarization is conducted. In addition, although the magnitude of asymmetry appears to show only small changes between test sessions, limb dominance does appear to fluctuate between test sessions, highlighting the value of also monitoring the direction of the imbalance.
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22
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Harry JR. MATLAB Guide for Analyzing Countermovement Jump Strategies and Performance Over Time. Strength Cond J 2021. [DOI: 10.1519/ssc.0000000000000624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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Phase-Specific Force and Time Predictors of Standing Long Jump Distance. J Appl Biomech 2021; 37:400-407. [PMID: 34243165 DOI: 10.1123/jab.2021-0093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/13/2021] [Accepted: 05/19/2021] [Indexed: 11/18/2022]
Abstract
This study sought to identify potential predictors of standing long jump (SLJ) performance using force-time strategy metrics within the unloading, eccentric yielding, eccentric braking, and concentric phases. Fifteen National Collegiate Athletic Association division 1 male soccer players (19 [1] y, 1.81 [0.94] m, 80.3 [22.4] kg) performed 3 maximum-effort SLJs, while 3-dimensional ground reaction force (GRF) data were obtained. Regularized regression models were used to investigate associations between force-time strategy metrics and 2 metrics of SLJ performance (ie, jump distance and modified reactive strength index). Jump height and eccentric yielding time were the only predictors of jump distance that also demonstrated large correlations to jump distance. Anterior-posterior unloading yank, average concentric vertical force, and concentric phase duration were the only predictors of modified reactive strength index that also demonstrated large correlations to modified reactive strength index. To maximize SLJ distance in high-level soccer athletes, human performance practitioners could design interventions to drive changes in strategy to increase jump height and decrease eccentric yielding time. To improve SLJ explosiveness, interventions to drive changes in unloading and concentric force application and decrease concentric time could be emphasized. Importantly, unique variable combinations can be targeted when training for SLJ distance and explosiveness adaptations.
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24
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Montalvo S, Gonzalez MP, Dietze-Hermosa MS, Eggleston JD, Dorgo S. Common Vertical Jump and Reactive Strength Index Measuring Devices: A Validity and Reliability Analysis. J Strength Cond Res 2021; 35:1234-1243. [PMID: 33629975 DOI: 10.1519/jsc.0000000000003988] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Montalvo, S, Gonzalez, MP, Dietze-Hermosa, M, Eggleston, JD, and Dorgo, S. Common vertical jump and reactive strength index measuring devices: A validity and reliability analysis. J Strength Cond Res 35(5): 1234-1243, 2021-Several field-test devices exist to assess vertical jump, but they either lack proper validation or have been validated for the countermovement jump (CMJ) only. This study aimed to quantify the validity and reliability of metrics, including jump height and the calculated reactive strength index (RSI), obtained using the flight-time method from 4 different assessment devices with 3 different vertical jump modalities in comparison to a force platform (criterion assessment). The Optojump, Push-Band 2.0, MyJump2 mobile application, and What'sMyVert mobile application were used synchronously and together with the force platforms. Thirty subjects (17 males and 13 females; age ± SD: 23.37 ± 1.87 years) performed 5 repetitions of CMJ, squat jump (SQJ), and drop jump (DJ) with a standardized 90° knee flexion for all jumps. Relative reliability was determined by intraclass correlation (ICC) and absolute reliability by coefficient of variation (CV) analyses. Excellent reliability was considered as ICC > 0.9 and CV < 10%. Validity was obtained through an ordinary least products regression, ICC, and CV. Significance was set at p < 0.05. Reliability was excellent on jump height for the CMJ (ICC ≥ 0.98; CV ≤ 8.14%) for all instruments. With the exception of the Optojump, all instruments also had excellent reliability for the SQJ (ICC ≥ 0.98; CV ≤ 6.62) and DJ (ICC ≥ 0.94; CV ≤ 8.19). For the RSI metric, all instruments had excellent relative reliability (ICC ≥ 0.92), but none had excellent absolute reliability (CV ≥ 12.5%). The MyJump2 and What'sMyVert apps showed excellent validity on all jump modalities and RSI. The Optojump and Push-Band 2.0 devices both showed system and proportional bias for several jump modalities and RSI. Overall, both mobile applications may provide coaches with a cost-effective and reliable measurement of various vertical jumps.
