Download or read book Load Analysis of Ankle Foot Orthoses During Gait written by Atichart Kwanyuang and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Different causes of gait deficiencies generate different symptoms. It is important for orthotists to gain a better understanding on how to design Ankle Foot Orthoses (AFOs) in order to address individual biomechanical requirements. The loads acting on AFOs during gait are important factors for orthotists to accurately understand so as to design AFOs more effectively. Therefore, the aim of this study is to develop a validated Finite Element (FE) model, which could be used to quantify and analyse the loads acting on an AFO during gait. In this thesis, for mutual comparison and confirmation, pressures acting on the AFO are recorded by two different types of pressure transducers: resistive and capacitive. Trends of the results obtained from the two sensors are similar; however, the magnitudes tend to be different. Furthermore, an accurate digital 3D scanning model of an AFO is captured using the 3D digitiser which can be modified by Computer Aided Design (CAD) software before being exported to Finite Element Analysis (FEA) software to create an FE model. Both the loads measured from the experiment and the assumed constraint during heel off are then applied to the FE model. To make the analysis more complete, a number of features of AFO and a range of FEA methods are conducted. The results are validated by both empirical findings from previous literature and an additional experiment carried out. Based on a healthy subject with no pathological gait, this study reveals that, on the one hand, the AFO is able to assist walking by carrying 6.89% of the overall magnitude of ground reaction force. On the other hand, it resists walking by generating 18.63% in dorsiflexion of the overall magnitude of the moment generated by the plantarflexors. It is therefore claimed that these findings are useful for orthotists involved in fitting AFOs, in order to efficiently design and construct them.

Download or read book Improvement of Ankle Joint Stability in Foot Drop Patients During Walking by 3D Printed Ankle Foot Orthoses written by Harish Banga and published by GRIN Verlag. This book was released on 2018-10-04 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Document from the year 2018 in the subject Medicine - Anatomy, Physiology, Cytology, grade: 10.0, , language: English, abstract: Lower leg foot orthoses are orthotic gadgets that help the decrease leg joint and are suitable for a few pathologies, typically those that improve the foot drop circumstance, which is resulting from a lower leg joint insufficiency. In the existing paintings, a custom designed model of decrease leg foot orthosis applied as a part of the human frame has been created. Additive Manufacturing structures has been utilized to create the lower leg foot orthosis (Selective Laser Sintering Technology). Kinematic estimations had been received in a stride lab from foot drop sufferers, with and with out three-D plastic printed lower leg foot orthoses on unmarried toes. The consequences got proven that with the orthoses, the lower leg joint conduct is sort of a instantly torsional spring, with out a hysteresis. With an goal to check the sufficiency of the AFO, Clinical GAIT Analysis of Foot Drop Patients has been performed. Customized 3-d printed Ankle Foot orthosis has been established to present higher GAIT cycle execution. The consequences of this look at indicated that development of gait in foot drop sufferers with 3-d published ankle foot orthosis that's measured via Clinical Gait evaluation.

