scholarly journals Effect of Barbell Load on Vertical Jump Landing Force-Time Characteristics

2021 ◽  
Vol 35 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Jason P. Lake ◽  
Peter D. Mundy ◽  
Paul Comfort ◽  
John J. McMahon ◽  
Timothy J. Suchomel ◽  
...  
Keyword(s):  
Vertical Jump ◽  
Jump Landing ◽  
Force Time

scholarly journals Concurrent Validity of a Portable Force Plate Using Vertical Jump Force–Time Characteristics

2018 ◽  
Vol 34 (5) ◽  
pp. 410-413 ◽  
Author(s):  
Jason Lake ◽  
Peter Mundy ◽  
Paul Comfort ◽  
John J. McMahon ◽  
Timothy J. Suchomel ◽  
...  
Keyword(s):  
Concurrent Validity ◽  
Vertical Jump ◽  
Reaction Force ◽  
Force Plate ◽  
Vertical Force ◽  
Jump Height ◽  
Strength Index ◽  
Limits Of Agreement ◽  
Force Time ◽  
Plate System

This study examined concurrent validity of countermovement vertical jump reactive strength index modified and force–time characteristics recorded using a 1-dimensional portable and laboratory force plate system. Twenty-eight men performed bilateral countermovement vertical jumps on 2 portable force plates placed on top of 2 in-ground force plates, both recording vertical ground reaction force at 1000 Hz. Time to takeoff; jump height; reactive strength index modified; and braking and propulsion impulse, mean net force, and duration were calculated from the vertical force from both force plate systems. Results from both systems were highly correlated (r ≥ .99). There were small (d < 0.12) but significant differences between their respective braking impulse, braking mean net force, propulsion impulse, and propulsion mean net force (P < .001). However, limits of agreement yielded a mean value of 1.7% relative to the laboratory force plate system (95% confidence limits, 0.9%–2.5%), indicating very good agreement across all of the dependent variables. The largest limits of agreement were for jump height (2.1%), time to takeoff (3.4%), and reactive strength index modified (3.8%). The portable force plate system provides a valid method of obtaining reactive strength measures, and several underpinning force–time variables, from unloaded countermovement vertical jump. Thus, practitioners can use both force plates interchangeably.

scholarly journals The use of yank-time signal as an alternative to identify kinematic events and define phases in human countermovement jumping

2020 ◽  
Vol 7 (8) ◽  
pp. 192093
Author(s):  
Sofyan B. Sahrom ◽  
Jodie C. Wilkie ◽  
Kazunori Nosaka ◽  
Anthony J. Blazevich
Keyword(s):  
Muscle Activation ◽  
Vertical Jump ◽  
Reaction Force ◽  
Mass Movement ◽  
Time Signal ◽  
Time Data ◽  
Vertical Ground Reaction Force ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Force Time

Detailed examinations of both the movement and muscle activation patterns used by animals and humans to complete complex tasks are difficult to obtain in many environments. Therefore, the ability to infer movement and muscle activation patterns after capture of a single set of easily obtained data is highly sought after. One possible solution to this problem is to capture force-time data through the use of appropriate transducers, then interrogate the signal's derivative, the yank-time signal, which amplifies, and thus highlights, temporal force-time changes. Because the countermovement vertical jump (CMJ) is a complex movement that has been well studied in humans, it provides an excellent preliminary model to test the validity of this solution. The aim of the present study was therefore to explore the use of yank-time signal, derived from vertical ground reaction force-time data, to identify and describe important kinematic (captured using three-dimensional motion analysis) and kinetic events in the CMJ, and to relate these to possible muscle activation (electromyography) events that underpin them. It was found that the yank-time signal could be used to accurately identify several key events during the CMJ that are likely to be missed or misidentified when only force-time data are inspected, including the first instances of joint flexion and centre of mass movement. Four different jump profiles (i.e. kinematic patterns) were inferred from the yank-time data, which were linked to different patterns of muscle activation. Therefore, yank-time signal interrogation provides a viable method of estimating kinematic patterns and muscle activation strategies in complex human movements.

scholarly journals Changes in Plantar Loading Based on Shoe Type and Sex During a Jump-Landing Task

2013 ◽  
Vol 48 (5) ◽  
pp. 601-609 ◽  
Author(s):  
Justin C. DeBiasio ◽  
Mary E. Russell ◽  
Robert J. Butler ◽  
James A. Nunley ◽  
Robin M. Queen
Keyword(s):  
Contact Area ◽  
Stress Fractures ◽  
Maximum Force ◽  
Lower Extremity Injury ◽  
Jump Landing ◽  
Time Integral ◽  
Running Shoes ◽  
History Of ◽  
Force Time ◽  
Force Time Integral