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Affiliation(s)
- Samuel Montalvo
- Fitness Research Facility, Department of Kinesiology, The University of Texas at El Paso, El Paso, Texas; and
| | - Matthew P Gonzalez
- Fitness Research Facility, Department of Kinesiology, The University of Texas at El Paso, El Paso, Texas; and
| | - Martin S Dietze-Hermosa
- Fitness Research Facility, Department of Kinesiology, The University of Texas at El Paso, El Paso, Texas; and
| | - Jeffrey D Eggleston
- Stanley E. Fulton Gait Research and Movement Analysis Laboratory, Department of Kinesiology, The University of Texas at El Paso, El Paso, Texas
| | - Sandor Dorgo
- Fitness Research Facility, Department of Kinesiology, The University of Texas at El Paso, El Paso, Texas; and
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25
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Baus J, Harry JR, Yang J. Optimization-based subject-specific planar human vertical jumping prediction: Model development and validation. Proc Inst Mech Eng H 2021; 235:805-818. [PMID: 33863254 DOI: 10.1177/09544119211010924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Jumping biomechanics may differ between individuals participating in various sports. Jumping motion can be divided into different phases for research purposes when seeking to understand performance, injury risk, or both. Experimental-based methods are used to study different jumping situations for their capabilities of testing other conditions intended to improve performance or further prevent injuries. External loading training is commonly used to simulate jumping performance improvement. This paper presents the optimization-based subject-specific planar human vertical jumping to develop the prediction model with and without a weighted vest and validate it through experiments. The skeletal model replicates the human motion for jumping (weighting, unweighting, breaking, propulsion) in the sagittal plane considering four different loading conditions (0% and 10% body mass): unloaded, split-loaded, front-loaded, and back-loaded. The multi-objective optimization problem is solved using MATLAB® with 35 design variables and 197 nonlinear constraints. Results show that the model is computationally efficient, and the predicted jumping motion matches the experimental data trend. The simulation model can predict vertical jumping motion and can test the effect of different loading conditions with weighted vests and arm-swing strategy on the ground reaction forces. This work is novel in the sense that it can predict ground reaction forces, joints angles, and center of mass position without any experimental data.
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Affiliation(s)
- Juan Baus
- Department of Mechanical Engineering, Human-Centric Design Research Lab, Texas Tech University, Lubbock, TX, USA
| | - John R Harry
- Department of Kinesiology and Sport Management, Human Performance & Biomechanics Lab, Texas Tech University, Lubbock, TX, USA
| | - James Yang
- Department of Mechanical Engineering, Human-Centric Design Research Lab, Texas Tech University, Lubbock, TX, USA
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Grozier CD, Cagle GK, Pantone L, Rank KB, Wilson SJ, Harry JR, Seals S, Simpson JD. Effects of medial longitudinal arch flexibility on propulsion kinetics during drop vertical jumps. J Biomech 2021; 118:110322. [PMID: 33607594 DOI: 10.1016/j.jbiomech.2021.110322] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/12/2021] [Accepted: 02/02/2021] [Indexed: 11/30/2022]
Abstract
This study examined the effects of medial longitudinal arch (MLA) flexibility on kinetics during the eccentric and concentric subphases of a drop vertical jump (DVJ). Physically active adults with flexible (n = 16) and stiff (n = 16) MLA completed DVJs onto a force platform from a height of 30 cm. Eccentric and concentric subphases of the DVJ were identified from the vertical ground reaction force (GRF) data. Jump height, ground contact time, reactive strength index (RSI), vertical center-of-mass depth, vertical stiffness and time of the eccentric and concentric subphases were evaluated. Amortization force, peak vertical GRF and vertical impulse were also obtained for the eccentric and concentric subphases of the DVJ. Dependent variables were compared between groups using independent samples t-tests (p < 0.05). Significantly greater vertical stiffness (p = 0.048; ES = 0.63) was found in the stiff arch group (-173.91 ± 99.73 N/kg/m) compared to the flexible arch group (-122.95 ± 63.42 N/kg/m). A moderate-magnitude difference (ES = 0.58) was observed for RSI between flexible (0.89 ± 0.39) and stiff arch (1.20 ± 0.70) groups, but was not significant (p = 0.063). The active and passive structures supporting the MLA may be used differently to achieve similar vertical jump height during a DVJ. Additional research is warranted to further understand the contributions of MLA flexibility to jumping performance.
