Orthosis Research Articles

Do lower limb motor-evoked potentials predict walking outcomes post-stroke?

BackgroundThis observational study examined whether lower limb (LL) motor-evoked potentials (MEPs) 1 week post-stroke predict recovery of independent walking, use of ankle-foot orthosis (AFO) or walking aid, at 3 and...

Peritalar Osteotomy for Rigid Pes Cavus and Cavovarus

Category: Other; Hindfoot Introduction/Purpose: Pes cavus and pes cavovarus deformities create varus loading during stance phase of gait that often presents as lateral ligament instability, peroneal tendon rupture or lateral column overload. When flexible, management ranges from the use of custom foot orthoses or an ankle-foot orthosis, to a combination of soft tissue releases, tendon transfer and/or corrective osteotomy. When rigid, clinical management involves corrective osteotomies or triple arthrodesis. The Ilizarov method of gradual correction of structural bony deformities provides a powerful tool to achieve a stable plantigrade foot in patients with complex multiplanar structural deformities. This investigation presents a method of a continuous multiple bone “peri-talar” osteotomy, combined with acute correction of the multiplanar deformity, for treating severe rigid structural pes cavus and pes cavovarus. Methods: Following IRB approval, patients were identified based on a combination of CPT (Current Procedural Terminology) codes and confirmed by chart review. Standard demographics, etiology of deformity and weight-bearing radiographs (before and after surgery) were reviewed. Perioperative complications, clinical evaluation and type of footwear used were recorded. A favorable clinical outcome was defined as a foot that is ulcer and infection-free, and able to walk in the community with standard oxford shoes. Surgical technique involved an osteotomy from the dorsal calcaneus, carried anterior and inferior for approximately fifty percent of the calcaneus, and then carried anteriorly into the mid cuboid. A second osteotomy through a separate medial incision is made from medial to lateral, splitting the navicular, and connecting to the initial lateral osteotomy. Acute correction of the multiplanar deformity is accomplished. Maintenance of the correction is then achieved with the use of an Ilizarov-like “mitre” circular external fixation construct. Results: 17 patients (three bilateral) were included, with average follow-up of 58.3 (range 12-183) months. One patient developed a postoperative wound infection that required formal surgical debridement. He died of unrelated causes before removal of the external fixator. A second postoperative wound infection was managed with local wound care. One pin-site infection required debridement following removal of the external fixator. Due to the rotational component of the deformities, meaningful measurement of deformity correction could not be accomplished. This clinical outcome was based primarily on the ability to walk without complex bracing. Sixteen of the twenty feet achieved ambulation with standard oxford footwear. Three patients required a short AFO, but were unrestricted community ambulators. A review of the non-standardized x-rays was not able to yield meaningful data. Conclusion: There have been very few clinical reports of surgical correction of patients with severe rigid pes cavovarus or equinovarus deformities. This small series of patients underwent correction of complex rigid pes cavovarus type deformities with a peritalar osteotomy, acute correction of deformity and maintenance of correction with a “mitre frame” circular external fixator. Several proponents of the Ilizarov method have described individual patients with very similar methodology. This small series of patients suggests that one can achieve an acute, or gradual, correction of complex deformity with multiple related osteotomies, and maintenance of that correction with an adjustable circular external fixator.

Conservative Treatment with Arch Support Inflatable Ankle-Foot Orthosis Does Not Correct Progressive Collapsing Foot Deformity: A Prospective Comparative and Controlled Study

