scholarly journals Design of a Semi-Active Prosthetic Knee for Transfemoral Amputees: Gait Symmetry Research by Simulation

2021 ◽  
Vol 11 (12) ◽  
pp. 5328
Author(s):  
Zhewen Zhang ◽  
Hongliu Yu ◽  
Wujing Cao ◽  
Xiaoming Wang ◽  
Qiaoling Meng ◽  
...  
Keyword(s):  
Hydraulic Cylinder ◽  
Swing Phase ◽  
Ball Screw ◽  
Gait Symmetry ◽  
Prosthetic Knee ◽  
Symmetry Index ◽  
Good Potential ◽  
Instantaneous Center ◽  
Index Value ◽  
Four Bar Linkage

The key technology of the prosthetic knee is to simulate the torque and angle of the biological knee. In this work, we proposed a novel prosthetic knee operated in semi-active mode. The structure with ball-screw driven by the motor and the passive hydraulic damping cylinder was presented. A four-bar linkage was adapted to track the instantaneous center motion of human knee. The mathematical models of hydraulic cylinder damping and active torque were established to simulate the knee torque and angle. The results show that the knee torque symmetry index is smaller than 10% in the whole gait. The knee angle symmetry index value is 34.7% in stance phase and 11.5% in swing phase. The angle in swing phase is closer to the intact knee. The semi-active prosthetic knee could provide similar torque and angle of the biological knee in the simulation. It has shown good potential in improving the gait symmetry of the transfemoral amputee.

Design of a novel bionic prosthetic knee joint

2016 ◽  
Vol 36 (4) ◽  
pp. 398-404 ◽  
Author(s):  
Xiufeng Zhang ◽  
Huiqun Fu ◽  
Xitai Wang ◽  
Guanglin Li ◽  
Rong Yang ◽  
...  
Keyword(s):  
Knee Joint ◽  
Design Method ◽  
Experimental Tests ◽  
Content Type ◽  
Prosthetic Knee ◽  
Theoretical Support ◽  
Instantaneous Center ◽  
And Performance ◽  
Swing Speed ◽  
Four Bar Linkage

Purpose This paper aims to find a new method that could be applied to the high and mid-grade prosthesis knee joint. Design/methodology/approach Based on analysis, calculation, modeling, simulation and experimental study of the motion law of knee joint, this paper not only determines the structure and parameters of the knee joint and calculates the instantaneous center but also analyzes the stance stability and completes the optimization. With the help of experimental tests (fatigue test and gait curve test), the quality and performance of the designed knee joint is verified. Findings The experimental results show that the gait curve of the designed knee joint is much closer to health people. The designed prosthesis knee joint, with adjustable swing speed and gait curve which are close to health limb, has a better performance when compared to the ordinary knee joint with four-bar linkage structure. Originality/value This paper developed a prosthesis knee joint based on a novel design method that could be applied to the “high and mid” grade prosthesis knee joint and verified its function on an amputee performed the lower amputation, which could provide theoretical support for researches and designs related to prosthesis knee joint in future.

scholarly journals Spatio-temporal gait parameters obtained from foot-worn inertial sensors are reliable in healthy adults in single- and dual-task conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Soulard ◽  
J. Vaillant ◽  
R. Balaguier ◽  
N. Vuillerme
Keyword(s):  
Dual Task ◽  
Inertial Sensors ◽  
Healthy Adults ◽  
Gait Symmetry ◽  
Symmetry Index ◽  
Task Effects ◽  
Gait Parameters ◽  
Task Conditions ◽  
Healthy Participants ◽  
Absolute Reliability

AbstractInertial measurement units (IMUs) are increasingly popular and may be usable in clinical routine to assess gait. However, assessing their intra-session reliability is crucial and has not been tested with foot-worn sensors in healthy participants. The aim of this study was to assess the intra-session reliability of foot-worn IMUs for measuring gait parameters in healthy adults. Twenty healthy participants were enrolled in the study and performed the 10-m walk test in single- and dual-task ('carrying a full cup of water') conditions, three trials per condition. IMUs were used to assess spatiotemporal gait parameters, gait symmetry parameters (symmetry index (SI) and symmetry ratio (SR)), and dual task effects parameters. The relative and the absolute reliability were calculated for each gait parameter. Results showed that spatiotemporal gait parameters measured with foot-worn inertial sensors were reliable; symmetry gait parameters relative reliability was low, and SR showed better absolute reliability than SI; dual task effects were poorly reliable, and taking the mean of the second and the third trials was the most reliable. Foot-worn IMUs are reliable to assess spatiotemporal and symmetry ratio gait parameters but symmetry index and DTE gait parameters reliabilities were low and need to be interpreted with cautious by clinicians and researchers.