Context: Metatarsal stress fractures are common in cleated-sport athletes. Previous authors have shown that plantar loading varies with footwear, sex, and the athletic task. Objective: To examine the effects of shoe type and sex on plantar loading in the medial midfoot (MMF), lateral midfoot (LMF), medial forefoot (MFF), middle forefoot (MidFF), and lateral forefoot (LFF) during a jump-landing task. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: Twenty-seven recreational athletes (14 men, 13 women) with no history of lower extremity injury in the last 6 months and no history of foot or ankle surgery. Main Outcome Measure(s): The athletes completed 7 jumping trials while wearing bladed-cleat, turf-cleat, and running shoes. Maximum force, contact area, contact time, and the force-time integral were analyzed in each foot region. We calculated 2 × 3 analyses of variance (α = .05) to identify shoe-condition and sex differences. Results: We found no shoe × sex interactions, but the MMF, LMF, MFF, and LFF force-time integrals were greater in men (P &lt; .03). The MMF maximum force was less with the bladed-cleat shoes (P = .02). Total foot and MidFF maximum force was less with the running shoes (P &lt; .01). The MFF and LFF maximum forces were different among all shoe conditions (P &lt; .01). Total foot contact area was less in the bladed-cleat shoes (P = .01). The MMF contact area was greatest in the running shoes (P &lt; .01). The LFF contact area was less in the running shoes (P = .03). The MFF and LFF force-time integrals were greater with the bladed-cleat shoes (P &lt; .01). The MidFF force-time integral was less in the running shoes (P &lt; .01). Conclusions: Independent of shoe, men and women loaded the foot differently during a jump landing. The bladed cleat increased forefoot loading, which may increase the risk for forefoot injury. The type of shoe should be considered when choosing footwear for athletes returning to activity after metatarsal stress fractures.

scholarly journals Stretch-Shortening Cycle in Countermovement Jump: Exclusive Review of Force-Time Curve Variables in Eccentric and Concentric Phases

2017 ◽  
Author(s):  
Mahdi Cheraghi ◽  
Javad Sarvestan ◽  
Masoud Sebyani ◽  
Elham Shirzad
Keyword(s):  
Peak Power ◽  
Vertical Jump ◽  
Average Power ◽  
Peak Force ◽  
Jump Height ◽  
Time Curve ◽  
Jump Performance ◽  
Volleyball Players ◽  
Time Variables ◽  
Force Time

The importance of vertical jump in sport fields and rehabilitation is widely recognized. Furthermore, Force-Time variables of vertical jump are factors affecting jumping height. Exclusive review of each of this variables, in eccentric and concentric phases, can lead to a specific focus on them during jumping exercises. So, the aims of his study were to a) reviewing the relationship between force-time curve variables of eccentric and concentric phases with jump height and b) description of this variables in Iran national youth volleyball players society. This is an observational study. 12 elite volleyball player (Male, Iran national youth volleyball players, 17&plusmn;0.7 years) have participated in this study. Correlation between Force-Time variables - included peak force (PF), relative peak force (RPP), peak power (PP), average power (AP), relative peak power (RPP), and Modified Reactive Strength Index (MRSI) - in eccentric and concentric phases and ultimate jump height has been studied. Results showed that the average power (r=0.7) and relative peak force (r=0.75) of concentric phase and MRSI (r=0.83) have significant correlation with ultimate jump height (JH). Relative peak power and average power of concentric phase can massively effect Jump Height in sports like volleyball, which vertical jump is an integral part of them. Focus on both of these factors, which has been studied in this research, in training programs, can improve athlete jump performance significantly.

Comparison of the Hang High Pull and Loaded Jump Squat for the Development of Vertical Jump and Isometric Force-Time Characteristics

2019 ◽  
Vol 33 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Dustin J. Oranchuk ◽  
Tracey L. Robinson ◽  
Zachary J. Switaj ◽  
Eric J. Drinkwater
Keyword(s):  
Isometric Force ◽  
Vertical Jump ◽  
Force Time

Muscle Activity Estimation at Drop Vertical Jump Landing Using Passive Muscle Mechanical Model

2021 ◽  
Author(s):  
Hinako Suzuki ◽  
Akihiko Murai ◽  
Yosuke Ikegami ◽  
Emiko Uchiyama ◽  
Ko Yamamoto ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Mechanical Model ◽  
Vertical Jump ◽  
Jump Landing ◽  
Passive Muscle ◽  
Activity Estimation ◽  
Drop Vertical Jump

scholarly journals The adaptation to standing long jump distance in parkour is performed by the modulation of specific variables prior and during take-off

2017 ◽  
pp. 27-37
Author(s):  
Sidney Grosprêtre ◽  
Pierre Ufland ◽  
Daniel Jecker
Keyword(s):  
Center Of Pressure ◽  
Vertical Jump ◽  
Standing Long Jump ◽  
Jump Distance ◽  
Long Jump ◽  
Reaction Forces ◽  
Similar Distance ◽  
Force Time ◽  
Jump Trajectory ◽  
Curvilinear Trajectory

The present study aimed at investigating different variables that can be manipulated prior to and during take-off, to execute a specific standing long jump (SLJ) distance, according to jump expertise in parkour practitioners (= traceurs). Fourteen healthy young traceurs were included and separated into two groups: beginners (BEG) and experts (EXP). Firstly, classical vertical jump battery was used to characterize participants arm use and leg efficiency. Secondly, standing long jump (SLJ) performances were analyzed at four distances: 70, 80, 90, and 100% of each participant’s maximal SLJ distance. The force-time curves of the ground reaction forces (GRF) and the center of pressure (CoP) trajectory were measured with a force platform during the jump impulses. Take-off speed, angle and jump trajectory were estimated. For all of the participants, take-off speed and angle, power output, and vertical GRF during jump preparation (counter movement) varied with distance. The EXP group exhibited greater backward CoP excursion, greater arm participation, greater take-off velocity and a greater modulation of take-off angle than BEG group. When comparing jumps of similar distance, EXP exhibited a more curvilinear trajectory with a higher peak than BEG. To conclude, different motor strategies can be adopted based on the jump distance, and these strategies can evolve as parkour experience increases.

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