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Objective: This paper aims to analyse the human musculoskeletal and energetic adaptation mechanisms when physically interacting with a unilateral knee orthosis during treadmill walking. Methods: Test subjects participated in two walking trials, whereby the orthosis was controlled to deliver five predefined torque profiles of different duration (as % of a gait cycle). The adaptations to assistive torques of different duration were analysed in terms of gait parameters, metabolic effort, and muscle activity. Results: Orthotic assistances kinematic effects remain local to the assisted leg and joint, unlike the muscles spanning the knee joint, which engage in a balancing-out action to retain stability. Duration of assistive torque significantly affects only the timing of the knee joints peak flexion angle in the stance phase, while the observed joint kinematics and muscle activity demonstrate different recovery times upon changing robotic support (washout effects). Conclusion: Human body adaptations to external robotic knee joint assistance during walking take place on multiple levels and to a different extent in a joint effort to keep the gait stable. Significance: This paper provides important insights into the human bodys multiple adaptation mechanisms in the presence of external robotic assistance.

[Purpose] To investigate the effects of a flexible brace, by analyzing whether its usage; the difference in wearing pressure could change the joint position sensation in healthy participants; and develop a flexible knee brace for patients with knee osteoarthritis. [Participants and Methods] The study included eight healthy males with 14 knee joints (mean age, 22.0 ± 3.1 years). To measure joint position sense, an "angle reproduction test" was performed in three experimental conditions: 1) participants not wearing the brace, 2) the brace was secured with an appropriate force, and 3) the brace was fully secured using hook-and-loop fasteners. [Results] No significant difference was observed among groups comprising of those not wearing, those wearing with the standard force, and those wearing with the tight force. When the maximum hook-and-loop fastener was squeezed, the sensory error in joint position was maximized at both 30° and 60° flexion. [Conclusion] Joint position sense improvement was confirmed to be poor by orthosis, and an error occurred in the joint position sense by increasing the wearing pressure in orthosis. In future, measurements should be performed on patients with knee osteoarthritis who have decreased joint position sense and verify the effect of different wearing pressures verified.

Knee orthoses are designed to reestablish the normal kinematics of the knee joint. However, the data on the effectiveness of them on modifying the internal joint kinematics are scarce. The aim of this study was to develop a method to allow accurate comparison of the knee contact kinematics in osteoarthritic (OA) subjects with and without wearing a valgus knee orthosis using imaging techniques. Biplane x-ray images of a subject (68 yrs., female, 1.70 m, 89 kg, left knee) was recorded during a weight-bearing squat at five positions. The same squat trial was repeated while wearing the orthosis. The 3D models of the knee were reconstructed from the biplane x-rays and the joint kinematics as well as the tibiofemoral contact point locations and bone-to-bone distance were compared at each posture. This could be seen as a proof of concept for the use of contact point locations as a parameter for evaluating the effectiveness of knee orthoses.Clinical Relevance- Joint kinematics derived from the skin markers suffer from low accuracy. The real impact of the knee orthoses on the skeleton takes vigorous techniques, which allows detecting the subtle kinematics changes directly at the joint level.

Objective In normal walking, the ground reaction forces pass through the medial compartment of the knee and produce an external adduction torque around the knee joint. External adduction moment of the knee can lead to medial knee osteoarthritis. Adjustment of the knee alignment and modifying the biomechanical forces on the knee can reduce pain, increase performance, and parameters of walking and improve the quality of life. The use of knee orthoses is recommended to remove weight from the affected compartment and reduce pain in patients with knee osteoarthritis. However the effect of the knee orthosis height on external adduction moment and abduction force has not been measured in previous studies, so the purpose of this study was to assess of the new three-point pressure knee orthosis (e-life) on the mentioned parameters in the patients with mild to moderate knee osteoarthritis Materials & Methods The study subjects were 10 patients (9 females, 1 male) with mild to moderate knee Osteoarthritis (OA) that after receiving OA 2 or 3 degree by a specialist, were referred to the Rehabilitation Research Center of the Faculty of Rehabilitation. Each subject spent five different conditions in the study. Ordering and sequencing of the process was done through randomization for each individual. These five stages included no orthosis, orthosis with long lift length, common-loaded orthosis, medium-angle abdominal orthosis, and maxillary abdominal orthosis. In this study, a three-dimensional QTM motion analysis system (Version 7.2, made in Sweden) with seven 100-kHz camera (Produced by Qualisys, USA) and one Kistler force detection plate (500×600 mm, model AA 9260, manufactured by Kistler, Switzerland) was used to collect the kinetic and kinematic data variables of walking at the Musculoskeletal Research Center of Isfahan University of Medical Sciences. Visual 3D software (C-Motion USA Version 4) was used to musculoskeletal modelling of the lower limb. The temporal and spatial parameter, the moments applied to knee joint and knee range of motion were measured for each individual at all stages. SPSS (version 22) was used for data analysis and Shapiro-Wilk test to verify the normal distribution of data. The repeated-measures ANOVA test was used to compare the effect of orthosis on the parameters mentioned before and after the use of knee orthosis. Results Spatial parameters did not show significant differences (P>0.05). There was no significant difference between the range of motion in all three pages in different orthodontic states (P>0.05). The maximum extensor torque was applied to the knee joint without brace, but the results of statistical analysis did not show any significant difference (P>0.05). Adductor torque was significantly lower in orthosis with a lower lever arm than without brace (P

