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IntroductionThe incidence of knee osteoarthritis (KOA) is moderately correlated with age and body weight and increases with life span and weight gain, associated with tearing and wearing the knee joints. KOA can adjust the force through the human lower limbs, redistribute the load of the knee joint, reduce the pain, and restore mobility when the arthritis changes are mild. However, most of the existing knee orthosis cannot be adjusted adaptively according to the needs of patients.MethodologyThis study establishes a biomechanical model of the knee joint to analyze the medial and lateral forces acting on the joint. The new adjustable knee orthosis is designed. It applies the principle of four-point bending to apply pressure to both sides of the knee joint, thereby adjusting the varus angle and modifying the medial and lateral forces on the knee joint. Through structural optimization, the prototype of the knee orthosis weighs only 324 g. Utilizing three-dimensional scanning technology, discrete point cloud data of the leg surface is obtained, reconstructed, and processed to create a 3D model of the human leg surface. The design ensures a close fit to the human leg surface, offering comfortable wear. A pressure sensing film system is employed to build a pressure sensing test system, where the knee orthosis is worn on a prosthesis for pressure testing to evaluate its ability to adjust knee joint forces.ResultsThe pressure test results demonstrate that the knee orthosis can stably provide an adjustment angle of 0–7° and sustain a maximum force of 10N on both sides of the knee joint over extended periods. A self-developed 8-channel plantar pressure sensing insole is calibrated against commercial plantar pressure sensors. Human wear tests on 15 subjects show that during the operation of the knee orthosis, it significantly adjusts plantar pressures, reducing lateral foot pressures by 22% overall, with more pronounced corrective effects observed in lighter participants.DiscussionIn this study, a wedge-shaped adaptive knee orthosis was provided for KOA patients. The four-point force principle was used to balance the force between femurs and tibia and adjust the meniscus contact gap. The orthotic appliance has the advantages of simple mechanical structure, adjustable correction Angle and good wearing comfort.

Knee rehabilitation therapy after trauma or neuromotor diseases is fundamental to restore the joint functions as best as possible, exoskeleton robots being an important resource in this context, since they optimize therapy by applying tailored forces to assist or resist movements, contributing to improved patient outcomes and treatment efficiency. One of the points that must be taken into account when using robots in rehabilitation is their interaction with the patient, which must be safe for both and guarantee the effectiveness of the treatment. Therefore, the objective of this study was to assess the interaction between humans and an exoskeleton during the execution of knee flexion–extension movements under various configurations of robot assistance and resistance. The evaluation encompassed considerations of myoelectric activity, muscle recruitment, robot torque, and performed movement. To achieve this, an experimental protocol was implemented, involving an individual wearing the exoskeleton and executing knee flexion–extension motions while seated, with the robot configured in five distinct modes: passive (P), assistance on flexion (FA), assistance on extension (EA), assistance on flexion and extension (CA), and resistance on flexion and extension (CR). Results revealed distinctive patterns of movement and muscle recruitment for each mode, highlighting the complex interplay between human and robot; for example, the largest RMS tracking errors were for the EA mode (13.72 degrees) while the smallest for the CR mode (4.47 degrees), a non-obvious result; in addition, myoelectric activity was demonstrated to be greater for the completely assisted mode than without the robot (the maximum activation levels for the vastus medialis and vastus lateralis muscles were more than double those when the user had assistance from the robot). Tracking errors, muscle activations, and torque values varied across modes, emphasizing the need for careful consideration in configuring exoskeleton assistance and resistance to ensure effective and safe rehabilitation. Understanding these human–robot interactions is essential for developing precise rehabilitation programs, optimizing treatment effectiveness, and enhancing patient safety. [ABSTRACT FROM AUTHOR]

