scholarly journals Effect of jump heights, landing techniques, and participants on vertical ground reaction force and loading rate during landing on three different Korean teeterboards

Author(s):  
Marion Cossin ◽  
Annie Ross ◽  
François Prince

Korean teeterboard is one of the most physically and technically demanding circus disciplines. Two performers take turns jumping vertically and land with high impact. The aims of this study were to (1) compare the stiffness across three different teeterboards, and (2) compare Peak Landing Force (PLF) and Maximal Loading Rate (MLR) of four acrobats performing jumps from three teeterboards using four landing techniques (normal, smooth, straight legs, and empty board). Pressure sensors were used to determine recorded forces under the feet, while Boosted Regression Trees (BRT) was used to analyze factors contributing to PLF and MLR. Standard static loading protocol was used to estimate teeterboard stiffness. PLF and MLR increased with jump height. PLF and MLR were reached when landing on the teeterboard with the highest stiffness. The “normal” and “straight legs” landing techniques were associated with higher PLF and MLR. The BRT model was able to associate both PLF and MLR with jump height, participant, teeterboard, and landing technique factors. PLF reached 13.5 times the body weight when landing on the stiffer teeterboard using the straight legs technique. Trainers should be aware of the injury risk to teeterboard acrobats during landing.

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 957 ◽  
Author(s):  
Anas M. Tahir ◽  
Muhammad E. H. Chowdhury ◽  
Amith Khandakar ◽  
Sara Al-Hamouz ◽  
Merna Abdalla ◽  
...  

Gait analysis is a systematic study of human locomotion, which can be utilized in various applications, such as rehabilitation, clinical diagnostics and sports activities. The various limitations such as cost, non-portability, long setup time, post-processing time etc., of the current gait analysis techniques have made them unfeasible for individual use. This led to an increase in research interest in developing smart insoles where wearable sensors can be employed to detect vertical ground reaction forces (vGRF) and other gait variables. Smart insoles are flexible, portable and comfortable for gait analysis, and can monitor plantar pressure frequently through embedded sensors that convert the applied pressure to an electrical signal that can be displayed and analyzed further. Several research teams are still working to improve the insoles’ features such as size, sensitivity of insoles sensors, durability, and the intelligence of insoles to monitor and control subjects’ gait by detecting various complications providing recommendation to enhance walking performance. Even though systematic sensor calibration approaches have been followed by different teams to calibrate insoles’ sensor, expensive calibration devices were used for calibration such as universal testing machines or infrared motion capture cameras equipped in motion analysis labs. This paper provides a systematic design and characterization procedure for three different pressure sensors: force-sensitive resistors (FSRs), ceramic piezoelectric sensors, and flexible piezoelectric sensors that can be used for detecting vGRF using a smart insole. A simple calibration method based on a load cell is presented as an alternative to the expensive calibration techniques. In addition, to evaluate the performance of the different sensors as a component for the smart insole, the acquired vGRF from different insoles were used to compare them. The results showed that the FSR is the most effective sensor among the three sensors for smart insole applications, whereas the piezoelectric sensors can be utilized in detecting the start and end of the gait cycle. This study will be useful for any research group in replicating the design of a customized smart insole for gait analysis.


2020 ◽  
Vol 29 (5) ◽  
pp. 541-546
Author(s):  
Caroline Lisee ◽  
Tom Birchmeier ◽  
Arthur Yan ◽  
Brent Geers ◽  
Kaitlin O’Hagan ◽  
...  

Context: Landing kinetic outcomes are associated with injury risk and may be persistently altered after anterior cruciate ligament injury or reconstruction. However, it is challenging to assess kinetics clinically. The relationship between sound characteristics and kinetics during a limited number of functional tasks has been supported as a potential clinical alternative. Objective: To assess the relationship between kinetics and sound characteristics during a single-leg landing task. Design: Observational Setting: Laboratory. Participants: There was total of 26 healthy participants (15 males/11 females, age = 24.8 [3.6] y, height = 176.0 [9.1] cm, mass = 74.9 [14.4] kg, Tegner Activity Scale = 6.1 [1.1]). Intervention: Participants completed single-leg landings onto a force plate while audio characteristics were recorded. Main Outcome Measures: Peak vertical ground reaction force, linear loading rate, instantaneous loading rate, peak sound magnitude, sound frequency were measured. Means and SDs were calculated for each participant’s individual limbs. Spearman rho correlations were used to assess the relationships between audio characteristics and kinetic outcomes. Results: Peak sound magnitude was positively correlated with normalized peak vertical ground reaction force (ρ = .486, P = .001); linear loading rate (ρ = .491, P = .001); and instantaneous loading rate (ρ = .298, P = .03). Sound frequency was negatively correlated with instantaneous loading rate (ρ = −.444, P = .001). Conclusions: Peak sound magnitude may be more helpful in providing feedback about an individual’s normalized vertical ground reaction force and linear loading rate, and sound frequency may be more helpful in providing feedback about instantaneous loading rate. Further refinement in sound measurement techniques may be required before these findings can be applied in a clinical population.


