Orthosis Research Articles

Biomechanical effects of foot orthoses on jump landing performance: A systematic review

Jumping is involved in a wide range of sports and activities, and foot orthoses (FO) are suggested to enhance performance and prevent injury. The aim of this systematic review was to investigate whether using FO with different modifications affects jump landing biomechanics and improves performance in healthy individuals. The search strategy included 7 databases that identified 19 studies. The study quality was evaluated using a modified Downs and Black index. The primary outcome measures were joint kinematics, kinetics, muscle activity, vertical jump height, and horizontal jump distance. Our findings indicated that incorporating arch support with a rearfoot post and softer forefoot region into FO may improve several biomechanical variables during jump landing activities. Improvements in vertical ground reaction force loading rates, knee and ankle kinematics, and muscle cocontraction during jumping with FO could enhance jumping performance. In addition, improvements in hip, knee, ankle, and tibial kinematics and vertical ground reaction force loading rates during landing could reduce impact forces and related injuries. Although a limited number of studies have addressed the effects of FO on vertical jump height and horizontal jump distance, inserting such FO inside shoes with optimum bending stiffness could facilitate jumping performance. A rigorous exploration of the effect and mechanism of FO designs on jumping performance could benefit jumping-related activities and prevent ankle and knee injuries.

Efficacy of Lower Limb Orthoses in the Rehabilitation of Children Affected by Cerebral Palsy: A Systematic Review.

Lower limb orthoses are frequently used in children suffering from cerebral palsy (CP) alongside rehabilitation. The aim of this study was to analyze the effectiveness of ankle-foot orthosis (AFO) and knee-ankle-foot orthosis (KAFO) in walking, balance maintenance, spasticity, and quality of life improvement during rehabilitation in children affected by CP. The hypothesis was that the use of orthoses could improve the parameters compared to non-use. A systematic review was conducted in the main databases, including English language RCTs published about the use of AFO and KAFO in combination or not with rehabilitation methods in children affected by CP and studies mentioning walking, balance, muscle length, and quality of life as outcomes. From an initial number of 1484 results, a final number of 11 RCTs were included, comprising a total number of 442 participants and showing an overall high risk of bias in 10 studies and some concerns in one study. Six studies investigated the domain of walking, four studies investigated the domain of balance, and two studies investigated how KAFO and AFO orthoses could improve and prevent muscle contractures. Using highly heterogeneous study designs, different kinds of orthoses and different assessment tools were used. Further studies conducted with higher methodological quality are needed to establish whether AFO and KAFO are useful or not in combination with rehabilitation in improving the investigated domains.

Comparing the effects of lower limb orthoses on knee pain, function, quality of life, and knee joint alignment in people with medial knee osteoarthritis.

The purpose of this study was to compare the impact of three types of orthoses (knee orthosis, ankle foot orthosis (AFO), and foot orthosis) on knee alignment, pain, function, and quality of life in individuals with medial knee osteoarthritis (MKOA). Thirty patients took part in this study and were randomly assigned to three groups (n = 10 in each group) based on the type of intervention. Knee function was assessed using the knee injury and osteoarthritis outcome score (KOOS) questionnaire, and knee alignment was evaluated by measuring angles using the images of bony prominence (AMI) method. After using knee orthosis and AFO, all subscales of KOOS showed significant improvement (p < .05). However, there was no significant difference in the results after using foot orthosis (p > .05). The findings indicate that knee orthosis or AFO for 6weeks can improve clinical outcomes for individuals with MKOA. This suggests that clinicians can consider using knee orthosis and AFO among the available treatment options to improve clinical outcomes.

Provision of ankle foot orthoses for children with cerebral palsy in Norway.