Knee osteoarthritis (OA) is a degenerative condition that critically affects locomotor ability and quality of life and, the condition is particularly prevalent in the senior population. The current review presents a gait biomechanics conceptual framework for designing active knee orthoses to prevent and remediate knee OA. Constant excessive loading diminishes knee joint articular cartilage and, therefore, measures to reduce kinetic stresses due to the fact of adduction moments and joint compression are an essential target for OA prevention. A powered orthosis enables torque generation to support knee joint motions and machine-learning-driven “smart systems” can optimise the magnitude and timing of joint actuator forces. Although further research is required, recent findings raise the possibility of exoskeleton-supported, non-surgical OA interventions, increasing the treatment options for this prevalent, painful and seriously debilitating disease. Combined with advances in regenerative medicine, such as stem cell implantation and manipulation of messenger ribonucleic acid (m-RNA) transcription, active knee orthoses can be designed to incorporate electro-magnetic stimulators to promote articular cartilage resynthesis.

Knee orthosis is commonly used in supporting the knee movement and protecting the anterior cruciate ligament (ACL) injuries from worsening. In clinical practices, there are many types of ready-made orthoses that available in the market. However, different types of orthoses may provide different performances for patient’s knee joint. Therefore, this paper attempt to investigate the performance of knee orthoses for ACL-injured knee. Two groups took part in the study; (Group 1) six ACL-injured, (Group 2) four healthy participants, where two types of knee orthoses were adopted; (Brace 1) hinge brace, (Brace 2) sleeve brace with bilateral hinges. The knee joint motions were calculated using kinematics data while comfortability was conducted through surveys. From the findings, Brace 1 produced normal range of motion (ROM) for internal rotation at 5.47° while Brace 2 fall outside of the normal range at 2.165°. Meanwhile, the external rotation for Brace 1 (-13.25°) was lower than Brace 2 (-33.25°). Furthermore, the comfortability analysis suggested that Brace 1 (60%) was more effective than Brace 2 (40%). To conclude, Brace 1 portrayed optimal performance than Brace 2 during dynamic balance activities with reduction in ROM to prevent excessive knee rotation.

Valgus bracing in medial knee osteoarthritis aims to improve gait function by reducing the loading of the medial compartment. Orthosis composition and optimal adjustment is essential to achieve biomechanical and clinical effectiveness.To investigate biomechanical functionality during gait, pain relief and compliance in patients with knee osteoarthritis using a lightweight adjustable knee unloader orthosis.Prospective observational clinical trial.Instrumented gait analysis in 22 patients with unilateral medial knee osteoarthritis was performed after a 2-week orthosis acclimatisation period. Kinematics and kinetics during gait as well as force transmission from the orthosis to the knee were analysed. Measurements were performed without, at individualised and at reduced orthosis setting. The assessment was supplemented by patient-related pain sensation and compliance questionnaires.Orthosis wear significantly reduced the knee adduction moment by up to 20% depending on orthosis adjustment, whereas pain sensation was significantly reduced by 16%. A significant positive correlation was found between force transmissions and knee adduction moment as well as for frontal knee angle. Compliance was good with a main daily use of 2-6 h.The orthosis provides significant biomechanical improvements, pain relief and good patient compliance. Patients had a biomechanical benefit for the individualised and reduced orthosis adjustments. Clinical relevance In patients with medial knee osteoarthritis, a lightweight medial unloader orthosis effectively reduced external knee adduction moment and pain sensation during daily activities. Thus, use of lightweight orthoses effectively supports conservative treatment in medial knee osteoarthritis.

Conventional knee orthosis are prescribed for people suffering from symptomatic knee osteoarthritis and from anterior cruciate ligament injuries. This case study aims to quantify the biomechanical response of the tibiofemoral joint complex to a non-linear spring-loaded (NLSL) knee joint orthosis (KJO). Joint angles and forces obtained from two dynamic trials were applied to a customized OpenSim computational musculoskeletal model, and a static equilibrium problem was solved at each instant during the squat cycle, with and without a NLSL KJO, to find individual muscle forces of the lower extremity. The NLSL KJO was seen to increase the gluteus maximus muscle force while decreasing the rectus femoris and soleus muscle forces. Due to the increased activation occurring in the gluteus maximus during the brace-on descent, the knee joint axis moved in a less anterior direction then what was seen in the brace-off descent. As a result, the pelvis translated in a more posterior direction due to the tension supplied by the gluteus maximus and the ease of the soleus. Furthermore, knee flexion was decreased in the upright position during the brace-on conditions. Results suggest that the NLSL KJO could be used as a performance tool to encourage a more balanced synergy that employs the posterior chain musculature versus a quadriceps dominant strategy while preventing hyperextension tendencies.

