Influence of the Hip Joint Modeling Approaches on the Kinematics of Human Gait

The influence of the hip joint formulation on the kinematic response of the model of human gait is investigated throughout this work. To accomplish this goal, the fundamental issues of the modeling process of a planar hip joint under the framework of multibody systems are revisited. In particular, the formulations for the ideal, dry, and lubricated revolute joints are described and utilized for the interaction of femur head inside acetabulum or the hip bone. In this process, the main kinematic and dynamic aspects of hip joints are analyzed. In a simple manner, the forces that are generated during human gait, for both dry and lubricated hip joint models, are computed in terms of the system's state variables and subsequently introduced into the dynamics equations of motion of the multibody system as external generalized forces. Moreover, a human multibody model is considered, which incorporates the different approaches for the hip articulation, namely, ideal joint, dry, and lubricated models. Finally, several computational simulations based on different approaches are performed, and the main results are presented and compared to identify differences among the methodologies and procedures adopted in this work. The input conditions to the models correspond to the experimental data capture from an adult male during normal gait. In general, the obtained results in terms of positions do not differ significantly when different hip joint models are considered. In sharp contrast, the velocity and acceleration plotted vary significantly. The effect of the hip joint modeling approach is clearly measurable and visible in terms of peaks and oscillations of the velocities and accelerations. In general, with the dry hip model, intrajoint force peaks can be observed, which can be associated with the multiple impacts between the femur head and the cup. In turn, when the lubricant is present, the system's response tends to be smoother due to the damping effects of the synovial fluid.

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Morphological patterns of the hip joint structure in students of choreography schools and young athletes involved in sports associated with the art of movement

Voprosy praktičeskoj pediatrii ◽

10.20953/1817-7646-2020-6-90-93 ◽

2020 ◽

Vol 15 (6) ◽

pp. 90-93

Author(s):

O.S. Vasiliev ◽

◽

S.P. Levushkin ◽

E.E. Achkasov ◽

◽

...

Keyword(s):

Hip Joint ◽

Young Athletes ◽

Hip Joints ◽

Joint Structure ◽

Normal Limits ◽

Rhythmic Gymnastics ◽

Key Words Hip ◽

Coxa Valga ◽

Key Words Hip Dysplasia ◽

Morphological Patterns

Students of choreography schools and young athletes involved in sports associated with the art of movement usually have dysplastic hip joints with normal acetabular coverage and femoral Coxa valga, whose normal limits require further discussion. We have identified 5 X-Ray morphological patterns of the hip joint structure typical of such individuals, and analyzed their association with professional qualities. Key words: hip dysplasia, dysplastic constitution, Coxa valga, young athletes, rhythmic gymnastics, choreography, ballet

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A novel PID control parameters tuning approach for robot manipulators mounted on oscillatory bases

Robotica ◽

10.1017/s0263574706003298 ◽

2007 ◽

Vol 25 (4) ◽

pp. 467-477 ◽

Cited By ~ 11

Author(s):

J. Lin ◽

Z.-Z. Huang

Keyword(s):

Pid Control ◽

Pid Controller ◽

Low Cost ◽

Equations Of Motion ◽

Grey Theory ◽

Control Parameters ◽

State Variables ◽

Relational Analysis ◽

Parameters Tuning ◽

Grey Relational

SUMMARYThis research focuses on the issue of dynamic modeling and controlling a robotic manipulator attached to a compliant base. Such a system is known under the name macro–micro system, characterized by the number of control actuators being less than the number of state variables. The equations of motion for a two-link planar elbow arm mounted on an oscillatory base has been presented in this investigation. In order to study the sensitivity of tuning the PID parameters to achieve the desired performance, the Grey relational analysis has first been proposed. Therefore, the aim of this work is to apply Grey theory to optimize parameters for partial states feedback of a PID controller for such a structure. The experimental results of the proposed methodology also show that it is technically and economically feasible to develop a low-cost, reliable, automatic, less time-consuming controller for robotics mounted on oscillatory bases.

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Trajectory Tracking of Underactuated Multibody Systems

Volume 4: 8th International Conference on Multibody Systems, Nonlinear Dynamics, and Control, Parts A and B ◽

10.1115/detc2011-47207 ◽

2011 ◽

Author(s):

Stefan Reichl ◽

Wolfgang Steiner

Keyword(s):

Trajectory Tracking ◽

Multibody Systems ◽

Degrees Of Freedom ◽

Inverse Dynamics ◽

Feedforward Control ◽

Equations Of Motion ◽

Three Dimensional ◽

Differential Algebraic Equations ◽

State Variables ◽

Algebraic Equations

This work presents three different approaches in inverse dynamics for the solution of trajectory tracking problems in underactuated multibody systems. Such systems are characterized by less control inputs than degrees of freedom. The first approach uses an extension of the equations of motion by geometric and control constraints. This results in index-five differential-algebraic equations. A projection method is used to reduce the systems index and the resulting equations are solved numerically. The second method is a flatness-based feedforward control design. Input and state variables can be parameterized by the flat outputs and their time derivatives up to a certain order. The third approach uses an optimal control algorithm which is based on the minimization of a cost functional including system outputs and desired trajectory. It has to be distinguished between direct and indirect methods. These specific methods are applied to an underactuated planar crane and a three-dimensional rotary crane.