Practice of ankle-foot orthoses (AFO) provision for ambulatory children with cerebral palsy is underreported and the literature is not consistent on choice of AFO-design. This study describes clinical practice of AFO provision for children with cerebral palsy and evaluates how clinical practice aligns with existing recommendations. An online, cross-sectional survey was conducted, inviting all Norwegian orthotists working with children with cerebral palsy. Orthotic practice was investigated using a self-reported survey design. From all eligible orthotists, 54% responded, revealing that AFO provision involves patients, physicians, and physiotherapists at different stages. Patient preference directly influenced the ultimate AFO-design. Shank vertical angle was evaluated by 79%. For children with crouch gait and those with short gastrocnemius, a majority preferred a combination of rigid and articulated/flexible AFO-designs. Instrumented gait analysis was conducted by 51% at AFO delivery stage. The findings show that AFO provision in Norway is collaborative, involving clinical team members and consideration of patient preferences. A discrepancy between clinical practice and existing recommendations for children with crouch gait and those with short gastrocnemius is observed.

Clinical and Radiological Outcomes of Halo Vest Application for Type II and III Odontoid Fractures.

To assess halo vest applications for type II and III odontoid fractures and to ascertain the radiological and clinical outcomes of this approach. A cross-sectional retrospective study was conducted by reviewing the medical charts of selected patients having type II and III odontoid fractures who underwent halo vest treatment at the King Saud Medical City Orthopaedic Department. Radiographic evaluations for the cervical spine (anterior-posterior, lateral, and open-mouth views) were used. Computed tomography scans were used to delineate the extent of the fracture and to measure the magnitude of displacement, the degree of the angulation, the vertebrae involved, and the fracture type. A total of 45 patients with odontoid fractures (55.6% of the patients with type II odontoid fractures and 44.4% of patients with type III) received halo vest treatment. In the present study, in type II odontoid fractures, union was achieved in 15.6% of patients, 28.9% of patients had malunion and 11.1% had nonunion. In type III odontoid fractures, union cases comprised 15.6% of patients, while malunion cases accounted for 28.9% of patients and nonunion cases were found in 4.4% of the patients. The halo vest management for type II and III odontoid fracture requires a prolonged course of cervical immobilisation. Multiple factors contribute to the alteration of the management protocol, patient adherence, and difficulties related to HV, and a significant rate of reduction loss ultimately results in malunion or nonunion.

Machine-learning-based coordination of powered ankle-foot orthosis and functional electrical stimulation for gait control.

This study proposes a novel gait rehabilitation method that uses a hybrid system comprising a powered ankle-foot orthosis (PAFO) and FES, and presents its coordination control. The developed system provides assistance to the ankle joint in accordance with the degree of volitional participation of patients with post-stroke hemiplegia. The PAFO adopts the desired joint angle and impedance profile obtained from biomechanical simulation. The FES patterns of the tibialis anterior and soleus muscles are derived from predetermined electromyogram patterns of healthy individuals during gait and personalized stimulation parameters. The CNN-based estimation model predicts the volitional joint torque from the electromyogram of the patient, which is used to coordinate the contributions of the PAFO and FES. The effectiveness of the developed hybrid system was tested on healthy individuals during treadmill walking with and without considering the volitional muscle activity of the individual. The results showed that consideration of the volitional muscle activity significantly lowers the energy consumption by the PAFO and FES while providing adaptively assisted ankle motion depending on the volitional muscle activities of the individual. The proposed system has potential use as an assist-as-needed rehabilitation system, where it can improve the outcome of gait rehabilitation by inducing active patient participation depending on the stage of rehabilitation.

Design and characterization of a variable-stiffness ankle-foot orthosis.

