scholarly journals Asymmetry Indices in Female Runners as Predictors of Running Velocity

2019 ◽  
Vol 26 (3) ◽  
pp. 3-8 ◽  
Author(s):  
Piotr Tabor ◽  
Andrzej Mastalerz ◽  
Dagmara Iwańska ◽  
Olga Grabowska
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Vertical Jump ◽  
Reaction Force ◽  
Vertical Component ◽  
Distance Runners ◽  
Training Experience ◽  
Time Symmetry ◽  
Lower Limb Muscles ◽  
Support Phase

AbstractIntroduction. This paper aimed to establish relationships between the level of functional and dynamic asymmetry in advanced and intermediate-level runners and running velocity. Furthermore, evaluation of dynamic symmetry (running and vertical jump) was made using indices, taking into account the continuous character of the signals of the ground reaction force and angular positions in individual joints of the lower limb.Material and methods. Symmetry was assessed in a group of 12 Polish elite female middle-distance runners for the following parameters: 1) strength of lower limb muscles, 2) impulse of the vertical component of the ground reaction force during a CMJ jump, and 3) kinematics of a 50-m run in a straight line.Results. More advanced athletes (group A) were significantly taller and stronger than the athletes with less training experience (B). They were also characterized by a significantly longer step, a more extended swing phase, and a shorter support phase. There were no statistically significant differences between groups A and B in the level of asymmetry. Running velocity was significantly influenced by muscle strength symmetry (b = −5.77; p < 0.01) and support phase time symmetry (b = −6.64; p < 0.03). A reduction in each of these indices leads to an increase in running velocity.Conclusion. No morphological or functional asymmetry was found in female middle-distance runners with different training experience.

Short-Term Effects of Kinesio Taping on Muscle Recruitment Order During a Vertical Jump: A Pilot Study

2018 ◽  
Vol 27 (4) ◽  
pp. 319-326 ◽  
Author(s):  
Guillermo Mendez-Rebolledo ◽  
Rodrigo Ramirez-Campillo ◽  
Eduardo Guzman-Muñoz ◽  
Valeska Gatica-Rojas ◽  
Alexis Dabanch-Santis ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Vertical Jump ◽  
Reaction Force ◽  
Countermovement Jump ◽  
Short Term ◽  
Male Athletes ◽  
Squat Jump ◽  
Kinesio Taping ◽  
Recruitment Order

Context: Kinesio taping is commonly used in sports and rehabilitation settings with the aim of prevention and treatment of musculoskeletal injuries. However, limited evidence exists regarding the effects of 24 and 72 hours of kinesio taping on trunk and lower limb neuromuscular and kinetic performance during a vertical jump. Objective: The purpose of this study was to analyze the short-term effects of kinesio taping on height and ground reaction force during a vertical jump, in addition to trunk and lower limb muscle latency and recruitment order. Design: Single-group pretest–posttest. Setting: University laboratory. Participants: Twelve male athletes from different sports (track and field, basketball, and soccer). Interventions: They completed a single squat and countermovement jump at basal time (no kinesio taping), 24, and 72 hours of kinesio taping application on the gluteus maximus, biceps femoris, rectus femoris, gastrocnemius medialis, and longissimus. Main Outcome Measures: Muscle onset latencies were assessed by electromyography during a squat and countermovement jump, in addition to measurements of the jump height and normalized ground reaction force. Results: The kinesio taping had no effect after 24 hours on either the countermovement or squat jump. However, at 72 hours, the kinesio taping increased the jump height (P = .02; d = 0.36) and normalized ground reaction force (P = .001; d = 0.45) during the countermovement jump. In addition, 72-hour kinesio taping reduced longissimus onset latency (P = .03; d = 1.34) and improved muscle recruitment order during a countermovement jump. Conclusions: These findings suggest that kinesio taping may improve neuromuscular and kinetic performance during a countermovement jump only after 72 hours of application on healthy and uninjured male athletes. However, no changes were observed on a squat jump. Future studies should incorporate a control group to verify kinesio taping’s effects and its influence on injured athletes.

scholarly journals The Influence of an Additional Load on Time and Force Changes in the Ground Reaction Force During the Countermovement Vertical Jump

