A Robotic Ankle-Foot Orthosis for Daily-Life Assistance and Rehabilitation

2018 ◽  
Author(s):  
Md Rejwanul Haque ◽  
Hao Zheng ◽  
Saroj Thapa ◽  
Geza Kogler ◽  
Xiangrong Shen
Keyword(s):  
Daily Life ◽  
Human Movement ◽  
Gear Ratio ◽  
Assistive Device ◽  
Wearable Robot ◽  
Performance Goal ◽  
Natural Interaction ◽  
Ankle Foot Orthosis ◽  
Finite State ◽  
Foot Orthosis

The ankle plays an important role in human movement as it supplies the majority of energy to support an individual’s walking. In this paper, the authors present a robotic ankle-foot orthosis (RAFO), which is essentially a wearable robot that acts in parallel to the user’s biological ankle for motion assistance. Unlike most of the existing robotic ankle-foot ortheses, the RAFO in this paper is a compact and portable assistive device with full energy autonomy, which enables its use in a user’s daily life without the typical limitation associated with tethered operation. The primary performance goal in the design of the RAFO is to provide a torque capacity equivalent to 35% of a 75 kg healthy person’s maximum ankle torque in slow walking, while keeping the weight of the device less than 2 kg. To reach such goal, the orthotic joint is actuated with a compact flat motor coupled with a two-stage transmission that provides a total 200:1 gear ratio. Additionally, a novel two-degree-of-freedom (2-DOF) joint design is incorporated. In addition to the powered dorsiflexion – plantarflexion, the 2-DOF joint also allows passive inversion – eversion of the joint, which greatly improves the comfort in the prolonged wearing of the device. For the control of the powered joint, a finite-state, friction-compensated impedance controller is developed to provide natural interaction with the user and reliable triggering of the powered push-off in walking. A prototype of the RAFO has been fabricated and assembled, and preliminary results demonstrated its effectiveness in assisting the user’s locomotion in treadmill walking experiments.

scholarly journals Gastrocnemius operating length with ankle foot orthoses in cerebral palsy

2016 ◽  
Vol 41 (3) ◽  
pp. 274-285 ◽  
Author(s):  
Hwan Choi ◽  
Tishya Anne Leong Wren ◽  
Katherine Muterspaugh Steele
Keyword(s):  
Cerebral Palsy ◽  
Classification System ◽  
Daily Life ◽  
System Level ◽  
Foot Orthoses ◽  
Functional Classification ◽  
Ankle Foot Orthosis ◽  
Ankle Foot Orthoses ◽  
Children With Cerebral Palsy ◽  
Foot Orthosis

Background:Many individuals with cerebral palsy wear ankle foot orthoses during daily life. Orthoses influence joint motion, but how they impact muscle remains unclear. In particular, the gastrocnemius is commonly stiff in cerebral palsy. Understanding whether orthoses stretch or shorten this muscle during daily life may inform orthosis design and rehabilitation.Objectives:This study investigated the impact of different ankle foot orthoses on gastrocnemius operating length during walking in children with cerebral palsy.Study design:Case series, within subject comparison of gastrocnemius operating length while walking barefoot and with two types of ankle foot orthoses.Methods:We performed gait analyses for 11 children with cerebral palsy. Each child was fit with two types of orthoses: a dynamic ankle foot orthosis (Cascade dynamic ankle foot orthosis) and an adjustable dynamic response ankle foot orthosis (Ultraflex ankle foot orthosis). Musculoskeletal modeling was used to quantify gastrocnemius musculotendon operating length and velocity with each orthosis.Results:Walking with ankle foot orthoses could stretch the gastrocnemius more than barefoot walking for some individuals; however, there was significant variability between participants and orthoses. At least one type of orthosis stretched the gastrocnemius during walking for 4/6 and 3/5 of the Gross Motor Functional Classification System Level I and III participants, respectively. AFOs also reduced peak gastrocnemius lengthening velocity compared to barefoot walking for some participants, with greater reductions among the Gross Motor Functional Classification System Level III participants. Changes in gastrocnemius operating length and lengthening velocity were related to changes in ankle and knee kinematics during gait.Conclusion:Ankle foot orthoses impact gastrocnemius operating length during walking and, with proper design, may assist with stretching tight muscles in daily life.Clinical relevanceDetermining whether ankle foot orthoses stretch tight muscles can inform future orthotic design and potentially provide a platform for integrating therapy into daily life. However, stretching tight muscles must be balanced with other goals of orthoses such as improving gait and preventing bone deformities.