Ankle-foot orthoses (AFOs) are a type of assistive device that can improve the walking ability of individuals with neurological disorders. Adjusting stiffness is a common way to customize settings according to individuals' impairment. This study aims to design a variable-stiffness AFO by stiffness module and characterize the AFO stiffness range to provide subject-specific settings for the users. We modeled AFO using bending beams with varying fulcrum positions to adjust the stiffness. To characterize the stiffness range and profile, we used the superposition method to generate the theoretical model to analyze the AFO numerically. The intrinsic deformation of the bending beam in the AFO is considered a combination of 2 bending deformations to replicate actual bending conditions. The corresponding experiments in different fulcrum positions were performed to compare with and optimize the theoretical model. The curve fitting method was applied to tune the theoretical model by adding a fulcrum position-related coefficient. The AFO stiffness increased as the fulcrum moved to the proximal position. The maximum stiffness obtained was 1.77 Nm/° at a 6-cm fulcrum position, and the minimum stiffness was 0.82 Nm/° at a 0.5-cm fulcrum position with a 0.43-cm thick fiberglass beam. The corresponding theoretical model had maximum and minimum stiffness of 1.71 and 0.80 Nm/°, respectively. The theoretical model had a 4.08% difference compared with experimental values. The stiffness module can provide adjustable stiffness with the fulcrum position and different kinds of fiberglass bars, especially the thickness and material of the beam. The theoretical model with different fulcrum positions can be used to profile the real-time stiffness of the AFO in a dynamic motion and to determine the appropriate dimensions of the bending beam.

Applying elastic resistance bands for gait training: A simulation-based study to determine how band configuration affects gait biomechanics and muscle activation

BackgroundWearable robotic exoskeletons and leg braces are desirable for gait rehabilitation because they can apply loads directly to an affected joint. Yet, they are not widely used in clinics because they are costly and complex to set up. Conversely, tethered devices, such as elastic resistance bands, are widely available in clinics, are low-cost, and are quick to set up. However, resistance bands will affect walking differently based on how they are configured to pull on the leg (e.g., pulling forward or backward). Research questionHow can a resistance band be configured to alter muscle activation and gait biomechanics based on the segment it is attached to and the angle with which it attaches? MethodsWe used an open-source musculoskeletal modeling platform to emulate several configurations of an elastic band pulling on the ankle, calf, and thigh at various angles during non-pathological walking. We evaluated gait biomechanics and simulated muscle activation using computed muscle control (CMC) and identified a subset of four configurations with potential applications for gait training. Eight non-pathological participants then walked on a treadmill under these configurations to verify how these configurations altered muscle activation. ResultsWe found that muscle activity greatly varied based on the location where the elastic band is attached and the angle with which the elastic band pulls on the leg. Notably, specific angles can be used to pull on the legs to elicit an increase or decrease in muscle activation. SignificanceThis study provides insight into how tethered devices can be configured to provide assistance or resistance during gait training. This information can be applied when developing low-cost gait training solutions for addressing individuals’ impairments.

Immediate Effects of Ankle Eversion Taping on Balance and Gait in Recovering Stroke Patients: A Pre- Post Experimental Study

Background: Poststroke decrement in balance and gait ability disturbs daily routine of patients and increases the risk of falling. Several factors contribute to it, foot drop being one primary cause. Therefore, treating foot drop seems to be a representative approach to retain balance and gait, and the most common available options of treatment are first functional electrical stimulation (FES) and second ankle foot orthosis (AFO). However, FES and AFO are costly, inconvenient, and unattractive. Hence, to avoid these reasons, taping as an ailing method is used, because it is easily applicable and inexpensive. Aims: The aim of this study is to study and compare the effect of ankle eversion taping (AET) on balance and gait ability before and after its application. Settings and Designs: This study was conducted in the outpatient department of physiotherapy (O. P. D. 16) S. S. G. hospital, Vadodara, A pre-post experimental study. Subjects and Methods: Stroke diagnosed 50 patients participated in this study. AET consists of two stages: first of which is the application of tape for posterior talar glide and second stage is eversion taping which places ankle in more everted (neutral) position. Pre- and post-intervention assessment after an hour of an intervention scores of Berg Balance Scale and dynamic gait index were assessed and analyzed. Statistical Analysis Used: Paired t-test was to find out the efficiency of AET on balancing and gait ability in recovering patients of stroke. Results and Conclusions: Obtained P value for both the two outcomes was P &lt; 0.05 at 95% confidence interval, suggesting high significant effect. AET is effective in improving balance and gait and its parameters in recovering stroke patients.