2019 ◽  
Vol 47 (4) ◽  
pp. 968-973 ◽  
Author(s):  
J.J. Hannigan ◽  
Christine D. Pollard

Background: A recent study suggested that maximal running shoes may increase the impact force and loading rate of the vertical ground-reaction force during running. It is currently unknown whether runners will adapt to decrease the impact force and loading rate over time. Purpose: To compare the vertical ground-reaction force and ankle kinematics between maximal and traditional shoes before and after a 6-week acclimation period to the maximal shoe. Study Design: Controlled laboratory study. Methods: Participants ran in a traditional running shoe and a maximal running shoe during 2 testing sessions 6 weeks apart. During each session, 3-dimensional kinematics and kinetics were collected during overground running. Variables of interest included the loading rate, impact peak, and active peak of the vertical ground-reaction force, as well as eversion and dorsiflexion kinematics. Two-way repeated measures analyses of variance compared data within participants. Results: No significant differences were observed in any biomechanical variable between time points. The loading rate and impact peak were higher in the maximal shoe. Runners were still everted at toe-off and landed with less dorsiflexion, on average, in the maximal shoe. Conclusion: Greater loading rates and impact forces were previously found in maximal running shoes, which may indicate an increased risk of injury. The eversion mechanics observed in the maximal shoes may also increase the risk of injury. A 6-week transition to maximal shoes did not significantly change any of these measures. Clinical Relevance: Maximal running shoes are becoming very popular and may be considered a treatment option for some injuries. The biomechanical results of this study do not support the use of maximal running shoes. However, the effect of these shoes on pain and injury rates is unknown.


The Knee ◽  
2018 ◽  
Vol 25 (3) ◽  
pp. 398-405 ◽  
Author(s):  
Ronaldo Valdir Briani ◽  
Marcella Ferraz Pazzinatto ◽  
Marina Cabral Waiteman ◽  
Danilo de Oliveira Silva ◽  
Fábio Mícolis de Azevedo

1999 ◽  
Vol 15 (4) ◽  
pp. 404-417 ◽  
Author(s):  
C. Mark Woodard ◽  
Margaret K. James ◽  
Stephen P. Messier

Our purpose was to compare methods of calculating loading rate to the first peak vertical ground reaction force during walking and provide a rationale for the selection of a loading rate algorithm in the analysis of gait in clinical and research environments. Using vertical ground reaction force data collected from 15 older adults with symptomatic knee osteoarthritis and 15 healthy controls, we: (a) calculated loading rate as the first peak vertical force divided by the time from touchdown until the first peak; (b) calculated loading rate as the slope of the least squares regression line using vertical force and time as the dependent and independent variables, respectively; (c) calculated loading rate over discrete intervals using the Central Difference method; and (d) calculated loading rate using vertical force and lime data representing 20% and 90% of the first peak vertical force. The largest loading rate, which may be of greatest clinical importance, occurred when loading rates were calculated using the fewest number of data points. The Central Difference method appeared to maximize our ability to detect differences between healthy and pathologic cohorts. Finally, there was a strong correlation between methods, suggesting that all four methods are acceptable. However, if maximizing the chances of detecting differences between groups is of primary importance, the Central Difference method appears superior.


2013 ◽  
Vol 19 (4) ◽  
pp. 737-745
Author(s):  
Carlos Gabriel Fábrica ◽  
Paula V. González ◽  
Jefferson Fagundes Loss

Parameters associated with the performance of countermovement jumps were identified from vertical ground reaction force recordings during fatigue and resting conditions. Fourteen variables were defined, dividing the vertical ground reaction force into negative and positive external working times and times in which the vertical ground reaction force values were lower and higher than the participant's body weight. We attempted to explain parameter variations by considering the relationship between the set of contractile and elastic components of the lower limbs. We determined that jumping performance is based on impulsion optimization and not on instantaneous ground reaction force value: the time in which the ground reaction force was lower than the body weight, and negative external work time was lower under fatigue. The results suggest that, during fatigue, there is less contribution from elastic energy and from overall active state. However, the participation of contractile elements could partially compensate for the worsening of jumping performance.