2013 ◽  
Vol 38 ◽  
pp. 191-200 ◽  
Author(s):  
Frantisek Vaverka ◽  
Zlatava Jakubsova ◽  
Daniel Jandacka ◽  
David Zahradnik ◽  
Roman Farana ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Repeated Measures ◽  
Vertical Jump ◽  
Reaction Force ◽  
Force Plate ◽  
Total Duration ◽  
Vertical Component ◽  
Acceleration Phase ◽  
Additional Load ◽  
Relationship Of

Abstract The aim of this study was to determine how an additional load influences the force-vs-time relationship of the countermovement vertical jump (CMVJ). The participants that took part in the experiment were 18 male university students who played sport recreationally, including regular games of volleyball. They were asked to perform a CMVJ without involving the arms under four conditions: without and with additional loads of 10%, 20%, and 30% of their body weight (BW). The vertical component of the ground reaction force (GRF) was measured by a force plate. The GRF was used to calculate the durations of the preparatory, braking, and acceleration phases, the total duration of the jump, force impulses during the braking and acceleration phases, average forces during the braking and acceleration phases, and the maximum force of impact at landing. Results were evaluated using repeated-measures ANOVA. Increasing the additional load prolonged both the braking and acceleration phases of the jump, with statistically significant changes in the duration of the acceleration phase found for an additional load of 20% BW. The magnitude of the force systematically and significantly increased with the additional load. The force impulse during the acceleration phase did not differ significantly between jumps performed with loads of 20% and 30% BW. The results suggest that the optimal additional load for developing explosive strength in vertical jumping ranges from 20% to 30% of BW, with this value varying between individual subjects.

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.

scholarly journals Muscle forces and the demands of human walking

Biology Open ◽  
2021 ◽  
Vol 10 (7) ◽  
Author(s):  
Adam D. Sylvester ◽  
Steven G. Lautzenheiser ◽  
Patricia Ann Kramer
Keyword(s):  
Lower Limb ◽  
Reaction Force ◽  
The Body ◽  
Muscle Forces ◽  
Skeletal Morphology ◽  
Lower Limb Muscles ◽  
Fossil Hominins ◽  
Force Curves ◽  
Behavior Function ◽  
The Relationship

ABSTRACT Reconstructing the locomotor behavior of extinct animals depends on elucidating the principles that link behavior, function, and morphology, which can only be done using extant animals. Within the human lineage, the evolution of bipedalism represents a critical transition, and evaluating fossil hominins depends on understanding the relationship between lower limb forces and skeletal morphology in living humans. As a step toward that goal, here we use a musculoskeletal model to estimate forces in the lower limb muscles of ten individuals during walking. The purpose is to quantify the consistency, timing, and magnitude of these muscle forces during the stance phase of walking. We find that muscles which act to support or propel the body during walking demonstrate the greatest force magnitudes as well as the highest consistency in the shape of force curves among individuals. Muscles that generate moments in the same direction as, or orthogonal to, the ground reaction force show lower forces of greater variability. These data can be used to define the envelope of load cases that need to be examined in order to understand human lower limb skeletal load bearing.

scholarly journals Ground reaction force patterns during gait in patients with lower limb lymphedema

2016 ◽  
Vol 23 (4) ◽  
Author(s):  
Isabel Forner-Cordero ◽  
Fabianne Furtado ◽  
Juan Cervera-Deval ◽  
Arturo Forner-Cordero
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Reaction Force

scholarly journals Effectiveness of Insole Colour on Impact Loading and Lower-Limb Kinematics When Running at Preferred and Nonpreferred Speeds

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Yi Wang ◽  
Wing-Kai Lam ◽  
Lok-Yee Pak ◽  
Charis K.-W. Wong ◽  
Mohammad F. Tan ◽  
...  
Keyword(s):  
Impact Loading ◽  
Ground Reaction Force ◽  
Lower Limb ◽  
Repeated Measures ◽  
Loading Rate ◽  
Reaction Force ◽  
Human Perception ◽  
Movement Variability ◽  
Mean Values ◽  
Maximum Loading