Category: Midfoot/Forefoot; Hindfoot Introduction/Purpose: Progressive Collapsing Foot Deformity (PCFD) can present with independent deformities, characterized by five classes: hindfoot valgus (Class A), midfoot abduction (Class B), forefoot varus (Class C), Peritalar Subluxation (PTS) (Class D) and ankle valgus (Class E). Conservative treatment includes the use of corrective insoles and orthotics. Arch support inflatable Ankle-Foot orthoses (IAFO) can help control symptoms in PCFD patients. However, the ability of IAFOs to correct deformities in PCFD is unknown. The aim of this prospective comparative and controlled study was to assess the ability of arch support IAFOs to correct 3D overall PCFD alignment as well as the five different PCFD classes independently. We hypothesized that IAFOs would correct PCFD 3D overall alignment as well as the five independent classes of deformity. Methods: After IRB approval, we enrolled 24 symptomatic PCFD and 24 controls matched on age, sex, and BMI. Flexible PCFD patients and controls were scanned using Weight-Bearing CT (WBCT) with and without an arch support IAFO. The Foot and Ankle Offset (FAO) was used to assess the 3D foot overall alignment. We measured the Hindfoot moment arm (HMA, Class A), the Talonavicular coverage angle (TNCA, Class B), the Meary’s angle and medial cuneiform-to-floor distance (C1-floor) for the Class C and the middle facet uncoverage (MFunco, Class D). No Class E patients were included. Measurements were performed by two fellowship-trained surgeons. A power-analysis hypothesizing that IAFOs would be two times less efficient than the PCFD surgery in correcting the FAO, the requisite number of subjects was 24 per group. Data normality was assessed by Shapiro-Wilk test. Comparisons used normality based paired T-tests or paired-Wilcoxon tests. P-values < 0.05 were considered significant. Results: PCFD measurements performed in controls were all significantly less pronounced than unbraced PCFD patients, confirming the presence of collapse (ps < 0.0001). Comparing PCFD without and with IAFO, the FAO did not show significant improvement (respectively 6.6+/-3.7% vs 5.5+/-4.2%, p=0.101). The HMA (8.8+/-5.8 vs 8.1+/-5.8, p=0.66), the TNCA (24.2+/-10.6 vs 21.9+/-9.7, p=0.44) and the MFunco (37+/-12% vs 31+/-18%, p=0.17) also did not portray significant improvements when applying the IAFOs. The Meary’s angle (17.6+/-7.2 vs 10.8+/-7.3, p=0.002) and C1-floor (17.2+/-3.3mm vs 24.1+/-5.3mm, p< 0.001) were the only to improve significantly with use of IAFOs. When comparing braced PCFD and controls, the only measurement that improved to normal values, similar to controls, in braced PCFD was the C1-floor (24.1+/-5.3mm in PCFD with IAFO vs 25.7+/- 5.4mm in controls, p=0.31). Conclusion: In this prospective comparative and controlled study, we found that arch support IAFOs was not able to correct overall 3D deformity and most of the specific classes in PCFD. The orthosis did not improve hindfoot valgus (Class A), midfoot abduction (Class B) or peritalar subluxation (Class D) in PCFD. The only deformity pattern to improve with the use of IAFOs was the medial longitudinal arch height (Class C). These improvements were expected by the presence of the inflatable bladder of the IAFO on the plantar aspect of the foot, pushing the longitunal arch up but not correcting the entire PCFD.

Ankle Foot Orthosis for Patients with Drop Foot Using Shape-Memory-Alloy Actuators

AbstractGait disorders can lower the quality of life of patients. Drop foot, a causative factor of deviated gait patterns, renders patients unable to lift their forefoot towards the body. Hence, a light and compact ankle–foot orthosis (AFO), which is the most common treatment for drop foot, must be designed, especially for patients with impaired lower limb muscles as oxygen consumption increases by 30% per 1.96 N load on their foot. Furthermore, the limited range of ankle angles in the first 10% of the gait cycle (GC) is a major drawback for patients with drop foot compared to healthy individuals. This limited range of ankle angles can be improved by gaining support from an AFO composed of shape memory alloy (SMA) actuators (SMA-AFO). Therefore, in this study, an SMA was used to fabricate a soft actuator to reduce the weight of the AFO. An adaptive frequency oscillator (AO) was implemented in real time for continuous gait phase detection. Walk tests were performed on a treadmill with the SMA-AFO attached to the participants (N = 3). The experimental results showed that the participants could lift their forefoot in the dorsiflexion direction with an ankle angle of 8.75° in the first 10% of the GC. Furthermore, the current required to operate the SMA actuator can be supplied to only 45.3% of the GC, reducing the power consumption. Therefore, the proposed SMA-AFO can be used in patients with drop foot.

