scholarly journals Control Reference Parameter for Stance Assistance Using a Passive Controlled Ankle Foot Orthosis—A Preliminary Study

2019 ◽  
Vol 9 (20) ◽  
pp. 4416 ◽  
Author(s):  
Dimas Adiputra ◽  
Mohd Azizi Abdul Rahman ◽  
Ubaidillah ◽  
Saiful Amri Mazlan ◽  
Nurhazimah Nazmi ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Standard Error ◽  
Walking Speed ◽  
Parameters Estimation ◽  
Ankle Foot Orthosis ◽  
Preliminary Study ◽  
Reference Parameters ◽  
Walking Speeds ◽  
Foot Orthosis

This paper aims to present a preliminary study of control reference parameters for stance assistance among different subjects and walking speeds using a passive-controlled ankle foot orthosis. Four young male able-bodied subjects with varying body mass indexes (23.842 ± 4.827) walked in three walking speeds of 1, 3, and 5 km/h. Two control references, average ankle torque (aMa), and ankle angular velocity (aω), which can be implemented using a magnetorheological brake, were measured. Regression analysis was conducted to identify suitable control references in the three different phases of the stance. The results showed that aω has greater correlation (p) with body mass index and walking speed compared to aMa in the whole stance phase (p1(aω) = 0.666 > p1(aMa) = 0.560, p2(aω) = 0.837 > p2(aMa) = 0.277, and p3(aω) = 0.839 > p3(aMa) = 0.369). The estimation standard error (Se) of the aMa was found to be generally higher than of aω (Se1(aMa) = 2.251 > Se1(aω) = 0.786, Se2(aMa) = 1.236 > Se2(aω) = 0.231, Se3(aMa) = 0.696 < Se3(aω) = 0.755). Future studies should perform aω estimation based on body mass index and walking speed, as suggested by the higher correlation and lower standard error as compared to aMa. The number of subjects and walking speed scenarios should also be increased to reduce the standard error of control reference parameters estimation.

scholarly journals Effectiveness of an ankle–foot orthosis on walking in patients with stroke: a systematic review and meta-analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoo Jin Choo ◽  
Min Cheol Chang
Keyword(s):  
Stride Length ◽  
Walking Speed ◽  
Sagittal Plane ◽  
Meta Analysis ◽  
Step Length ◽  
Stride Time ◽  
Plane Angle ◽  
Ankle Foot Orthosis ◽  
Biomechanical Parameters ◽  
Foot Orthosis

AbstractWe conducted a meta-analysis to investigate the effectiveness of ankle–foot orthosis (AFO) use in improving gait biomechanical parameters such as walking speed, mobility, and kinematics in patients with stroke with gait disturbance. We searched the MEDLINE (Medical Literature Analysis and Retrieval System Online), CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane, Embase, and Scopus databases and retrieved studies published until June 2021. Experimental and prospective studies were included that evaluated biomechanics or kinematic parameters with or without AFO in patients with stroke. We analyzed gait biomechanical parameters, including walking speed, mobility, balance, and kinematic variables, in studies involving patients with and without AFO use. The criteria of the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate the methodological quality of the studies, and the level of evidence was evaluated using the Research Pyramid model. Funnel plot analysis and Egger’s test were performed to confirm publication bias. A total of 19 studies including 434 participants that reported on the immediate or short-term effectiveness of AFO use were included in the analysis. Significant improvements in walking speed (standardized mean difference [SMD], 0.50; 95% CI 0.34–0.66; P < 0.00001; I2, 0%), cadence (SMD, 0.42; 95% CI 0.22–0.62; P < 0.0001; I2, 0%), step length (SMD, 0.41; 95% CI 0.18–0.63; P = 0.0003; I2, 2%), stride length (SMD, 0.43; 95% CI 0.15–0.71; P = 0.003; I2, 7%), Timed up-and-go test (SMD, − 0.30; 95% CI − 0.54 to − 0.07; P = 0.01; I2, 0%), functional ambulation category (FAC) score (SMD, 1.61; 95% CI 1.19–2.02; P < 0.00001; I2, 0%), ankle sagittal plane angle at initial contact (SMD, 0.66; 95% CI 0.34–0.98; P < 0.0001; I2, 0%), and knee sagittal plane angle at toe-off (SMD, 0.39; 95% CI 0.04–0.73; P = 0.03; I2, 46%) were observed when the patients wore AFOs. Stride time, body sway, and hip sagittal plane angle at toe-off were not significantly improved (p = 0.74, p = 0.07, p = 0.07, respectively). Among these results, the FAC score showed the most significant improvement, and stride time showed the lowest improvement. AFO improves walking speed, cadence, step length, and stride length, particularly in patients with stroke. AFO is considered beneficial in enhancing gait stability and ambulatory ability.

Classifications of Intentions for Controlling of a Multifunctional Knee-Ankle-Foot Orthosis

2011 ◽  
Author(s):  
Sai-Kit Wu ◽  
Tad Driver ◽  
Xiangrong Shen
Keyword(s):  
Walking Speed ◽  
Accuracy Rate ◽  
Bayes Method ◽  
Ankle Foot Orthosis ◽  
Significant Step ◽  
Reaction Forces ◽  
Velocity Information ◽  
Foot Orthosis ◽  
Motion Intention

This paper describes motion intention classifiers which utilize reaction forces signals from heel and toe; and hip velocity information to predict subject’s intention. Those classifiers using Bayes method to predict (i) walk-to-stop, (ii) walking-speed-changing, and (iii) stop-to-motions. They are very accurate (most of them have accuracy rate higher than 90%) and a significant step in order to develop a multifunctional knee-ankle-foot orthosis.

