Design Of Orthosis Research Articles

Clinical Efficacy of Different Ankle Foot Orthosis Design in Subjects with Foot Drop after Stroke: A Review and Comparison

Clinical Efficacy of Different Ankle Foot Orthosis Design in Subjects with Foot Drop after Stroke: A Review and Comparison

Design and application of static progressive ankle foot orthosis

The scar contracture of Achilles tendon in burn patients after operation is easy to cause " foot drop" , which leads to ankle dorsiflexion dysfunction. To solve this problem, the authors designed and made a static progressive ankle foot orthosis. The foot support part and the crus support part of the orthotic device are connected by rivets, and the distal end of the foot support part and the proximal end of the crus support part are pulled by the traction belt on both sides, gradually improving the ankle dorsiflexion function. This static progressive ankle foot orthosis is simple, practical, cost-effective, and worthy of clinical promotion.

Design and evaluation of a modularized ankle-foot orthosis with quick release mechanism.

Ankle foot orthosis (AFO) stiffness affects ankle range of motion but can also provide energy storage and return to improve mobility. To perform multiple activities during the day, a person may want to change their AFO stiffness to meet their activity's demand. Carrying multiple AFOs and changing AFOs is inconvenient and could discourage users from engaging in multiple activities. This project will develop a new quick-release mechanism (QRM) that allows users to easily change posterior strut elements to change AFO stiffness. The QRM attaches to the AFO and requires no tools to operate. The proposed QRM includes a quick-release key, weight-bearing pin, receptacle anchor, and immobilization pin. A prototype was modelled with SolidWorks and simulated with SolidWorks Simulation. The QRM was designed to have no mechanical failure during intense activities such as downhill walking and jogging. Unlike a solid screw connection, the QRM needed an additional part to eliminate unsecured motion related to clearance between the quick release key and receptacle anchor. Mechanical test results and measurement data proved no deformation on each part after mechanical testing.Clinical Relevance- The quick release AFO has the potential to improve user's activities range by tuning from stiffness free mode to high stiffness mode.

Motor-Augmented Wrist-Driven Orthosis: Flexible Grasp Assistance for People with Spinal Cord Injury.

This paper presents the design of a motor-augmented wrist-driven orthosis (MWDO) for improved grasp articulation for people with C6-C7 spinal cord injuries. Based on the traditional passive, wrist-driven orthotic (WDO) mechanism, the MWDO allows for both body-powered and motorized actuation of the grasping output thus enabling more flexible and dexterous operation. Here, the associated control scheme enables active decoupling of wrist and finger articulation, which can be useful during certain phases of manipulation tasks. An additional modification to the traditional WDO is the integration of a magnetic latch at the Distal Interphalangeal (DIP) joint allowing for improved pinching. These abilities are demonstrated with common activities of daily living (ADL).

Investigating the Impact of the User Interface for a Powered Hip Orthosis on Metabolic Cost and User Comfort: A Preliminary Study

ABSTRACT Introduction Powered orthoses have the potential to benefit pathologic or geriatric populations by increasing the quality of their mobility, reducing metabolic cost, and helping restore functional status. However, user interface design of powered orthoses is rarely considered, and may limit their clinical impact. The aim of this study was to design and evaluate a novel user interface for a powered hip orthosis. We hypothesized that our interface design would reduce metabolic costs, reduce skin irritation, increase user comfort, and reduce pain during ambulation when compared with an off-the-shelf (OTS) interface. Methods A novel, custom-fit torso user interface was designed to have extended trimlines and load the iliac crests. This allows for improved purchase over anatomic structures and potentially improves weight distribution of the powered hip orthosis. The design was compared with an OTS user interface. Subjects ambulated in three conditions: without a powered orthosis, with an OTS interface, and with the novel interface. Five healthy subjects (23.6 ± 2.2 years) with no neuromuscular limitations ambulated on a treadmill for 6 minutes at 0.8 m/s while measuring metabolic cost for three levels of torque assistance. Subjects repeated this procedure for all three conditions. After ambulating in each interface, skin was inspected at t = 0, 10, and 30 minutes. They completed the OPUS (Orthotics and Prosthetics User’s Survey) Satisfaction with Device survey and reported pain on a 1-to-10 scale (0 = no pain). Results The novel interface reduced metabolic cost for all conditions when compared with OTS componentry. Maximal difference was at the 13% torque assistance level where the difference was 0.18 W/kg ± 0.11 (SEM) (9.48%). The novel design generally reduced pain scale and skin irritation. The average pain rating decreased from a 3/10 ± 1.17 (SEM) in the OTS condition to 2/10 ± 0.84 (SEM). The novel design generally increased OPUS Satisfaction with Device score when compared with the OTS condition; the OPUS score increased from an average of 32/45 ± 2.56 (SEM) for the OTS condition to 36/45 ± 2.1 (SEM). Discussion The novel design tended to reduce metabolic cost for all tested powered orthotic conditions. This may be explained by the novel design's more proximal trimlines and increased loading of anatomic structures. These features may be due to maximized biomechanical leverage and minimized compensatory motions during ambulation. Conclusions The user interface may impact metabolic cost of walking and user comfort. Moving forward, it should be considered an essential element of powered orthosis design. It is critical to optimize the user interface in future powered hip orthotic designs due to minimal surface area available for weight-bearing and reduced number of actuated joints. Therefore, those interested in optimizing powered hip orthotic user interface designs should focus on loading anatomic structures, including the shoulders and iliac crests, and on supporting the curvature of the lumbar spine.