While colour of red can play a significant role in altering human perception and performances, little is known about its perceptual-motor effect on running mechanics. This study examined the effects of variations in insole colours on impact forces, ankle kinematics, and trial-to-trial reliability at various running speeds. Sixteen male recreational runners ran on instrumented treadmill at slow (90%), preferred (100%), and fast (110%) running speeds when wearing insoles in red, blue, and white colours. We used synchronized force platform and motion capturing system to measure ground reaction force, ankle sagittal and frontal kinematics, and movement variability. A two-way (colour x speed) ANOVA with repeated measures was performed with Bonferroni adjusted post hoc comparisons, with alpha set at 0.05. Data analyses indicated that participants demonstrated higher impact and maximum loading rate of ground reaction force, longer stride length, shorter contact time, and smaller touchdown ankle inversion as well as larger ankle sagittal range of motion (RoM), but smaller frontal RoM in fast speed as compared with preferred P < 0.05 and slow speeds P < 0.001 . Although insole colour had minimal effect on mean values of any tested variables P > 0.05 , participants wearing red-coloured orthoses showed higher coefficient of variation values for maximum loading rate than wearing blue insoles P = 0.009 . These results suggest that running at faster speed would lead to higher impact loading and altered lower-limb mechanics and that colour used on the tops of insoles influences the wearers’ movement repeatability, with implications for use of foot insole in running.

scholarly journals Segmental contributions to the ground reaction force in the single support phase of gait

2014 ◽  
Vol 5 (2) ◽  
pp. 37-52 ◽  
Author(s):  
D. S. Mohan Varma ◽  
S. Sujatha
Keyword(s):  
Ground Reaction Force ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Center Of Mass ◽  
Reaction Force ◽  
Experimental Studies ◽  
Vertical Component ◽  
Frontal Plane ◽  
Mathematical Form ◽  
Dynamics Models

Abstract. An inverse dynamics model for the single support (SS) phase of gait is developed to study segmental contributions to the ground reaction force (GRF). With segmental orientations as the generalized degrees of freedom (DOF), the acceleration of the body's center-of-mass is expressed analytically as the summation of the weighted kinematics of individual segments. The weighting functions are constants that are functions of the segment masses and center-of-mass distances. Using kinematic and anthropometric data from literature as inputs, and using the roll-over-shape (ROS) to model the foot-ground interaction, GRF obtained from the inverse model are compared with measured GRF data from literature. The choice of the generalized coordinates and mathematical form of the model provides a means to weigh individual segment contributions, simplify models and choose more kinetically accurate inverse dynamics models. For the kinematic data used, an anthropomorphic model that includes the frontal plane rotation of the pelvis in addition to the sagittal DOF of the thigh and shank most accurately captures the vertical component of the GRF in the SS phase of walking. Of the two ROS used, the ankle-foot roll-over shape provides a better approximation of the kinetics in the SS phase. The method presented here can be used with additional experimental studies to confirm these results.

scholarly journals A Smart Terrain Identification Technique Based on Electromyography, Ground Reaction Force, and Machine Learning for Lower Limb Rehabilitation

2020 ◽  
Vol 10 (8) ◽  
pp. 2638 ◽  
Author(s):  
Shuo Gao ◽  
Yixuan Wang ◽  
Chaoming Fang ◽  
Lijun Xu
Keyword(s):  
Machine Learning ◽  
Ground Reaction Force ◽  
Lower Limb ◽  
Confusion Matrix ◽  
Reaction Force ◽  
Simple System ◽  
Support Vector ◽  
Terrain Classification ◽  
Limb Rehabilitation ◽  
Lower Limb Rehabilitation

Automatic terrain classification in lower limb rehabilitation systems has gained worldwide attention. In this field, a simple system architecture and high classification accuracy are two desired attributes. In this article, a smart neuromuscular–mechanical fusion and machine learning-based terrain classification technique utilizing only two electromyography (EMG) sensors and two ground reaction force (GRF) sensors is reported for classifying three different terrains (downhill, level, and uphill). The EMG and GRF signals from ten healthy subjects were collected, preprocessed and segmented to obtain the EMG and GRF profiles in each stride, based on which twenty-one statistical features, including 9 GRF features and 12 EMG features, were extracted. A support vector machine (SVM) machine learning model is established and trained by the extracted EMG features, GRF features and the fusion of them, respectively. Several methods or statistical metrics were used to evaluate the goodness of the proposed technique, including a paired-t-test and Kruskal–Wallis test for correlation analysis of the selected features and ten-fold cross-validation accuracy, confusion matrix, sensitivity and specificity for the performance of the SVM model. The results show that the extracted features are highly correlated with the terrain changes and the fusion of the EMG and GRF features produces the highest accuracy of 96.8%. The presented technique allows simple system construction to achieve the precise detection of outcomes, potentially advancing the development of terrain classification techniques for rehabilitation.

Sign in / Sign up

Export Citation Format

Share Document