To simulate the biomechanical changes of knee joint before and after wearing the orthosis in patients with knee osteoarthritis (KOA) by constructing a finite element model of the knee joint and a customized additively manufactured knee orthosis, so as to verify the decompression effect of the orthosis, and aimed at orthopaedics, a quantitative research on the therapeutic effect of knee orthosis was conducted to evaluate the clinical efficacy of knee orthosis.This experiment was approved by the Ethics Committee of the Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. A woman with knee osteoarthritis was recruited, and the knee joint was subjected to optical body surface and CT scans. A custom-made additively manufactured knee orthosis was designed according to the principle of unilateral decompression. After boundary setting and other steps, software such as ANSYS was used to build a finite element model of the knee joint and a customized additively manufactured knee joint orthosis. By applying a compressive load of 1100 N to the knee joint along the direction of the lower limb load-bearing axis, a simulation and stress analysis was performed to study the deloading effect of a custom additively manufactured knee orthosis on the knee compartment. A finite element analysis of KOA characteristics was conducted for verification, considering the influence of cartilage, ligament, and lower limb skin on the bearing capacity of the knee joint. Compared with the case without wearing any orthosis, after wearing the customized knee orthosis, the varus angle of the knee joint was reduced, the medial pressure of the knee joint was shifted to the lateral side, and the pressure of the medial compartment of the knee joint was significantly reduced. The custom additively manufactured knee orthosis can reduce the pressure generated by the medial compartment of the knee joint during walking in patients with early and mid-stage medial compartment knee osteoarthritis, and the load reduction effect is significant.

Knee orthosis plays a vital role in enhancing the wellbeing and quality of life of individuals suffering from knee arthritis. This study explores a machine-learning-based methodology for predicting a user's gait subphase using inertial measurement units (IMUs) for a semiactive orthosis. A musculoskeletal simulation is employed with the help of existing experimental motion-capture data to obtain essential metrics related to the gait cycle, which are then normalized and scaled. A meticulous data capture methodology using foot switches is used for precise synchronization with IMU data, resulting in comprehensive labeled subphase datasets. The integration of simulation results and labeled datasets provides activation data for effective knee flexion damping following which multiple supervised machine learning algorithms are trained and evaluated for performances. The time series forest classifier emerged as the most suitable algorithm, with an accuracy of 86 percent, against randomized convolutional kernel transform, K-neighbor time series classifier, and long short-term memory–fully convolutional network, with accuracies of 68, 76, and 78, respectively, showcasing exceptional performance scores, thereby rendering it an optimal choice for identifying gait subphases and achieving the desired level of damping for magnetorheological brake-mounted knee orthosis based on simulated results. [ABSTRACT FROM AUTHOR]

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Knee rehabilitation therapy after trauma or neuromotor diseases is fundamental to restore the joint functions as best as possible, exoskeleton robots being an important resource in this context, since they optimize therapy by applying tailored forces to assist or resist movements, contributing to improved patient outcomes and treatment efficiency. One of the points that must be taken into account when using robots in rehabilitation is their interaction with the patient, which must be safe for both and guarantee the effectiveness of the treatment. Therefore, the objective of this study was to assess the interaction between humans and an exoskeleton during the execution of knee flexion–extension movements under various configurations of robot assistance and resistance. The evaluation encompassed considerations of myoelectric activity, muscle recruitment, robot torque, and performed movement. To achieve this, an experimental protocol was implemented, involving an individual wearing the exoskeleton and executing knee flexion–extension motions while seated, with the robot configured in five distinct modes: passive (P), assistance on flexion (FA), assistance on extension (EA), assistance on flexion and extension (CA), and resistance on flexion and extension (CR). Results revealed distinctive patterns of movement and muscle recruitment for each mode, highlighting the complex interplay between human and robot; for example, the largest RMS tracking errors were for the EA mode (13.72 degrees) while the smallest for the CR mode (4.47 degrees), a non-obvious result; in addition, myoelectric activity was demonstrated to be greater for the completely assisted mode than without the robot (the maximum activation levels for the vastus medialis and vastus lateralis muscles were more than double those when the user had assistance from the robot). Tracking errors, muscle activations, and torque values varied across modes, emphasizing the need for careful consideration in configuring exoskeleton assistance and resistance to ensure effective and safe rehabilitation. Understanding these human–robot interactions is essential for developing precise rehabilitation programs, optimizing treatment effectiveness, and enhancing patient safety.