Design of a Hand Orthosis for People with Deficiency of the Medial, Radial, and Ulnar Nerves

The reduced mobility in hand is a problem that prevents daily activities such as feeding, bathing, brushing, dressing, grabbing objects, and losing autonomy in everyday situations. The hand disability is mainly due to the deficiency of the ulnar, medial, and radial nerves, which prevents adequate hand movements. In consequence, various assistive technologies are proposed to assist mobility, communication, self-help, and domestic activities. An alternative is the use of active orthosis, which by this proof of concept, the person can perform adequate hand movements. This paper aims to introduce a 3D active orthosis of PLA Plus designed by the Creative Lab in the Universidad Santiago de Cali, which includes an actuator and a low-cost myoelectric signal acquisition system, with two input channels. Finger flexion/extension movements and resting-state were performed. The user’s intention is decoded processing rectified and integrated myoelectric signals. An on-off control algorithm was implemented to generate commands that control orthosis movements. The system is controlled by a person who has a disability due to a C5 and C6 spinal trauma that generated muscular atrophy in the distal level of the hand. Results showed the controlled flexion and extension of the fingers with a good performance. This system assists people with disabilities in the ulnar, medial, and radial nerves to make proper hand movements. The design of the above-mentioned orthosis allows individuals to carry out daily living activities to improve their quality of life.

Design of a lightweight passive orthosis for tremor suppression

BackgroundTremor is the most common movement disorder with the highest prevalence in the upper limbs. The mechanical suppression of involuntary movements is an alternative and additional treatment to medication or surgery. Here we present a new, soft, lightweight, task asjustable and passive orthosis for tremor suppression.MethodsA new concept of a manual, textile-based, passive orthosis was designed with an integrated, task adjustable, air-filled structure, which can easily be inflated or deflated on-demand for a certain daily activity. The air-filled structure is placed on the dorsal side of the wrist and gets bent and compressed by movements when inflated. In a constant volume air-filled structure, air pressure increases while it is inflating, creating a counterforce to the compression caused by bending. We characterised the air-filled structure stiffness by measuring the reaction torque as a function of the angle of deflection on a test bench. Furthermore, we evaluated the efficacy of the developed passive soft orthosis by analysing the suppression of involuntary movements in the wrist of a tremor-affected patient during different activities of daily living (i.e. by calculating the power spectral densities of acceleration).ResultsBy putting special emphasis on the comfort and wearability of the orthosis, we achieved a lightweight design (33 g). The measurements of the angular deflection and resulting reaction torques show non-linear, hysteretic, behaviour, as well as linear behaviour with a coefficient of determination (R2) between 0.95 and 0.99. Furthermore, we demonstrated that the soft orthosis significantly reduces tremor power for daily living activities, such as drinking from a cup, pouring water and drawing a spiral, by 74 to 82% (p = 0.03); confirmed by subjective tremor-reducing perception by the patient.ConclusionThe orthosis we developed is a lightweight and unobtrusive assistive technology, which suppresses involuntary movements and shows high wearability properties, with the potential to be comfortable. This air-structure technology could also be applied to other movement disorders, like spasticity, or even be integrated into future exoskeletons and exosuits for the implementation of variable stiffness in the systems.