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Multi-Parameter Optimization of Damped Linear Continuous Systems

Journal of Engineering for Industry ◽

10.1115/1.3428112 ◽

1972 ◽

Vol 94 (1) ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

O. B. Dale ◽

R. Cohen

Keyword(s):

Optimal Parameter ◽

Equations Of Motion ◽

Analytic Solutions ◽

System Response ◽

Continuous Systems ◽

Frequency Interval ◽

State Variables ◽

Initial Value ◽

Unknown Parameters ◽

One Dimensional

A method is presented for obtaining and optimizing the frequency response of one-dimensional damped linear continuous systems. The systems considered are assumed to contain unknown constant parameters in the boundary conditions and equations of motion which the designer can vary to obtain a minimum resonant response in some selected frequency interval. The unknown parameters need not be strictly dissipative nor unconstrained. No analytic solutions, either exact or approximate, are required for the system response and only initial value numerical integrations of the state and adjoint differential equations are required to obtain the optimal parameter set. The combinations of state variables comprising the response and the response locations are arbitrary.

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Limitations of demand- and pressure-driven modeling for large deficient networks

Drinking Water Engineering and Science ◽

10.5194/dwes-10-93-2017 ◽

2017 ◽

Vol 10 (2) ◽

pp. 93-98 ◽

Cited By ~ 10

Author(s):

Mathias Braun ◽

Olivier Piller ◽

Jochen Deuerlein ◽

Iraj Mortazavi

Keyword(s):

Water Distribution ◽

Network Models ◽

Distribution Networks ◽

Computer Applications ◽

State Variables ◽

Modeling Process ◽

Uniqueness Of The Solution ◽

Basic Equations ◽

Physical Phenomena ◽

Pressure Driven

Abstract. The calculation of hydraulic state variables for a network is an important task in managing the distribution of potable water. Over the years the mathematical modeling process has been improved by numerous researchers for utilization in new computer applications and the more realistic modeling of water distribution networks. But, in spite of these continuous advances, there are still a number of physical phenomena that may not be tackled correctly by current models. This paper will take a closer look at the two modeling paradigms given by demand- and pressure-driven modeling. The basic equations are introduced and parallels are drawn with the optimization formulations from electrical engineering. These formulations guarantee the existence and uniqueness of the solution. One of the central questions of the French and German research project ResiWater is the investigation of the network resilience in the case of extreme events or disasters. Under such extraordinary conditions where models are pushed beyond their limits, we talk about deficient network models. Examples of deficient networks are given by highly regulated flow, leakage or pipe bursts and cases where pressure falls below the vapor pressure of water. These examples will be presented and analyzed on the solvability and physical correctness of the solution with respect to demand- and pressure-driven models.

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Joint Modeling of Longitudinal Changes of Respiratory Rate, Pulse Rate and Oxygen Saturation With Time to Convalescence Among Pneumonia Patients: A comparison of Separate and Joint Models

10.21203/rs.3.rs-150912/v1 ◽

2021 ◽

Author(s):

Yenefenta Wube Bayleyegne ◽

Sindu Azmeraw Kassahun

Keyword(s):

Oxygen Saturation ◽

Respiratory Rate ◽

Pulse Rate ◽

Recovery Time ◽

Child Survival ◽

Joint Modeling ◽

Joint Models ◽

Longitudinal Outcomes ◽

Under Five ◽

Cohort Study Design

Abstract Background: Globally, pneumonia is the first infectious disease which is the leading cause of children under age five morbidity and mortality with 98% of deaths in developing countries. Objective: The study aimed to identify the determinant factors that jointly affect the longitudinal measures of pneumonia (respiratory rate, pulse rate and oxygen saturation) and time to convalescence or recovery of under five admitted pneumonia patients at Felege Hiwot Referral Hospital, Bahir Dar, Ethiopia.Methods: A prospective cohort study design was used on 101 sampled under five admitted pneumonia patients from December 2019 to February 2020. The study was conducted using joint model of longitudinal outcomes and survival outcomes.Results: The significant values of shared parameters in the survival sub model shows that the use of joint modeling of multivariate longitudinal outcomes with the time to event outcome is the best model compared to separate models. The estimated values of the association parameters for γ_1, γ_2 and γ_3 were -0.297, -0.121 and 0.5452 respectively and indicates that; respiratory rate and pulse rate were negatively related with recovery time, whereas oxygen saturation was positively associated with recovery time. As age of patients increased by one month, the average respiratory rate and pulse rate were significantly decreased by 0.3759 bpm and 1.1012 bpm respectively keeping other variables constant, but age has no information about oxygen saturation. Conclusion: Residence, birth order, severity and visit were found as determinants of the longitudinal measures of pneumonia and time to recovery of under-five admitted pneumonia patients jointly. To improve child survival, the community should be responsible for post ponding child birth and marriage.

