An Appropriate Criterion Reveals that Low Pass Filtering Can Improve the Estimation of Counter-movement Jump Height from Force Plate Data

Author(s):  
Brendan L. Pinto ◽  
Jack P. Callaghan
2007 ◽  
Vol 23 (3) ◽  
pp. 180-189 ◽  
Author(s):  
Niell G. Elvin ◽  
Alex A. Elvin ◽  
Steven P. Arnoczky

Modern electronics allow for the unobtrusive measurement of accelerations outside the laboratory using wireless sensor nodes. The ability to accurately measure joint accelerations under unrestricted conditions, and to correlate them with jump height and landing force, could provide important data to better understand joint mechanics subject to real-life conditions. This study investigates the correlation between peak vertical ground reaction forces, as measured by a force plate, and tibial axial accelerations during free vertical jumping. The jump heights calculated from force-plate data and accelerometer measurements are also compared. For six male subjects participating in this study, the average coefficient of determination between peak ground reaction force and peak tibial axial acceleration is found to be 0.81. The coefficient of determination between jump height calculated using force plate and accelerometer data is 0.88. Data show that the landing forces could be as high as 8 body weights of the jumper. The measured peak tibial accelerations ranged up to 42 g. Jump heights calculated from force plate and accelerometer sensors data differed by less than 2.5 cm. It is found that both impact accelerations and landing forces are only weakly correlated with jump height (the average coefficient of determination is 0.12). This study shows that unobtrusive accelerometers can be used to determine the ground reaction forces experienced in a jump landing. Whereas the device also permitted an accurate determination of jump height, there was no correlation between peak ground reaction force and jump height.


2018 ◽  
Vol 63 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Michał Górski ◽  
Michał Starczewski ◽  
Anna Pastuszak ◽  
Joanna Mazur-Różycka ◽  
Jan Gajewski ◽  
...  

Abstract The aim of the study was to investigate changes of strength and power of the lower extremities in adolescent handball players during a two-year training cycle. Thirty-one male handball players (age 16.0 ± 0.2 years, body mass 81.4 ± 9.7 kg, body height 188.2 ± 6.4 cm) took part in this study. All tests were conducted three times at the beginning of a one-year training programme. The maximum joint torque (JT) of flexors and extensors of the elbow, shoulder, hip, knee and trunk was measured under static conditions. Power of lower extremities was assessed with a repeated sprint ability (RSA) test on a cycloergometer and jump tests: akimbo counter-movement jump (ACMJ), counter-movement jump (CMJ) and spike jump tests on a force plate. Peak power (PP) increased from 914.8 ± 93.9 to 970.0 ± 89.2 and 1037.8 ± 114.4 W (p < 0.05) following the RSA test results. Maximum power increased significantly (p < 0.05) in ACMJ (1951.9 ± 359.7 to 2141.9 ± 378.5 and 2268.5 ± 395.9 W) and CMJ tests (2646.3 ± 415.6 to 2831.2 ± 510.8 and 3064.6 ± 444.5 W). Although significant differences in JT (p < 0.05) were observed during the two year period, their values related to body mass for the lower right extremity, sum of the trunk and sum of all muscle groups increased significantly between the first and the second measurement (from 13.7 ± 1.8 to 14.58 ± 1.99 N·m·kg-1, from 9.3 ± 1.5 to 10.39 ± 2.16 N·m·kg-1, from 43.4 ± 5.2 to 46.31 ± 6.83 N·m·kg-1, respectively). The main finding of the study is that PP in the RSA test and maximal power in the ACMJ and CMJ increase in relation to training experience and age in the group of youth handball players.


2013 ◽  
Vol 37 (3) ◽  
pp. 463-466 ◽  
Author(s):  
T. Caderby ◽  
E. Yiou ◽  
N. Peyrot ◽  
B. Bonazzi ◽  
G. Dalleau

2018 ◽  
Vol 34 (5) ◽  
pp. 410-413 ◽  
Author(s):  
Jason Lake ◽  
Peter Mundy ◽  
Paul Comfort ◽  
John J. McMahon ◽  
Timothy J. Suchomel ◽  
...  

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.


2010 ◽  
Vol 2 (2) ◽  
pp. 3481
Author(s):  
Christian Baumgart ◽  
Volker Lange-Berlin ◽  
Rüdiger Hofmann ◽  
Jürgen Freiwald

2018 ◽  
Author(s):  
Jean-Benoit Morin ◽  
Pedro Jiménez-Reyes ◽  
Matt Brughelli ◽  
Pierre Samozino

Lower limb maximal power output (Pmax) is a key physical component of performance in many sports. During squat jump (SJ) and countermovement jump (CMJ) tests, athletes produce high amounts of mechanical work over a short duration to displace their body mass (i.e. the dimension of mechanical power). Thus, jump height has been frequently used by the sports science and medicine communities as an indicator of Pmax. However, in this article, we contended that SJ and CMJ height are in fact poor indicators of Pmax in trained populations. To support our opinion, we first detailed why, theoretically, jump height and Pmax are not fully related. Specifically, we demonstrated that individual body mass, distance of push-off, optimal loading and force-velocity characteristics confound the jump height-Pmax relationship. We also discussed the poor relationship between SJ or CMJ height and Pmax measured with a force plate based on data reported in the literature, which added to our own experimental evidence.Finally, we discussed the limitations of existing practical solutions (regression-based estimation equations and allometric scaling), and advocated using a valid, reliable and simple field-based procedure to compute individual Pmax directly from jump height, body mass and push-off distance. The latter may allow researchers and practitioners to reduce bias in their assessment of Pmax by using jump height as an input with a simple yet accurate computation method, and not as the first/only variable of interest.