A Multifunctional Ankle Foot Orthosis Utilizing a Magnetorheological Actuator

The intelligent material, so-called magnetorheological (MR) fluid, is used in the design of an ankle foot orthosis. This paper presents the configuration of a multifunctional ankle foot orthosis that is equipped with a novel MR actuator. At first, the structure of the orthosis is introduced. Then, according to the mounting position of the actuator, the MR actuator is conceived by designing the structure and magnetic circuit. The actuator has three working modes, assistant, resistant and free modes. Finally, the manual power consumptions of two conditions, gait with and without the orthosis, are investigated; electricity consumptions of two cases, orthosis with and without the MR actuator, are compared.

Additively manufactured textiles and parametric modelling by generative algorithms in orthopaedic applications

PurposeThe purpose of this paper is to implement a new process aimed at the design and production of orthopaedic devices fully manufacturable by additive manufacturing (AM). In this context, the use of generative algorithms for parametric modelling of additively manufactured textiles (AMTs) also has been investigated, and new modelling solutions have been proposed.Design/methodology/approachA new method for the design of customised elbow orthoses has been implemented. In particular, to better customise the elbow orthosis, a generative algorithm for parametric modelling and creation of a flexible structure, typical of an AMT, has been developed.FindingsTo test the developed modelling algorithm, a case study based on the design and production of an elbow orthosis made by selective laser sintering was investigated. The obtained results have demonstrated that the implemented algorithm overcomes many drawbacks typical of the traditional computer aided design (CAD) modelling approaches. The parametric CAD model of the orthosis obtained through the new approach is characterised by a flexible structure with no deformations or mismatches and has been effectively used to produce the prototype through AM technologies.Originality/valueThe obtained results present innovative elements of originality in the CAD modelling sector, which can contribute to solving problems related to modelling for AM in different application fields.

Design, Implementation and Preliminary Testing of a Novel Orthosis for Reducing Erector Spinae Muscle Activity, and Improving Balance Control for Hyperkyphotic Elderly Subjects

Background: Aging often results in thoracic kyphosis and adverse postural changes. This may interfere with physiologic activity of paraspinal muscles. Few styles of spinal orthosis have been already used to reduce thoracic kyphosis. This paper describes the development of a novel orthosis, which is designed based on the anatomy of the back muscles. This novel orthosis may potentiate muscle activity and balance control among older hyper kyphotic subjects.Objectives: The object of this study was to design and preliminary testing of a new orthosis to potentiate muscle activity and balance control among older hyper kyphotic subjectsMaterial and Methods: In this quasi-experimental study, a new postural control orthosis with a textile band structure was designed to provide an additional support for spine and muscles of the back. The functional impact of this orthosis was evaluated in six older hyper-kyphotic subjects. According to the results, the paraspinal muscles activity and balance control were significantly improved.Results: The RMS sEMG of the lumbar and thoracic erector spinae muscles reduced significantly (p<0.05), and a significant improvement (p<0.05) was observed in the balance test when patients put on the novel orthosis (p<0.05).Conclusion: The new orthosis can considerably improve the paraspinal muscles activity at both the upper and lower lumbar levels. It can also recover balance control among elderly subjects

Ankle-foot orthosis design between the tradition and the computerized perspectives.

This study focuses on the drop foot case related to hyperthyroidism of the ankle joint resulting in the relaxation of the toes during walking. This condition requires treatment using an ankle-foot orthosis. Traditional orthosis techniques lack precision and depend on the skill of the fabricator. This research aims to make a bias in ankle-foot orthosis design and analysis methods, where a complete methodology of numerical design and testing has been proposed using advanced engineering software. A numerical model of the patient's foot was generated and used to design an ankle-foot orthosis model using SolidWorks. The designed model was mechanically analyzed by the finite element method using ANSYS Workbench 16.1 under different static and dynamic loading conditions. The ankle-foot orthosis model was numerically designed and analyzed before the manufacturing process. This is believed to reduce time and material loss and foster the use of numerical models in biomedical applications. This study suggests focusing on the design and analysis of orthoses according to the patient's measurements. This is expected to increase the comfort and raise the level of treatment. Numerical design methods also enable precise manufacturing using computerized devices such as three-dimensional printers.