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Affiliation(s)
- Corey D Grozier
- Department of Movement Sciences and Health, University of West Florida, Pensacola, FL, United States; Department of Kinesiology, University of North Alabama, Florence, AL, United States
| | - Gretchen K Cagle
- Department of Movement Sciences and Health, University of West Florida, Pensacola, FL, United States
| | - Lauren Pantone
- Department of Movement Sciences and Health, University of West Florida, Pensacola, FL, United States
| | - Kyle B Rank
- Department of Movement Sciences and Health, University of West Florida, Pensacola, FL, United States
| | - Samuel J Wilson
- Department of Health Sciences and Kinesiology, Georgia Southern University, Statesboro, GA, United States
| | - John R Harry
- Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, United States
| | - Samantha Seals
- Department of Mathematics and Statistics, University of West Florida, Pensacola, FL, United States
| | - Jeffrey D Simpson
- Department of Movement Sciences and Health, University of West Florida, Pensacola, FL, United States.
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Mitchell A, Holding C, Greig M. Factors influencing optimum countermovement jump performance and movement strategy in Championship professional football players: implications for player profiling. Res Sports Med 2020; 30:30-40. [PMID: 33302721 DOI: 10.1080/15438627.2020.1860049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Single leg countermovement jump (CMJ) is a common profiling test influenced by sport, age, sex and playing level. Controlling for these confounding variables, outfield players from an English Championship squad (n = 36) were retrospectively categorized as best (n = 10) or worst (n = 10), based on mean single leg CMJ height and flight time:contraction time ratio. Movement strategy was quantified as force-time history metrics differentiating eccentric and concentric phases. Jump height revealed that best performers elicited greater rate of force development in both phases (P ≤ 0.033), with concentric impulse the strongest predictor of performance. Time ratio also differentiated best performers as utilizing a shallower (P = 0.002) countermovement, with concentric rate of force development the strongest predictor of good performance. Successful jump height performance can mask ineffectual eccentric and stretch shortening cycle neuromuscular characteristics. Time ratio is therefore advocated as the key performance indicator, with movement strategy prioritized over gross outcome measures.
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Affiliation(s)
- Andy Mitchell
- Medical Department, Blackburn Rovers Football Club, Blackburn, UK
| | - Craig Holding
- Medical Department, Blackburn Rovers Football Club, Blackburn, UK
| | - Matt Greig
- Sports Injuries Research Group, Edge Hill University, Ormskirk, UK
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Force-Time Waveform Shape Reveals Countermovement Jump Strategies of Collegiate Athletes. Sports (Basel) 2020; 8:sports8120159. [PMID: 33276573 PMCID: PMC7761544 DOI: 10.3390/sports8120159] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/28/2020] [Accepted: 11/30/2020] [Indexed: 11/16/2022] Open
Abstract
The purpose of this study was to relate the shape of countermovement jump (CMJ) vertical ground reaction force waveforms to discrete parameters and determine if waveform shape could enhance CMJ analysis. Vertical ground reaction forces during CMJs were collected for 394 male and female collegiate athletes competing at the National Collegiate Athletic Association (NCAA) Division 1 and National Association of Intercollegiate Athletics (NAIA) levels. Jump parameters were calculated for each athlete and principal component analysis (PCA) was performed on normalized force-time waveforms consisting of the eccentric braking and concentric phases. A K-means clustering of PCA scores placed athletes into three groups based on their waveform shape. The overall average waveforms of all athletes in each cluster produced three distinct vertical ground reaction force waveform patterns. There were significant differences across clusters for all calculated jump parameters. Athletes with a rounded single hump shape jumped highest and quickest. Athletes with a plateau at the transition between the eccentric braking and concentric phase (amortization) followed by a peak in force near the end of the concentric phase had the lowest jump height and slowest jump time. Analysis of force-time waveform shape can identify differences in CMJ strategies in collegiate athletes.