Implementation of robotic ankle–foot orthosis with an impedance-based assist-as-needed control strategy

2021 ◽  
pp. 1-40
Author(s):  
Bing Chen ◽  
Bin Zi ◽  
Bin Zhou ◽  
Zhengyu Wang
Keyword(s):  
Level Control ◽  
Ankle Foot Orthosis ◽  
Low Level ◽  
Ankle Impedance ◽  
Torque Generation ◽  
Ankle Rehabilitation ◽  
Finite State ◽  
Proportional Derivative Controller ◽  
High Level ◽  
Foot Orthosis

Abstract In this paper, a robotic ankle–foot orthosis (AFO) is developed for individuals with a paretic ankle, and an impedance-based assist-as-needed controller is designed for the robotic AFO to provide adaptive assistance. First, a description of the robotic AFO hardware design is presented. Next, the design of the finite state machine is introduced, followed by an introduction to the modelling of the robotic AFO. Additionally, the control of the robotic AFO is presented. An impedance-based high-level controller that is composed of an ankle impedance based torque generation controller and an impedance controller is designed for the high-level control. A compensated low-level controller that is composed of a braking controller and a proportional-derivative controller with a compensation part is designed for the low-level control. Finally, a pilot study is conducted, and the experimental results demonstrate that with the proposed control algorithm, the robotic AFO has the potential for ankle rehabilitation by providing adaptive assistance. In the assisted condition with a high level of assistance, reductions of 8% and 20.1% of the root mean square of the tibialis anterior and lateral soleus activities are observed, respectively.

scholarly journals Carbon fibre reinforced plastic knee-ankle-foot orthosis with a partially flexible thigh cuff: A modification for comfort while sitting on a toilet seat

2007 ◽  
Vol 31 (2) ◽  
pp. 133-137 ◽  
Author(s):  
K. Hachisuka ◽  
K. Arai ◽  
M. Arai
Keyword(s):  
Carbon Fibre ◽  
Daily Life ◽  
Acrylic Resin ◽  
Carbon Fibres ◽  
Ankle Foot Orthosis ◽  
Toilet Seat ◽  
Reinforced Plastic ◽  
Carbon Fibre Reinforced Plastic ◽  
Foot Orthosis

At the request of a polio survivor, a partially flexible thigh cuff made of leather and canvas for a carbon KAFO was devised to allow the wearer to feel more comfortable while sitting on a toilet seat. The original, acrylic resin, thigh cuff was partially excised to make an opening (15×10 cm), which was stuffed with rubber sponge, and was sealed with leather and canvas. The opening's surround was vertically and horizontally reinforced with carbon fibres. This modification provided relief to the polio survivor from the discomfort previously experienced while sitting on a toilet seat, and satisfied her needs in daily life.

scholarly journals Use and usability of custom-made knee-ankle-foot orthoses in polio survivors with knee instability: A cross-sectional survey

2021 ◽  
Author(s):  
Bart Raijmakers ◽  
Roelofine A. Berendsen-de Gooijer ◽  
Hilde E. Ploeger ◽  
Fieke S. Koopman ◽  
Frans Nollet ◽  
...  
Keyword(s):  
Daily Life ◽  
Walking Ability ◽  
Foot Orthoses ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Ankle Foot Orthosis ◽  
Custom Made ◽  
Ankle Foot Orthoses ◽  
Polio Survivors ◽  
Foot Orthosis

Objective: To investigate the use of custom-made knee-ankle-foot-orthoses in daily life and differences in usability factors of knee-ankle-foot-orthoses between users and discontinued users. Design: Cross-sectional survey study. Subjects: A total of 163 polio survivors provided with a knee-ankle-foot-orthosis at an outpatient clinic of a university hospital. Methods: Use and usability of knee-ankle-foot-orthoses in daily life were assessed with a postal questionnaire. Usability factors were formulated using the International Organization for Standardization (ISO) 9241-11 standard. Results: A total of 106 respondents (65%) returned the questionnaire. Of these, 98 were eligible for analysis. Seventy-four respondents (76%) reported using their knee-ankle-foot-orthosis. Compared with discontinued users (24%), users experienced more limitations when walking without an orthosis (p = 0.001), were more often experienced with wearing a previous orthosis (p < 0.001) and were more often prescribed with a locked rather than a stance-control knee-ankle-foot-orthosis (p = 0.015). Furthermore, users reported better effectiveness of their knee-ankle-foot-orthosis (p < 0.001), more satisfaction with goals of use and knee-ankle-foot-orthosis-related aspects (p < 0.001). Conclusion: The majority of polio survivors used their custom-made knee-ankle-foot-orthoses in daily life. Factors related to continued use, such as walking ability without orthosis, expectations of the orthosis, previous orthosis experience and type of knee-ankle-foot-orthosis provided, should be considered and discussed when prescribing a knee-ankle-foot-orthosis in polio survivors. 

