Active Ankle Research Articles

Effects of Raised Heel Insole on Muscle Activity during ankle Sudden Inversion in Normal Adults

Raised heel insoles increase the plantar flexion angle of the ankle and cause ankle inversion sprain. The purpose of this study was to artificially create an ankle sudden inversion situation, which is a mechanical situation of actual ankle joint damage, and investigate the effect of the raised heel insole on ankle joint muscle activity. The subjects of this study were forty subjects with normal adults. The subjects performed sudden ankle inversion on the trapdoor with no raised heel insole, insole heights of 3cm, and insole heights of 7cm. The application of the raised heel insole was conducted randomly. The subjects performed the trapdoor test three times using dominant feet with a 60-second rest period between tests. This study assessed muscle activity during sudden ankle inversion three times. Raised heel insoles showed a significant decrease in Tibialis Anterior, Peroneus Longus, and Peroneus Brevis muscle activity than no raised heel insole (p<.05). Raised heel insoles showed a significant increase in Gastrocnemius muscle activity than no raised heel insole (p<.05). Raised heel insoles increase the risk of ankle sprain injury by reducing tibialis anterior and peroneus muscle activity during sudden ankle inversion.

Abstract 4121816: Viral Venture: A Case of Myocarditis and IgA Vasculitis from Adenovirus Infection

Case Description: A 19-year-old man presented to the emergency department for 3 days of shortness of breath, progressive bilateral lower extremity rash, generalized fatigue, and diffuse joint following an earlier visit to urgent care for pharyngitis symptoms. Physical exam was notable for tachycardia, pain with active wrist and ankle range of motion, pharyngeal erythema, cervical adenopathy, and confluent erythematous palpable purpura and petechiae noted on bilateral lower extremities with scattered lesions on his thighs, arms, and back. Laboratory workup notable for markedly elevated high-sensitivity troponin to 3398 ng/L, and elevated CRP. Further workup was notable for normal urinalysis, negative streptococcus antigen, negative ANCA antibodies, ANA, Hepatitis B and C, and cryoglobulins. Imaging and cardiac workup were notable for normal left ventricular function and cardiac MRI notable for late gadolinium enhancement in the anteroapical mid-myocardial region suggestive of myocarditis. Skin biopsy ultimately revealed immunodeposition of IgA on superficial capillaries compatible with a diagnosis of IgA vasculitis. The patient was started on steroids for IgA vasculitis with rapid improvement in his symptoms and he was discharged home in good condition. Discussion: Recognizing the severe complications of viral infection can lead to prompt treatment and prevention of progression to severe end organ damage. Our case highlights rarely reported cardiac involvement of IgA vasculitis secondary to adenovirus infection based on laboratory and imaging diagnosis with cardiac MRI. To date, only 16 cases of cardiac involvement in IgA vasculitis have been reported. This case adds to the limited body of published cases describing this presentation of IgA vasculitis and is also consistent with the results of prior cases suggesting that an immunosuppressive regimen including glucocorticoids may help to prevent disease progression and induce remission in cases with cardiac involvement without the need for endomyocardial biopsy.

Functional Outcome of Tibialis Posterior Tendon Transfer to Tibialis Anterior & Peroneus Longus among Foot Drop Patients- a Prospective Study

Introduction: Foot drop is described as the loss of active ankle dorsiflexion due to neurologic, systemic, or traumatic causes. The purpose of this study was to assess the functional outcome of tibialis posterior tendon transfer to tibialis anterior and peroneus longus in patients with foot drop. Aim of the study: The aim of this study was to evaluate the functional outcome of tibialis posterior tendon transfer to tibialis anterior and peroneus longus in patients with foot drop. Methods: This study was a randomized clinical trial that evaluate the results of tibialis posterior tendon transfer surgeries for patients with foot drop. The patients met certain inclusion and exclusion criteria, and gave written consent before the surgeries. The patients were followed up for six months after the surgery, and evaluated using the Stanmore assessment questionnaire and other measures. Result: The study enrolled 30 patients (26 males and 4 females) with mean age being 35.40 years. We evaluate tibialis posterior tendon transfer to tibialis anterior and peroneus longus for foot drop in the patients. After 24 weeks, all patient improved in foot dorsiflexion, eversion, function, posture, and satisfaction. 26 (86.70%) patients did not need orthosis and 28 (93.30%) had balanced foot posture with no deformity. Conclusion: The results showed all patient had significant improvement after the surgery. Therefore, this study concluded that tibialis posterior tendon transfer can be used effectively and safely for the management of foot drop.