Comparative Effects of Ankle-Foot Orthosis and Functional Electrical Stimulation on Gait Endurance and Participant Preference in Individuals with Foot Drop of Central Pathology: Systematic Review

ABSTRACT Introduction Ankle-foot orthosis (AFO) and functional electrical stimulation (FES) are commonly used interventions for patients with foot drop caused by a central neurological origin. The aim of this systematic review is to analyze the available evidence on the improvement of gait endurance in people with foot drop caused by a central neurological origin when comparing effectiveness of AFO and FES. The secondary aim is to evaluate the available evidence for the difference between the use of FES and AFO on perception of walking function. Methods A literature search was conducted using MEDLINE/PubMed, Cochrane, JBI, CINAHL, Nursing and Allied Health, Ovid Emcare, PsycInfo, Scopus, and Web of Science. All articles published through July 2020 were included in this review. Randomized control trials or crossover trials addressing the comparison of AFO to FES in people with foot drop of central neurological origin on gait endurance and perception of improvement in walking function were assessed. PEDro scale was used to assess methodological quality. Two independent reviewers screened titles, abstracts, and full articles, and a third reviewer resolved any disagreements. Results Twenty-five records were screened with 16 full-text articles assessed for eligibility using the PEDro score. Eleven final studies (PEDro scores range from 5 to 7) were included in qualitative analysis. Only two of the nine studies that evaluated gait endurance reported significant improvement in gait endurance in favor of FES. Seven of the eight studies evaluated the participant preference of device for various walking functions, which showed significance in favor of the use of FES. Conclusions Our review reveals inconclusive evidence to support the use of FES compared with AFO for improving gait endurance. However, qualitative analysis of device preference for walking by participants reveals that FES was the preferred device in this population compared with AFO. Clinical Relevance For patients with foot drop of central nervous system pathology, FES or AFO can be used to improve gait endurance. However, FES may be the preferred device by participants for their walking function.

Comparison of Two Design Principles of Unpowered Ankle-Foot Orthoses for Supporting Push-Off: A Case Study.

Ankle propulsion is essential for efficient human walking. In recent years, several working principles have been investigated and applied to ankle-foot orthoses (AFOs) to enhance the work of the plantarflexor muscles and achieve proper propulsion during gait. Comparing the performance and effectiveness of different designs is difficult because researchers do not have a standardized set of criteria and procedures to follow. This leads to a wide range of tests being conducted, with variations in important factors such as walking speed and assistance provided, which greatly affect users' kinematics and kinetics. In this work, we investigate the possibilities and potential benefits of two of the most important design principles for supporting ankle propulsion with unpowered AFOs. To this end, we present and evaluate two AFO prototypes with springs parallel to the Achilles tendon based on: (i) a linear compression spring, and (ii) a customized leaf spring-cam transmission with a non-linear ankle torque-angle curve. The effects of both AFOs are reported for a case study with one healthy participant using both prototypes at two walking speeds under the same experimental conditions. Large reductions in muscular activity were found when the user received assistance, and ankle kinematics were influenced by the different assistance approaches. This case study was intended as a first step to provide insights on how two promising principles can passively support push-off during gait.

Design of a Quasi-Passive Ankle-Foot Orthosis with Customizable, Variable Stiffness.

Most commercial ankle-foot orthoses (AFOs) are passive structures that cannot modulate stiffness to assist with a diverse range of activities, such as stairs and ramps. It is sometimes possible to change the stiffness of passive AFOs through reassembly or benchtop adjustment, but they cannot change stiffness during use. Passive AFOs are also limited in their ankle mechanics and cannot replicate a biomimetic, nonlinear torque-angle relationship. Many research labs have developed ankle exoskeletons that show promise as viable alternatives to passive AFOs, but they face challenges with reliability, mass, and cost. Consequently, commercial translation has largely failed to date. Here we introduce the Variable Stiffness Orthosis (VSO), a quasi-passive variable stiffness ankle-foot orthosis that strikes a balance between powered and passive systems, in terms of mass, complexity, and onboard intelligence. The VSO has customizable torque-angle relationships via a cam transmission, and can make step-to-step stiffness adjustments via motorized reconfiguration of a spring support along a lead-screw. In this work, we introduce two versions: a nominal and a stiff prototype, which differ primarily in their mass and available stiffness levels. The available torque-angle relationships are measured on a custom dynamometer and closely match model predictions. The experimental results showed that the prototypes are capable of producing ankle stiffness coefficients between 9 - 330 Nm/rad.

Effects of ankle-foot orthosis on gait pattern and spatiotemporal indices during treadmill walking in hemiparetic stroke.

