scholarly journals Defect free optimization of a polycentric prosthetic knee design using imperialist competition-inspired optimization method

2021 ◽  
Author(s):  
Nejlaoui M ◽  
◽  
Alateyah A. I. ◽  
El-Garaihy W. H. ◽  
◽  
...  
Keyword(s):  
Knee Joint ◽  
Sagittal Plane ◽  
Knee Prosthesis ◽  
Tracking Error ◽  
Lower Limbs ◽  
Optimization Approach ◽  
Center Of Rotation ◽  
Multi Objective ◽  
Flexion Extension ◽  
Instantaneous Center

The disability of lower limbs is one of the major problems facing human lives. In order to restore the missing functionality and aesthetic feature of the amputee's locomotion, finding the optimal design of the human lower limb knee prosthesis is crucial. This paper focuses the design optimization of a four bar knee mechanism capable to reproduce the complex flexion/extension knee joint motion in the sagittal plane with variable instantaneous center of rotation positions. Thus an optimization approach with appropriate constraints is formulated in order to consider the degree of compatibility between the instantaneous center of rotation trajectories of the human reference knee joint and the four bar knee mechanism. To solve this high nonlinear optimization problem, an algorithm based on multi-objective modified imperialist competitive method is proposed where all the constraints are managed with the penalty method. The results obtained by the multi-objective modified imperialist competitive method showed the capability to reach a small tracking error. The obtained results prove the effectiveness of the proposed optimization approach for the optimal synthesis of the four bar knee mechanism, compared with other literature techniques.

scholarly journals The Effects of External Loads and Muscle Forces on the Knee Joint Ligaments during Walking: A Musculoskeletal Model Study

2021 ◽  
Vol 11 (5) ◽  
pp. 2356
Author(s):  
Carlo Albino Frigo ◽  
Lucia Donno
Keyword(s):  
Knee Joint ◽  
Cruciate Ligament ◽  
Musculoskeletal Model ◽  
Optimization Approach ◽  
Muscle Forces ◽  
Collateral Ligaments ◽  
Flexion Extension ◽  
Lateral Collateral Ligaments ◽  
Gastrocnemius Muscles ◽  
External Loads

A musculoskeletal model was developed to analyze the tensions of the knee joint ligaments during walking and to understand how they change with changes in the muscle forces. The model included the femur, tibia, patella and all components of cruciate and collateral ligaments, quadriceps, hamstrings and gastrocnemius muscles. Inputs to the model were the muscle forces, estimated by a static optimization approach, the external loads (ground reaction forces and moments) and the knee flexion/extension movement corresponding to natural walking. The remaining rotational and translational movements were obtained as a result of the dynamic equilibrium of forces. The validation of the model was done by comparing our results with literature data. Several simulations were carried out by sequentially removing the forces of the different muscle groups. Deactivation of the quadriceps produced a decrease of tension in the anterior cruciate ligament (ACL) and an increase in the posterior cruciate ligament (PCL). By removing the hamstrings, the tension of ACL increased at the late swing phase, while the PCL force dropped to zero. Specific effects were observed also at the medial and lateral collateral ligaments. The removal of gastrocnemius muscles produced an increase of tension only on PCL and lateral collateral ligaments. These results demonstrate how musculoskeletal models can contribute to knowledge about complex biomechanical systems as the knee joint.

scholarly journals Modelling of the Human Knee Joint Supported by Active Orthosis

2018 ◽  
Vol 23 (1) ◽  
pp. 107-120
Author(s):  
V. Musalimov ◽  
Y. Monahov ◽  
M. Tamre ◽  
D. Rõbak ◽  
A. Sivitski ◽  
...  
Keyword(s):  
Knee Joint ◽  
Sagittal Plane ◽  
Low Cost ◽  
Lower Limbs ◽  
Human Knee ◽  
Human Knee Joint ◽  
Healthy Knee ◽  
Knee Joint Motion ◽  
Injured Knee ◽  
Active Orthosis

AbstractThe article discusses motion of a healthy knee joint in the sagittal plane and motion of an injured knee joint supported by an active orthosis. A kinematic scheme of a mechanism for the simulation of a knee joint motion is developed and motion of healthy and injured knee joints are modelled in Matlab. Angles between links, which simulate the femur and tibia are controlled by Simulink block of Model predictive control (MPC). The results of simulation have been compared with several samples of real motion of the human knee joint obtained from motion capture systems. On the basis of these analyses and also of the analysis of the forces in human lower limbs created at motion, an active smart orthosis is developed. The orthosis design was optimized to achieve an energy saving system with sufficient anatomy, necessary reliability, easy exploitation and low cost. With the orthosis it is possible to unload the knee joint, and also partially or fully compensate muscle forces required for the bending of the lower limb.