Background: Osteoarthritis (OA) of knee joint is a degenerative disease that results in decreased function and pain. Orthotic devices can reduce knee adduction moment, pain, and improve function in knee OA. The purpose of this study was to examine knee orthosis uptake in reducing pain in patients with knee osteoarthritis. Subjects and Method: A meta-analysis and systematic review was conducted by search published articles from PubMed, Science Direct, Google Sscholar, Mendeley, and Clinical key databases. Keywords used “knee orthosis” OR “KO” AND “valgus knee brace” AND “brace” AND “knee support” AND “valgus knee support” AND “osteoarthritis” AND “patellofemoral osteoarthritis” AND “knee pain” AND “effect knee orthosis for osteoarthritis” AND “randomized controlled trial”. The inclusion criteria were full text and using randomized controlled trial study design. The articles were selected by PRISMA flow chart and the quantitative data were analyzed by Revman 5.3. Results: 6 studies reported that knee orthosis uptake reduces pain in patients with knee osteoarthritis (Mean Difference= -0.53; 95% CI= -1.39 to 0.33; p= 0.230) with heterogeneity I2= 95%. Conclusion: Knee orthosis uptake reduces pain in patients with knee osteoarthritis. Keywords: osteoarthritis, pain, knee orthosis, knee valgus brace Correspondence: Atika Febri Anggriani. Masters Program in Public Health, Universitas Sebelas Maret. Jl. Ir. Sutami 36A, Surakarta 57126, Central Java. Email: atikaanggriani07@gmail.com. Mobile: 085728794960. DOI: https://doi.org/10.26911/the7thicph.05.44

The sit-to-stand (STS) motion is difficult for elderly people in need of care. These individuals generally require assistance from two caregivers in order to go to the toilet-one to help them maintain a standing posture, and the other to assist them in undressing and dressing. Therefore, a robot that could help only one person assist in elder care is very desirable. In previous studies, robots have been designed to assist elderly users to maintain a standing posture by supporting part of their weight during STS motion. However, these robots are big and heavy. In addition, they apply pressure to one part of the body, potentially causing the user discomfort. Here, we consider knee instability or buckling, which is a sudden knee flexion. This represents a situation that one caregiver cannot handle alone. In this study, to prevent knee buckling, we developed a small, lightweight robot knee orthosis. First, we analyzed knee buckling during STS motion, and demonstrated that one caregiver is sufficient when knee buckling is prevented. Next, we developed a robot knee orthosis with a ratchet mechanism and control system to prevent buckling. Finally, we conducted experiments with the developed device, and confirmed its effectiveness in preventing falls.

Walking disturbance is one of the dysfunctions caused by stroke. In walking rehabilitation, it is common to shift to an ankle-foot-orthosis after using a knee-ankle-foot-orthosis for patients with stroke. However, there exist such danger of falling due to knee bending. The purpose of this research is to develop a robotic knee orthosis for hemiplegic patients to prevent falls. The equipment prevents falling by locking the knee joint when knee bending occurs. We analyzed the falling motion according to knee bending and designed the control system focusing on the result that the speed of the center of gravity in the traveling direction becomes zero. In the experiments, we demonstrated the effectiveness of the proposed method by reproducing the knee bending during walking of a healthy subject. As the result, it was demonstrated that the device was operating before the knee bending occurs and it was possible to prevent falls.

Recently, Powered Knee Orthosis (PKO) becomes an essential assisting device in serving rehabilitation activities such as gait, neuropathic gait and stroke gait. Existing PKOs are mainly designed to perform rehabilitation activities and most of them fully utilized PKO to drive knee movement. This may contributed to discouragement of the voluntary able-body to perform knee movement activities and led to muscle degradation. This paper presents the development of PKO for knee swing activities aided by functional electrical stimulation, FES. The PKO is designed with high back-drive ability to allows FES-assisted movement during knee extension. The experiments were implemented on two healthy subjects performing knee swing for three different conditions; Knee swing with PKO, with FES and with both FES and PKO. The knee angle movement were measured and recorded. The results demonstrate the successful of the proposed FES-assisted knee swing with PKO. Thus the developed PKO is able to contribute to the FES-assisted knee swing activities.