In medical sector, the necessity of developing orthotic devices has been felt, nowadays, due to the increasing number of patients with stroke or spinal injury cases. In this regard, knee orthosis plays a vital role to enliven the patients having issues related to knee movements. There exist a few designs of orthotic devices in the literature. However, these are yet to be made more compact and energy efficient. In this study, a novel optimal design of an energy-economic knee orthosis has been obtained. To serve this purpose, an efficient and intelligent optimization algorithm, namely Self-adaptive Bonobo Optimizer (SaBO), has been developed with the inclusion of memory, past experiences, and novel repulsion-based learning for the parameters’ updating. To examine the performance of the proposed SaBO, initially, thirty difficult-to-solve CEC’14 benchmark functions have been solved and the obtained results are found to be the better compared to that of other six recently developed optimization techniques. Next, it has been applied to solve the complex knee-orthosis design problem. Here, the optimal design of knee-orthosis yielded by the developed SaBO is seen to be the most energy-efficient one. It is to be noted that the required maximum motor torque is found to be decrease up to 22% compared to that obtained using other optimization tools. [ABSTRACT FROM AUTHOR]

Background/aims: Knee braces can change loading direction on knees in people with osteoarthritis, thereby reducing symptoms and progression of the disease. The aims of this study were to explore the immediate effect of two types of braces, a pneumatic knee brace with air pressure embedded in a sandal cuff (sandal cuff pressure) and a conventional knee brace on gait, pain and satisfaction during walking in patients with knee medial osteoarthritis. Methods: A total of 28 patients with knee medial osteoarthritis were assigned to two groups, 14 patients used a conventional brace and 14 used a prototype brace with a pneumatic system, which was designed and fabricated by the authors, and followed the mechanism of variable pressures in the stance and swing phases of a gait cycle in a patient's knee. The gait parameters (walking self-selected speed, cadence, step length, knee range of motion, and maximum knee adduction moment, walking speed, cadence and step length) were measured with a Kistler force plate and Vicon motion analysis under two conditions: with and without brace for the conventional brace group, and under three conditions of no brace, brace with sandal cuff pressure, and brace without sandal cuff pressure for the pneumatic brace group. Patients' pain and satisfaction were also measured using a visual analogue scale and Likert scale respectively. Results: Both groups showed a significant reduction in maximum knee adduction moment and pain wearing braces in comparison to no brace during walking (P<0.05). The knee range of motion was significantly decreased in the pneumatic brace group with and without sandal cuff pressure compared with no brace (P<0.001). No significant difference was found for any of the variables when using the pneumatic brace with and without sandal cuff pressure (P>0.05). In the between-group comparison, only patients' satisfaction was significantly reduced when using the pneumatic brace in both walking with (P=0.041) and without (P=0.02) sandal cuff pressure compared to those using the conventional brace. Conclusions: Both conventional and pneumatic braces led to reduced knee adduction moment and pain in patients with knee osteoarthritis. However, using a pneumatic brace reduced the knee range of motion and satisfaction of patients, which could be because the brace was a prototype. [ABSTRACT FROM AUTHOR]

Knee orthosis plays a vital role in enhancing the wellbeing and quality of life of individuals suffering from knee arthritis. This study explores a machine-learning-based methodology for predicting a user’s gait subphase using inertial measurement units (IMUs) for a semiactive orthosis. A musculoskeletal simulation is employed with the help of existing experimental motion-capture data to obtain essential metrics related to the gait cycle, which are then normalized and scaled. A meticulous data capture methodology using foot switches is used for precise synchronization with IMU data, resulting in comprehensive labeled subphase datasets. The integration of simulation results and labeled datasets provides activation data for effective knee flexion damping following which multiple supervised machine learning algorithms are trained and evaluated for performances. The time series forest classifier emerged as the most suitable algorithm, with an accuracy of 86 percent, against randomized convolutional kernel transform, K-neighbor time series classifier, and long short-term memory–fully convolutional network, with accuracies of 68, 76, and 78, respectively, showcasing exceptional performance scores, thereby rendering it an optimal choice for identifying gait subphases and achieving the desired level of damping for magnetorheological brake-mounted knee orthosis based on simulated results.

