Knee Rehabilitation Research Articles

Ultrasonography for quantitative assessment of knee joint effusions-useful tool for objective evaluation of rehabilitation progress?

We sought to externally validate ultrasonography (US) for quantification of suprapatellar effusion size to improve diagnosis and individualised rehabilitation strategies in knee rehabilitation after anterior cruciate ligament reconstruction (ACLR) surgery. US was performed on 35 patients as part of the ongoing CAMOPED study. Data were collected in ACLR and post surgery in defined intervals up to oneyear post-operation. The palpatory assessment was graded using the International Knee Documentation Committee (oIKDC). In a total of 164 sonographies, a strong correlation between palpatory and US effusion (r = 0.83, p < 0.01) with lower deviations in US quantification compared to palpatory quantification Y = 1.15 + 0.15* x was seen. Threshold values could be determined for the detection of effusions by palpation and for the differentiation between mild and moderate/severe effusions (effusion depth: 2.6mm and resp. 5.8mm, respectively). As demonstrated in this multicenter study, the size of suprapatellar effusions can be easily quantified with high accuracy using standardised bedside ultrasound. Especially in moderate to severe effusions, US provides a practical and reliable tool for outcome measurement superior to palpatory assessment with the goal of optimising individual recommendations during the rehabilitation course. Furthermore, for the first time, it has been possible to define sonographic threshold values for the detection of effusion and differentiation of mild vs. moderate/severe effusion by means of palpation.

Role of Aquatic Therapy in Knee Rehabilitation: A Narrative review

Background: Knee pain is a prevalent issue affecting adolescents and adults, with various causes ranging fromacute injuries to chronic conditions like osteoarthritis. The knee is particularly susceptible to injury, especiallyamong athletes. Aquatic therapy has gained attention as a promising approach to knee rehabilitation because ofits unique properties, including buoyancy, hydrostatic pressure, and viscosity, which can aid in reducing painand enhancing recovery. This narrative review explores the effectiveness of aquatic therapy in knee rehabilitationacross different knee conditions and presents findings from several studies conducted between 2006 and 2022.Methodology: A comprehensive search strategy was implemented using keywords in Google Scholar andPubMed. The search was limited to randomized controlled trials, systematic reviews, and pilot studies conductedbetween 2006 and 2022, published in English. Inclusion criteria encompassed original research with outcomesrelated to knee rehabilitation and aquatic therapy, while articles that did not focus on knee rehabilitation andaquatic therapy or were published prior to 2006 were excluded.Results: Several studies were reviewed to assess the effectiveness of aquatic therapy in knee rehabilitation fordifferent conditions. A total of 7 articles were selected that said the effectiveness of aquatic therapy in kneerehabilitation.Conclusion: In this review, aquatic therapy is effective in all knee conditions

Acute muscle swelling effects of a knee rehabilitation exercise performed with and without blood flow restriction.

This study assessed the acute effect of adding blood flow restriction (BFR) to quad sets on muscle-cross sectional area (mCSA), muscle thickness (MT), echo intensity (EI), and subcutaneous fat-normalized EI (EINORM) of the superficial quadriceps muscles. Twelve males and 12 females (mean±SD; age (yrs): 21.4±2.9; stature (m): 1.76±0.1; body mass (kg): 77.7±2.9) performed 70 repetitions (one set of 30, three sets of 15 repetitions) of bodyweight quad sets separately on each leg, with or without BFR (CON) applied. Rating of perceived exertion was recorded following each set. Panoramic ultrasound images of the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) were captured prior to (PRE), immediately after (IMM-POST), 30- (30-POST), and 60-minutes after (60-POST) after exercise. Sex x condition x time repeated measures ANOVAs assessed differences at p<0.05 for each muscle and dependent variable separately. Although males had larger VM and VL mCSA and VL MT (p<0.05), there were no acute changes from PRE to IMM-POST (p>0.05). There was a 3-way interaction in VL mCSA (p = 0.025) which indicated BFR was greater than CON at IMM-POST by 7.6% (p = 0.019) for males only. Females had greater EI in the VM and VL than males (p<0.05), yet males had greater EINORM for each muscle (p>0.05) and EINORM did not change over time or treatment (p>0.05). The lack of changes in MT, EI, and EINORM indicate that unloaded quad sets do not provide a stimulus to promote fluid shifts or acute changes in muscle size with the exception of IMM-POST in the VL for males. Future research should attempt to elucidate the acute muscular responses of BFR application for lightly loaded rehabilitation exercises in the clinical populations for which they are prescribed.

