scholarly journals A Three-Dimensional Mass-Spring Walking Model Could Describe the Ground Reaction Forces

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Huiqi Liang ◽  
Wenbo Xie ◽  
Zhiqiang Zhang ◽  
Peizi Wei ◽  
Changhui Cui
Keyword(s):  
Experimental Data ◽  
Three Dimensional ◽  
Bipedal Walking ◽  
Ground Reaction Forces ◽  
Dynamic Parameters ◽  
Nonlinear Dynamic Model ◽  
Lateral Direction ◽  
Reaction Forces ◽  
The Impact ◽  
2D Model

The oscillatory behavior of the center of mass (CoM) and the ground reaction forces (GRFs) of walking people can be successfully explained by a 2D spring-loaded inverted pendulum (SLIP) model. However, the application of the 2D model is just restricted to a two-dimensional plane as the model fails to take the GRFs in the lateral direction into consideration. In this article, we simulated the gait cycle with a nonlinear dynamic model—a three-dimensional bipedal walking model—that compensated for defects in the 2D model. An experiment was conducted to compare the simulation results with the experimental data, which revealed that the experimental data of the ground reaction forces were in good agreement with the results of numerical simulation. A correlation analysis was also conducted between several initial dynamic parameters of the model. Through an examination of the impact of 3D dynamic parameters on the peaks of GRFs in three directions, we found that the 3D parameters had a major effect on the lateral GRFs. These findings demonstrate that the characteristics of human walking can be interpreted from a simple spring-damper system.

A Technique to Evaluate Foot Function During the Stance Phase of Gait

1995 ◽  
Vol 16 (12) ◽  
pp. 764-770 ◽  
Author(s):  
Karen Lohmann Siegel ◽  
Thomas M. Kepple ◽  
Paul G. O'Connell ◽  
Lynn H. Gerber ◽  
Steven J. Stanhope
Keyword(s):  
Stance Phase ◽  
Center Of Pressure ◽  
Three Dimensional ◽  
Ground Reaction Forces ◽  
Coordinate Systems ◽  
Future Studies ◽  
Case Examples ◽  
Reaction Forces ◽  
Foot Function ◽  
The Impact

A technique to measure foot function during the stance phase of gait is described. Advantages of the method include its three-dimensional approach with anatomically based segment coordinate systems. This allows variables such as ground reaction forces and center of pressure location to be expressed in a local foot coordinate system, which gives more anatomical meaning to the interpretation of results. Application of the measurement technique to case examples of patients with rheumatoid arthritis demonstrated its ability to discriminate normal from various levels of pathological function. Future studies will utilize this technique to study the impact of pathology and treatment on foot function.

scholarly journals The Effects of Posture on the Three-Dimensional Gait Mechanics of Human Walking in Comparison to Bipedal Chimpanzees

2021 ◽  
Author(s):  
Russell T. Johnson ◽  
Matthew C. O'Neill ◽  
Brian R. Umberger
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Three Dimensional ◽  
Bipedal Walking ◽  
Human Walking ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Gait Mechanics ◽  
Reaction Forces ◽  
Vertical Ground

Humans walk with an upright posture on extended limbs during stance and with a double-peaked vertical ground reaction force. Our closest living relatives, chimpanzees, are facultative bipeds that walk with a crouched posture on flexed, abducted hind limbs and with a single-peaked vertical ground reaction force. Differences in human and bipedal chimpanzee three-dimensional kinematics have been well quantified; however, it is unclear what the independent effects of using a crouched posture are on three-dimensional gait mechanics for humans, and how they compare with chimpanzees. Understanding the relationships between posture and gait mechanics, with known differences in morphology between species, can help researchers better interpret the effects of trait evolution on bipedal walking. We quantified pelvis and lower limb three-dimensional kinematics and ground reaction forces as humans adopted a series of upright and crouched postures and compared them with data from bipedal chimpanzee walking. Human crouched posture gait mechanics were more similar to bipedal chimpanzee gait than normal human walking, especially in sagittal plane hip and knee angles. However, there were persistent differences between species, as humans walked with less transverse plane pelvis rotation, less hip abduction, and greater peak horizontal ground reaction force in late stance than chimpanzees. Our results suggest that human crouched posture walking reproduces only a small subset of the characteristics of three-dimensional kinematics and ground reaction forces of chimpanzee walking, with the remaining differences likely due in large part to the distinct musculoskeletal morphologies of humans and chimpanzees.

