scholarly journals Effects of Different Surface Coefficient of Restitution and Drop Height on Vertical Ground Reaction Force, Joint Angular Velocity, Moment and Muscle Activity during Drop Landing

2013 ◽  
Vol 15 (2) ◽  
pp. 127-138
Author(s):  
이진석 ◽  
Sungjin Yoon ◽  
김창균
Keyword(s):  
Angular Velocity ◽  
Ground Reaction Force ◽  
Muscle Activity ◽  
Reaction Force ◽  
Coefficient Of Restitution ◽  
Drop Height ◽  
Vertical Ground Reaction Force ◽  
Drop Landing ◽  
Vertical Ground ◽  
Velocity Moment

scholarly journals Peak Vertical Ground Reaction Force during Two-Leg Landing: A Systematic Review and Mathematical Modeling

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Wenxin Niu ◽  
Tienan Feng ◽  
Chenghua Jiang ◽  
Ming Zhang
Keyword(s):  
Mathematical Modeling ◽  
Systematic Review ◽  
Mathematical Model ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Influence Factors ◽  
Vertical Ground Reaction Force ◽  
Surface Stiffness ◽  
Drop Landing ◽  
Vertical Ground

Objectives. (1) To systematically review peak vertical ground reaction force (PvGRF) during two-leg drop landing from specific drop height (DH), (2) to construct a mathematical model describing correlations between PvGRF and DH, and (3) to analyze the effects of some factors on the pooled PvGRF regardless of DH.Methods. A computerized bibliographical search was conducted to extract PvGRF data on a single foot when participants landed with both feet from various DHs. An innovative mathematical model was constructed to analyze effects of gender, landing type, shoes, ankle stabilizers, surface stiffness and sample frequency on PvGRF based on the pooled data.Results. Pooled PvGRF and DH data of 26 articles showed that the square root function fits their relationship well. An experimental validation was also done on the regression equation for the medicum frequency. The PvGRF was not significantly affected by surface stiffness, but was significantly higher in men than women, the platform than suspended landing, the barefoot than shod condition, and ankle stabilizer than control condition, and higher than lower frequencies.Conclusions. The PvGRF and root DH showed a linear relationship. The mathematical modeling method with systematic review is helpful to analyze the influence factors during landing movement without considering DH.

A Subject Specific Kinematic and Kinetic Relationship During a Single-Leg Drop Landing

2012 ◽  
Author(s):  
Chi-Yin Tse ◽  
Hamid Nayeb-Hashemi ◽  
Ashkan Vaziri ◽  
Paul K. Canavan
Keyword(s):  
Ground Reaction Force ◽  
Knee Flexion ◽  
Reaction Force ◽  
Vertical Ground Reaction Force ◽  
Valgus Angle ◽  
Drop Landing ◽  
Average Maximum ◽  
Significant Difference ◽  
Subject Specific ◽  
Vertical Ground

A single-leg landing is a common type of high-risk maneuver performed by athletes. The majority of anterior cruciate ligament injury is accounted for by non-contact mechanisms, such as single-leg landings. The purpose of this study was to develop a subject specific single-leg drop landing to analyze the kinematics and kinetics of two different types of landings. Kinematic data was analyzed at five points during the landing phase: initial contact (IC), peak vertical ground reaction force (pVGRF), peak joint reaction force (pJRF), maximum knee flexion (MKF), and maximum valgus angle (MFP). A linear relationship was noted in comparing the average maximum peak vertical ground reaction force, average maximum knee flexion, and average maximum valgus angle to the platform heights in both landing styles. An increase in platform height was directly related to increased knee valgus angle in both landing styles. Significant difference (p < 0.05) was noted in the peak vertical ground reaction force between the 60% and 80% platform heights, as well as between 60% and 100% with arms above. Landing with arms across the body yielded more significant difference (p < 0.05) between platform heights in both frontal and sagittal planes. However, comparing both landing styles to each other only yielded significant difference (p < 0.05) at the 100% platform height. A valgus-varus-valgus movement was observed in all landings, and is a probable contributor to single-leg landing ACL ruptures.

scholarly journals Variable Heights Influence Lower Extremity Biomechanics and Reactive Strength Index during Drop Jump: An Experimental Study of Male High Jumpers