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Risk factors for venous thrombosis in patients with endoprosthetics of hip joints

Journal of Education, Health and Sport ◽

10.12775/jehs.2021.11.09.102 ◽

2021 ◽

Vol 11 (9) ◽

pp. 875-885

Author(s):

Ihor Venher ◽

Sviatoslav Kostiv ◽

Dymytrii Khvalyboha

Keyword(s):

Connective Tissue ◽

Femoral Neck ◽

Inferior Vena Cava ◽

Venous Thrombosis ◽

Hip Joint ◽

Hip Replacement ◽

Inferior Vena ◽

Vena Cava ◽

Hip Joints ◽

Connective Tissue Dysplasia

Background. Important part of orthopaedic surgery is endoprosthetics of hip joints, which eliminates pain syndrome, restores the amplitude of movements and the support ability of the lower limb. But there is a number of complications; venous thromboembolism among them occupies a leading place. Material and methods. 219 patients with a mean age of 64.7 ± 3.8 years were operated. In 137 (62.1%) observations, total cement hip replacement was performed for osteoarthritis. 82 (37.4%) patients received total and unipolar cement hip replacement for cervical femoral neck fractures. Results. Clinical manifestations of non-specific connective tissue dysplasia were detected in 83 (37.9%) patients, which were confirmed by the laboratory determination of the level of general, bound and free oxyproline. In the postoperative period, the thrombotic process in the venous system of the inferior vena cava was diagnosed in 23 (10.5%) observations. Operative intervention on the hip joint in patients with nonspecific dysplasia of connective tissue in 11 (13.3%) cases was complicated by the development of venous thrombosis. In patients without non-specific connective tissue dysplasia, postoperative thrombosis in the system of the inferior vena cava was diagnosed in 12 (8.8%) observations. Conclusions. Patients with osteoarthrosis of the hip joint and the femoral neck fracture accompanied by the non-specific dysplasia of the connective tissue are characterized by expressed levels of endothelial dysfunction and increased activity of the blood-coagulation system.

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A multi-station hip joint simulator study of the performance of 22 mm diameter zirconia-ultra-high molecular weight polyethylene total replacement hip joints

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1243/0954411991534825 ◽

1999 ◽

Vol 213 (2) ◽

pp. 77-90 ◽

Cited By ~ 39

Author(s):

A A J Goldsmith ◽

D Dowson

Keyword(s):

Molecular Weight ◽

High Molecular Weight ◽

Hip Joint ◽

Hip Joints ◽

Total Replacement ◽

Simulator Study ◽

Ultra High Molecular Weight ◽

Hip Joint Simulator

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The functional use of the reciprocal hip mechanism during gait for paraplegic patients walking in the Louisiana State University reciprocating gait orthosis

Prosthetics and Orthotics International ◽

10.3109/03093649909071627 ◽

1999 ◽

Vol 23 (2) ◽

pp. 152-162 ◽

Cited By ~ 23

Author(s):

P. M. Dall ◽

B. Müller ◽

I. Stallard ◽

J. Edwards ◽

M. H. Granat

Keyword(s):

Hip Joint ◽

Swing Phase ◽

Spinal Injuries ◽

Small Contribution ◽

State University ◽

Hip Joints ◽

Cable Tension ◽

Louisiana State University ◽

Hip Flexion ◽

Limb Flexion

Reciprocally linked orthoses used for paraplegic walking have some form of linkage between the two hip joints. It has been assumed that flexion of the swinging leg is driven by extension of the stance leg. The aims of this study were to investigate the moments generated around the hip joint by the two cables in a Louisiana State University Reciprocating Gait Orthosis (LSU-RGO). Six (6) subjects were recruited from the Regional Spinal Injuries Centre at Southport, who were experienced RGO users. The cables were fitted with strain gauged transducers to measure cable tension. Foot switches were used to divide the gait into swing and stance phases. A minimum of 20 steps were analysed for each subject. Moments about the hip joint for each phase of gait were calculated. There were no moments generated by the front cable in 4 of the subjects. In only 2 subjects did the cable generate a moment that could assist hip flexion during the swing phase. These moments were very low and at best could only have made a small contribution to limb flexion. The back cable generated moments that clearly prevented bilateral flexion. It was concluded that the front cable, as used by these experienced RGO users, did not aid flexion of the swinging limb.

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