An exploratory study of functional brain activity associated with gross motor function improvement in children with unilateral cerebral palsy

ABSTRACT Purpose Identify relations of gross motor function and primary motor cortex (M1) functional activity pre and post gross motor interventions for children with unilateral cerebral palsy (UCP). Methods Thirteen children with UCP completed a gross motor intervention. Pre/post-intervention functional MRI outcomes included the laterality index (LI), activation volume, and spatial overlap of M1 activation during active ankle dorsiflexion. Advanced gross motor function (Challenge) was assessed pre/post-intervention, and 2–6 months later. Bivariate correlations and linear regression assessed relations between neuroimaging and motor function. Results Mean pre-intervention M1 activity was contralateral during dominant (LI = +0.85, SD 0.21) but variable during the affected (LI = +0.43, SD 0.57) ankle dorsiflexion. Changes in motor function and neuroimaging outcomes were not significantly associated. However, smaller affected ankle activation and less spatial overlap between ankle activations pre-intervention predicted Challenge improvements post-intervention (adjusted R2 = 0.74, p = .001.) Conclusions This exploratory study identified pre-intervention neuroimaging predictors of post-intervention improvements in advanced gross motor function.

Control of stance-leg motion and zero-moment point for achieving perfect upright stationary state of rimless wheel type walker with parallel linkage legs

Abstract The authors have studied models and control methods for legged robots without having active ankle joints that can not only walk efficiently but also stop and developed a method for generating a gait that starts from an upright stationary state and returns to the same state in one step for a simple walker with one control input. It was clarified, however, that achieving a perfect upright stationary state including zero dynamics is impossible. Based on the observation, in this paper we propose a novel robotic walker with parallel linkage legs that can return to a perfect stationary standing posture in one step while simultaneously controlling the stance-leg motion and zero-moment point (ZMP) using two control inputs. First, we introduce a model of a planar walker that consists of two eight-legged rimless wheels, a body frame, a reaction wheel, and massless rods and describe the system dynamics. Second, we consider two target control conditions; one is control of the stance-leg motion, and the other is control of the ZMP to stabilize zero dynamics. We then determine the control input based on the two conditions with the target control period derived from the linearized model and consider adding a sinusoidal control input with an offset to correct the resultant terminal state of the reaction wheel. The validity of the proposed method is investigated through numerical simulations.

Effect of Dry Needling Plus Static Stretching on Plantar Flexors Spasticity in Chronic Stroke Patients.

Stroke is a leading cause of disability worldwide and is often accompanied by complications such as spasticity. Static stretching (SS) is a common physiotherapy intervention for reducing spasticity, whereas dry needling (DN) is a novel approach. However, the combined effects of DN and SS on spasticity have not been thoroughly investigated. Given the pivotal effect of spasticity on daily activities, mitigating spasticity can significantly contribute to restoring patient independence. This study will explore the impact of DN plus SS on spasticity, alpha motor neuron excitability, overall function, and quality of life in patients with chronic stroke. A double-blind, randomized, sham-controlled trial will be conducted in patients with post-stroke spasticity in the plantar flexor muscles. Twentyeight participants will be randomly assigned to either an intervention or control group. The intervention group will receive DN (60s × 3 days/week; 1 week) plus SS (20 min × 5 days/ week; 1 week). The control group will undergo sham DN (60s × 3 days/week; 1 week) and SS (20 min × 5 days/week; 1 week). DN plus SS or sham DN plus SS. Both groups will be assessed at baseline, immediately post-treatment, and after 1 week of follow-up. Outcome measures will include the Modified Modified Ashworth Scale, H-reflex latency, Hmax/Mmax ratio, active and passive ankle dorsiflexion range of motion, timed up and go test, and the EuroQol questionnaire. Results from this randomized, sham-controlled study will provide evidence for the effectiveness of DN in combination with SS for spasticity. The additional impact of DN in conjunction with SS, a widely used method for reducing muscle tone, remains unclear and warrants investigation. This study, with a high level of evidence, aims to address this knowledge gap.