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Zehao Tong ◽  
Feng Zhai ◽  
Hang Xu ◽  
Wenjia Chen ◽  
Jiesheng Cui
Keyword(s):  
Lower Extremity ◽  
Hip Joint ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Lower Limbs ◽  
Drop Height ◽  
Strength Index ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground ◽  
Biomechanical Parameters

Introduction. This study finds the lower limbs’ reactive strength index and biomechanical parameters on variable heights. Objective. This research aims to reveal the effects of drop height on lower limbs’ reactive strength index and biomechanical parameters. Methods. Two AMTI force platforms and Vicon motion capture system were used to collect kinematic and dynamic signals of the lower limbs. Results. The drop height had significant effects on peak vertical ground reaction force and peak vertical ground reaction force in the extension phase, lower limbs’ support moment, eccentric power of the hip joint, eccentric power of the knee joint, eccentric power of the ankle joint, and concentric power of the hip joint. The drop height had no significant effects on the reactive strength index. Reactive strength index (RSI) had no significant correlations with the personal best of high jumpers. The optimal loading height for the maximum reactive strength index was 0.45 m. Conclusion. The optimal loading height for the reactive strength index can be used for explosive power training and lower extremity injury prevention.

Effects of Toe Direction on Biomechanics of Trunk, Pelvis, and Lower-Extremity During Single-Leg Drop Landing

2020 ◽  
Vol 29 (8) ◽  
pp. 1069-1074
Author(s):  
Aiko Sakurai ◽  
Kengo Harato ◽  
Yutaro Morishige ◽  
Shu Kobayashi ◽  
Yasuo Niki ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Repeated Measures ◽  
Reaction Force ◽  
Abduction Angle ◽  
Vertical Ground Reaction Force ◽  
Knee Ligament ◽  
Drop Landing ◽  
Peak Knee ◽  
Knee Abduction ◽  
Vertical Ground

Context: Toe direction is an important factor affecting knee biomechanics during various movements. However, it is still unknown whether toe direction will affect trunk and pelvic movements. Objective: To examine and clarify the effects of toe directions on biomechanics of trunk and pelvis as well as lower-extremities during single-leg drop landing (SLDL). Design: Descriptive laboratory study. Setting: Research laboratory. Participants: A total of 27 male recreational-level athletes. Intervention(s): Subjects performed SLDL under 3 different toe directions, including 0° (toe neutral), 20° (toe-in [TI]), and −20° (toe-out). SLDL was captured using a motion analysis system. Nondominant leg (27 left) was chosen for the analysis. Main Outcome Measures: Peak values of kinematic and kinetic parameters during landing phase were assessed. In addition, those parameters at the timing of peak vertical ground reaction force were also assessed. The data were statistically compared among 3 different toe directions using 1-way repeated measures of analysis of variance or Friedman χ2 r test. Results: Peak knee abduction angle and moment in TI were significantly larger than in toe neutral and toe-out (P < .001). Moreover, peak greater anterior inclination, greater inclination, and rotation of trunk and pelvis toward the nonlanding side were seen in TI (P < .001). At the timing of peak vertical ground reaction force, trunk inclined to the landing side with larger knee abduction angle in TI (P < .001). Conclusions: Several previous studies suggested that larger knee abduction angle and moment on landing side as well as trunk and pelvic inclinations during landing tasks were correlated with knee ligament injury. However, it is still unknown concerning the relationship between toe direction and trunk/pelvis movements during landing tasks. From the present study, TI during SLDL would strongly affect biomechanics of trunk and pelvis as well as knee joint, compared with toe neutral and toe-out.

Neuromuscular and Biomechanical Adaptations of Patients with Isolated Deficiency of the Posterior Cruciate Ligament

2005 ◽  
Vol 33 (7) ◽  
pp. 982-989 ◽  
Author(s):  
Cristián A. Fontboté ◽  
Timothy C. Sell ◽  
Kevin G. Laudner ◽  
Marcus Haemmerle ◽  
Christina R. Allen ◽  
...  
Keyword(s):  
Posterior Cruciate Ligament ◽  
Ground Reaction Force ◽  
Cruciate Ligament ◽  
Reaction Force ◽  
Control Group ◽  
Vertical Ground Reaction Force ◽  
Drop Landing ◽  
Grade Ii ◽  
Vertical Ground ◽  
Deficient Group