scholarly journals Ground Reaction Forces of Dressage Horses Performing the Piaffe

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 436 ◽  
Author(s):  
Hilary Mary Clayton ◽  
Sarah Jane Hobbs
Keyword(s):  
Coefficient Of Variation ◽  
Three Dimensional ◽  
Individual Variability ◽  
The Other ◽  
Ground Reaction Forces ◽  
High Coefficient ◽  
Reaction Forces

The piaffe is an artificial, diagonally coordinated movement performed in the highest levels of dressage competition. The ground reaction forces (GRFs) of horses performing the piaffe do not appear to have been reported. Therefore, the objective of this study was to describe three-dimensional GRFs in ridden dressage horses performing the piaffe. In-ground force plates were used to capture fore and hindlimb GRF data from seven well-trained dressage horses. Peak vertical GRF was significantly higher in forelimbs than in the hindlimbs (7.39 ± 0.99 N/kg vs. 6.41 ± 0.64 N/kg; p < 0.001) with vertical impulse showing a trend toward higher forelimb values. Peak longitudinal forces were small with no difference in the magnitude of braking or propulsive forces between fore and hindlimbs. Peak transverse forces were similar in magnitude to longitudinal forces and were mostly directed medially in the hindlimbs. Both the intra- and inter-individual variability of longitudinal and transverse GRFs were high (coefficient of variation 25–68%). Compared with the other diagonal gaits of dressage horses, the vertical GRF somewhat shifted toward the hindlimbs. The high step-to-step variability of the horizontal GRF components is thought to reflect the challenge of balancing on one diagonal pair of limbs with no forward momentum.

Footwear and Elevated Heel Influence On Barbell Back Squat: a Review

2021 ◽  
Author(s):  
Aaron Michael Pangan ◽  
Matthew J Leineweber
Keyword(s):  
Ground Reaction Forces ◽  
Specific Effects ◽  
Back Squat ◽  
Running Shoes ◽  
Different Types ◽  
Reaction Forces ◽  
Joint Loads ◽  
The Impact ◽  
Kinematics And Kinetics ◽  
Full Body

Abstract The back squat is one of the most effective exercises in strengthening the muscles of the lower extremity. Understanding the impact of footwear has on the biomechanics is imperative for maximizing the exercise training potential, preventing injury, and rehabilitating from injury. This review focuses on how different types of footwear affect the full-body kinematics, joint loads, muscle activity, and ground reaction forces in athletes of varying experience performing the weighted back squat. The literature search was conducted using three databases, and fourteen full-text articles were ultimately included in the review. The majority of these studies demonstrated that the choice of footwear directly impacts kinematics and kinetics. Weightlifting shoes were shown to decrease trunk lean and generate more plantarflexion relative to running shoes and barefoot lifting. Elevating the heel through the use of external squat wedges is popular clinical exercise during rehabilitation and was shown to provide similar effects to WLS. Additional research with a broader array of populations, particularly novice and female weightlifters, should be conducted to generalize the research results to non-athlete populations. Further work is also needed to characterize the specific effects of sole stiffness and heel elevation height on squatting mechanics.

Reliable and Accurate Prediction of Three-Dimensional Separation in Asymmetric Diffusers Using Large-Eddy Simulation

2009 ◽  
Author(s):  
Hayder Schneider ◽  
Dominic von Terzi ◽  
Hans-Jo¨rg Bauer ◽  
Wolfgang Rodi
Keyword(s):  
Experimental Data ◽  
Reverse Flow ◽  
Separation Bubble ◽  
Pressure Coefficient ◽  
Three Dimensional ◽  
Large Eddy Simulations ◽  
Navier Stokes ◽  
Eddy Simulation ◽  
Large Eddy ◽  
The Impact

Reynolds-Averaged Navier-Stokes (RANS) calculations and Large-Eddy Simulations (LES) of the flow in two asymmetric three-dimensional diffusers were performed. The numerical setup was chosen to be in compliance with previous experiments. The aim of the present study is to find the least expensive method to compute reliably and accurately the impact of geometric sensitivity on the flow. RANS calculations fail to predict both the extent and location of the three-dimensional separation bubble. In contrast, LES is able to determine the amount of reverse flow and the pressure coefficient within the accuracy of experimental data.