scholarly journals Development of an ankle – foot orthosis with an oil damper

2005 ◽  
Vol 29 (3) ◽  
pp. 209-219 ◽  
Author(s):  
S. Yamamoto ◽  
A. Hagiwara ◽  
T. Mizobe ◽  
O. Yokoyama ◽  
T. Yasui
Keyword(s):  
Mechanical Properties ◽  
Ankle Joint ◽  
Essential Feature ◽  
Plantar Flexion ◽  
Eccentric Contraction ◽  
Assistive Device ◽  
Hip Joints ◽  
Ankle Foot Orthosis ◽  
Paretic Side ◽  
Foot Orthosis

The purpose of the present study was to develop an ankle – foot orthosis (AFO) that satisfies the requirements for an AFO for patients with hemiplegia as determined in a previous study. An oil damper has been introduced as an assistive device. The oil damper provides a resistive moment to plantar flexion of the ankle joint during initial stance on the paretic side. This function improves the insufficient eccentric contraction of the dorsiflexors. The magnitude of the resistive moment generated by this newly developed AFO can be changed easily to adjust its properties in accordance with the requirements of each patient. The mechanical properties of the AFO were measured, and the results showed that the AFO generated a sufficient resistive moment. Hemiplegic gaits with various types of AFOs were assessed, and it was found that the properties of the AFO affected the movements of the ankle, the knee, and the hip joints. The effects of the resistive moment on the alignment of the shank to the floor during initial stance are also discussed. Based on the results of this study, it is concluded that adjustability will be an essential feature for future AFOs.

Can a new ergonomical ankle–foot orthosis (AFO) device improve patients’ daily life? A preliminary study

2019 ◽  
Vol 20 (6) ◽  
pp. 763-772 ◽  
Author(s):  
Redha Taiar ◽  
Chiboub Adel ◽  
Gael Belassian ◽  
Damien Lamare ◽  
Jean Dumont ◽  
...  
Keyword(s):  
Daily Life ◽  
Ankle Foot Orthosis ◽  
Preliminary Study ◽  
Foot Orthosis

scholarly journals Examining Ankle Foot Orthosis Wear Time in Patients With Peripheral Artery Disease

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 211-211
Author(s):  
Sara Myers ◽  
Danae Dinkel ◽  
Mahdi Hassan ◽  
Holly Despiegelaere ◽  
Jason Johanning ◽  
...  
Keyword(s):  
Peripheral Artery Disease ◽  
Assistive Device ◽  
Leg Pain ◽  
Accelerometer Data ◽  
Peripheral Artery ◽  
Post Intervention ◽  
Ankle Foot Orthosis ◽  
Wear Time ◽  
Artery Disease ◽  
Foot Orthosis

Abstract Peripheral artery disease (PAD) impacts over 8.5 million Americans and the prevalence of PAD increases with age. PAD restricts blood flow to the leg and its most common manifestation is claudication, a severe impairment of walking produced by ischemia-related, leg pain during exercise. An ankle foot orthosis (AFO) could improve these symptoms. To understand the potential impact of AFO usage, it is critical to determine wearability of the device in patients with PAD. The purpose of this study was to monitor wear time of an AFO and explore perceptions of the device. Participants (n=14) with PAD and claudication wore an AFO for three months. An accelerometer was placed directly on the AFO for 7 days and participants completed semi-structured interviews at midpoint (1.5 months) and post intervention (3 months). Based on accelerometer data at midpoint participants wore the AFO for an average of 4.9±2.3 out of 7 days and for an average of 7.5±4.2 hours each day. At post, participants wore the AFO for an average of 4.8±2.2 days for an average of 7.4±4.6 hours per day. In the interviews, almost all participants noted multiple barriers to wearing the AFO such as difficulty putting the AFO on and off, using stairs, walking on uneven ground, and driving. Our study found that participants wore the AFO ~7 hours/day but experienced barriers which may have limited their wear outside of these monitoring periods suggesting patients would wear an assistive device if design could be improved to address barriers.

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.

scholarly journals Design of an assistive device to detect freezing episodes and provide audio/vibratory cues to avoid falls

2018 ◽  
Vol 7 (2.31) ◽  
pp. 114
Author(s):  
Vivek Chowdhury ◽  
Arka Goswami ◽  
Rakshit Nigam ◽  
P A Sridhar
Keyword(s):  
Parkinson Disease ◽  
Daily Life ◽  
Freezing Of Gait ◽  
Assistive Device ◽  
Parkinsons Disease ◽  
Gait Abnormality ◽  
The Subject

This paper primarily discusses the Freezing of Gait which is a type of gait abnormality and generally occurs in Parkinson Disease patients which cause an interruption to their life. During a FOG episode, the subject is rendered unable to continue moving or even manoeuver. These episodes give rise to the danger of the patient landing on the ground and often renders a person immobile. The aim of this device is to develop a technique to identify the effect of ‘Freezing of Gait’ in people suffering from Parkinsons Disease and to provide feedback on detection and improving self-efficiency in about their daily life.

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