Background: Medial knee osteoarthritis can contribute to pain and stiffness, interfere with balance and limit functional activities of daily living. Unloader knee orthosis or lateral wedged insoles are current conservative approaches used to treat these conditions. The aim of this study was to identify and compare the effects of them on the balance parameters. Methods: 66 subjects with mild to moderate medial knee osteoarthritis were randomly assigned to wear unloader knee brace or full-length 6° lateral wedge insole. Primary outcome balance parameters were stability %, path length and average velocity of center of pressure and mobility score which were investigated by HUMAC® Balance and Tilt system. Secondary outcome measures were knee function score using Knee Injury and Osteoarthritis Outcome Score scale. Assessment was performed at baseline and six months post orthotic intervention period. Findings: Both orthoses improved all parameters compared to the baseline condition (p < 0.05). Unloader knee orthosis showed a significant improvement in all balance parameters compared to lateral wedged insoles (p < 0.001) except mobility scores (p=0.527). Except activities of daily living (p=0.752) and sports and recreational activities (p=0.437), unloader knee orthosis had a greater effect on the pain (p=0.002) and symptoms (p < 0.001) sub scales than lateral wedged insoles. However, quality of life sub-scale scores for insoles were more effective than the knee orthosis. Interpretation: Unloader knee orthosis improved balance and knee function scores more than lateral wedged insole, though both orthoses produced significantly improved results compared to baseline assessment. [ABSTRACT FROM AUTHOR]

The Japanese agriculture industry, faced with the problem of declining and aging farmers, has keenly called for the development of body assist orthoses for aiding agricultural workers. Therefore, in this study, we propose an endoskeleton-type knee joint assist orthosis for assisting knee joints in half-sitting postures or crouching postures. The proposed endoskeleton-type knee joint assist orthosis uses two McKibben-type artificial muscles per leg and four in total, placed from the waist to the foot along the forward part of the leg to generate assisting power. With the proposed orthosis in use, the contraction forces generated by the McKibben-type artificial muscles are converted into torque via the knees to assist the knee joints. This paper first presents the appearance of the prototyped endoskeleton-type knee joint assist orthosis, and then describes its components and the McKibben-type artificial muscles. To verify its actual effects on muscles, we conducted fitting experiments using a surface myoelectric electrometer to determine its assisting effects; these effects were found on certain experimental subjects, but there were no tangible effects on others. The experimental results suggest that the prototyped endoskeleton-type knee joint assist orthosis requires further improvement. [ABSTRACT FROM AUTHOR]

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 assistance’s 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 joint’s 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 body’s multiple adaptation mechanisms in the presence of external robotic assistance. [ABSTRACT FROM AUTHOR]

Introduction: The incidence of knee osteoarthritis (KOA) is moderately correlated with age and body weight and increases with life span and weight gain, associated with tearing and wearing the knee joints. KOA can adjust the force through the human lower limbs, redistribute the load of the knee joint, reduce the pain, and restore mobility when the arthritis changes are mild. However, most of the existing knee orthosis cannot be adjusted adaptively according to the needs of patients., Methodology: This study establishes a biomechanical model of the knee joint to analyze the medial and lateral forces acting on the joint. The new adjustable knee orthosis is designed. It applies the principle of four-point bending to apply pressure to both sides of the knee joint, thereby adjusting the varus angle and modifying the medial and lateral forces on the knee joint. Through structural optimization, the prototype of the knee orthosis weighs only 324 g. Utilizing three-dimensional scanning technology, discrete point cloud data of the leg surface is obtained, reconstructed, and processed to create a 3D model of the human leg surface. The design ensures a close fit to the human leg surface, offering comfortable wear. A pressure sensing film system is employed to build a pressure sensing test system, where the knee orthosis is worn on a prosthesis for pressure testing to evaluate its ability to adjust knee joint forces., Results: The pressure test results demonstrate that the knee orthosis can stably provide an adjustment angle of 0-7° and sustain a maximum force of 10N on both sides of the knee joint over extended periods. A self-developed 8-channel plantar pressure sensing insole is calibrated against commercial plantar pressure sensors. Human wear tests on 15 subjects show that during the operation of the knee orthosis, it significantly adjusts plantar pressures, reducing lateral foot pressures by 22% overall, with more pronounced corrective effects observed in lighter participants., Discussion: In this study, a wedge-shaped adaptive knee orthosis was provided for KOA patients. The four-point force principle was used to balance the force between femurs and tibia and adjust the meniscus contact gap. The orthotic appliance has the advantages of simple mechanical structure, adjustable correction Angle and good wearing comfort., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhou, Liu, Hao, Liu and Tang.)