scholarly journals Relationship between Asymmetry of Gait and Muscle Torque in Patients after Unilateral Transfemoral Amputation

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Alicja Rutkowska-Kucharska ◽  
Mateusz Kowal ◽  
Sławomir Winiarski
Keyword(s):  
Hip Joint ◽  
Reaction Force ◽  
Transfemoral Amputation ◽  
Gait Symmetry ◽  
Symmetry Index ◽  
Muscle Torque ◽  
Effective Form ◽  
Gait Asymmetry ◽  
Torque Values ◽  
Therapy Programme

Many studies have shown that unilateral transfemoral amputation involves asymmetric gait. Transfemoral amputation leads to muscle atrophy in a tight stump resulting in asymmetry in muscle torque between the amputated and intact limb. This research is aimed at verifying if a relationship between torque values of hip joint flexors and extensors and gait asymmetry in patients with TFA exists. Fourteen adult subjects with unilateral TFA took part in the experiment. Gait symmetry was evaluated based on the ground reaction force (GRF). Measurements of muscle torque of hip flexors and extensors were taken with a Biodex System. All measurements were taken under isokinetic (60°/s and 120°/s) and isometric conditions. The symmetry index of vertical GRF components was from 7.5 to 11.5%, and anterio-posterior GRF from 6.2 to 9.3%. The symmetry index for muscle torque was from 24.3 to 44% for flexors, from 39 to 50.5% for extensors, and from 28.6 to 50% in the flexor/extensor ratio. Gait asymmetry correlated with muscle torque in hip joint extensors. Therapy which enhances muscle torque may be an effective form of patient therapy. The patient needs to undergo evaluation of their muscle strength and have the therapy programme adjusted to their level of muscle torque deficit.

scholarly journals Association between pain and gait instability in patients with lumbar disc herniation

2021 ◽  
Vol 49 (8) ◽  
pp. 030006052110393
Author(s):  
Keunjae Lee ◽  
Eun-San Kim ◽  
Boyoung Jung ◽  
Sang-Won Park ◽  
In-Hyuk Ha
Keyword(s):  
Lumbar Disc Herniation ◽  
Disc Herniation ◽  
Rating Scale ◽  
Lumbar Disc ◽  
Linear Regression Analysis ◽  
Lumbar Pain ◽  
Multivariate Linear Regression Analysis ◽  
Cross Sectional ◽  
Gait Symmetry ◽  
Symmetry Index

Objective To determine whether pain is associated with gait instability in patients with lumbar disc herniation (LDH). Methods This retrospective cross-sectional study used data from electronic medical records. Among patients with lumbar back pain caused by LDH between January 2017 and July 2019, patients that underwent gait analysis were included. LDH was diagnosed using magnetic resonance imaging. An OptoGait photoelectric cell system was used for gait evaluation. Instability was measured using a gait symmetry index. Multivariate linear regression analysis was performed to determine the association between lumbar pain and gait instability. Results A total of 29 patients (12 females [41.4%] and 17 males [58.6%]; mean ± SD age, 40.6 ± 12.0 years) with LDH were enrolled in the study. With each 1-point increase in lumbar pain on the numeric rating scale, the symmetry index of the stance phase (0.33; 95% confidence interval [CI] 0.04, 0.62), swing phase (0.78; 95% CI 0.14, 1.43) and single support (0.79; 95% CI 0.15, 1.43) increased. Conclusions Gait instability in patients with LDH may occur due to an increase in pain.