The objective of this work was to design and build a fully mechanical knee orthosis. A knee orthosis should both allow control of the angle of flexion of the knee during the stance phase of the gait cycle and leave the joint free during the swing phase. Knee orthoses are normally used to assist the walking of people suffering from muscle weaknesses or gait pathologies in order to avoid excessive knee flexion during the stance phase. The design of the orthosis proposed in the present work is characterized by allowing the knee to be locked at any angle of flexion during the stance phase, and because the orthosis can be unlocked to allow the joint to be released in the swing phase without the action of any external agent, i.e., without requiring external electrical or electronic systems for the control and performance of the orthosis. These characteristics mean that the design can be adapted to the gait of any user. The proposed design consists of a set of three rods, one attached to the user's thigh, another to the calf, and the other to the foot, connected to each other by a self-locking planetary gear train (PGT).

It has long been held that hip abduction compensates for reduced swing-phase knee flexion angle, especially in those after stroke. However, there are other compensatory motions such as pelvic obliquity (hip hiking) that could also be used to facilitate foot clearance with greater energy efficiency. Our previous work suggested that hip abduction may not be a compensation for reduced knee flexion after stroke. Previous study applied robotic knee flexion assistance in people with post-stroke Stiff-Knee Gait (SKG) during pre-swing, finding increased abduction despite improved knee flexion and toe clearance. Thus, our hypothesis was that hip abduction is not a compensation for reduced knee flexion. We simulated the kinematics of post-stroke SKG on unimpaired individuals with three factors: a knee orthosis to reduce knee flexion, an ankle-foot orthosis commonly worn by those post-stroke, and matching gait speeds. We compared spatiotemporal measures and kinematics between experimental factors within healthy controls and with a previously recorded cohort of people with post-stroke SKG. We focused on frontal plane motions of hip and pelvis as possible compensatory mechanisms. We observed that regardless of gait speed, knee flexion restriction significantly increased pelvic obliquity (2.79°, p

International audience; This study is devoted to investigate the influence of a knee orthosis for human walking by using a mathematical model for a 7-links planar biped-composed with two identical legs, two feet and one trunk-with an orthosis attached to both thigh and calf, during walking. In the first part, we design a cyclic walking gait in the sagittal plane for human without the orthosis. The second part we consider that the human looses his muscular possibilities in one of his knees. To overcome his handicap the human is equipped of a knee orthosis. We analyse the positive effect of the orthosis over the assisted knee to track the previous designed reference trajectory. By using at each time an optimisation algorithm, we minimise the torques provided by the human. The numerical tests confirm the possibility to reduce the torque produced in the disabled knee. The next step is to take into account explicitly an information from EMG signal during a walking to modulate the power of the orthosis.

Patients' with a hemiplegic gait and difficulties with activities of daily living may improve through intensive training of their paretic lower limbs. This study examined the possibility of improving their gait by immobilizing the non-paretic knee joint in extension and promoting weight shift toward the paretic side. Single-case ABABA studies were conducted, involving three patients with hemiplegia. The patients walked with their non-paretic knee joints immobilized in extension using a dial-lock knee orthosis during the intervention (B1 and B2) periods. Measurement items included (1) temporal and distance factors and (2) hip, knee, and ankle joint angles during gait. In all subjects, the stance phase was significantly prolonged on the paretic side during all intervention periods following the first baseline (A1) period. In Subject 1, hip extension in the stance phase improved during all intervention periods following the A1 period, and, in Subjects 2 and 3, the knee hyperextension in the stance phase, which was observed during the A1 period, was resolved during the second (A2) and third (A3) baseline periods. Gait training with non-paretic knee immobilization may promote weight shift toward the paretic side to overcome a swing limitation on the immobilized side, consequently providing an opportunity for training in weight bearing for the paretic limb and an improved, more symmetrical gait pattern.