A reciprocal walking orthosis hip joint for young paediatric patients with a variety of pathological conditions

2001 ◽  
Vol 25 (1) ◽  
pp. 47-52 ◽  
Author(s):  
P. J. Woolam ◽  
B. Lomas ◽  
J. Stallard
Keyword(s):  
Hip Joint ◽  
Sagittal Plane ◽  
Vertical Axis ◽  
Lower Limbs ◽  
Knee Joints ◽  
Hip Joints ◽  
Flexion Extension ◽  
Total Body ◽  
Lateral Rigidity ◽  
Adjustable Range

A growing trend in the use of reciprocal walking orthoses for infant paraplegic patients, and their application for control of the lower limbs in very young total body involved cerebral palsy patients, has created a need for smaller components. A prototype design of a hip joint has been produced which provides the following features: adjustable range of flexion/extension control; override on stops to permit sitting; high lateral rigidity; no lateral bearing play; very high rigidity in the sagittal plane; low friction bearings; high resistance to torque about the vertical axis. In addition a size envelope which is more in keeping with the dimensions of infant patients was an important objective. Comparisons were made of the computed structural properties of the prototype joint and existing routinely available standard orthotic hip joints. In each plane of loading the prototype joint had the highest identified structural property. The hinge-bearing material was tested in a representative joint with 200,000 cycles of typical loading. It was also field tested on adult orthoses over a minimum of a 12-month period with the most vigorous of walkers. In neither test did excessive play develop. The mechanical properties of the joint were established using tests advocated in the British Standard on testing lower limb orthosis knee joints. These showed the joint had structurally equivalent performance to a successful reciprocal walking orthosis hip joint, and that the mode of failure was essentially ductile in nature. Production development of the joint is now being undertaken.

scholarly journals Instantaneous center of rotation behavior of the lumbar spine with ligament failure

2013 ◽  
Vol 18 (6) ◽  
pp. 617-626 ◽  
Author(s):  
Yunus Alapan ◽  
Cihan Demir ◽  
Tuncay Kaner ◽  
Rahmi Guclu ◽  
Serkan İnceoğlu
Keyword(s):  
Lumbar Spine ◽  
Range Of Motion ◽  
Load Transfer ◽  
Sagittal Plane ◽  
Element Model ◽  
Ligament Injury ◽  
Center Of Rotation ◽  
Lower Lumbar Spine ◽  
Ligament Failure ◽  
Instantaneous Center

Object The goal of this study was to investigate the effect of ligament failure on the instantaneous center of rotation (ICR) in the lower lumbar spine. Methods A 3D finite element model of the L4–5 segment was obtained and validated. Ligament failure was simulated by reducing ligaments in a stepwise manner from posterior to anterior. A pure bending moment of 7.5 Nm was applied to the model in 3 anatomical planes for the purpose of validation, and a 6-Nm moment was applied to analyze the effect of ligament failure. For each loading case, ligament reduction step, and load increment, the range of motion of the segment and the ICR of the mobile (L-4) vertebra were calculated and characterized. Results The present model showed a consistent increase in the range of motion as the ligaments were removed, which was in agreement with the literature reporting the kinematics of the L4–5 segment. The shift in the location of the ICR was below 5 mm in the sagittal plane and 3 mm in both the axial and coronal planes. Conclusions The location of the ICR changed in all planes of motion with the simulation of multiple ligament injury. The removal of the ligaments also changed the load sharing within the motion segment. The change in the center of rotation of the spine together with the change in the range of motion could have a diagnostic value, revealing more detailed information on the type of injury, the state of the ligaments, and load transfer and sharing characteristics of the segment.

scholarly journals Inverse Modeling of Human Knee Joint Based on Geometry and Vision Systems for Exoskeleton Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Eduardo Piña-Martínez ◽  
Ernesto Rodriguez-Leal
Keyword(s):  
Knee Joint ◽  
Vision System ◽  
Kinematic Model ◽  
Measurement Tool ◽  
Vision Systems ◽  
Severe Injuries ◽  
Center Of Rotation ◽  
Human Knee ◽  
Human Knee Joint ◽  
Instantaneous Center

Current trends in Robotics aim to close the gap that separates technology and humans, bringing novel robotic devices in order to improve human performance. Although robotic exoskeletons represent a breakthrough in mobility enhancement, there are design challenges related to the forces exerted to the users’ joints that result in severe injuries. This occurs due to the fact that most of the current developments consider the joints as noninvariant rotational axes. This paper proposes the use of commercial vision systems in order to perform biomimetic joint design for robotic exoskeletons. This work proposes a kinematic model based on irregular shaped cams as the joint mechanism that emulates the bone-to-bone joints in the human body. The paper follows a geometric approach for determining the location of the instantaneous center of rotation in order to design the cam contours. Furthermore, the use of a commercial vision system is proposed as the main measurement tool due to its noninvasive feature and for allowing subjects under measurement to move freely. The application of this method resulted in relevant information about the displacements of the instantaneous center of rotation at the human knee joint.