Design and development of orthosis for clubfoot correction in infants an additive manufacturing approach

Clubfoot is a rare complex congenital deformity found in new born babies, with foot twisted inwards and downward. This condition, if not treated at infancy, may lead to permanent deformity. The victims suffer pain and difficulty in walking which result in failure to access education and employment leading to exclusion from society. Patients suffering from this deformity can be seen throughout the world and are generally mistaken to be affected by polio. The only non-invasive treatment is use of casting method (Ponseti) which has wide range of disadvantages. This method has not been properly substituted due to the lack of a better alternative. Current study suggests the development of a custom – made orthosis. 3D printing technique can be used to fabricate this deformity correction orthosis. The 3D printed orthosis has an upper hand over the conventional casting process. Various parameters related to the treatment were considered in designing the orthosis. Prominent parameters being three dimensional movements, ease of use, comfort, immobilization and cost. The orthosis can be used throughout the treatment process without frequent replacement; this is a distinct advantage over the Ponseti method. The orthosis will replace the casting process and will prove to provide better treatment. Even though printing the orthosis on spot takes longer time than the conventional cast, its countless benefits make up for the waiting time. In the current work design and development of orthosis is achieved with CAD software and fabrication is made with FDM 3D printer using PLA filament.

Development of a Decision Support System for Ankle-Foot Orthosis (AFO) Design Based on Lumped Parameter Models for Human Locomotion Prediction

This work aims to develop a decision support system (DSS) to help orthotic clinicians design AFOs to correct pathological gait patterns that result from various nerve impairments. The DSS utilizes lumped parameter models to predict key joint angles, step length, and swing and stance durations based on anthropometric data, impairment and AFO design. The predicted gait patterns by DSS were in general agreement with data from available literature. In the presented drop foot example, the DSS shows that increasing AFO stiffness would result in increased stride duration on both sides; proper AFO stiffness may result in increased stride length on both sides comparing with stride length for pathological gait without AFO. The DSS can be used by clinicians to suggest proper AFO’s mechanical properties, such as stiffness and range of motion, to help improve abnormal gait patterns resulting from underlying nerve impairments.

A systematic review of the effect of footwear, foot orthoses and taping on lower limb muscle activity during walking and running.

External devices are used to manage musculoskeletal pathologies by altering loading of the foot, which could result in altered muscle activity that could have therapeutic benefits. To establish if evidence exists that footwear, foot orthoses and taping alter lower limb muscle activity during walking and running. Systematic literature review. CINAHL, MEDLINE, ScienceDirect, SPORTDiscus and Web of Science databases were searched. Quality assessment was performed using guidelines for assessing healthcare interventions and electromyography methodology. Thirty-one studies were included: 22 related to footwear, eight foot orthoses and one taping. In walking, (1) rocker footwear apparently decreases tibialis anterior activity and increases triceps surae activity, (2) orthoses could decrease activity of tibialis posterior and increase activity of peroneus longus and (3) other footwear and taping effects are unclear. Modifications in shoe or orthosis design in the sagittal or frontal plane can alter activation in walking of muscles acting primarily in these planes. Adequately powered research with kinematic and kinetic data is needed to explain the presence/absence of changes in muscle activation with external devices. This review provides some evidence that foot orthoses can reduce tibialis posterior activity, potentially benefitting specific musculoskeletal pathologies.

Using the Bioelectric Signals to Control of Wearable Orthosis of the Elbow Joint with Bi-Muscular Pneumatic Servo-Drive

SUMMARYThis study presents a new design of a wearable orthosis of elbow joint with a bimuscular pneumatic servo-drive (PSD) with control based on the recording of bioelectric signals (BESs). The authors analyzed the impact of the induced brain activity and the muscular tension within the head of the participant on the BESs that can be used to control the PSD of the elbow joint orthosis. To control the elbow joint orthosis, a distributed control system (DCS) was developed, which contains two control layers: a master layer connected to the device for recording the BES and a direct layer contained in a wireless manner with the controller of the PSD. A kinematic-dynamic model of the elbow joint orthosis, patterned after the biological model of human biceps–triceps, was used in the programming of the PSD controller. A biomimetic dynamic model of the pneumatic muscle actuator (PMA) was used, in which the contraction force results from the adopted exponential static model of the pneumatic muscle (PM). The use of direct visual feedback (DVF) makes it possible for the participant to focus on the movement of the orthosis taking into account the motoric functions of the elbow.

Design and Validation of a Partial-Assist Knee Orthosis with Compact, Backdrivable Actuation.