International audience; The knee is the largest joint in the body and supports high loads, up to several times the body weight. It is vulnerable to injury during sport or professional activities, potentially leading to chronic knee instability. This instability is a functional issue to the patient and is characterized by a “wobbly” feeling. Different internal structures take part in joint stabilization by passive (ligaments, capsule) or active (neuro-muscular system and proprioception) action. The most common injury involves the anterior cruciate ligament (ACL) complete or partial rupture: it is involved in 24% of all knee injuries and 59% of ligamentous injuries [1]. In the United States,the annual incidence in the general population is approximately 1 in 3500 with 100,000 ACL reconstructions performed each year [2, 3]. These conditions are a huge burden on individualsand healthcare systems. Diagnosis of knee instability involves a discussion with the patient and a clinical examination, usually the Lachman test. It consists in a manual anterior translation of the tibia aiming at putting the ACL in tension. By practice, the examiner is able to grade the laxity by severity [4]. However, its sensitivity and specificity to detect complete ACL ruptures depends on the experience of the examiner, the patient’s body type and the delay between the accident and examination [5]. In order to reduce this variability, arthrometers were developed.These devices apply an increasing force to induce a postero-anterior drawer and measure the corresponding translation. Displacement-load curves of the healthy and injured knees are compared; ACL rupture is ascertained when differential laxity is higher than a certain threshold. Well-known arthrometer devices are the KT-1000 developed by [6] and the GNRB® [7]. The former is very popular and has been widely studied; its sensitivity to detect complete ACL ruptures is 77% and its specificity 90% (threshold: differential laxity of 3 mm at 130 N). Thelatter was developed recently; two studies [5, 7] highlighted the superiority of this device compared to similar apparatus. A differential threshold of 3 mm at 134 N is used to determine complete rupture: its sensitivity is 70% and specificity 99%. This arthrometer device is also used to diagnose partial ruptures (threshold of 1.5 mm at 134 N) with a sensitivity of 80% and a specificity of 87%.Knee braces or orthoses are usually part of the standard therapy for knee instability and are commonly prescribed by physicians and medical practitioners. Their claimed mechanical effects are to support/align the joint and increase proprioceptive input [8]. However, very few studies actually show significant actions, from biomechanical studies to therapeutic trials [9, 10]. Mechanical/ physiological effects have been emphasized, but the mechanisms of action have been poorly characterized [8, 9, 10, 11, 12, 13]. What is more, subjective evaluations of patients highlight a large demand for these products; therefore, their efficiency is still widely discussed among medical experts. In particular, therelative importance of the two principal stabilizing mechanisms is not known:- joint stiffening by adding supporting structures, e.g. hinged bars secured to the joint by straps and fabric (passive mechanism)- neuromuscular control enhancement by proprioceptive effect (active mechanism)As a consequence of these uncertainties, medical practitioners and manufacturers still lack a simple evaluation tool for knee orthoses. A French committee of experts highlighted this problem [14] and stated that orthoses must be evaluated by taking both the mechanisms of action and the desired therapeutic effects into account.Although the passive action of knee braces to prevent a drawer motion has already been characterized on surrogate limbs [15, 16, 17], only one attempt has been made to link these measures to corresponding expected in-vivo actions through numerical modelling [18, 19], highlighting a passive stiffening much lower than what is brought by intact ligaments. However, a real clinical study is still needed to validate the numerical results and investigate the influence of patient-specific factors such as morphology, injury severity, neuromuscular adaptation and instability feeling control.This study is aimed at objectively quantifying the joint stiffening action of various commercial braces in-vivo using a GNRB® arthrometer on a number of pathological patients.

Existing robotic transtibial prostheses provide only ankle joint actuation and do not restore biarticular function of the gastrocnemius muscle. This paper presents the first powered biarticular transtibial prosthesis, which is a combination of a commercial powered ankle-foot prosthesis and a motorized robotic knee orthosis. The orthosis is controlled to emulate the human gastrocnemius based on neuromuscular models of matched nonamputees. Together with the ankle-foot prosthesis, the devices provide biarticular actuation. We evaluate differences between this biarticular condition and a monoarticular condition with the orthosis behaving as a free-joint. Six participants with transtibial amputation walk with the prosthesis on a treadmill while motion, force, and metabolic data are collected and analyzed for differences between conditions. The biarticular prosthesis reduces affected-side biological knee flexion moment impulse and hip positive work during late-stance knee flexion, compared to the monoarticular condition. The data do not support our hypothesis that metabolism decreases for all participants, but some participants demonstrate large metabolic reductions with the biarticular condition. These preliminary results suggest that a powered artificial gastrocnemius may be capable of providing large metabolic reductions compared to a monoarticular prosthesis, but further study is warranted to determine an appropriate controller for achieving more consistent metabolic benefits., United States. National Aeronautics and Space Administration (Grant NNX12AM16G)

Nowadays, Powered Knee Orthosis (PKO) becomes an important assisting device in helping rehabilitation activities such as hemiplegic gait, neuropathic gait and stroke gait. A few existing PKO are mainly designed to assist the rehabilitation activities. However, most of the developed PKO restricted to external power to drive them to perform knee flexion or extension. This leads to discouragement of natural volunteer able-body in assisting movement with PKO and avoid the use of functional electrical stimulation, FES simultaneously with the developed PKO. This paper presents the design and development of a novel powered knee orthosis with high back-driveability that allows knee free swing activities and knee extension with PKO for rehabilitation purposes. The PKO designed uses the Outrunner type of brushless DC motor (BLDCM) as an actuator that used to give an external power to drive knee flexion or extension and also able to allows natural volunteer able body movement. A knee free swing and knee extension experiments were carried out and tested on three healthy subjects by measuring the knee angle movement both with and without the PKO. The results demonstrate the effectiveness of the proposed PKO. Thus the developed PKO is able to assist knee free swing and knee extension activities with highly back drivability with no external power.

In this study, we evaluate the support effect of a knee orthosis that uses the elasticity element from the perspective of human motor control. The speeds during level-ground walking and the angles during slope walking were varied during the experiments. It was observed that the support effect was remarkable at 4 km/h during the level-ground walking. In particular, at 12° during slope walking, the strength of the stretching muscle decreased for the knee joint in the stance phase and the hip joint in the swing phase. The results show that this orthosis exhibits a different effect from the conventional type adjustment to damping in the swing phase.