scholarly journals The physiological cost index of walking with a powered knee–ankle–foot orthosis in subjects with poliomyelitis: A pilot study

2015 ◽  
Vol 40 (4) ◽  
pp. 454-459 ◽  
Author(s):  
Mokhtar Arazpour ◽  
Monireh Ahmadi Bani ◽  
Mohammad Samadian ◽  
Mohammad E Mousavi ◽  
Stephen W Hutchins ◽  
...  
Keyword(s):  
Walking Speed ◽  
Knee Joints ◽  
Cost Index ◽  
Ankle Foot Orthosis ◽  
Physiological Cost ◽  
Active Flexion ◽  
Quasi Experimental ◽  
Locked Knee ◽  
Foot Orthosis ◽  
Flexion And Extension

Background: A powered knee–ankle–foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. Objective: The purpose of this study was to determine its effect on the physiological cost index, walking speed and the distance walked in people with poliomyelitis compared to when walking with a knee–ankle–foot orthosis with drop lock knee joints. Study design: Quasi experimental study. Methods: Seven subjects with poliomyelitis volunteered for the study and undertook gait analysis with both types of knee–ankle–foot orthosis. Results: Walking with the powered knee–ankle–foot orthosis significantly reduced walking speed ( p = 0.015) and the distance walked ( p = 0.004), and also, it did not improve physiological cost index values ( p = 0.009) compared to walking with the locked knee–ankle–foot orthosis. Conclusion: Using a powered knee–ankle–foot orthosis did not significantly improve any of the primary outcome measures during walking for poliomyelitis subjects. Clinical relevance This powered knee–ankle–foot orthosis design did not improve the physiological cost index of walking for people with poliomyelitis when compared to walking with a knee–ankle–foot orthosis with drop lock knee joints. This may have been due to the short training period used or the bulky design and additional weight of the powered orthosis. Further research is therefore warranted.

The effect of a knee ankle foot orthosis incorporating an active knee mechanism on gait of a person with poliomyelitis

2013 ◽  
Vol 37 (5) ◽  
pp. 411-414 ◽  
Author(s):  
Mokhtar Arazpour ◽  
Ahmad Chitsazan ◽  
Monireh Ahmadi Bani ◽  
Gholamreza Rouhi ◽  
Farhad Tabatabai Ghomshe ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Walking Speed ◽  
Horizontal Displacement ◽  
Step Length ◽  
Knee Extension ◽  
Knee Joints ◽  
Ankle Foot Orthosis ◽  
Stance Control ◽  
Control Knee ◽  
Foot Orthosis

Background: The aim of this case study was to identify the effect of a powered stance control knee ankle foot orthosis on the kinematics and temporospatial parameters of walking by a person with poliomyelitis when compared to a knee ankle foot orthosis. Case description and methods: A knee ankle foot orthosis was initially manufactured by incorporating drop lock knee joints and custom molded ankle foot orthoses and fitted to a person with poliomyelitis. The orthosis was then adapted by adding electrically activated powered knee joints to provide knee extension torque during stance and also flexion torque in swing phase. Lower limb kinematic and kinetic data plus data for temporospatial parameters were acquired from three test walks using each orthosis. Findings and outcomes: Walking speed, step length, and vertical and horizontal displacement of the pelvis decreased when walking with the powered stance control knee ankle foot orthosis compared to the knee ankle foot orthosis. When using the powered stance control knee ankle foot orthosis, the knee flexion achieved during swing and also the overall pattern of walking more closely matched that of normal human walking. The reduced walking speed may have caused the smaller compensatory motions detected when the powered stance control knee ankle foot orthosis was used. Conclusion: The new powered SCKAFO facilitated controlled knee flexion and extension during ambulation for a volunteer poliomyelitis person. Clinical relevance The powered stance control knee ankle foot orthosis has the potential to improve knee joint kinematics in persons with poliomyelitis when ambulating.

scholarly journals Prediction of Functional Outcome at Six Months Following Total Hip Arthroplasty

2012 ◽  
Vol 92 (11) ◽  
pp. 1386-1394 ◽  
Author(s):  
Emily J. Slaven
Keyword(s):  
Body Mass Index ◽  
Logistic Regression ◽  
Total Hip Arthroplasty ◽  
Functional Outcome ◽  
Body Mass ◽  
Hip Arthroplasty ◽  
Walking Speed ◽  
Assistive Device ◽  
Total Hip ◽  
Cart Analysis

Background Recovery of function such as the ability to walk without an assistive device after total hip arthroplasty (THA) is not always automatic. Objective This study investigated whether predetermined variables could be used to identify patients who might have functional limitations at 6 months following THA. Design A prospective, observational cohort design was used. Method Demographics and baseline measures, including age, sex, and preoperative Lower Extremity Functional Scale (LEFS) score, were collected 1 to 3 weeks prior to surgery from 40 participants who were scheduled to undergo THA. Six weeks after surgery, a second LEFS score was recorded along with each participant's body mass index and the THA procedure performed; walking speed and balance also were assessed at this time using the 10-Meter Walk Test, the Timed “Up & Go” Test, and the Functional Reach Test. At 6 months following surgery, each participant's functional outcome was determined from the final LEFS score and the need for an assistive device. Classification and regression tree (CART) analyses and logistic regression were used to establish which of the variables could predict outcome at 6 months. Results Body mass index, sex, and age were identified by CART analysis as predictors to classify participants who did not reach successful outcome status. Logistic regression revealed that sex (female) was the only individual variable that predicted outcome at 6 months. Walking speed was the only performance variable identified as a predictor for outcome using CART analysis. Limitations Only a limited number of variables were observed due to the small sample size. Conclusion It is possible to identify those patients who are at risk for an unsuccessful outcome through the use of variables such as body mass index, age, and sex.

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