Prospective randomized comparison of functional bracing versus rigid immobilization with early weightbearing after modified percutaneous achilles tendon repair under local anesthesia

ObjectiveThe optimal treatment and rehabilitation strategy for acute Achilles tendon rupture (ATR) remain a debate. This study aimed to compare the results of the two postoperative regimens after treatment for ATR with modified closed percutaneous repair under local anesthesia. MethodsIn a 4-year study, 72 consecutive patients with acute complete ATR were randomized after percutaneous repair into a functional group (FG), using a modified brace (28 males, three females; mean age 41.9 [29–71] years) and an immobilization group (IG), wearing a rigid plaster (28 males, two females; mean age 42.2 [29–57] years), for a period of 6 weeks. Except for immobilization, they followed the same weight-bearing and rehabilitation protocols. The follow-up period was 3 years. The complication rate, active and passive ankle range of motion, standing heel-rise test, clinical outcome using the American Foot and Ankle Society (AOFAS) hindfoot-ankle score, return to the previous activity level, and subjective assessment were assessed. ResultsThere was one rerupture in the IG and two transient sural nerve disturbances in the FG and one in the IG, and one suture extrusion in the IG, with no other complications. The average AOFAS scores were 96.9 ± 4.3 and 96.0 ± 4.9 in the FG and IG, respectively. Patients in the FG reached a final range of motion and muscular strength sooner without limping and were more satisfied with the treatment. No significant differences could be detected between groups according to the results in any of the assessed parameters. ConclusionEarly dynamic functional bracing in patients with ATR treated with modified closed percutaneous repair under local anesthesia resulted in earlier functional recovery with similar final results in terms of complications and functional outcomes, such as rigid postoperative immobilization with standardized rehabilitation and weight-bearing protocol. Level of evidenceI, Prospective randomized study

Design and Implementation of an Active Prosthetic Ankle and Adaptive Equipment for Bike Riding In Lower Limb Amputees

Lower limb amputees often face challenges in regaining mobility andparticipating in physical activities such as bike riding. Existing prosthetic systemsstrive to replicatehuman locomotion; however, conventional prostheticfeetutilized in India typically feature stationary ankles. Despite advancements inprosthetic technology, including hydraulic or externally powered systems, thesesolutions fail to meet the practical requirements of motorcycle riding for thispatient population. To address this issue, this study proposes a cost-effectivesolutioninvolvingthemodificationofmotorcycleswithleft-handthumb-controlledgearshiftingandfore footup-and-downmotion.Thisinnovativeapproach aims to improve mobility and alleviate discomfort for lower limbamputees,facilitatingtheirengagementinmotorcycletransportationwithgreatereaseandsafety.

Interactive Virtual Ankle Movement Controlled by Wrist sEMG Improves Motor Imagery: An Exploratory Study.

Virtual reality (VR) techniques can significantly enhance motor imagery training by creating a strong illusion of action for central sensory stimulation. In this article, we establish a precedent by using surface electromyography (sEMG) of contralateral wrist movement to trigger virtual ankle movement through an improved data-driven approach with a continuous sEMG signal for fast and accurate intention recognition. Our developed VR interactive system can provide feedback training for stroke patients in the early stages, even if there is no active ankle movement. Our objectives are to evaluate: 1) the effects of VR immersion mode on body illusion, kinesthetic illusion, and motor imagery performance in stroke patients; 2) the effects of motivation and attention when utilizing wrist sEMG as a trigger signal for virtual ankle motion; 3) the acute effects on motor function in stroke patients. Through a series of well-designed experiments, we have found that, compared to the 2D condition, VR significantly increases the degree of kinesthetic illusion and body ownership of the patients, and improves their motor imagery performance and motor memory. When compared to conditions without feedback, using contralateral wrist sEMG signals as trigger signals for virtual ankle movement enhances patients' sustained attention and motivation during repetitive tasks. Furthermore, the combination of VR and feedback has an acute impact on motor function. Our exploratory study suggests that the sEMG-based immersive virtual interactive feedback provides an effective option for active rehabilitation training for severe hemiplegia patients in the early stages, with great potential for clinical application.