This paper presents the mechatronic design and initial validation of a partial-assist knee orthosis for individuals with musculoskeletal disorders, e.g., knee osteoarthritis and lower back pain. This orthosis utilizes a quasi-direct drive actuator with a low-ratio transmission (7:1) to greatly reduce the reflected inertia for high backdrivability. To provide meaningful assistance, a custom Brushless DC (BLDC) motor is designed with encapsulated windings to improve the motor's thermal environment and thus its continuous torque output. The 2.69 kg orthosis is constructed from all custom-made components with a high package factor for lighter weight and a more compact size. The combination of compactness, backdrivability, and torque output enables the orthosis to provide partial assistance without obstructing the natural movement of the user. Several benchtop tests verify the actuator's capabilities, and a human subject experiment demonstrates reduced quadriceps muscle activation when assisted during a repetitive lifting and lowering task.

A Lightweight Linear Actuating System for Finger Articulation: A Proof-of-Concept Study.

This paper provides a proof of concept for an actuating system comprised of a linear actuator and a spring steel strip that enables bidirectional articulation of a finger by transmitting the force directly to the finger tip. This proposed design can be distinguished from other orthosis designs, which use rigid linkages or cables with DC motors or fluidic systems for force generation and transmission. We designed an experimental setup with a 3D-printed model finger to mimic a passive human finger on which the actuation system was mounted and tested. The finger was positioned such that it would curl upward to lift various masses when articulated by the actuating system to demonstrate the system's force generation capability. We tested two linear actuators and two steel strips, using a wide range of masses to determine which would be the most suitable components for our design. We analyzed motion profiles, joint angles, force generation, and actuator stroke velocities during various experimental trials. Our results demonstrate that our actuating system is capable of generating sufficient forces and motions with an adequate response time to be used in the design of a hand orthosis for grasping/releasing assistance. From our tests, a prototype was designed with three linear actuators positioned on the dorsal side of the hand and actuated the thumb, index, and middle fingers. Future work will include sensor integration and performance evaluation of the orthosis.

A review of simulation methods for human movement dynamics with emphasis on gait

Human gait analysis is a complex problem in biomechanics because of highly nonlinear human motion equations, muscle dynamics, and foot-ground contact. Despite a large number of studies in human gait analysis, predictive human gait simulation is still challenging researchers to increase the accuracy and computational efficiency for evaluative studies (e.g., model-based assistive device controllers, surgical intervention planning, athletic training, and prosthesis and orthosis design). To assist researchers in this area, this review article classifies recent predictive simulation methods for human gait analysis according to three categories: (1) the human models used (i.e., skeletal, musculoskeletal and neuromusculoskeletal models), (2) problem formulation, and (3) simulation solvers. Human dynamic models are classified based on whether muscle activation and/or contraction dynamics or joint torques (instead of muscle dynamics) are employed in the analysis. Different formulations use integration and/or differentiation or implicit-declaration of the dynamic equations. A variety of simulation solvers (i.e., semi- and fully-predictive simulation methods) are studied. Finally, the pros and cons of the different formulations and simulation solvers are discussed.

Carpal Tunnel Syndrome: A Summary of Clinical Practice Guideline Recommendations-Using the Evidence to Guide Physical Therapist Practice.

Carpal tunnel syndrome (CTS) is the most common upper extremity nerve compression syndrome. Patients with CTS experience reduced sensation, dexterity, and function. Irreversible changes in nerve structure and function due to demyelination and axonal damage can occur in long-standing cases. Published in the May 2019 issue of JOSPT, clinical practice guidelines for CTS summarize the best available evidence on incidence and prevalence, pathophysiology, classification, risk factors, examination techniques, and interventions. These guidelines provide practical recommendations for physical therapy examination, diagnosis, and treatment. J Orthop Sports Phys Ther 2019;49(5):359-360. doi:10.2519/jospt.2019.0501.

Ring orthosis design and production by rapid prototyping approach

Study DesignIn this study, ring orthosis design and manufacturing was performed by using rapid prototyping technology. IntroductionSwan neck and boutonniere deformities may occur because of various reasons such as tendon injuries, sharp object injuries, or rheumatic diseases. Although the ring orthoses are the most commonly used conservative treatment method for swan neck and buttonhole deformities, they cannot be widely used because they are both difficult to produce and esthetically unsatisfied with the patients. Purpose of the StudyIn this study, it was aimed to manufacture with an orthosis design that is fully compatible, more esthetic, faster, and easily produced. Methods3D printing technologies are used in design and manufacturing. The 3D scanner is used in the measurement process, and the 3D printer is used in the manufacturing process. ResultsAs a result of the study, a more esthetically pleasing and comfortable orthosis was made faster. Discussion and ConclusionsAs a result of the study, the thickness of the material should not be less than 5 mm.