Featured Application: Knee osteoarthritis (OA) can be prevented using orthoses with actuators controlled using real-time biofeedback from wearable motion-sensors and multi-function exoskeletons and, incorporating integrated electro-magnetic stimulators may also enhance regenerative medicine treatments for knee OA. 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. [ABSTRACT FROM AUTHOR]

Background: Proprioception includes joint position and motion. Sensory information, central processes, and neuromuscular control are important in improving joint stability. The effective use of knee joint orthosis on knee joint performance, balance and coordination is still highly controversial and has slight information on the effect of the orthotic use on proprioceptive function. Objective: To analyze the effect of knee orthosis on proprioception function in adult male health’s subjects. Method: This study used an experimental research with pre-post study design. The sample of this study was the male patient of Physical and Rehabilitation treatment that met inclusion criteria. The data was taken by consecutive sampling in February 2017. The subjects were 11 healthy male adults who aged of 21-40 years old that meeting the inclusion criteria. All the subjects were measured proprioception function before and at 30 minutes using knee orthosis. Joint position sense (JPS) and time to detect passive movement (TTDPM), were measured by the cybex isokinetic dynamometer tool to measure the function of proprioception. Result: All the mean values of JPS before and at 30 minutes by using orthosis on both sides did not statistically show a significant difference (p >0.05), except at the corner of the JPS 60° on the right-sided knee (p <0.05). It meant TTDPM before and during 30 minutes using orthosis on both sides of the knee also did not show a significant difference (p >0.05). Conclusion: The use of ambulatory knee-ankle-foot orthosis caused the change in proprioception (JPS) at the right side 60o knee angle on the subject before and at 30 minutes using knee orthosis. [ABSTRACT FROM AUTHOR]

The knee joint performs a significant amount of positive or negative mechanical work during gradient walking, and targeted assistance during periods of high mechanical work could yield strong human augmentation benefits. This paper explores the biomechanical effects of providing knee extension assistance during the early stance phase of the gait cycle using a powered unilateral knee exoskeleton during gradient walking on able-bodied subjects. Twelve subjects walked on 15% gradient incline and decline surfaces with the exoskeleton providing knee extension assistance during the early stance phase of the gait cycle. For both incline and decline walking, the exoskeleton assistance reduced the muscle activation of the knee extensors on the assisted leg (${p}< {0.05}$). However, only approximately half the individuals responded to exoskeleton assistance positively by reducing their metabolic cost of walking for both incline and decline tasks. The results indicate that, unlike the individuals who did respond, the individuals who did not respond to the assistance may have penalized their metabolic cost by their biomechanical compensatory behaviors from the unassisted leg. [ABSTRACT FROM AUTHOR]

To assess the postural strategies developed over the first 2 months following surgery by ACL patients during rehabilitation and highlight the sensory-motor impairment recovery, 21 patients were measured at three timeframes. Three two-legged standing conditions were assessed: with the eyes open, with the eyes closed either wearing or not wearing a knee orthosis. The results indicate that the weight-bearing asymmetry, initially observed (i.e., 56-44% of body-weight), disappeared progressively during rehabilitation (51-49%). The comparison of the plantar center-of-pressure displacements under both sound and operated legs demonstrated noticeable differences that also tended to decrease but without reaching a matched behavior during the last measures. These effects were seen in both eyes open and eyes closed conditions with the greatest effects in the latter condition. Wearing a knee orthosis inferred no particular changes in the postural control behaviors. These data could be used as benchmarks for highlighting the effects on undisturbed postural control of various surgery techniques and/or rehabilitation protocols. [ABSTRACT FROM AUTHOR]

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.