Ankle-foot orthosis (AFO) is known to correct abnormal gait patterns and improve walking stability and speed in patients with hemiparesis. To quantify these benefits in post-stroke gait, a three-dimensional motion analysis of gait pattern was conducted. Forty patients with hemiparesis were enrolled. A three-dimensional motion analysis system was used to analyze patients' treadmill walking with/without an AFO. Outcome measures were 12 abnormal gait indices (forefoot contact, knee extensor thrust, retropulsion of the hip, flexed-knee gait, medial whip in the stance phase, circumduction gait, hip hiking, insufficient knee flexion during the swing phase, excessive lateral shifting of the trunk, contralateral vaulting, excessive hip external rotation, and posterior pelvic tilt), calculated using kinematic data and spatiotemporal indices, and the symmetry index of double-stance and single-stance time and step length. Forefoot contact (without AFO vs. with AFO: 71.0 vs. 65.8, P < 0.001), circumduction gait (65.0 vs. 57.9, P < 0.001), and contralateral vaulting (78.2 vs. 72.2, P = 0.003) were significantly reduced, whereas excessive hip external rotation (53.7 vs. 62.8, P = 0.003) significantly increased during walking with an AFO. Hip hiking (77.1 vs. 71.7) showed marginal reduction with the use of AFO ( P = 0.096). The absolute symmetry index of double-stance time (21.9 vs. 16.1, P = 0.014) significantly decreased during walking with an AFO. AFO effectively mitigates abnormal gait patterns typical of hemiparetic gait. A 3D motion analysis system with clinically oriented indices can help assess intervention efficacy for gait abnormalities.

Properties of abaca/epoxy composites modified by activated carbon particles for orthosis application

Abaca fiber (AF), epoxy (EP), and activated carbon particle (ACPs) incorporated composites have been previously studied to improve their mechanical properties. A study on integrating AF and ACPs to reinforce EP has not been done for comparison. The current study investigates the mechanical (tensile and flexural) and physical (water absorption) properties of AF/EP composites with 20 vol% AF modified by ACPs at 1% to 10% levels, and ACPs/EP composite with 20 vol% ACPs. Optical and scanning electron microscopy examined ACPs and the composite’s fracture surface morphologies. X-ray diffraction was used to identify the ACPs’ phase. The results showed that adding 5 vol% ACPs to AF/EP led to an optimum tensile strength of 42.50 MPa, which was slightly lower than AF/EP (43.00 MPa), and an optimum flexural strength of 62.10 MPa, which was slightly higher than AF/EP (60.50 MPa). Besides, adding 20% ACPs to EP resulted in a tensile strength of 31.93 MPa, higher than the previous result of ACPs/EP (26.34 MPa), also by adding 20% ACPs. Introducing ACPs to AF/EP could reduce water absorption in the composite by 6.52%. The measured flexural modulus of AF/EP added with 5 vol% ACPs was selected as the best material used in the simulation of ankle-foot orthosis (AFO) by Autodesk Inventor integrated with ANSYS Workbench 2019 R1. Applying a load of 27 N resulted in a von Misses stress of 54.018 MPa and a deformation of 44.675 mm.

Segmental instability failures in transmission line towers

This paper presents the results of the detailed studies conducted on premature failures of transmission line towers during full-scale testing. Configuration and proportioning of base width, hamper width, the height of each segment and selection of bracing patterns play a vital role in providing geometric stability to the tower. In the present study, three towers of different voltage clauses failed during testing, investigated and found that geometric instability caused the premature failure. In the case of a 500 kV tower with a rectangular configuration, the staggered bracing pattern continuously for multiple segments for about 20 m height without a diaphragm bracing in between caused geometric instability in the tower. Nonlinear FEA results of the tower modelled with diaphragm bracing showed that tower failure can be prevented by introducing diaphragm bracing at different heights. The 400 kV double circuit dead-end type tower with a 15 m height bottom segment and 161 kV suspension towers analysed based on the conventional static analysis ignoring geometric instability failed prematurely and FE analysis clearly shows the failure due to geometric instability. It is recommended to divide the single segment into two segments such that the included angle between the leg and primary bracing member can be increased, and thereby additional moments in the leg members are reduced by making the bracing member contribute to sharing the shear. The code recommended minimum included angle of 15° between the leg and primary bracing member is only a guiding parameter for the designers. Based on this study, it is recommended that the designers shall check the tower geometry for segmental / panel instability by modelling and nonlinear FE analysis of the tower with beam elements in place of conventional space truss elements.