2021 ◽  
Author(s):  
Morikawa Masanori ◽  
Maeda Noriaki ◽  
Komiya Makoto ◽  
Kobayashi Toshiki ◽  
Urabe Yukio

Abstract Background: Ankle orthotics decreases the maximal vertical jump height. It is essential to maximize jump height and minimize ground contact time during athletic performance. However, the effect of ankle orthotics on athletic performance has not been reported. We aimed to investigate the effect of ankle orthotics on squat jump (SJ), countermovement jump (CMJ), and repetitive rebound jump (RJ) performance and the relationship between jump performance and restriction in sagittal ankle range of motion. Methods: Twenty healthy volunteers performed SJ, CMJ, repetitive RJ under no-orthosis and two orthotic conditions (orthosis 1 and orthosis 2). During SJ and CMJ, we measured the vertical ground reaction force and calculated the following parameters: jump height, peak vertical ground reaction force, rate of force development, net vertical impulse, and peak power. During repetitive RJ, the jump height, contact time, and RJ index were measured. A two-dimensional motion analysis was used to quantify the ankle range of motion in the sagittal plane during SJ, CMJ, and repetitive RJ. Results: Multivariate analysis of variance and the post hoc test showed a significant decrease in the vertical jump height (p = 0.003), peak power (p = 0.007), and maximum plantarflexion and dorsiflexion angles (p <0.001) during SJ using orthosis 2 compared to those using the no-orthosis condition. Additionally, orthosis 2 significantly decreased the jump height at the end of repetitive RJ (p = 0.046), during which a significant negative correlation was found between jump height and maximum dorsiflexion angle (r = 0.485, p = 0.030). Conclusions: An ankle orthosis-induced restriction of dorsiflexion is associated with a reduction in jump height during static jump and repetitive RJ performance.


2015 ◽  
Vol 49 (4) ◽  
pp. 173-181
Author(s):  
KA Thiagarajan ◽  
Tvisha Parikh ◽  
Anees Sayed ◽  
MB Gnanavel ◽  
S Arumugam

ABSTRACT Cricket fast bowling action involves complex three-dimensional (3D) motion of the body and poses a high risk of injury more so in schoolboys. It is not known how the bowling technique varies between skilled and less skilled fast bowlers. The aim of this study is to compare the differences in bowling technique between young sub-elite (skilled) and amateur university level cricketers. Twelve players, 6 skilled and six amateur, were attached with 35 retro-reflective markers using the full body Plug-in-Gait marker set and asked to bowl 6 deliveries at a good length. Their bowling action was captured with 12 Vicon 3D cameras and the ground reaction force was measured using AMTI force plates. The best delivery from each bowler was selected. Their bowling action types were classified and parameters like shoulder counter rotation (scr), pelvicshoulder separation angle at back foot contact, trunk lateral flexion, front knee angle, front foot vertical ground reaction force (vGRF) and ball release speed were measured. The results were analyzed with Levene's test for Equality of Variances and a t-test for equality of means. The skilled bowlers showed faster ball release speed and experienced larger vGRF while the other parameters did not show any significant differences. How to cite this article Thiagarajan KA, Parikh T, Sayed A, Gnanavel MB, Arumugam S. Cricket Biomechanics Analysis of Skilled and Amateur Fast Bowling Techniques. J Postgrad Med Edu Res 2015;49(4):173-181.


2020 ◽  
pp. 1-12
Author(s):  
Landon B. Lempke ◽  
Jeonghoon Oh ◽  
Rachel S. Johnson ◽  
Julianne D. Schmidt ◽  
Robert C. Lynall

Context: Laboratory-based movement assessments are commonly performed without cognitive stimuli (ie, single-task) despite the simultaneous cognitive processing and movement (ie, dual task) demands required during sport. Cognitive loading may critically alter human movement and be an important consideration for truly assessing functional movement and understanding injury risk in the laboratory, but limited investigations exist. Objective: To comprehensively examine and compare kinematics and kinetics between single- and dual-task functional movement among healthy participants while controlling for sex. Design: Cross-sectional study. Setting: Laboratory. Patients (or Other Participants): Forty-one healthy, physically active participants (49% female; 22.5 ± 2.1 y; 172.5 ± 11.9 cm; 71.0 ± 13.7 kg) enrolled in and completed the study. Intervention(s): All participants completed the functional movement protocol under single- and dual-task (subtracting by 6s or 7s) conditions in a randomized order. Participants jumped forward from a 30-cm tall box and performed (1) maximum vertical jump landings and (2) dominant and (3) nondominant leg, single-leg 45° cuts after landing. Main Outcome Measures: The authors used mixed-model analysis of variances (α = .05) to compare peak hip, knee, and ankle joint angles (degrees) and moments (N·m/BW) in the sagittal and frontal planes, and peak vertical ground reaction force (N/BW) and vertical impulse (Ns/BW) between cognitive conditions and sex. Results: Dual-task resulted in greater peak vertical ground reaction force compared with single-task during jump landing (mean difference = 0.06 N/BW; 95% confidence interval [CI], 0.01 to 0.12; P = .025) but less force during dominant leg cutting (mean difference = −0.08 N/BW; 95% CI, −0.14 to −0.02; P = .015). Less hip-flexion torque occurred during dual task than single task (mean difference = −0.09 N/BW; 95% CI, −0.17 to −0.02). No other outcomes were different between single and dual task (P ≥ .053). Conclusions: Slight, but potentially important, kinematic and kinetic differences were observed between single- and dual-task that may have implications for functional movement assessments and injury risk research. More research examining how various cognitive and movement tasks interact to alter functional movement among pathological populations is warranted before clinical implementation.


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