Functional ankle taping correction on plantar foot ulcer healing in diabetic patients: Randomized controlled trial

BACKGROUND: High pressure in diabetic foot plantar areas causes ulcer formation, leading to disability and amputations. Around 25% of diabetics experience foot ulcers, with prevalence rates varying among Africans, Asians, and Europeans. Egypt has the highest rates, ranging from 6.1% to 29.3%. OBJECTIVE: To investigate the impact of functional ankle taping correction on plantar foot ulcer healing in diabetic patients. METHODS: A double-blinded randomized controlled trial design. A total of 70 patients with plantar foot ulcers PFUs were randomly divided into two groups: group A, which received ankle taping in addition to usual medical therapy and debridement, and group B, which received ankle taping without routine medical treatment and debridement. Over two months, all patients underwent evaluation using a Walkway pressure monitoring system, goniometer, wound workstation, and saline injection. This evaluation aimed to determine maximal peak plantar pressure, active ankle dorsiflexion, wound area, and volume sequentially. RESULTS: Initially, there was no meaningful difference between the two groups. However, after eight weeks of treatment, there was a substantial impact, as indicated by a p-value of 0.001 and an f-value of 87.49 for treatment effect at 95% CI.Furthermore, a statistically significant interaction was found between treatment and time in the ankle-taping group between pre-and post-treatment. However, no difference was identified in the control group. CONCLUSIONS: The correction of ankle taping has a significant impact on various factors, including peak plantar pressure, ankle dorsiflexion, wound area, and wound volume. This correction leads to a reduction in peak plantar pressure, wound area, and volume while also enhancing active ankle dorsiflexion.

The effects of ankle mulligan mobilisation in children with cerebral palsy: A randomized single blind control study.

To assess the impact of range of motion changes before and after Mulligan mobilisation with ankle movement interventions on the daily lives of children with diplegic cerebral palsy. The single blind randomised controlled study was conducted from July 30, 2022, to January 10, 2023, at 3 rehabilitation centres in Hebron, Palestine, after approval from the ethics review committee of Eastern Mediterranean University, Northern Cyprus, and comprised children with cerebral palsy, who were randomised into intervention group IG and control group CG. All the subjects received regular physiotherapy sessions, overseen by their parents, while those in group IG received mobilisation with ankle movement treatment 3 times per week for 4 weeks. Post-intervention assessment of ankle range of motion, balance, functional performance and quality of life was done using a goniometer, the timed up and go test, 88-item gross motor function measure, 6-minute walk test and the cerebral palsy quality of life questionnaire. Data was analysed using SPSS 24. Of the 64 patients, 40(63%) were girls, and 24(37%) were boys. The overall age range was aged 4-12 years. There were 32(50%) patients in each of the two groups. Mobilisation with movement had a significant effect on active and passive range of motion for the left and right ankles (p<0.05) as well as on balance, gross motor function and quality of life (p>0.05). However, mobilisation with movement had no significant effect on the the distance covered during the 6-minute walk test (p>0.05). Mobilisation with movement had a significant impact on active and passive ankle range of motion, balance and quality of life in diplegic children with cerebral palsy, but it had no impact on gait function. The study was registered at the United States National Institutes of Health (ClinicalTrials.gov) with registration number NCT05500924.

Assistance force-line of exosuit affects ankle multidimensional motion: a theoretical and experimental study