Evaluation of a Smart Knee Brace for Range of Motion and Velocity Monitoring during Rehabilitation Exercises and an Exergame.

Anterior cruciate ligament (ACL) injuries often require a lengthy duration of rehabilitation for patients to return to their prior level of function. Adherence to rehabilitation during this prolonged period can be subpar due to the treatment duration and poor adherence to home exercises. This work evaluates whether a smart instrumented knee brace system is capable of monitoring knee range of motion and velocity during a series of common knee rehabilitation exercises and an exergame. A total of 15 healthy participants completed a series of common knee rehabilitation exercises and played an exergame while wearing a smart instrumented knee brace. The range of motion (ROM) and velocity of the knee recorded by the knee brace was compared to a reference optoelectronic system. The results show good agreement between the knee brace system and the reference system for all exercises performed. Participants were able to quickly learn how to play the exergame and scored well within the game. The system investigated in this study has the potential to allow rehabilitation to occur outside of the clinic with the use of remote monitoring, and improve adherence and outcomes through the use of an exergame.

Development of a Real-Time Knee Extension Monitoring and Rehabilitation System: Range of Motion and Surface EMG Measurement and Evaluation.

In this paper, a real-time knee extension monitoring and rehabilitation system for people, such as patients, the elderly, athletes, etc., is developed and tested. The proposed system has three major functions. The first function is two-channel surface electromyography (EMG) signal measurement and processing for the vastus lateralis (VL) and vastus medialis (VM) muscles using a developed EMG device set. The second function is the knee extension range of motion (ROM) measurement using an angle sensor device set (i.e., accelerometer sensor). Both functions are connected and parallelly processed by the NI-myRIO embedded device. Finally, the third function is the graphical user interface (GUI) using LabVIEW, where the knee rehabilitation program can be defined and flexibly set, as recommended by physical therapists and physicians. Experimental results obtained from six healthy subjects demonstrated that the proposed system can efficiently work with real-time response. It can support multiple rehabilitation users with data collection, where EMG signals with mean absolute value (MAV) and root mean square value (RMS) results and knee extension ROM data can be automatically measured and recorded based on the defined rehabilitation program. Furthermore, the proposed system is also employed in the hospital for validation and evaluation, where bio-feedback EMG and ROM data from six patients, including (a) knee osteoarthritis, (b) herniated disc, (c) knee ligament injury, (d) ischemic stroke, (e) hemorrhagic stroke, and (f) Parkinson are obtained. Such data are also collected for one month for tracking, evaluation, and treatment. With our proposed system, results indicate that the rehabilitation people can practice themselves and know their rehabilitation progress during the time of testing. The system can also evaluate (as a primary treatment) whether the therapy training is successful or not, while experts can simultaneously review the progress and set the optimal treatment program in response to the rehabilitation users. This technology can also be integrated as a part of the Internet of Things (IoT) and smart healthcare systems.

Joint mechanical properties estimation with a novel EMG-based knee rehabilitation robot: A machine learning approach.

Joint dynamic properties play essential roles in a wide range of biomechanical movement control. This paper develops a device with a novel mechatronic design to apply small-amplitude perturbations to the human knee. Surface Electromyography is employed to record such information; at the same time, force and position sensors collect measurements to be sent to identify human joint dynamics. For classification and estimation of force, support vector machine and support vector regression techniques are applied, respectively. We devise a genetic algorithm for parameter optimization and feature extraction within the proposed methods to improve the estimation accuracy. These are then analyzed and compared to the output of our estimation model to provide a reliable comparison. Our extensive experimental results reveal a high estimation accuracy for lower limb muscles to regulate robot impedance parameters. Although the identification method sounds similar to traditional ones, knee joint properties can be estimated by the machine learning approach from the surface Electromyography without perturbations.