A Method for Optimal Synthesis of a Biomimetic Four-Bar Linkage Knee Joint for a Knee-Ankle-Foot Orthosis

2017 ◽  
Vol 32 ◽  
pp. 20-28 ◽  
Author(s):  
Ganesh M. Bapat ◽  
S. Sujatha
Keyword(s):  
Knee Joint ◽  
Optimal Synthesis ◽  
Average Error ◽  
Optimization Approach ◽  
Knee Motion ◽  
Human Knee ◽  
Ankle Foot Orthosis ◽  
Flexion Extension ◽  
Four Bar Linkage ◽  
Foot Orthosis

A Knee-Ankle-Foot orthosis (KAFO) is used as a supportive device by individuals with lower limb disability. A type of KAFO that allows knee flexion-extension is prescribed for people who need knee stability in the transverse and frontal planes. In such an orthosis, mimicking the human knee motion is vital to avoid relative motion (called pistoning) between the limb and the orthosis. A four-bar mechanism, owing to its polycentric nature, simplicity and ease of fabrication can provide a customizable, biomimetic solution. This paper presents an improved and robust optimization approach to synthesize a four-bar mechanism to closely mimic the anatomical knee motion. The reference human knee centrode is obtained from literature. A genetic algorithm is used for optimal synthesis of the fourbar mechanism. Results show that the average error between the reference centrode and the centrode of the synthesized four-bar mechanism is very small (0.2 mm). Thus, the synthesized crossed four-bar linkage can reproduce better anthropomorphic characteristics of the knee joint. The methodology can be used for the design of customized orthotic knee joints for KAFOs and knee braces.

scholarly journals Design and Experimental Research of Knee Joint Prosthesis Based on Gait Acquisition Technology

Biomimetics ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 28
Author(s):  
Yonghong Zhang ◽  
Erliang Wang ◽  
Miao Wang ◽  
Sizhe Liu ◽  
Wenjie Ge
Keyword(s):  
Knee Joint ◽  
Lower Limbs ◽  
Movement Trajectory ◽  
Human Knee ◽  
Motion Data ◽  
Human Knee Joint ◽  
Lower Limb Prosthesis ◽  
Knee Joint Motion ◽  
Normal Human ◽  
Instantaneous Center

Whether the lower limb prosthesis can better meet the needs of amputees, the biomimetic performance of the knee joint is particularly important. In this paper, Nokov(metric) optical 3D motion capture system was used to collect motion data of normal human lower limbs, and the motion instantaneous center of multi-gait knee joint was obtained. Taking the error of knee joint motion instantaneous center line as the objective function, a set of six-bar mechanism prosthetic knee joint was designed based on a genetic algorithm. The experimental results show that the movement trajectory of the instantaneous center of the knee joint is basically similar to that of the human knee joint, so it can help amputees complete a variety of gaits and has good biomimetic performance. Gait acquisition technology can provide important data for prosthetic designers and it will be widely used in prosthetic design and other fields.

Correction of Posture Deviations in the Sagittal Plane Using the Pilates Method

2019 ◽  
pp. 3-13
Author(s):  
Alexandru Cîtea ◽  
George-Sebastian Iacob
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Postural Control ◽  
Human Body ◽  
Sagittal Plane ◽  
The Body ◽  
Lower Limbs ◽  
Low Back ◽  
Pilates Method ◽  
The Relationship

Posture is commonly perceived as the relationship between the segments of the human body upright. Certain parts of the body such as the cephalic extremity, neck, torso, upper and lower limbs are involved in the final posture of the body. Musculoskeletal instabilities and reduced postural control lead to the installation of nonstructural posture deviations in all 3 anatomical planes. When we talk about the sagittal plane, it was concluded that there are 4 main types of posture deviation: hyperlordotic posture, kyphotic posture, rectitude and "sway-back" posture.Pilates method has become in the last decade a much more popular formof exercise used in rehabilitation. The Pilates method is frequently prescribed to people with low back pain due to their orientation on the stabilizing muscles of the pelvis. Pilates exercise is thus theorized to help reactivate the muscles and, by doingso, increases lumbar support, reduces pain, and improves body alignment.

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