Semi-active knee orthosis (SAKO) is a kind of wearable lower-limb exoskeleton that uses actuators to support the regular biomechanical functions. It is much better than conventional knee orthosis (CKO) devices because of its high torque to volume ratio (TVR) and low mass. Magnetorheological (MR) brake is one of the smart actuators that can be used as an active resistance device in SAKO. It has advantages of fast response, low power consumption, and low vibration operation. This smart brake also has wide applications in the robotic and automotive industries. However, the electromagnetic setup in MR brakes has a hysteresis problem. This paper aims to turn this hysteresis problem into an advantage to save the power consumption of MR brake. Since the SAKO needs precise torque control, this research studied the hysteresis effect on the torque performance of MR brake. A less energy-consuming PWM actuation signal is proposed to activate the MR brake. The effects of frequency and duty cycle of PWM actuation signal on MR brake performance are also investigated. The electromagnetic (EM) and mechanical models of the MR brake were developed to simulate performance. Initial validation of these models is done by simulating the MR brake model with the DC actuation signal in finite element analysis software. For the final validation, the model simulation results are compared with experimental results. The factors affecting the steady torque and the response time of the MR brake are studied to find the optimal frequency and duty cycle for the applied PWM signal. This study revealed that the proposed new PWM actuation signal with a 5 kHz frequency and 60% duty cycle can power the MR brake to maintain steady torque. By turning hysteresis into an advantage, it saves 40% power consumption of MR brake compared to DC signal.

Background. The anterior cruciate ligament (ACL) plays a significant role in controlling anterior tibial translation and rotation. A variety of treatment approaches, including knee orthoses, are used to restore the performance of subjects with ACL injuries. The aim of this review is to explore the efficiency of knee orthoses on the functional performance (walking, standing, jumping and running) of individuals with ACL injury. Method. A literature search was conducted. Key words (knee, orthosis, anterior cruciate ligament, rupture, brace and/or walking, standing, running, jumping and ACL injury) were inputted into selected databases (ISI Web of knowledge, PubMed, Google scholar, Ebsco and Embasco) using Boolean search terms. The quality of obtained studies was evaluated using the PEDro scale. Results. Initial search results yielded 250 papers. Following review of titles and abstracts and application of inclusion criteria, 39 papers were selected. Of these, 32 focused on motion analysis of individuals following ACL injury (with/without reconstruction); 3 were biomechanical evaluations conducted on cadavers and 4 on the effect of a knee orthosis on the performance of able-bodied subjects. Overall, the quality of studies was rated between 3 and 7 in the PEDro scale. Conclusion. Results showed insufficient evidence to suggest that knee orthoses have a significant effect on standing, walking and running performances of the individuals with ACL injury and those who had reconstruction surgery. However, the use of an orthosis increased energy consumption during walking. Based on the available literature, it is debatable whether the use of an orthosis has a positive effect on the treatment. Future research of appropriate design is required to further explore changes in performance of ACL-injured subjects using different knee orthoses. [ABSTRACT FROM AUTHOR]

Physical changes such as leg length discrepancy, the addition of a mass at the distal end of the leg, the use of a prosthetic, and stroke frequently result in an asymmetric gait. This paper presents a metric that can potentially serve as a benchmark to categorize and differentiate between multiple asymmetric bipedal gaits. The combined gait asymmetry metric (CGAM) is based on modified Mahalanobis distances, and it utilizes the asymmetries of gait parameters obtained from motion capture and force data recorded during human walking. The gait parameters that were used in this analysis represent spatio-temporal, kinematic, and kinetic parameters. This form of a consolidated metric will help researchers identify overall gait asymmetry by showing them if the overall gait symmetry is improving and avoid the case where one parameter's symmetry is improving while another is getting worse. The CGAM metric successfully served as a measure for overall symmetry with eleven different gait parameters and successfully showed differences among gait with multiple physical asymmetries. The results showed that mass at the distal end had a larger magnitude on overall gait asymmetry compared to leg length discrepancy. It also showed that the combined effects are varied based on the cancelation effect between gait parameters. The metric was also successful in delineating the differences of prosthetic gait and able-bodied gait at three different walking velocities.