Magnitude and Spatial Distribution of Impact Intensity Under the Foot Relates to Initial Foot Contact Pattern

2017 ◽  
Vol 33 (6) ◽  
pp. 431-436 ◽  
Author(s):  
Bastiaan Breine ◽  
Philippe Malcolm ◽  
Veerle Segers ◽  
Joeri Gerlo ◽  
Rud Derie ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Loading Rate ◽  
Ground Reaction Forces ◽  
Contact Pattern ◽  
Intensity Measure ◽  
Foot Kinematics ◽  
Contact Patterns ◽  
Reaction Forces ◽  
Local Impact ◽  
The Impact

In running, foot contact patterns (rear-, mid-, or forefoot contact) influence impact intensity and initial ankle and foot kinematics. The aim of the study was to compare impact intensity and its spatial distribution under the foot between different foot contact patterns. Forty-nine subjects ran at 3.2 m·s−1 over a level runway while ground reaction forces (GRF) and shoe-surface pressures were recorded and foot contact pattern was determined. A 4-zone footmask (forefoot, midfoot, medial and lateral rearfoot) assessed the spatial distribution of the vertical GRF under the foot. We calculated peak vertical instantaneous loading rate of the GRF (VILR) per foot zone as the impact intensity measure. Midfoot contact patterns were shown to have the lowest, and atypical rearfoot contact patterns the highest impact intensities, respectively. The greatest local impact intensity was mainly situated under the rear- and midfoot for the typical rearfoot contact patterns, under the midfoot for the atypical rearfoot contact patterns, and under the mid- and forefoot for the midfoot contact patterns. These findings indicate that different foot contact patterns could benefit from cushioning in different shoe zones.

scholarly journals Compensatory Ground Reaction Forces during Scoliotic Gait in Subjects with and without Right Adolescent Idiopathic Scoliosis

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2372
Author(s):  
Paul S. Sung ◽  
Moon Soo Park
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Stance Phase ◽  
Three Dimensional ◽  
Asymmetry Index ◽  
Ground Reaction Forces ◽  
Significant Group ◽  
Reaction Forces ◽  
And Gender

Although the asymmetries of scoliotic gait in adolescent idiopathic scoliosis (AIS) groups have been extensively studied, recent studies indicated conflicting results regarding the ground reaction forces (GRFs) during gait in subjects with spinal deformity. The asymmetry during the stance phase might be clarified with three-dimensional (3D) compensations of GRFs between similar characteristics of subjects with and without AIS. The purpose of this study was to compare the normalized 3D GRF differences during the stance phase of gait while considering age, BMI, and Cobb angle between subjects with and without right AIS. There were 23 subjects with right convexity of thoracic idiopathic scoliosis and 22 age- and gender-matched control subjects. All subjects were right upper/lower limb dominant, and the outcome measures included the Cobb angles, normalized GRF, and KAI. The mediolateral (M/L) third peak force on the dominant limb decreased in the AIS group (t = 2.58, p = 0.01). Both groups demonstrated a significant interaction with the 3D indices (F = 5.41, p = 0.02). The post-hoc analysis identified that the M/L plane of asymmetry was significantly different between groups. The Cobb angles were negatively correlated with the vertical asymmetry index (r = −0.45, p = 0.03); however, there was no significant correlation with age (r = −0.10, p = 0.65) or body mass index (r = −0.28, p = 0.20). The AIS group demonstrated decreased GRF in the dominant limb M/L plane of the terminal stance phase. This compensatory motion was confirmed by a significant group difference on the M/L plane of the KAI. This KAI of vertical asymmetry correlated negatively with the Cobb angle. The asymmetric load transmission with compensatory vertical reactions was evident due to abnormal loading in the stance phase. These kinetic compensatory patterns need to be considered with asymmetry on the dominant limb when developing rehabilitation strategies for patients with AIS.

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