The NewGait Rehabilitative Device Corrects Gait Deviations in Individuals With Foot Drop.

The purpose of this quasiexperimental study was to test the effects of wearing the NewGait rehabilitative device on walking abilities in individuals with foot drop. The study involved 16 participants with foot drops caused by stroke (11 participants), multiple sclerosis (one participant), and peripheral neuropathies (four individuals). During a single testing session, participants walked 12 m at their self-selected speed in four experimental conditions: walking without any orthotic device; walking while wearing a regular plastic posterior leaf ankle foot orthosis (AFO); walking with the NewGait device assisting ankle dorsiflexion only; and walking with the NewGait device assisting the hip, knee, and ankle joint motions. Body motions during walking were recorded using a 3D system for motion analysis and analyzed with a set of spatiotemporal and kinematic parameters and a gait decomposition index. The gait decomposition index indicated sagittal interjoint coordination in the three joint pairs (hip-knee, knee-ankle, and hip-ankle) of the paretic (foot drop) leg during walking and was validated in a previous study. Overall, wearing all three orthotic devices improved the gait velocity, ankle dorsiflexion, and foot clearance compared to gait trials in which no assistive devices were used. However, wearing the AFO significantly restricted the plantarflexion range of motion and decreased interjoint coordination as measured by joint decomposition. In contrast, the NewGait device altered the ankle plantarflexion motions but also increased coordinated movement (reduced the decomposition) in most lower-extremity joint pairs and conditions. Therefore, the NewGait rehabilitative device can be considered superior to a regular AFO in correcting gait deviations caused by foot drop.

Selective orthotic constraint of lower limb movement during walking reveals new insights into neuromuscular adaptation.

A concern expressed by the clinical community is that the constraint of motion provided by an ankle foot orthosis (AFO) may lead the user to become dependent on its stiffness, leading to learned non-use. To examine this, we hypothesized that using an experimental AFO-footwear combination (exAFO-FC) that constrains ankle motion during walking would result in reduced soleus and tibialis anterior EMG compared to free (exAFO-FC) and control (no AFO, footwear only) conditions. A total of 14 healthy subjects walked at their preferred speed (1.34 ± 0.09 m·s-1) for 15 min, in three conditions, namely, control, free, and stop. During the stance phase of walking in the stop condition, ipsilateral soleus integrated EMG (iEMG) declined linearly, culminating in a 32.1% reduction compared to the control condition in the final 5 min interval of the protocol. In contrast, ipsilateral tibialis anterior iEMG declined in a variable fashion culminating in an 11.2% reduction compared to control in the final 5 min interval. During the swing phase, the tibialis anterior iEMG increased by 6.6% compared to the control condition during the final 5 min interval. The contralateral soleus and tibialis anterior exhibited increased iEMG in the stop condition. An AFO-FC functions as a biomechanical motion control device that influences the neural control system and alters the output of muscles experiencing constraints of motion.

Risk of Skull Perforation with Halo Vest Skull Pins.

A halo vest is an immobilization device widely used to stabilize the cervical spine. Pain and infection at the skull pin insertion site are common complications, but skull perforation is rare, and most published studies are case reports. This study aimed to identify risk factors for skull perforation by comparing patients who did and did not develop perforation. Overall thickness and the thicknesses of the internal and external laminae of the skull at the skull pin insertion sites were measured on cranial computed tomography scans of 66 patients fitted with a halo vest. The results were compared between patients who did and did not develop perforation. Four patients developed perforations. All patients with perforation were older women, and their external and internal laminae were significantly thinner than those of patients who did not develop perforation. The reported causes of skull pin perforation include infection around the pin, osteoporosis, and an enlarged frontal sinus. However, most patients with perforation in the present study were older women, and the cause was the thinning of the external and external laminae.