BackgroundThe talocrural joint and the subtalar joint are the two major joints of the ankle-joint complex. The position and direction of the exosuit force line relative to these two joint axes can influence ankle motion. We aimed to understand the effects of different force-lines on ankle multidimensional motion.MethodsIn this article, three assistance force line schemes for ankle exosuits were proposed: perpendicular to the talocrural joint axis (PT), intersecting with the subtalar joint axis (IS), and parallel to the triceps surae (PTS). A theoretical model was proposed to calculate the exosuit’s assistance moment. Seven participants completed four experimental tests of ankle plantarflexion, including three passive motions assisted by the PT, PTS and IS schemes, and one active motion without exosuit assistance (Active).ResultsThe simulation results demonstrated that all three exosuits were able to produce significant moments of ankle plantarflexion. Among these, the PT scheme exhibited the highest moments in all dimensions, followed by the PTS and IS schemes. The experimental findings confirmed the effectiveness of all three exosuit schemes in assisting ankle plantarflexion. Additionally, as the assistive force lines approached the subtalar joint, there was a decrease in ankle motion assisted by the exosuits in non-plantarflexion directions, along with a reduction in the average distance of ankle angle curves relative to active ankle motion. Furthermore, the linear correlation coefficients between inversion and plantarflexion, adduction and plantarflexion, and adduction and inversion gradually converged toward active ankle plantarflexion motion.ConclusionsOur research indicates that the position of the exosuit force line to the subtalar joint has a significant impact on ankle inversion and adduction. Among all three schemes, the IS, which has the closest distance to the subtalar joint axes, has the greatest kinematic similarity to active ankle plantarflexion and might be a better choice for ankle assistance and rehabilitation.

Acute effects of self-myofascial release compared to dry needling on myofascial pain syndrome related outcomes: Range of motion, muscle soreness and performance. A randomized controlled trial

Objectivesmyofascial pain syndrome (MPS) is associated with reductions in range of movement (ROM), decrease in physical function and performance and increase in pain in different populations. Elucidating the best prevention and treatment strategies for MPS has been one of the main goals in the last decade. The objective of the present study was to compare the acute effects of self-myofascial foam rolling release (SFR) and dry-needling (DN) techniques on ankle dorsiflexion ROM, soreness post-needling and performance through countermovement jump (CMJ) height. Methodsa prospective crossover design composed by 12 active adults, aged 23.41 ± 1.68 years (weight: 78.33 ± 9.02 Kg; height: 1.79 ± 0.088 m) with active ankle dorsiflexion restriction was performed. Participants were randomized into the SFR and DN techniques to analyze its effects on ankle dorsiflexion ROM, muscle soreness and jump height at pre, post and 24 h post-intervention. Resultssignificant improvements were found by DN on ankle dorsiflexion at 24 h post intervention and muscle soreness by SFR at the same time point. No significant differences were found between conditions. ConclusionsBoth SFR and DN are effective in improving ankle dorsiflexion and performance in young adults without producing an acute effect in muscle soreness.

Active Ankle–Foot Orthosis Design and Computer Simulation with Multi-Objective Parameter Optimization

There are many current active orthosis designs to assist with disabilities related to foot-drop, with most of them intervening during the whole gait cycle. We propose that, for the treatment of foot-drop, it is possible to design an ankle–foot device that will assist a walking user only during the dorsiflexion stages of the gait, avoiding interference with other stages, by using a single actuator with a simple transmission and a suspension block. This design can be improved by the use of multi-objective optimization to obtain a static set of parameters that are applicable to varying initial conditions. We present a computer simulation study of an active ankle–foot orthosis design, based on the interaction of a cam and lever with a suspension block, with the objective of assisting only with dorsiflexion during the gait cycle, leaving the rest of the movements unimpeded while reducing the complexity and weight of the device. This design is validated using a full simulation environment that includes the movements of the lower leg and foot, as they interact with our device and a ground element. As part of the design and validation, we found sets of mechanical and control parameters that provoke adequate output behavior of the orthosis to help the wearer perform a moderate-speed, normal gait. To optimize the design, we proposed three objectives to warrant ankle angle accuracy, minimal oscillations, and low energy consumption. A set of solutions was obtained with multi-objective optimization algorithms NSGA-II and RVEA to tune the parameters of the active orthosis. The solutions set from RVEA resulted in lower mean and standard deviation values for the oscillations and energy objectives in comparison to the solutions from NSGA-II, while for the MSE objective, NSGA-II obtained lower mean and standard deviation; for the energy consumption objective, the mean score using RVEA is 17% less than with NSGA-II. The orthosis is shown to be robust to differences in initial ankle angles. We observed that it is possible to obtain a broad set of solutions with a good performance during the gait cycle in controlled spaces and that in this application, the RVEA algorithm results in a better option for optimization to balance the objectives.