A retrospective evaluation of a knee rehabilitation class following evidence-based modifications

Knee pain is a common musculoskeletal disorder and contributes a large socio-economic burden to health systems around the world. The traditional strategy to manage knee pain has been exercise. However, there is growing recognition to include coping and self-management educational strategies to improve psychosocial outcomes. Purpose: The purpose of this evaluation was to compare the effectiveness of a revised knee rehabilitation class that incorporated an evidence-based educational component (2021-22) to the previous knee rehabilitation class that did not incorporated an evidence-based educational component (2020–21) by comparing pre-class and post-class outcome measurement scores. Method: A retrospective evaluation of the knee rehabilitation classes at an NHS Trust in North London, United Kingdom was conducted using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Lower Extremity Functional Scale (LEFS) from two cohorts of participants from 2020-21 and 2021-22. Data from the two classes were analysed separately and then compared. Satisfaction scores were captured using a questionnaire which participants completed at the end of each class. Data were analysed using the Statistical Software for Excel (XLSTAT) package. Results: A total of 46 and 52 patients attended the 2020-21 and 2021-22 classes respectively. Both classes showed significant improvements in KOOS and LEFS when analysed separately, but no significant difference when compared. The 2020-21 class had a mean satisfaction score of 87.2%, and the 2021-22 class had a mean satisfaction score of 91.7%. Conclusion: The addition of an evidence-based educational component incorporating coping and self-management strategies in a knee rehabilitation class showed improvement in outcome measurement scores but cannot be considered superior to a class which consisted of an exercise component only.

Clinical Trajectory control for lower Knee rehabilitation using ADRC method

The design and study of the Active Disturbance Rejection Control (ADRC) approach for control and disturbance rejection for lower knee rehabilitation utilizing a residential exoskeleton system are provided in this paper. Linear ADRC (LADRC) and Nonlinear ADRC (NADRC) are two controllers that are considered for control purposes based on the structure of ADRC. The contrasts between them are thoroughly discussed in this work. The LADRC is made up of a tracking differential (TD), a linear proportional derivative (LPD) controller, and a linear extended state observer (LESO), whereas the NADRC is made up of the same LESO but with a nonlinear PD (NPD) and a modified optimized TD (MTD). In terms of robustness against the ability to reject applied disturbances, a comparison of LADRC and NADRC has been done. The fundamental challenge with ADRC is that its constituent parameters must be fine-tuned. Grey Wolf Optimizer (GWO) has been proposed for tuning the parameters of ADRC to have the least amount of error variation in order to improve the controlled system's dynamic performance. When a prescribed disturbing torque is applied, the results of a MATLAB simulation show that the LADRC has greater disturbance rejection capabilities than the NADRC.

Dynamics analysis of knee joint during sit-stand movement

Sit-stand movement is one of the most common movement behaviors of the human body. The knee joint is the main bearing joint of this movement. Thus, the dynamic analysis of knee joint during this movement has deeply positive influences. According to the principle of moment balance, the dynamics of the knee joint during the movement were analyzed. Furthermore, combined with the data obtained from optical motion capture and six-dimensional ground reaction force test, the curve of knee joint torque was calculated. To verify the accuracy of the analysis of dynamic, the human body model was established, the polynomial equations of angle and angular velocity were fitted according to the experimental data, and the knee joint simulation of the movement was carried out. The result revealed that in terms of range and trend, the theoretical data and simulation data were consistent. The relationship between knee joint torque and ground reaction force was revealed based on the variation law of knee joint torque. During the sit-stand movement, the knee joint torque and the ground reaction force were directly proportional to each other, and the ratio was 5 to 6. In the standing process, the acceleration first increased and then decreased and finally increased in reverse, and the maximum knee torque occurred at an angle of about 140°. In the sitting process, the torque was maximized in the initial stage. The results of the dynamics analysis of knee joint during sit-stand movement are beneficial to the optimal design and force feedback control of seated rehabilitation aids, and can provide theoretical guidance for knee rehabilitation training.