Órtese tornozelo-pé em pacientes com distrofia muscular de Duchenne: um estudo retrospectivo

Abstract Introduction: Duchenne muscular dystrophy (DMD) is a recessive genetic disease linked to the X chromosome, leading to progressive muscle tissue loss. Initially, there is difficulty getting up from the floor and an increased frequency of falls. Maintaining ambulation as long as possible is essential, and the use of ankle-foot orthosis (AFO) has been investigated as an ally in this process. Objective: To verify the prescription and use of an AFO for ambulant boys with DMD. Methods: Information was collected using the medical records of 181 patients with DMD from the Neuropediatric Service of the Instituto de Puericultura e Pediatria Martagão Gesteira of the Universidade Federal do Rio de Janeiro. Variables used were: age at the first medical appointment, age at first symptoms, age at loss of independent gait, time between the first symptoms and loss of gait, prescription of orthosis, time of use, and surgical intervention in the lower limbs. Results: The orthosis was prescribed for 63.5% of patients and used by 38.1%. The range of orthosis time was 2 to 4 years (62.3%). The night sleep period was the most prescribed for orthosis use, with 67.2%. Patients who used the orthosis for a longer time were older at gait loss. However, the children who arrived earlier for the first appointment had a higher frequency of orthosis prescriptions and later loss of gait. Conclusion: The use of AFO can help maintain ambulation for longer in boys with DMD.

Footwear, Orthoses, and Insoles and Their Effects on Balance in Older Adults: A Scoping Review.

Footwear, orthoses, and insoles have been shown to influence balance in older adults; however, it remains unclear which features, singular or in combination, are considered optimal. The aim of this scoping review was to identify and synthesise the current evidence regarding how footwear, orthoses, and insoles influence balance in older adults. Four electronic databases (MEDLINE, CINAHL, Embase, and AMED) were searched from inception to October 2023. Key terms such as "shoe*," "orthoses," "postural balance" and "older people" were employed in the search strategy. Studies meeting the following criteria were included: (i) participants had a minimum age ≥60 years, and were free of any neurological, musculoskeletal, and cardiovascular diseases; (ii) an active intervention consisting of footwear, foot orthoses, or insoles was evaluated; and (iii) at least one objective outcome measure of balance was reported. A total of 56 studies from 17 different countries were included. Three study designs were utilised (cross-sectional study, n = 44; randomised parallel group, n = 6; cohort study n = 6). The duration of studies varied considerably, with 41 studies evaluating immediate effects, 14 evaluating effects from 3 days to 12 weeks, and 1 study having a duration of 6 months. Seventeen different interventions were evaluated, including/consisting of textured insoles (n = 12), heel elevation (n = 8), non-specific standardised footwear and changes in sole thickness or hardness (n = 7 each), sole geometry or rocker soles, contoured or custom insoles and high collar height (n = 6 each), insole thickness or hardness and vibrating insoles (n = 5 each), outsole tread (n = 4), minimalist footwear and slippers (n = 3 each), balance-enhancing shoes, footwear fit, socks, and ankle-foot orthoses (n = 2 each), and eversion insoles, heel cups, and unstable footwear (n = 1 each). Twenty-three different outcomes were assessed, and postural sway was the most common (n = 20), followed by temporo-spatial gait parameters (n = 17). There was uncertainty regarding intervention effectiveness. Overall, features such as secure fixation, a textured insole, a medium-to-hard density midsole and a higher ankle collar, in isolation, were able to positively impact balance. Conversely, footwear with an elevated heel height and the use of socks and slippers impaired balance. There is a substantial body of literature exploring the effects of footwear, orthoses, and insoles on balance in older adults. However, considerable uncertainty exists regarding the efficacy of these interventions due to variability in methodological approaches. Further high-quality research is necessary to determine whether a singular intervention or a combination of interventions is most effective for enhancing balance in older adults.

Verification of the usefulness of shape acquisition using plastic casts during fabrication of a metal strut ankle-foot orthosis.