Physical changes such as leg length discrepancy, the addition of a mass at the distal end of the leg, the use of a prosthetic, and stroke frequently result in an asymmetric gait. This paper presents a metric that can potentially serve as a benchmark to categorize and differentiate between multiple asymmetric bipedal gaits. The combined gait asymmetry metric (CGAM) is based on modified Mahalanobis distances, and it utilizes the asymmetries of gait parameters obtained from motion capture and force data recorded during human walking. The gait parameters that were used in this analysis represent spatio-temporal, kinematic, and kinetic parameters. This form of a consolidated metric will help researchers identify overall gait asymmetry by showing them if the overall gait symmetry is improving and avoid the case where one parameter's symmetry is improving while another is getting worse. The CGAM metric successfully served as a measure for overall symmetry with eleven different gait parameters and successfully showed differences among gait with multiple physical asymmetries. The results showed that mass at the distal end had a larger magnitude on overall gait asymmetry compared to leg length discrepancy. It also showed that the combined effects are varied based on the cancelation effect between gait parameters. The metric was also successful in delineating the differences of prosthetic gait and able-bodied gait at three different walking velocities. [ABSTRACT FROM AUTHOR]

Background: 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.Objectives: To investigate biomechanical functionality during gait, pain relief and compliance in patients with knee osteoarthritis using a lightweight adjustable knee unloader orthosis.Study Design: Prospective observational clinical trial.Methods: 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.Results: 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.Conclusion: 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. [ABSTRACT FROM AUTHOR]

• Biomechanical evaluation of a novel tricompartment offloader (TCO) knee brace that provides extension assistance via liquid spring technology in patients with multicompartment knee osteoarthritis. • Study results demonstrate that the TCO significantly reduces net knee flexion moment and quadriceps muscle activity during a chair rise and lower. • Knee flexion moment and quadriceps activity are key contributors to knee joint contact forces, therefore, it is expected that the biomechanical changes resulting from TCO brace wear will result in unloading of the knee joint. • Study participants reported significant decreases in knee pain while wearing the TCO compared to not wearing the TCO brace. • The study results support the intended mechanism of joint unloading via extension assistance, and support use of the TCO brace as a conservative management tool to reduce knee pain in patients with multicompartment knee OA. The Levitation tricompartment offloader (TCO) knee brace provides an assistive knee extension moment with the goal of unloading all three compartments of the knee and reducing pain for individuals with multicompartment knee osteoarthritis (OA). This study aimed to determine the effect of the TCO brace on sagittal plane knee moments, quadriceps muscle activity, and pain in individuals with multicompartment knee OA. Lower limb kinematics, kinetics, and electromyography data were collected during a chair rise and lower to determine differences between bracing conditions. TCO brace use significantly decreased the peak net knee external flexion moment in high power mode, providing extension assistance during chair rise [ p <0.001; mean difference (MD) (98.75% CI) -0.8 (-1.0, -0.6)%BWxH] and bodyweight support during chair lower [ p <0.001; -1.1 (-1.6, -0.7)%BWxH]. Quadriceps activation intensity was significantly reduced with brace use by up to 67% for the vastus medialis [ Z = -2.55, p = 0.008] and up to 39% for the vastus lateralis [ Z = -2.67, p = 0.004]. Participants reported significantly reduced knee pain with the TCO brace worn in high power mode compared to the no brace condition [ p = 0.014; MD (97.5% CI) -18.8 (-32.22, -2.34) mm]. These results support the intended mechanism of joint unloading via extension assistance with the TCO brace. The observed biomechanical changes were accompanied by immediate reductions in user reported pain levels, and support the use of the TCO for conservative management to reduce knee pain in patients with multicompartment knee OA. [ABSTRACT FROM AUTHOR]