Surface electromyography‐based biofeedback and knee rehabilitation: A review of the literature

AbstractThe number of total knee arthroplasties (TKA) performed yearly is rapidly increasing. Additionally, upwards of 50% of patients who receive TKA never achieve a full functional recovery. This suggests considerable room for improvement. This need for improvement expands beyond TKA as similar effects are noted across knee injuries. Electromyography‐based biofeedback (EMGBF) involves the delivery of feedback based on the activity of targeted muscle. By providing feedback contingent on changes in muscle amplitude, EMGBF may be an effective tool for strengthening quadricep muscles. This review aims to evaluate the utility of sEMGBF during physical therapy for various knee injuries. All studies were evaluated for the effectiveness of sEMGBF at improving muscle strength, range of motion, and reducing pain. Most studies reviewed found that including sEMGBF in physical therapy produced greater clinical benefits for patients than exercise alone. Further research is necessary to determine the best practice for including EMGBF in physical therapy.

Simplified mechanical system for knee rehabilitation

Muscle atrophy refers to the thinning of muscles losing their tone and strength. Knee rehabilitators are usually based on a 4-bar system due to its simplicity, and the passive movement sought the rehabilitation of joints, seeking comfort in the patient. This research determines the critical movements and the correct selection of the 4-bar mechanism, considering the restrictions according to the rules of the flat mechanisms. In addition, a kinematic analysis based on geometric models is carried out for validation through a computer program for its subsequent selection of the actuator to obtain the desired movement according to the initial conditions of the knee rehabilitator that considers the rehabilitation of the patient in a sedentary position. The result shows a mechanism with an isokinetic movement employed for knee rehabilitation.

ACL Research Retreat IX Summary Statement: The Pediatric Athlete, March 17-19, 2022; High Point, North Carolina.

ACL Research Retreat IX Summary Statement: The Pediatric Athlete, March 17-19, 2022; High Point, North Carolina.

RBF neural network-based admittance PD control for knee rehabilitation robot

AbstractEarly-stage rehabilitation therapy for post-stroke patients consists of intensive and accurate training sessions. During these sessions, the therapist moves the patient’s joint within its range of motion repetitively. Patients, at this stage, often cannot control their muscles, and neurological disorders may occur and lead to undesirable movements. Thus, the therapist should train the joint gently to handle any sudden involuntary movements. Otherwise, the joint may undergo excessive torques, which may injure it. In this paper, we address this case and develop a clinical rehabilitation robotic system for training the knee joint taking into account the occurrence of these undesirable movements. The developed system has an innovative mechanism to measure interaction torques exerted by involuntary movements. Then, we introduce a new control approach consisting of an admittance controller and a proportional-derivative controller augmented by a radial basis function (PD-RBF) neural network. The PD-RBF guides the robot joint along a predefined trajectory, while the admittance part tracks any sudden interaction torques and updates the predefined trajectory accordingly. Thus, the robot trains the knee joint and once an undesirable movement occurs the robot gets along with this movement smoothly, then it gets back to the predefined trajectory. To validate the performance of the proposed admittance PD-RBF controller, we consider two controllers, an admittance adaptive sliding mode control and an admittance conventional PD one. Then, a compatarive study is conducted on these controllers via real-world experiments. The obtained results verify the efficiency of the admittance PD-RBF and prove its superiority over the other aforementioned controllers.

The Effect of Lower Limb Exoskeleton Alignment on Knee Rehabilitation Efficacy.