[Purpose] When fabricating metal strut ankle-foot orthoses, previous studies have reported that shape acquisition is more efficient with a plastic cast than with a plaster of Paris bandage; however, this has not been quantitatively evaluated. This study aimed to clarify the usefulness of plastic casts by quantitatively evaluating the time spent and body shape accuracy among different methods of shape acquisition. [Participants and Methods] We compared the time spent and acquired shapes among the plaster of Paris bandage, plastic cast, and trace methods in 30 limbs of 15 healthy participants. Three-dimensional scans of the lower legs of participants were used as references to compare the three methods. [Results] The plastic cast method required less time than the plaster of Paris bandage method and provided a more accurate shape than the trace method did. However, the plastic cast method resulted in an increased overall width and circumferential diameter owing to the thickness of the stockinette and plastic cast. [Conclusion] The plastic cast method may be useful in reducing the time and burden of fabricating metal strut ankle-foot orthoses. The use of slightly narrow dimensions during the metal strut bending process can account for the increased width and diameter.

Doctor, Can We Reuse this Brace; Patient Attitudes towards Reuse of Orthopedic Braces

Introduction: Climate change presents an important threat to human health and wellbeing. Paradoxically, many facets of healthcare provision contribute significantly to greenhouse gas emissions. An important example of this is the use of single use, disposable orthopedic orthotics, widely dispensed in emergency departments and fracture clinics. This study aimed to understand patients’ attitudes towards climate change, single use plastics, and recycling of orthotics. Materials and methods: Fracture clinic patients wearing orthotics were invited to complete a questionnaire examining attitudes toward climate change and the recycling of orthotics. Questions explored patient attitudes towards climate change, single use plastics and re-use of orthotics. Free text was also included to identify any patient’s perceived concerns regarding brace re-use. Results: 93 out of 211 patients in clinic wore orthoses (44.1%). 40 completed the questionnaire giving a 43% response rate. 95% of patients were aware of climate change, attributing an average importance of 7.7 on a Likert scale of 0 (least important) to 10 (most important). 92.5% understood the issue of single use plastics, ascribing an average score of 8 to this. 90% of patients were willing to recycle their orthosis, with 90% also willing to use a recycled orthosis. Free text analysis revealed concerns with infection and brace integrity. Conclusions: Orthopedic trauma patients recognize the danger of climate change and welcome efforts to address the issue of single use plastic in orthoses by recycling braces. Further research is required to facilitate the production of reusable orthoses and the reprocessing of current orthoses.

A proposed evidence-guided algorithm for the adjustment and optimization of multi-function articulated ankle-foot orthoses in the clinical setting.

Individuals with neuromuscular pathologies are often prescribed an ankle-foot orthosis (AFO) to improve their gait mechanics by decreasing pathological movements of the ankle and lower limb. AFOs can resist or assist excessive or absent muscular forces that lead to tripping, instability, and slow inefficient gait. However, selecting the appropriate AFO with mechanical characteristics, which limit pathological ankle motion in certain phases of the gait cycle while facilitating effective ankle movement during other phases, requires careful clinical decision-making. The aim of this study is to propose an explicit methodology for the adjustment of multi-function articulated AFOs in clinical settings. A secondary aim is to outline the evidence supporting this methodology and to identify gaps in the literature as potential areas for future research. An emerging class of AFO, the multi-function articulated AFO, offers features that permit more comprehensive, iterative, and reversible adjustments of AFO ankle alignment and resistance to ankle motion. However, no standard method exists for the application and optimization of these therapeutic devices in the clinical setting. Here we propose an evidence-guided methodology applicable to the adjustment of multi-function articulated AFOs in the clinical setting. Characteristic load-deflection curves are given to illustrate the idealized yet complex resistance-angle behavior of multi-function articulated AFOs. Research is cited to demonstrate how these mechanical characteristics can help mitigate specific pathologic ankle and knee kinematics and kinetics. Evidence is presented to support the effects of systematic adjustment of high resistance, alignable, articulated AFOs to address many typical pathomechanical patterns observed in individuals with neuromuscular disorders. The published evidence supporting most decision points of the algorithm is presented with identified gaps in the evidence. In addition, two hypothetical case examples are given to illustrate the application of the method in optimizing multi-function articulated AFOs for treating specific gait pathomechanics. This method is proposed as an evidence-guided systematic approach for the adjustment of multi-function articulated AFOs. It utilizes observed gait deviations mapped to specific changes in AFO alignment and resistance settings as a clinical tool in orthotic treatment for individuals with complex neuromuscular gait disorders.