A Computer Model to Simulate the Swing Phase of a Transfemoral Prosthesis

2004 ◽  
Vol 20 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Brendan Burkett ◽  
James Smeathers ◽  
Timothy M. Barker
Keyword(s):  
Walking Speed ◽  
Swing Phase ◽  
Prosthetic Knee ◽  
Energy Demands ◽  
Swing Time ◽  
Significant Difference ◽  
Prosthetic Knee Joint ◽  
Transfemoral Prosthesis ◽  
Everyday Task ◽  
Phase Motion

For amputees to perform an everyday task, or to participate in physical exercise, it is crucial that they have an appropriately designed and functional prosthesis. Past studies of transfemoral amputee gait have identified several limitations in the performance of amputees and in their prosthesis when compared with able-bodied walking, such as asymmetrical gait, slower walking speed, and higher energy demands. In particular the different inertial characteristics of the prosthesis relative to the sound limb results in a longer swing time for the prosthesis. The aim of this study was to determine whether this longer swing time could be addressed by modifying the alignment of the prosthesis. The following hypothesis was tested: Can the inertial characteristics of the prosthesis be improved by lowering the prosthetic knee joint, thereby producing a faster swing time? To test this hypothesis, a simple 2-D mathematical model was developed to simulate the swing-phase motion of the prosthetic leg. The model applies forward dynamics to the measured hip moment of the amputee in conjunction with the inertial characteristics of prosthetic components to predict the swing-phase motion. To evaluate the model and measure any change in prosthetic function, we conducted a kinematic analysis on four Paralympic runners as they ran. When evaluated, there was no significant difference (p > 0.05) between predicted and measured swing time. Of particular interest was how swing time was affected by changes in the position of the prosthetic knee axis. The model suggested that lowering the axis of the prosthetic knee could reduce the longer swing time. This hypothesis was confirmed when tested on the amputee runners.

scholarly journals Measurement of Human Gait Symmetry using Body Surface Normals Extracted from Depth Maps

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 891 ◽  
Author(s):  
Trong-Nguyen Nguyen ◽  
Huu-Hung Huynh ◽  
Jean Meunier
Keyword(s):  
Body Surface ◽  
Lower Limbs ◽  
Upper Body ◽  
Whole Body ◽  
Human Gait ◽  
Gait Symmetry ◽  
Symmetry Index ◽  
Depth Maps ◽  
Abnormal Gait ◽  
3D Information

In this paper, we introduce an approach for measuring human gait symmetry where the input is a sequence of depth maps of subject walking on a treadmill. Body surface normals are used to describe 3D information of the walking subject in each frame. Two different schemes for embedding the temporal factor into a symmetry index are proposed. Experiments on the whole body, as well as the lower limbs, were also considered to assess the usefulness of upper body information in this task. The potential of our method was demonstrated with a dataset of 97,200 depth maps of nine different walking gaits. An ROC analysis for abnormal gait detection gave the best result ( AUC = 0.958 ) compared with other related studies. The experimental results provided by our method confirm the contribution of upper body in gait analysis as well as the reliability of approximating average gait symmetry index without explicitly considering individual gait cycles for asymmetry detection.

KINETOSTATIC ANALYSIS FOR FOUR-BAR LINKAGE MECHANISM OF PROSTHETIC KNEE JOINT

2019 ◽  
Vol 19 (04) ◽  
pp. 1950018 ◽  
Author(s):  
XUHUI LIU ◽  
TIANTIAN GUO ◽  
JIAHAO ZHANG ◽  
GUANG YANG ◽  
LUCHAN SUN ◽  
...  
Keyword(s):  
Knee Joint ◽  
Group Method ◽  
Linkage Mechanism ◽  
Analysis Software ◽  
Prosthetic Knee ◽  
Damping Effect ◽  
D’Alembert Principle ◽  
Prosthetic Knee Joint ◽  
Four Bar Linkage ◽  
The Relationship

In this paper, a mathematical model of four-bar linkage mechanism is built to investigate the prosthetic knee joint, by means of the bar group method, and the motion of the prosthetic knee joint is simulated by motion analysis software. In the state of motion of the four linkage mechanism, to the moving component of the mechanism, the relationship between the moving displacement, velocity and acceleration are obtained. On the basis of the above investigation, dynamic statics analysis for the moving component of four-bar linkage mechanism are completed by the ‘D’Alembert principle. The research results show that, with the change of the rotating angle of the active part, the counter-force of rotating pair and the balance torque on active component are all changeable, which will provide a theoretical basis for the design of prosthetic knee joint mechanism with longer life and better damping effect.

The Influence of Four-Bar Linkage Knees on Prosthetic Swing-Phase Floor Clearance

1996 ◽  
Vol 8 (2) ◽  
pp. 34-40 ◽  
Author(s):  
Steven A. Gard ◽  
Dudley S. Childress ◽  
Jack E. Uellendahl
Keyword(s):  
Swing Phase ◽  
Four Bar Linkage
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