Effects of dry needling on spasticity, cortical excitability, and range of motion in a patient with multiple sclerosis: a case report

BackgroundDry needling is an intervention used by physiotherapists to manage muscle spasticity. We report the effects of three sessions of dry needling on ankle plantar flexor muscle spasticity and cortical excitability in a patient with multiple sclerosis.Case presentationThe patient was a 40-year-old Iranian woman with an 11-year history of multiple sclerosis. The study outcomes were measured by the modified modified Ashworth scale, transcranial magnetic stimulation parameters, and active and passive ankle range of motion. They were assessed before (T0), after three sessions of dry needling (T1), and at 2-week follow-up (T2). Our result showed: the modified modified Ashworth scale was improved at T2 from, 2 to 1. The resting motor threshold decreased from 63 to 61 and 57 at T1 and T2, respectively. The single test motor evokes potential increased from 76.2 to 78.3. The short intracortical inhibition increased from 23.6 to 35.4 at T2. The intracortical facilitation increased from 52 to 76 at T2. The ankle active and passive dorsiflexion ROM increased ~ 10° and ~ 6° at T2, respectively.ConclusionThis case study presented a patient with multiple sclerosis who underwent dry needling of ankle plantar flexors with severe spasticity, and highlighted the successful use of dry needling in the management of spasticity, ankle dorsiflexion, and cortical excitability. Further rigorous investigations are warranted, employing randomized controlled trials with a sufficient sample of patients with multiple sclerosis.Trial registration IRCT20230206057343N1, registered 9 February 2023, https://en.irct.ir/trial/68454

Comparison of Arthroscopic Microfracture for Osteochondral Lesions of the Talus With and Without Small and Shallow Subchondral Cysts.

Whether arthroscopic microfracture is effective in treating cystic osteochondral lesions of the talus (OLTs) remains controversial. In this study, outcome parameters in patients with small and shallow subchondral cysts are compared to patients without cysts with the hypothesis that equivalent outcomes may be found after primary microfracture treatment. From 2018 to 2021, all 50 OLTs treated with arthroscopic microfracture in the authors' hospital were retrospectively reviewed for eligibility. Single unilateral symptomatic lesions were included and divided into the cyst and noncyst groups, whereas kissing lesions and arthritic lesions were excluded. Numeric rating scale (NRS) scores, American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scores, Tegner activity level scores, Foot and Ankle Ability Measure (FAAM) scores, and magnetic resonance (MR) imaging results were used to describe outcomes. A total of 35 patients were included, 16 in the cyst group and 19 in the noncyst group. The patient characteristics were similar between the 2 groups (P > .05). In the cyst group the average cysts depth was 5.0 ± 1.3 mm. After a mean follow-up duration of 36.2 ± 10.2 months, no significant differences were found between the 2 groups in NRS, AOFAS, FAAM, or Tegner score improvement (P > .05). Three patients (19%) in the cyst group had no NRS score improvement. OLTs with small and shallow subchondral cysts can be treated with arthroscopic microfracture and achieve similar outcomes as noncystic lesions. A few cystic lesions may not respond to microfracture treatment. Level III, retrospective comparative study.

PedBotLab: A Novel Video Game–Based Robotic Ankle Platform Created for Therapeutic Exercise for Children With Neurological Impairments

Aims Assess the potential benefits of using PedBotLab, a clinic based robotic ankle platform with integrated video game software, to improve ankle active and passive range of motion, strength, selective motor control, gait efficiency, and balance. Methods Ten participants with static neurological injuries and independent ambulation participated in a 10-week pilot study (Pro00013680) to assess feasibility and efficacy of PedBotLab as a therapeutic device twice weekly. Isometric ankle strength, passive and active ankle range of motion, plantarflexor spasticity, selective motor control of the lower extremity, balance, and gait speed were measured pre- and post-trial. Results Statistically significant improvements were seen in flexibility, active range of motion, and strength in multiple planes of ankle motion. Ankle dorsiflexion with knee flexion and knee extension demonstrated statistically significant results in all outcome measures. No significant changes were observed in gait speed outcomes. Conclusions The use of PedbotLab can lead to improvements in ankle strength, flexibility, and active range of motion for children with static neurological injuries. Future studies aim to evaluate the effect on gait quality and work toward developing a home-based device.