Background Functional adaptations of patients with posterior cruciate ligament deficiency (grade II) are largely unknown despite increased recognition of this injury. Hypothesis Posterior cruciate ligament-deficient subjects (grade II, 6- to 10-mm bilateral difference in posterior translation) will present with neuromuscular and biomechanical adaptations to overcome significant mechanical instability during gait and drop-landing tasks. Study Design Controlled laboratory study. Methods Bilateral comparisons were made among 10 posterior cruciate ligament-deficient subjects using radiographic, instrumented laxity, and range of motion examinations. Biomechanical and neuromuscular characteristics of the involved limb of the posterior cruciate ligament-deficient subjects were compared to their uninvolved limb and to 10 matched control subjects performing gait and drop-landing tasks. Results Radiographic (15.3 ± 2.9 to 5.6 ± 3.7 mm; P =. 008) and instrumented laxity (6.3 ± 2.0 to 1.4 ± 0.5 mm; P <. 001) examinations demonstrated significantly greater posterior displacement of the involved knee within the posterior cruciate ligament-deficient group. The posterior cruciate ligament-deficient group had a significantly decreased maximum knee valgus moment and greater vertical ground reaction force at midstance during gait compared to the control group. During vertical landings, the posterior cruciate ligament-deficient group demonstrated a significantly decreased vertical ground reaction force loading rate. All other analyses reported no significant differences within or between groups. Conclusion Posterior cruciate ligament-deficient subjects demonstrate minimal biomechanical and neuromuscular differences despite significant clinical laxity. Clinical Relevance The findings of this study indicate that individuals with grade II posterior cruciate ligament injuries are able to perform gait and drop-landing activities similar to a control group without surgical intervention.

scholarly journals Running ground reaction forces across footwear conditions are predicted from the motion of two body mass components

2019 ◽  
Vol 126 (5) ◽  
pp. 1315-1325 ◽  
Author(s):  
Andrew B. Udofa ◽  
Kenneth P. Clark ◽  
Laurence J. Ryan ◽  
Peter G. Weyand
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Time Patterns ◽  
Foot Strike ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Force Time

Although running shoes alter foot-ground reaction forces, particularly during impact, how they do so is incompletely understood. Here, we hypothesized that footwear effects on running ground reaction force-time patterns can be accurately predicted from the motion of two components of the body’s mass (mb): the contacting lower-limb (m1 = 0.08mb) and the remainder (m2 = 0.92mb). Simultaneous motion and vertical ground reaction force-time data were acquired at 1,000 Hz from eight uninstructed subjects running on a force-instrumented treadmill at 4.0 and 7.0 m/s under four footwear conditions: barefoot, minimal sole, thin sole, and thick sole. Vertical ground reaction force-time patterns were generated from the two-mass model using body mass and footfall-specific measures of contact time, aerial time, and lower-limb impact deceleration. Model force-time patterns generated using the empirical inputs acquired for each footfall matched the measured patterns closely across the four footwear conditions at both protocol speeds ( r2 = 0.96 ± 0.004; root mean squared error  = 0.17 ± 0.01 body-weight units; n = 275 total footfalls). Foot landing angles (θF) were inversely related to footwear thickness; more positive or plantar-flexed landing angles coincided with longer-impact durations and force-time patterns lacking distinct rising-edge force peaks. Our results support three conclusions: 1) running ground reaction force-time patterns across footwear conditions can be accurately predicted using our two-mass, two-impulse model, 2) impact forces, regardless of foot strike mechanics, can be accurately quantified from lower-limb motion and a fixed anatomical mass (0.08mb), and 3) runners maintain similar loading rates (ΔFvertical/Δtime) across footwear conditions by altering foot strike angle to regulate the duration of impact. NEW & NOTEWORTHY Here, we validate a two-mass, two-impulse model of running vertical ground reaction forces across four footwear thickness conditions (barefoot, minimal, thin, thick). Our model allows the impact portion of the impulse to be extracted from measured total ground reaction force-time patterns using motion data from the ankle. The gait adjustments observed across footwear conditions revealed that runners maintained similar loading rates across footwear conditions by altering foot strike angles to regulate the duration of impact.

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