Retos ◽  
2019 ◽  
pp. 820-826
Author(s):  
Sergio Miras Moreno

Las múltiples ventajas que aporta un buen control de la carga y la fatiga tanto en deportes de equipo como individuales son conocidas, aunque es importante determinar si un mismo método de control puede ser utilizado para cualquier tipo de deporte, ya que cada uno posee unas demandas metabólicas y neuromusculares diferentes. El objetivo de esta revisión fue recopilar conocimiento acerca de la fiabilidad de la altura del salto en contramovimiento (CMJ, por sus siglas en inglés) como instrumento de control de la carga y la fatiga neuromuscular en atletas de diferentes deportes. El objetivo complementario fue relacionar el CMJ con otras variables metabólicas sensibles a la fatiga neuromuscular. Dos bases de datos (PubMed y WebOfScience) fueron utilizadas para la búsqueda de un total de 1051 artículos científicos. La calidad metodológica para cada artículo se llevó a cabo mediante la escala de la base de datos sobre Fisioterapia Basada en la Evidencia (PEDro). Un total de 12 artículos siguieron los criterios de inclusión y exclusión. Se encontraron numerosas correlaciones con otras variables metabólicas como el nivel de cortisol en saliva, el amonio y lactato en sangre. La altura del CMJ es una herramienta fiable para medir tanto como la fatiga neuromuscular a lo largo de una temporada como para medir la fatiga aguda después de una sesión de entrenamiento, no obstante, es recomendable establecer un protocolo adecuado de medición y que se relacione con otros instrumentos o parámetros metabólicos para aumentar su fiabilidad dentro de los distintos deportes.Abstract: The many advantages of good load and fatigue control in team and individual sports are known, although it is important to determine if the same control method can be used for any type of sport, for each one has different metabolic and neuromuscular demands. To analyze the reliability of counter-movement jump height (CMJ) as an instrument for load and neuromuscular fatigue control in athletes of different sports. The secondary aim was to relate vertical jump height (VJH) with other metabolic variables sensitive to neuromuscular fatigue. Two databases (PubMed and Web Of Science) were used to search a total of 1051 scientific journals. The methodological quality for each article was carried out using the scale of the database on Evidence-Based Physiotherapy (PEDro). A total of 12 papers matched the inclusion criteria. Numerous correlations were found with other metabolic variables such as the level of cortisol in saliva, ammonium and lactate in the blood. The height of the CMJ is a reliable tool to measure neuromuscular fatigue over a season and acute fatigue after a training session; however, it is advisable to establish an adequate measurement protocol and compare it with other instruments to increase their reliability within different sports.


2021 ◽  
Vol 11 (24) ◽  
pp. 12025
Author(s):  
Stefan Marković ◽  
Milivoj Dopsaj ◽  
Sašo Tomažič ◽  
Anton Kos ◽  
Aleksandar Nedeljković ◽  
...  

The aim of the present study was to determine if an inertial measurement unit placed on the metatarsal part of the foot can provide valid and reliable data for an accurate estimate of vertical jump height. Thirteen female volleyball players participated in the study. All players were members of the Republic of Serbia national team. Measurement of the vertical jump height was performed for the two exemplary jumping tasks, squat jump and counter-movement jump. Vertical jump height estimation was performed using the flight time method for both devices. The presented results support a high level of concurrent validity of an inertial measurement unit in relation to a force plate for estimating vertical jump height (CMJ t = 0.897, p = 379; ICC = 0.975; SQJ t = −0.564, p = 0.578; ICC = 0.921) as well as a high level of reliability (ICC > 0.872) for inertial measurement unit results. The proposed inertial measurement unit positioning may provide an accurate vertical jump height estimate for in-field measurement of jump height as an alternative to other devices. The principal advantages include the small size of the sensor unit and possible simultaneous monitoring of multiple athletes.


Motor Control ◽  
2020 ◽  
Vol 24 (1) ◽  
pp. 39-56
Author(s):  
James Hackney ◽  
Jade McFarland ◽  
David Smith ◽  
Clinton Wallis

Most studies of high-speed lower body movements include practice repetitions for facilitating consistency between the trials. We investigated whether 20 repetitions of drop landing (from a 30.5-cm platform onto a force plate) could improve consistency in maximum ground reaction force, linear lower body stiffness, depth of landing, and jump height in 20 healthy, young adults. Coefficient of variation was the construct for variability used to compare the first to the last five repetitions for each variable. We found that the practice had the greatest effect on maximum ground reaction force (p = .017), and had smaller and similar effects on lower body stiffness and depth of landing (p values = .074 and .044, respectively), and no measurable effect on jump height. These findings suggest that the effect of practice on drop landing differs depending upon the variable measure and that 20 repetitions significantly improve consistency in ground reaction force.


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