Low Cost, User-Controlled Peroneal Stimulator for Foot Drop in Patients With Stroke

Foot drop is a common disabling condition following stroke. It has been conventionally managed using an ankle foot orthosis (AFO). An alternate rehabilitation option is the functional electrical stimulation (FES) systems that has undergone numerous improvisations over past few decades to make it more efficient and user friendly. This chapter aims to evaluate a prototype low-cost FES device in an Indian rehabilitation set-up to match the patients' cultural and socio-economic needs. It illustrates a pilot study designed to test the orthotic and clinical efficacy of the device in terms of dynamic ankle angle change during ambulation and comparing the walking speed and endurance with the AFO. A significant change with nearly two-thirds of normal ankle angle change during swing phase of the gait cycle was observed with nearly equivalent orthotic effects in terms of walking endurance and speed. In terms of receptivity, the device received a mixed response from the patients regarding its effectiveness as an orthosis.

Effect of Foot Orthoses in Children With Symptomatic Flexible Flatfoot Based on Ultrasonography of the Ankle Invertor and Evertor Muscles

Objective To examine the changes in the cross-sectional area (CSA) ratio of the ankle invertors and evertors following rigid foot orthosis (RFO) application in children with symptomatic flexible flatfoot and to determine the correlation between the degree of change in CSA ratio and pain-severity after RFO application.Methods We included 24 children with symptomatic flexible flatfoot without comorbidities and measured the CSAs of tibialis anterior (TA), tibialis posterior (TP), and peroneus longus (PL) using ultrasonography, resting calcaneal stance position (RCSP) angle, calcaneal pitch (CP), Meary’s angle, talonavicular coverage angle, and talocalcaneal angle using radiography, and foot function index (FFI) at baseline and 12 months after RFO application. We analyzed 48 data by measuring both feet of 24 children. The CSA ratios, the ratio of CSA of each muscle to the sum of CSA of TA, TP, and PL, were also compared. Correlations between the degree of change in FFI, each muscle’s CSA ratio, RCSP angle, and radiographic measurements were investigated.Results Following RFO application, significant increase in the PL ratio and CP and significant decrease in the RCSP angle, FFI total, pain, and disability scores were observed. The degree of change in the total score, pain, and disability score of FFI were significantly correlated with the degree of change in the PL ratio and RCSP angle.Conclusion RFOs applied to children with symptomatic flexible flatfoot might reduce the compensatory activities of the ankle invertors, thereby increasing the PL ratio, and pain decreases as the PL ratio increases.

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

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.

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

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.