Serious Game with Electromyography Feedback and Physical Therapy in Young Children with Unilateral Spastic Cerebral Palsy and Equinus Gait: A Prospective Open-Label Study.

The clinical effects of a serious game with electromyography feedback (EMGs_SG) and physical therapy (PT) was investigated prospectively in children with unilateral spastic cerebral palsy (USCP). An additional aim was to better understand the influence of muscle shortening on function. Thirty children with USCP (age 7.6 ± 2.1 years) received four weeks of EMGs_SG sessions 2×/week including repetitive, active alternating training of dorsi- and plantar flexors in a seated position. In addition, each child received usual PT treatment ≤ 2×/week, involving plantar flexor stretching and command strengthening on dorsi- and plantar flexors. Five-Step Assessment parameters, including preferred gait velocity (normalized by height); plantar flexor extensibility (XV1); angle of catch (XV3); maximal active ankle dorsiflexion (XA); and derived coefficients of shortening, spasticity, and weakness for both soleus and gastrosoleus complex (GSC) were compared pre and post treatment (t-tests). Correlations were explored between the various coefficients and gait velocities at baseline. After four weeks of EMGs_SG + PT, there was an increase in normalized gait velocity from 0.72 ± 0.13 to 0.77 ± 0.13 m/s (p = 0.025, d = 0.43), a decrease in coefficients of shortening (soleus, 0.10 ± 0.07 pre vs. 0.07 ± 0.08 post, p = 0.004, d = 0.57; GSC 0.16 ± 0.08 vs. 0.13 ± 0.08, p = 0.003, d = 0.58), spasticity (soleus 0.14 ± 0.06 vs. 0.12 ± 0.07, p = 0.02, d = 0.46), and weakness (soleus 0.14 ± 0.07 vs. 0.11 ± 0.07, p = 0.005, d = 0.55). At baseline, normalized gait velocity correlated with the coefficient of GSC shortening (R = -0.43, p = 0.02). Four weeks of EMGs_SG and PT were associated with improved gait velocity and decreased plantar flexor shortening. A randomized controlled trial comparing EMGs_SG and conventional PT is needed.

Design and Development of a Flexible Active Ankle Joint Orthosis for Locomotion Assistance

Design and Development of a Flexible Active Ankle Joint Orthosis for Locomotion Assistance

A Passive Polycentric Mechanism to Improve Active Mediolateral Balance in Prosthetic Walking.

Prosthetic legs are typically passive systems without active ankle control, restricting mediolateral balancing to a hip strategy. Resulting balance control impairments for persons with a lower extremity amputation may be mitigated by increasing hip strategy effectiveness, in which relatively small hip moments of force are adequate for mediolateral balancing. To increase hip strategy effectiveness we have developed a prosthetic leg prototype based on the Peaucellier mechanism, the Sideways Balance Mechanism (SBM). This polycentric mechanism adds a frontal plane degree of freedom, reducing mediolateral body displacements. Adding a passive joint alone introduces instability, in which mediolateral body rotation leads to CoM height loss, ultimately resulting in a fall. The SBM however provides stability typically absent by lengthening under rotation, thereby compensating for CoM height loss. By allowing for both foot rotation (in-/eversion), and increased mediolateral ground reaction force the SBM increases hip strategy effectiveness. We aimed to provide proof of principle that the SBM can improve active mediolateral balance control in prosthetic walking by increasing hip strategy effectiveness compared to a typical set-up. Comparison between a typical set-up and the SBM showed an increased mediolateral ground reaction force at equal hip moments of force for a 2D forwards dynamics computer simulation, and a reduced hip moment of force at equal mediolateral ground reaction force for a case study. Results validate increased hip strategy effectiveness of the SBM compared to a typical set-up, providing proof of principle that adding an SBM to a prosthetic set-up improves mediolateral balance control in prosthetic walking.