The Determination of Assistance-as-Needed Support by an Ankle-Foot Orthosis for Patients with Foot Drop.

Patients who suffer from foot drop have impaired gait pattern functions and a higher risk of stumbling and falling. Therefore, they are usually treated with an assistive device, a so-called ankle-foot orthosis. The support of the orthosis should be in accordance with the motor requirements of the patient and should only be provided when needed, which is referred to as assistance-as-needed. Thus, in this publication, an approach is presented to determine the assistance-as-needed support using musculoskeletal human models. Based on motion capture recordings of multiple subjects performing gaits at different speeds, a parameter study varying the optimal force of a reserve actuator representing the ankle-foot orthosis added in the musculoskeletal simulation is conducted. The results show the dependency of the simulation results on the selected optimal force of the reserve actuator but with a possible identification of the assistance-as-needed support required from the ankle-foot orthosis. The required increase in support due to the increasing severity of foot drop is especially demonstrated with the approach. With this approach, information for the required support of individual subjects can be gathered, which can further be used to derive the design of an ankle-foot orthosis that optimally assists the subjects.

Influence of Undergarments on the Comfort Level of Scoliosis Brace Wearers.

Bracing has proven to be an effective method for the conventional treatment of scoliosis in young people. A brace, a therapeutic device, covers the upper body and promotes healing by applying pressure to specific areas. However, wearing a scoliosis brace negatively affects the user's thermo-physiological well-being and often leads to discomfort. In this study, we investigated the influence of T-shirts as an undergarment on the thermo-physiological well-being of the brace wearer. For this purpose, we performed a comparative analysis of six T-shirts made from different special knitted fabrics. We carried out wearing tests in a computer-controlled climate chamber according to a predetermined protocol. The test subject wore the orthopedic brace over the different T-shirts at three different temperatures. The results indicate that the knitted fabrics of undergarments and environmental conditions considerably impact the wearer's thermo-physiological comfort. In the tests, the T-shirts made from the selected functional fabrics performed very well. The T-shirt made from the classic cotton fabric containing elastane yarn also performed well and was the most environmentally friendly. Currently, due to its lower price and easier availability, this cotton T-shirt can be recommended for wearing under a scoliosis brace.

Secondary Reconstruction of Late Deformities of the Orbitozygomaticomaxillary Complex using a Halo Device.

Reconstructing late deformities of the orbitozygomaticomaxillary complex after inadequate treatment of facial fractures requires zygomatic osteotomy to reposition the bony fragments to their anatomical position. However, confirming the position of the bone fragments can be challenging due to the loss of anatomic landmarks caused by bone remodeling, and swelling resulting from surgery, which might hinder locating the bone from the body surface. Here, the authors describe fixation of the halo of the Blue Device multi-vector distraction system to the patient's ear canal, with alignment of the position of the zygoma by measuring the distances between the halo and zygoma using several reference points. This technique allows for measurement not only from the body surface using a K-wire but also directly to the bone using a needle. The authors applied this technique in 2 cases of post-traumatic deformities after complex zygomatic fractures. Both cases achieved an almost symmetrical appearance of the infraorbital region.

Short-term effect of a carbon fiber custom dynamic orthosis and integrated rehabilitation on self-reported physical function, pain, speed, and agility in civilians.

Ankle-foot orthoses (AFOs) are widely used to restore mobility and reduce pain in individuals with lower extremity pain and disability. The use of a carbon fiber custom dynamic orthosis (CDO) with integrated physical training and psychosocial intervention has been shown to improve outcomes in a military setting, but civilian data are limited. To use existing clinical data to evaluate the initial effectiveness of an integrated CDO and rehabilitative program and identify baseline characteristics that impact patient response to the intervention. Retrospective cohort. Records of 131 adult patients who received a CDO and device specific training were reviewed. Patient-reported measures of pain and lower extremity function and physical measurements of walking and agility were extracted at baseline and on training completion. A majority of patients reported improved or greatly improved physical function (92%), maximum pain (69%), and typical pain (55%) and experienced improved or greatly improved walking speed (92%) and agility (52%) irrespective of age and sex. Regression models for examining short-term improvement in pain and physical function accounted for 52% (p < 0.001) and 26% (p < 0.001) of the outcome variance, respectively. Improvement in typical pain was influenced by baseline typical and maximum pain, and functional improvement was influenced by sex and baseline physical function. Most patients (92.4%) reported a positive initial outcome after intervention as measured using patient-reported and objective measures.