State-of-the-art transtibial prostheses provide only ankle joint actuation and thus do not provide the biarticular function of the amputated gastrocnemius muscle. We develop a prosthesis that actuates both knee and ankle joints and then evaluate the incremental effects of this prosthesis as compared to ankle actuation alone. The prosthesis employs a quasi-passive clutched-spring knee orthosis, approximating the largely isometric behavior of the biological gastrocnemius, and utilizes a commercial powered ankle-foot prosthesis for ankle joint functionality. Two participants with unilateral transtibial amputation walk with this prosthesis on an instrumented treadmill, while motion, force, and metabolic data are collected. Data are analyzed to determine differences between the biarticular condition with the activation of the knee orthosis and the monoarticular condition with the orthosis behaving as a free-joint. As hypothesized, the biarticular system is shown to reduce both affected-side knee and hip moment impulse and positive mechanical work in both participants during the late stance knee flexion phase of walking, compared to the monoarticular condition. The metabolic cost of walking is also reduced for both participants. These very preliminary results suggest that biarticular functionality may provide benefits beyond even those of the most advanced monoarticular prostheses., Massachusetts Institute of Technology. Media Laboratory

Several conservative treatments for medial knee osteoarthritis such as knee orthosis and laterally wedged insoles have been shown to reduce the load in the medial knee compartment. However, those treatments also present limitations such as patient compliance and inconsistent results regarding the treatment success.To analyze the effect of an ankle-foot orthosis on the knee adduction moment and knee joint alignment in the frontal plane in subjects with knee varus alignment.Controlled laboratory study, repeated measurements.In total, 14 healthy subjects with knee varus alignment were analyzed in five different conditions: without orthotic, with laterally wedged insoles, and with an ankle-foot orthosis in three different adjustments. Three-dimensional kinetic and kinematic data were collected during gait analysis.Significant decreases in knee adduction moment, knee lever arm, and joint alignment in the frontal plane were observed with the ankle-foot orthosis in all three different adjustments. No significant differences could be found in any parameter while using the laterally wedged insoles.The ankle-foot orthosis was effective in reducing the knee adduction moment. The decreases in this parameter seem to be achieved by changing the knee joint alignment and thereby reducing the knee lever arm in the frontal plane.This study presents a novel approach for reducing the load in the medial knee compartment, which could be developed as a new treatment option for patients with medial knee osteoarthritis.

Patients with medial compartment osteoarthritis of the knee suffer from pain and stiffness. However, current unloader braces are not being used for extended periods by knee osteoarthritis patients due to interface problems, so compliance is an issue. The aim of this study was to design a new bespoke orthosis that could be comfortable to wear while also providing the required correction to reduce medial compartment loading.A new knee orthosis design was initially tested for its frontal plane correction of knee varus using a surrogate knee model. It was then assessed by a volunteer subject with grade 2 medial compartment knee osteoarthritis using a static standing radiograph.When fitted to the surrogate knee model, the brace corrected the knee from 10° of varus to neutral alignment in the frontal plane. When worn in situ during static stance on the affected leg of the volunteer patient, it corrected the knee by 6° to a less varus position.The orthosis provided frontal plane correction of the knee during static standing. It could therefore prove to be suitable for use by knee osteoarthritis patients.

A 16-year-old boy sustained an acute first-time dislocation to his left patella when he was tackled from behind playing rugby, landing directly on the inside of his knee. The knee was immediately swollen. He went to hospital and was admitted, the patella having spontaneously reduced. He was treated conservatively with a free-moving hinged knee orthosis, discharged, and an MRI scan ordered and referred for advice on his further management.

A 54-year-old man was sent for a second opinion having presented 5 weeks previously complaining of right thigh pain for 2 weeks and then heard a pop from his knee which became acutely painful when he was walking. From then he had found it difficult to weight-bear and to straight leg raise. He had pain and tenderness superolateral to his patella. He had not sustained any injury. The pain was so severe that he was unable to move his knee. He had been placed in an extension knee orthosis and was using crutches. At presentation he was investigated and found to have a vastus intermedius tear on ultrasound, which was the working diagnosis. The pain had persisted, and he was really incapacitated, barely able to move his knee, and reluctant to remove his orthosis. He was on a plethora of drugs, including opiates, which were not controlling his pain.