This study focuses on a musculoskeletal analysis of human lower extremity and associated muscle forces during different rehabilitative tasks and exoskeleton alignment models. By changing the size and orientation of the impairment levels that could be caused by the misalignment of the exoskeleton and biological knee joint, muscle stress variations were observed. This indicates an increase in force such as that generated by the Vastus lateralis muscle up to 4.3% due to a 5 mm lateral offset from an anatomically healthy knee joint location. In another setting, while a subject moved the shank through a circular trajectory using an exoskeleton support, muscle strain due to misalignment was reflected at the rectus femoris with a variation of 44%, the biceps femoris large head with 32% and the gastrocnemius muscles with 31–33% variation. These results suggest that misalignment should be taken into account while using exoskeletons with certain trajectories for knee rehabilitation purposes. Based on the shortcomings of conventional physiotherapeutic tasks, the outcome of this study can be helpful in prescribing an impactful yet convenient configuration toward a safe and promising rehabilitation process. Assessment of exoskeleton alignment during rehabilitation is important to ensure user safety with a better therapy efficacy.

Parallel assistive robotic system for knee rehabilitation: kinematic and dynamic modeling validation

The knee joint is frequently exposed to injuries in people of all ages. In some cases, physical therapy is prescribed to recover the strength and mobility of a patient. The robotic assistance devices are gaining community attention and aim to improve the quality of life of people. In this work, we present the kinematic and dynamic modelling of a five-bar-linkage assistive device for knee rehabilitation according to anthropometric data from Latin-American population. We obtain a dynamic model of the proposed rehabilitation system and compare the knee trajectories with obtained using the assistive system to evaluate appropriate control strategies in the future. For this purpose, we present the kinematic formulation of the device, and then we derive the dynamics using two approaches to validate the model; we obtain the motion equation using the Lagrange approach and an algebraic method that simplifies modelling. Both approaches yield a unique model, which is validated either in simulation and by experimental trials, showing the functionality of the system and the validity of the models when performing rehabilitation routines.

Current Status and Future Perspectives of the Active Knee Joint Rehabilitation Device

Background: Today, living standards and medical technology are improving, and the aging global population is increasing. However, more and more older adults are suffering from knee diseases. This will seriously affect patients’ daily life and their mental state. In many studies, repetitive physical exercises and motor activities in real-world environments have been shown to help improve knee muscle strength and restore damaged nerves. Therefore, physical knee therapy is very necessary. The use of rehabilitation training devices for movement therapy has shown great potential. Objective: This study aimed at exploring the structural features, functions, and development status of the knee rehabilitation training device. Method: This review explores the structure and function of various current knee rehabilitation devices based on structural and kinematic properties of the knee joint in relation to requirements of physical knee rehabilitation. This paper aims to present a systematic guideline and outline a reference for future designers of rehabilitation devices. Results: By analyzing the structure and movement of the knee joint and combining the strategies of physical knee rehabilitation, movement requirements during knee rehabilitation training are concluded. According to the structure, drive form, transmission mode, and rehabilitation environment of knee rehabilitation devices, the devices are classified and compared; some typical features are summarized; some current problems are analyzed, and the future trends and development directions of rehabilitation devices are discussed. Conclusion: Current rehabilitation equipment has a variety of structures and functions, but a good balance between weight and volume is hardly maintained. The protection of the body needs to be further improved. Many knee rehabilitation devices are only concepts, not physical objects, and lack clinical trial data. Power sources and drives are large and heavy, which can compress the knee joint and burden the patient. Strong and lightweight materials should be chosen to assist knee rehabilitation. It will be a good development in the future.