Design and mechanical testing of an adjustable posterior leaf spring ankle-foot orthosis for patients with drop foot.

This study aimed to design an adjustable posterior leaf spring (PLS) ankle-foot orthosis (AFO) with an affordable material in low-income countries and investigate the mechanical properties between an adjustable PLS AFO and a standard PLS AFO. Static and dynamic mechanical testing. This study preliminarily tested a new adjustable PLS AFO against a standard PLS AFO. Each AFO design was tested with mechanical testing using an Instron 8801 universal testing machine. The stiffness value of the adjustable PLS AFO was greater than that of the standard PLS AFO during the static loading test. The energy dissipated ratios were lower in the adjustable PLS AFO than in the standard PLS AFO. After 110,000 cycles of fatigue testing, the distal rivet of the adjustable PLS AFO became loose, although the standard PLS AFO had no problem. The novel adjustable PLS AFO achieved noninferior mechanical properties except fatigue strength. The connecting area always initiated fatigue failure. It is suggested that this area must be prevented for stress concentration. As a preliminary study, this study is fundamental for future studies.

Efficacy of Personalized Foot Orthoses in Children with Flexible Flat Foot: Protocol for a Randomized Controlled Trial.

Pediatric flat foot (PFF) is a very frequent entity and a common concern for parents and health professionals. There is no established definition, diagnostic method, or clear treatment approach. There are multiple conservative and surgical treatments, the implantation of foot orthoses (FO) being the most used treatment. The evidence supporting FO is very thin. It is not clearly known what the effect of these is, nor when it is convenient to recommend them. The main objective of this protocol is to design a randomized controlled trial to determine if personalized FO, together with a specific exercise regimen, produce the same or better results regarding the signs and symptoms of PFF, compared to only specific exercises. In order to respond to the stated objectives, we have proposed a randomized controlled clinical trial, in which we intend to evaluate the efficacy of FO together with strengthening exercises, compared to a control group in which placebos will be implanted as FO treatment along with the same exercises as the experimental group. For this, four measurements will be taken throughout 18 months (pre-treatment, two during treatment and finally another post-treatment measurement). The combination of FO plus exercise is expected to improve the signs and symptoms (if present) of PFF compared to exercise alone and the placebo FO group. In addition, it is expected that in both conditions the biomechanics of the foot will improve compared to the initial measurements.

Materials and Manufacturing for Ankle–Foot Orthoses: A Review

Ankle–foot orthoses (AFOs) assist patients with gait impairment by correcting ankle and foot deformities, restoring mobility, reducing pain, and providing protection and immobilization. AFOs can effectively manage various types of gait pathologies, including foot drop, crouch gait, equinus gait, and stiff knee gait. AFOs are available in prefabricated or custom‐made forms in various designs. The selection criteria for the fabrication of an AFO are the duration of usage, the amount of applied force, the degree of axial loading, the patient's skin condition, and the cost. The accessibility of diverse materials in the last century has significantly improved orthoses. Ideal orthotic materials must be light, stiff, and strong, and can be made of plastics, metals, polymer‐based composites, leather, or a hybrid of different materials. A deeper understanding of the materials employed in the fabrication of AFOs holds the potential for more advanced and efficient orthoses, which can improve patients’ ability to ambulate in the real world. The present review provides insight into the various materials utilized for the fabrication of AFOs and describes the benefits and challenges associated with the materials. An attempt has also been made to highlight typical gait pathologies and design concepts in response to them.

Design and Evaluation of Hybrid Passive Spring Damper Ankle Foot Orthosis for Gait Performance in Drop Foot Patients: A Feasibility Study.