Utility and effectiveness of ankle-foot orthoses in individuals with hemiparesis: a literature review on cerebral palsy and stroke

Utility and effectiveness of ankle-foot orthoses in individuals with hemiparesis: a literature review on cerebral palsy and stroke

Human-Robot Joint Misalignment, Physical Interaction, and Gait Kinematic Assessment in Ankle-Foot Orthoses.

Lower limb exoskeletons and orthoses have been increasingly used to assist the user during gait rehabilitation through torque transmission and motor stability. However, the physical human-robot interface (HRi) has not been properly addressed. Current orthoses lead to spurious forces at the HRi that cause adverse effects and high abandonment rates. This study aims to assess and compare, in a holistic approach, human-robot joint misalignment and gait kinematics in three fixation designs of ankle-foot orthoses (AFOs). These are AFOs with a frontal shin guard (F-AFO), lateral shin guard (L-AFO), and the ankle modulus of the H2 exoskeleton (H2-AFO). An experimental protocol was implemented to assess misalignment, fixation displacement, pressure interactions, user-perceived comfort, and gait kinematics during walking with the three AFOs. The F-AFO showed reduced vertical misalignment (peak of 1.37 ± 0.90 cm, p-value < 0.05), interactions (median pressures of 0.39-3.12 kPa), and higher user-perceived comfort (p-value < 0.05) when compared to H2-AFO (peak misalignment of 2.95 ± 0.64 and pressures ranging from 3.19 to 19.78 kPa). F-AFO also improves the L-AFO in pressure (median pressures ranging from 8.64 to 10.83 kPa) and comfort (p-value < 0.05). All AFOs significantly modified hip joint angle regarding control gait (p-value < 0.01), while the H2-AFO also affected knee joint angle (p-value < 0.01) and gait spatiotemporal parameters (p-value < 0.05). Overall, findings indicate that an AFO with a frontal shin guard and a sports shoe is effective at reducing misalignment and pressure at the HRI, increasing comfort with slight changes in gait kinematics.

Development of Ankle-Foot Orthosis Using Servo Motor with On-Off Control System for Drop-Foot

This research addresses the imperative need for a lightweight, compact, and efficient design of an Active Ankle-Foot Orthosis (AFO), with the potential for everyday use and enhancement of gait cycles in individuals with drop-foot. The proposed AFO employs a servo motor to generate ankle moments based on gait phase detection, ensuring low power consumption and a structurally lightweight configuration. The study encompasses a kinematic analysis of the gait mechanism utilizing a graphical method, facilitating the determination of the requisite force for the motor actuator. Additionally, a finite element approach is employed to assess the strength of linkages. The connecting mechanism utilizes Poly (methyl methacrylate) or PMMA board due to its lightweight nature and ease of fabrication. Based on the simulation result, the minimum safety factor of link bars was 1.8. While, based on the kinematic analysis, the minimum required torque that should be provided by the servo motor is 3.838 Nm. The servo motor serves as the active element within the AFO, and an on-off control system, driven by a rotary encoder detecting gait phases, governs the AFO's movement. Ankle joint angle readings obtained through AFO implementation exhibit values within the range of normal individuals. The entire control system operates with remarkably low power consumption, registering at 0.06 W over one running cycle. Based on these analyses, a prototype has been developed for further evaluation in patient trials, underscoring the potential efficacy and practicality of the proposed active AFO design.