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Cohen DD, Restrepo A, Richter C, Harry JR, Franchi MV, Restrepo C, Poletto R, Taberner M. Detraining of specific neuromuscular qualities in elite footballers during COVID-19 quarantine. SCI MED FOOTBALL 2020; 5:26-31. [DOI: 10.1080/24733938.2020.1834123] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Daniel D. Cohen
- Masira Research Institute, University of Santander (UDES), Bucaramanga, Colombia
- Sports Science Center (CCD), Colombian Ministry of Sport (Mindeporte), Colombia
| | - Alfredo Restrepo
- Performance Department, América De Cali Football Club, Cali, Colombia
- Indervalle (Valle Del Cauca Institute of Sport, Physical Education and Recreation), Cali, Colombia
| | | | - John R. Harry
- Human Performance & Biomechanics Laboratory, Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, TX, USA
| | | | - Carlos Restrepo
- Performance Department, América De Cali Football Club, Cali, Colombia
| | - Rodrigo Poletto
- Performance Department, América De Cali Football Club, Cali, Colombia
| | - Matt Taberner
- School of Sport and Exercise Sciences, Liverpool John Moore’s University, Liverpool, UK
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30
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Chowning LD, Krzyszkowski J, Harry JR. Maximalist shoes do not alter performance or joint mechanical output during the countermovement jump. J Sports Sci 2020; 39:108-114. [PMID: 32787669 DOI: 10.1080/02640414.2020.1808277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This study examined potential differences between maximally cushioned (MAX) shoes and standard cushioned (STND) shoes during countermovement vertical jump (CMVJ) performance. Twenty-one males (23[2] y; 86.5[15.4] kg; 179.8[6.3] cm) completed eight jumps each in MAX and STND shoes while three-dimensional kinematic and kinetic data were collected. Paired-samples t-tests (α = 0.05) and Cohen's d effect sizes (ES) were used to compare the following variables: vertical jump displacement, jump time, hip, knee and ankle joint angles at the start of the countermovement, the end of the unloading phase, the end of the eccentric phase, and at takeoff, peak joint power, and the joint contributions to total lower extremity work during the eccentric and concentric phases. The ankle was more dorsiflexed at the end of the countermovement in the MAX shoe (p = 0.002; ES = 0.55) but greater plantarflexion occurred in the STND shoes at takeoff (p = 0.028; ES = 0.56). No other differences were observed. The result of this study suggests that unique ankle joint angular positioning may be employed when wearing MAX versus STND shoes. Since the unique ankle joint positioning did not alter jump performance, potential MAX footwear users might not need to consider the potential for altered CMVJ performance when determining whether to adopt MAX footwear.
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Affiliation(s)
- Luke D Chowning
- Human Performance & Biomechanics Laboratory, Department of Kinesiology & Sport Management, Texas Tech University , Lubbock, TX, USA
| | - John Krzyszkowski
- Human Performance & Biomechanics Laboratory, Department of Kinesiology & Sport Management, Texas Tech University , Lubbock, TX, USA
| | - John R Harry
- Human Performance & Biomechanics Laboratory, Department of Kinesiology & Sport Management, Texas Tech University , Lubbock, TX, USA
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Harry JR, Blinch J, Barker LA, Krzyszkowski J, Chowning L. Low-Pass Filter Effects on Metrics of Countermovement Vertical Jump Performance. J Strength Cond Res 2020; 36:1459-1467. [DOI: 10.1519/jsc.0000000000003611] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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