Inclusion Body Myositis (IBM) is an inflammatory myopathy that commonly affects quadriceps strength, resulting in knee buckling and falls. Therefore, patients with IBM should be ideal candidates for stance control orthoses (SCOs).Evaluate the effectiveness of SCO use in patients with IBM who have functional deficits due to quadriceps weakness.Cohort study.Nine subjects with IBM were provided a stance control orthosis and followed for six months of home use. All patients had objective testing of their strength and gait and completed a questionnaire at baseline and six months. Gait analysis was performed both with and without the orthosis.Velocity and cadence were lower and step width was higher when using the orthosis. Kinematic measures were largely unchanged with orthosis use. Subjects with less knee extensor weakness had a better outcome than weaker participants. Those who spent more time wearing the orthosis also had a more positive outcome. The participants felt that the SCO was helpful in safeguarding against falls and providing stability.SCO use will benefit patients with IBM, but care should be taken to choose the SCO option that best suits their individual clinical presentation.This is the first study to examine SCO use in the IBM population. Patients with IBM have quadriceps weakness and will potentially benefit from SCO use. This study suggests that successful SCO management of patients with IBM depends on severity of weakness.

Background: Knee orthosis has been recommended as part of conservative treatment for individuals with knee osteoarthritis (OA). However, the effects of common types of knee orthosis on function and pain during movement are still inconclusive. Objective: To compare the effect of two types of knee orthosis (knee sleeve and OA knee brace) on walking variables and knee pain in individuals with mild to moderate severity of knee OA and to determine the association between knee pain and type of knee orthosis that the participants felt most satisfied with. Materials and methods: Twenty-four individuals (20 females and 4 males) diagnosed with knee OA participated in this study. Participants rated the overall knee pain they experienced in the past month, answered the Knee injury and Osteoarthritis Outcome Score (KOOS) and underwent a 40-meter fast paced walk test in three conditions: no-orthosis, knee sleeve, and OA knee brace. Walking time (second) and speed (meter/second) to complete the test were recorded. After each condition, the participants reported the level of pain during walking by a numerical rating scale (NRS). After completing all the tests, the participants indicated the type of knee orthosis that they felt most satisfied with. One-way repeated measure analysis of variance and Friedman test were used to compare the results from the three conditions. Spearman’s rho was used to examine the correlation between level of pain and the type of knee orthosis that participants chose. The level of significant was set at pknee sleeve>no-orthosis condition. Comparing with no-orthosis, OA knee brace and knee sleeve conditions significantly reduced pain (p

Objective To develop an algorithm to help orthosis prescription for knee osteoarthritis patients. Material/Patients and methods Systematic review of the literature using a qualitative analysis on Pubmed databases, Cochrane Library and Pedro from 1966 to 2015, using the keywords “knee osteoarthritis”, “orthosis” with recommendations and highest quality trials. Development of a preliminary version of the algorithm using data from the literature and taking into account experience of different health professionals involved in the management of osteoarthritis patients. Validation of the algorithm by an international multidisciplinary expert college (PMR and sport medicine physician, rheumatologist, general practitioner, orthopaedic surgeon, physiotherapist, methodologist). New adaptations to obtain an acceptable final version. Results Elastic braces may be proposed in addition to the first-line non-pharmacological treatment (information/education, exercise and physical activity, weight reduction). Secondary a biomechanical analysis may be needed to provide a more rigid brace taking into account: the topography of pain, the lower limb static (varus/valgus), stability, any deformation reducibility. For unicompartimental OA, one can propose an unicompartmental discharge brace; a hinged stabilizing brace for bicompartmental OA with or without instability. For patellofemoral OA we can offer an orthotic with specific patellar device, Discussion/Conclusion Using an original methodology has produced an applicable algorithm in routine. A prospective validation in primary and secondary care to thirty patients is needed followed by an evaluation of the implementation of a wide range of health professionals in order to definitely validate the algorithm.

Individuals with quadriceps muscle weakness often have difficulty generating the knee-extension moments required to complete common mobility tasks. A new device that provides knee-extension moments through a range of knee angles was designed to help individuals perform stand-to-sit and sit-to-stand tasks. The novel knee-extension assist (KEA) was designed as a modular component to be incorporated into existing knee-ankle-foot orthoses or used in a knee orthosis. During stand-to-sit, a set of springs is loaded as the knee flexes under bodyweight and the KEA thus provides a knee-extension moment that aids in achieving a smoothly controlled knee flexion. The springs can be locked in place at the end of knee flexion to prevent unwanted knee extension while the user is seated. The entire knee extension assist can be disengaged to allow free joint motion anytime the affected leg is unloaded. During sit-to-stand, the KEA assists knee extension by returning the energy stored in the springs as an extension moment. In mechanical testing of a prototype of the new KEA, a mean maximum extension moment of 42.9 ± 0.46 Nm was provided by the device during flexion and 28.4 ± 0.28 Nm during extension. A biomechanical evaluation with two able-bodied individuals demonstrated the effectiveness of the KEA in successfully assisting stand-to-sit and sit-to-stand tasks. During stand-to-sit, the KEA provided 82% and 75% of the total (muscle and KEA) knee-extension moment required by the braced leg for the task for the two subjects, respectively; and during sit-to-stand, the KEA provided 56% and 50% of the total knee-extension moment for the two subjects, respectively. This KEA performance exceeded 50% knee-extension moment assistance for a 70 kg person.