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

Background: The knee joint is vulnerable to various injuries and degenerative conditions, potentially leading to functional instability. Usual treatments involve knee orthoses to support the joint. However, the level of mechanical action of these devices remains controversial despite high prescription and demand. Methods: The mechanical ability of three commercial hinged knee braces and one sleeve to prevent a static drawer was evaluated using a GNRB® arthrometer. The testing of both pathological and healthy joints was performed on 16 patients with documented injuries involving the ACL, and an original method allowed decoupling the contribution of the brace. Results: The mean stiffness of the three hinged braces ranged between 2.0 and 7.1 N/mm. The most efficient brace was able to exert a restraining force on the joint equivalent to the one exerted by a healthy ACL, up to a 2.8 mm anterior displacement of the tibia. For higher anterior displacements, the restraining force of the brace dropped below the level of action of the intact ACL because of the particular non-linear behaviour of this structure. Finally, the most efficient brace was found to vary from subject to subject. Conclusions: This study confirmed that fabric-based knee braces may effectively replace the passive mechanical role of the ACL within the low stiffness region of this structure. Although bracing may have other benefits (e.g. proprioception), this shows that they act as an effective passive restraint to low grade anterior laxities. Besides, a high patient-specificity of their effects highlighted the need of personalised objective testing for brace selection. [ABSTRACT FROM AUTHOR]

Objectives: Impaired proprioception and muscle weakness may not only be a consequence of knee osteoarthritis (OA) but also part of its pathogenesis. Thus, the enhancement of quadriceps strength and proprioceptive accuracy can play a pivotal role in the management of knee OA. This study aimed to investigate the effects of Kinesio tape and flexible knee orthosis in terms of clinical and neuromuscular outcomes in patients with knee OA., Methods: This clinical trial was conducted on 56 patients with knee OA, randomly allocated to two groups: knee orthosis or Kinesio tape. The knee orthosis group wore a neoprene knee support for 4 weeks. For participants in the Kinesio tape group, tape was applied once a week, for 4 weeks. The primary outcomes were pain intensity and physical function evaluated through the visual analog scale and the Western Ontario and McMaster OA index. The secondary outcomes were concentric and isometric quadriceps strength, Joint Position Sense (JPS), Threshold to Detect Passive Motion (TTDPM), and force sense (FS), all measured by isokinetic dynamometry., Results: All outcome measures were significantly improved in the orthosis group. The Kinesio tape group also demonstrated significant changes in all outcome measures except three proprioception components namely JPS (70° target), FS, and TTDPM. At the end of the fourth week, there were no significant between-group differences for measured parameters., Conclusion: Wearing a flexible knee orthosis and/or Kinesio tape for 4 weeks significantly improved knee pain, physical function, and quadriceps strength. Although knee orthosis showed significant beneficial effects on various components of proprioception, there were no significant differences between the two groups at the end of the 4-week intervention., Competing Interests: None

The aim of this study was to evaluate the effectiveness of the OAdjuster® (dj Orthopedics, Vista, CA, USA) brace on lateral compartment osteoarthritis (OA). The OAdjuster knee brace will effectively control joint angles in the frontal plane throughout the stance phase of the gait cycle. Two patients with valgus knee deformity diagnosed with lateral compartment OA in the right knee were included in this study. Both patients have been fitted with the OAdjuster knee brace in the treatment of OA. A subjective history was taken of each patient through a personal interview. Objective tests and measures were taken to rule out any other joint pathology. Each patient ambulated with and without the unloading brace and was filmed with two digital cameras. Analysis of joint angles and gait parameters was performed with the Ariel Performance Analysis System® (APAS) (Ariel Dynamics, Inc, San Diego, CA, USA). In case 1, the knee valgus angle at midstance decreased from 4.4° of valgus to 1.7° of valgus with the use of the brace. The hyperextension angle in the sagittal plane also decreased during single-limb stance on the braced limb from 12.1° to a neutral alignment. Other gait parameters in case 1 showed very little change with the use of the OAdjuster brace. Case 2 exhibited a decrease in valgus angle during midstance from 8.4° to 7.0°. The hyperextension angle during single-limb stance also decreased from 11.2° to 4.4°. Gait parameters also showed an improvement in case 2 with the use of the unloading brace. The OAdjuster brace may become a viable option for patients with lateral compartment OA and who are unable to undergo surgical procedures because of other comorbidities. The OAdjuster brace effectively controlled joint angles in the frontal and the sagittal plane throughout the stance phase of the gait cycle. [ABSTRACT FROM AUTHOR]

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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 \pm 0.46 Nm was provided by the device during flexion and 28.4 \pm 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. [ABSTRACT FROM AUTHOR]