A New 4-DOF Robot for Rehabilitation of Knee and Ankle-Foot Complex: Simulation and Experiment

Stationary robotic trainers are lower limb rehab robots which often incorporate an exoskeleton attached to a stationary base. The aim is to recover range of motion, increase muscles strength and reduce joint stiffness. The issue observed in the stationery trainers which involve knee and ankle-foot complex joints simultaneously is that they restrict the natural motion of ankle-foot in rehab trainings due to the insufficient Degrees of Freedom (DOFs) of these trainers. This restriction makes the joints deviate from their natural motion patterns, exerting potentially harmful forces and strain the joints. In this work, we propose a new stationary knee-ankle-foot rehab robot with all necessary DOFs including knee flexion/extension in addition to ankle plantarflexion/dorsiflexion, ankle-foot abduction-adduction and foot supination/pronation. Axes of motions are determined based on the kinematics of the joints. A typical rehab training exercise has been considered to evaluate the system performance. The chosen training (i.e., passive assistance) was first implemented in simulation to synthesize the control loop and to extract the parameters required for selecting the robot’s components. The robot was then fabricated and tested on a healthy subject. Results showed that all natural motions of the ankle-foot complex were generated during the training. Therefore, the proposed system fulfils the desired aim properly, so that it can be utilized in the design of rehab robots.

Adaptive Synergetic Motion Control for Wearable Knee-Assistive System: A Rehabilitation of Disabled Patients

In this study, synergetic-based adaptive control design is developed for trajectory tracking control of joint position in knee-rehabilitation system. This system is often utilized for rehabilitation of patients with lower-limb disabilities. However, this knee-assistive system is subject to uncertainties when applied to different persons undertaking exercises. This is due to the different masses and inertias of different persons. In order to cope with these uncertainties, an adaptive scheme has been proposed. In this study, an adaptive synergetic control scheme is established, and control laws are developed to ensure stable knee exoskeleton system subjected to uncertainties in parameters. Based on Lyapunov stability analysis, the developed adaptive synergetic laws are used to estimate the potential uncertainties in the coefficients of the knee-assistive system. These developed control laws guarantee the stability of the knee rehabilitation system controlled by the adaptive synergetic controller. In this study, particle swarm optimization (PSO) algorithm is introduced to tune the design parameters of adaptive and non-adaptive synergetic controllers, in order to optimize their tracking performances by minimizing an error-cost function. Numerical simulations are conducted to show the effectiveness of the proposed synergetic controllers for tracking control of the exoskeleton knee system. The results show that compared to classical synergetic controllers, the adaptive synergetic controller can guarantee the boundedness of the estimated parameters and hence avoid drifting, which in turn ensures the stability of the controlled system in the presence of parameter uncertainties.

Effects of proprioceptive training in the recovery of patients submitted to meniscus surgery: systematic review and meta-analysis

ObjectiveTo evaluate the effects of proprioceptive training on rehabilitation of knee after arthroscopic partial meniscectomy (APM).DesignPubMed, EMBASE, The Cochrane Library, Web of Science, China National Knowledge Infrastructure, Technology Periodical Database,...

Gravitational Base Parameters Identification for a Knee Rehabilitation Parallel Robot

New robotic technology is emerging nowadays to tackle lower limb rehabilitation issues. However, the commercial robots available for lower limb rehabilitation are usually oversize and expensive. Knee rehabilitation is generally aided by a professional therapist, making this clinical procedure an interesting scope for robotics. Parallel robots are suitable candidates for knee rehabilitation due to their high load capacity, stiffness, and accuracy compared to serial ones. In contrast, this robot has singular configurations inside its workspace, and its dynamic model is generally complex. For these reasons, a parallel robot for knee rehabilitation needs an advanced control unit to solve complex mathematical problems that ensure patient security. This study proposes the base parameters identification of a compact gravitational linear model of a 3UPS+RPU parallel robot using singular value decomposition. This paper recommends adding a statistical method focused on condition number minimization to the singular value decomposition process. This statistical method reduces the computational resources taken searching for the best inertial parameters combination at the beginning of the base parameter identification. The gravitational base parameters identified have a physical meaning and low complexity. This fact makes the results of this research the basis of an adaptative control applied to 3UPS+RPU parallel robot. This study shows that the gravitational term is the most influential for knee rehabilitation tasks, compared with the inertial, Coriolis, and centrifugal components, regarding the dynamic behavior of the parallel robot.