Background. Osteoarthritis (OA) is a disease which influences the performance of the knee joint. Moreover, the force and moments applied on the joint increase in contrast to normal subjects. Various types of knee orthoses have been designed to solve the mentioned problems. However, there are other problems in terms of distal migration during walking and the alignment of the orthosis which cannot be changed following the use of brace. Therefore, the main aim of the research was to design an orthosis to solve the aforementioned problems.Method. A new type of knee orthosis was designed with a modular structure. Two patients with knee OA participated in this research project. The force applied on the foot, moment transmitted through the knee joint, and spatiotemporal gait parameters were measured by use of a motion analysis system.Results. The results of the research showed that the adduction moment applied on the knee joint decreased while subjects walked with the new knee orthosis (P-value < 0.05).Conclusion. The new design of the knee brace can be used as an effective treatment to decrease the loads applied on the knee joint and to improve the alignment whilst walking.

Diabetic Osteopathy (diabetic neuroarthropathy, diabetic neuro-osteo-arthropathy, diabetic Charcot's joint) has been found more frequently in recent years ever since Jordan first described Charcot's joint in diabetic neuropathy in 1936.A 41-year-old woman presented herself with pain, in her right knee redness, swelling and a high fever. She had been treated with knee orthosis for diabetic neuroarthropathy of the knee. We suspected a knee infection, and treated her with continuous irrigation, but found no bacteria in the culture. We performed arthrodesis of the knee joint. We will report on diabetic neuroarthropathy and our literaty comments on our recent studies.

This paper presents the numerical methods used for the calculation of the functional axes of the knee joint on different flexion angles with and without knee brace and the axes of the knee brace using MRI data. These methods were developed during a student research project in the framework of the research project “Evaluation of the possibilities of a functional assessment of orthopedic assistive technologies using open MRI” at the Institute of Medical Engineering at the Technical University of Berlin, which is about exemplarily working out methods for determining the congruence of the instantaneous anatomical knee joint axis and a knee orthosis joint axis.

This paper presents – using the examples “knee orthosis” and “patellar stabilizing braces” – a method which delivers an insight into the “patient -orthopedic aid” system using an open low-field MRI, adapted MRI-sequences, MR compatible measurement techniques and self-build software. The basic principle is a consistent three-dimensional image acquisition and reconstruction of bony structures.

Fifty-five older subjects, who had been prescribed a lower leg brace (below knee orthosis - BKO) were interviewed to assess patient satisfaction and compliance. Over 80% of subjects were still using their brace: the majority (81 %) found them comfortable and a similar proportion said they were beneficial to their walking. Nearly half of the subjects (45%) were unable to put on their brace independently. Many of these individuals were very disabled, usually as a result of a stroke. Inability to apply the orthosis was related to disability, but not to patient age nor to the type of brace. Difficulties encountered by users included discomfort caused by the orthosis, problems with clothing and footwear and difficulties getting the orthosis modified or repaired. Improvements in brace design and service provision would help to minimize these problems.

This paper describes a new, automatic hinge system for leg orthoses, which provides knee stability in stance, and allows knee-flexion during swing. Indications for the hinge system are a paresis or paralysis of the quadriceps muscles. Instrumented gait analysis was performed in three patients, fitted with this new hinge system in a knee orthosis. The orthosis proves to satisfy the patients allowing them to walk without a knee-lock system.

A fixed-ankle, below-the-knee molded plastic splint designed to maintain the ankle in 5 degrees of dorsiflexion and correct any foot deformity was used on eighteen extremities of twelve children with spastic cerebral palsy and genu recurvatum. After an average follow-up of twenty-six months, the genu recurvatum was well controlled and gait was improved.

Recent years have seen the introduction of a great many knee orthosis designs prescribed for protection against ligamentous injury or reinjury of the knee. The configurations and materials incorporated in these designs vary greatly, but all claim to be very effective. A leg model and 11 different commercially available knee orthoses were tested with static loading to obtain objective data on the relative effectiveness of the 11 designs to protect the knee from externally applied valgus moments. From these data, the effectiveness of each orthosis was calculated in terms of the rigidity contributed to the leg/orthosis combination. At a static valgus loading of 78 Nm, there was an eightfold variation in the rigidities contributed by the various knee orthoses, ranging from a low of 0.9 Nm per degree valgus to a maximum of 7.2 Nm per degree. The authors related analyses of two aspects of knee orthosis design (orthosis length and orthosis rigidity) to effectiveness in protecting against knee valgus overload injuries. Correlations were found between design inadequacies noted theoretically and efficacy problems evident from the laboratory tests. Orthosis length and orthosis rigidity must both be adequate, or the orthosis will not be biomechanically effective.