Passive and hybrid passive Ankle foot orthoses (AFOs) are the prevalent prescription in drop foot patients to prevent toe dragging during the swing phase. While, these AFOs have some limitations like inability to overcome foot slap, limitation in forward propulsion and inappropriate power generate at the push off. The aim of this study was to design a novel spring damper and evaluate the immediate effects of this AFO on improving the ankle kinetic and kinematic in drop foot patients. This AFO was generated from carbon composite frame and foot section with posterior hinge and spring damper actuator that controlled plantar flexion resistance at the early stance, freely dorsi flexion movement with the ability to store energy during mid-stance movement as well as restore this energy at the pre swing phase. This AFO was assessed on ten drop foot patients who used Posterior Leaf Spring AFO conditions and walked at their self-comfortable walking speed. Then the ankle kinetic and kinematic data in two conditions of with PLS (Posterior Leaf Spring) AFO, and novel spring damper AFO were assessed. Results showed a significant improve in the immediate effect of the kinetic and kinematic parameters. In conclusion, spring damper AFO improved all ankle angles in entire gait cycle as well as the ankle moments and power. Therefore, this AFO should be consider as a selective AFO in drop foot patients.

Evaluation of Robotic Ankle-Foot Orthosis with Different Actuators Using Simscape Multibody for Foot-Drop Patients

Gait cycle plays a major role in human locomotion. Patients with neuromuscular problems are unable to walk normally. Foot drop causes difficulty in lifting the front part of the foot and affects the dorsiflexion (DF) and plantar flexion (PF) motion of the foot. Patient with foot drop must use ankle braces to achieve a normal gait. The existing ankle-foot orthosis (AFO) has its own limitations, as it does not produce adequate PF motion. To overcome this scenario, a study was conducted to analyse the two-degrees-of-freedom (DOF) motion of a robotic ankle foot orthosis (RAFO) with a spring-based series elastic actuator (SEA) and scissor actuator. The objective of this paper is to evaluate the two DOF of RAFO with two different actuators using simscape multibody. The RAFO with actuators were designed using Solidworks, and simulation was carried out using simscape multibody, to analyse the 2-DOF motion. The dynamic motion analysis was carried out using block libraries, bodies, joints, constraints, revolute joints, sensors and a proportional integral (PI) controller. From the simulation results, the total range of motion (ROM) 40° (PF angle of –25° and DF angle of 15°) is achieved by the proposed RAFO with different actuators. Further, based on the results, the input power consumption of spring-based SEA was found to be less than the scissor actuator. Similarly, torque and output power generation of the scissor actuator was found to be greater than spring-based SEA to achieve the normal human ROM. Hence, the designer can choose a hybrid actuator for foot-drop-disorder applications.

Surgical management of peroneal nerve injuries.

Traumatic peroneal nerve injuries are typically associated with high-energy injuries. The aim of this study was to evaluate the demographics and outcomes following surgical management of peroneal nerve injuries. Patients evaluated at a single institution with peroneal nerve injuries between 2001 and 2022 were retrospectively reviewed. Mechanism of injury, time to surgery, pre- and postoperative examinations, and operative reports were recorded. Satisfactory outcome, defined as the ability to achieve anti-gravity dorsiflexion strength or stronger following surgery, was compared between nerve grafting and nerve transfers in patients with at least 9 months of postoperative follow-up. Thirty-seven patients had follow-up greater than 9 months after surgery, with an average follow-up of 3.8 years. Surgeries included neurolysis (n=5), direct repair (n=2), tibial motor nerve fascicle transfer to the anterior tibialis motor branch (n=18), or interposition nerve grafting using sural nerve autograft (n=12). At last follow-up, 59.5% (n=22) of patients had anti-gravity strength or stronger dorsiflexion. Nineteen (51.4%) patients used an ankle-foot orthosis during all or some activities. In patients that underwent nerve grafting only across the peroneal nerve defect, 44.4% (n=4) were able to achieve anti-gravity strength or stronger dorsiflexion. In patients that had a tibial nerve fascicle transfer to the tibialis anterior motor branch of the peroneal nerve, 42.9% (n=6) were able to achieve anti-gravity strength or stronger dorsiflexion at last follow-up. There was no statistical difference between nerve transfers and nerve grafting in postoperative dorsiflexion strength (p = 0.51). Peroneal nerve injuries frequently occur in the setting of knee dislocations and similar high-energy injuries. Nerve surgery is not universally successful in restoration of ankle dorsiflexion, with one-third of patients requiring an ankle-foot orthosis at mid-term follow-up. Patients should be properly counseled on the treatment challenges and variable outcomes following peroneal nerve injuries.