Download or read book Evaluation of Gait and Muscle Function with Ankle Foot Orthoses written by Hwan Choi and published by . This book was released on 2016 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many individuals with cerebral palsy (CP) and stroke are prescribed ankle foot orthoses (AFOs) for use during daily life. AFOs have been shown to improve pathologic gait and walking speed in CP and stroke by providing support and alignment. There are many different types of AFOs available such as posterior leaf spring AFOs, rigid AFOs, and articulated AFOs. Further, there are many parameters that can be customized or tuned for each type of AFO, such as stiffness, heel height, shank to vertical angle, and foot plate length. However, how different types of AFOs and the customization of specific parameters impact muscle function remains unclear. The goals of this dissertation were to evaluate how different types of AFOs and different tuning parameters impact gait kinematics and muscle function. Of particular interest is the gastrocnemius, a key muscle that crosses the knee and ankle joints and is commonly tight among individuals with CP or stroke. Gastrocnemius operating length, defined as the total muscle and tendon length during a functional activity, influences ankle and knee kinematics during gait. Therefore, understanding and potentially controlling gastrocnemius operating length may help to properly select and optimize the design of AFOs to improve gait. To understand the impact of AFOs on gastrocnemius function, this dissertation includes four primary aims. The first aim was to evaluate how current methods for tuning, or adjusting patient-specific properties of AFOs, impact gastrocnemius operating length and gait kinematics using musculoskeletal modeling. We performed a case study of an adult stroke survivor who received three AFOs that were tuned by a trained orthotist. The orthotist observed the individual's shank to vertical angle (SVA, the angle of the tibia with respect to vertical, which is commonly assessed by orthotists during gait analysis) and adjusted the AFO's fixed plantarflexion angle and heel height to make the SVA more similar to unimpaired individuals. For this case study, we found that tuning the AFOs based on SVA resulted in a decrease in gastrocnemius operating length and increased knee flexion angle during swing. These results demonstrated how musculoskeletal modeling can be used to evaluate muscle function during walking and the impacts of adjusting SVA for stroke survivors. The second aim was to evaluate how different types of AFOs, representing the current standard of care, alter gastrocnemius operating length and gait kinematics in children with CP. We evaluated gastrocnemius operating length for eleven children with CP who each received two types of AFOs. Since individuals wear AFOs all day, we sought to evaluate if the gastrocnemius operated in a stretched or shortened position. For individuals with CP with more mild involvement, we found both types of AFOs stretched the gastrocnemius during walking for the majority of individuals. However, for individuals with CP and more severe involvement, we found only the more solid, Cascade AFOs stretched the gastrocnemius in some individuals. This study suggested AFOs can potentially be a rehabilitation modality by providing dynamic stretching exercise for a short and tight gastrocnemius during gait. The third aim was to create a flexible platform for fabricating AFOs with 3D printing and scanning technology, which could support research on how AFO stiffness impacts joint and musculotendon function. The current standard AFO designs are not only cost and time ineffective, but also provide limited control of AFO stiffness. This study demonstrated a novel method for fabricating a variable stiffness AFO using a 3D scanner and printer. To adjust the stiffness, elastic polymer bands were fabricated with varying stiffness. The 3D printed AFO is cost and labor effective compared to current AFO fabrication methods. 3D printed AFOs can also can provide adjustable AFO stiffness, as well as versatility to combine with various measurement tools such as ultrasound and electromyography. The forth aim was to evaluate how AFO stiffness and walking speed impact joint kinematics, gastrocnemius muscle length, and Achilles tendon (AT) length in unimpaired individuals. In this study we used the 3D printed AFO created in Aim 3. We found that as AFO stiffness increased, peak AT length, peak gastrocnemius activation level, and peak ankle dorsiflexion angle significantly decreased. However, peak gastrocnemius muscle length and peak AFO dorsiflexion moment increased with increasing AFO stiffness. Gastrocnemius muscle length and lengthening velocity significantly decreased with slower walking speeds. This study illustrated how human musculoskeletal system interplays with different stiffness AFOs. Building on these methods, future research can inform AFO prescription for individuals with neurologic injuries to maximize stretching or other rehabilitation or performance goals during walking. This dissertation provides important evidence for how humans adapt to various AFO properties and suggests important implications for the design and prescription of AFOs. This work provides a quantitative evaluation of how AFOs impact musculotendon dynamics among individuals with stroke (Aim 1) and cerebral palsy (Aim 2). The fabrication methods in Aim 3 creates a powerful and flexible research platform for evaluating AFO design, which may be extended to fabrication of AFOs for daily use with further improvements in additive manufacturing materials and methods. The final study (Aim 4), provides the first experimental evidence combining ultrasound and musculoskeletal modeling to understand how muscle and tendon length are impacted by AFO design. These evaluations provide guidance for future AFO design and prescription that can not only augment human mobility for unimpaired individuals, but also provide improve metrics for improving function and guiding rehabilitation for individuals with neurologic impairments.

Download or read book The Design and Control of Active Ankle foot Orthoses written by Kenneth A. Shorter and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ankle foot orthoses (AFOs) can be used to ameliorate the impact of impairments to the lower limb neuromuscular motor system that affect gait. Existing AFO technologies include passive devices with fixed and articulated joints, semi-active devices that modulate damping at the joint and active devices that make use of a variety of technologies to produce power to move the foot. Emerging technologies provide a vision for fully powered, untethered AFOs. In this dissertation, a novel portable powered ankle-foot orthosis (PPAFO) cabable of providing un-tethered assistance during gait is presented. The PPAFO provides both plantarflexor and dorsiflexor torque assistance via a bi-directional pneumatic rotary actuator. The system uses a portable pneumatic power source (compressed CO2 bottle) and embedded electronics to control the motion of the foot. Experimental data from two impaired and five healthy subjects were collected to demonstrate design functionality. The impaired subjects had bilateral impairments to the lower legs that caused weakness to the plantarflexors, in one case, and to the dorsiflexors in the other. Data from the healthy walkers demonstrated the PPAFO0́9s capability to provide correctly timed plantarflexor and dorsiflexor assistance during gait. The results from the impaired subjects demonstrated the PPAFO0́9s ability to provide functional assistance during gait. Additionally, this dissertation presented a modeling and control approach to address limitations present in the PPAFO through the introduction of a new hardware configuration and new control architecture. A combined model consisting of both the PPAFO and the human foot and shank segments was first derived and validated. Next, the current and the new PPAFO system configurations were evaluated both in simulation and experimentally during three simplified functional gait tasks: (1) motion control of the foot at the start of the gait cycle, (2) plantarflexor torque assistance during late stance, and (3) dorsiflexor position control of the foot during swing. The resulting analysis showed that the new system configuration both outperformed and was more efficient than the current PPAFO configuration. The stringent design requirements of light weight, small size, high efficiency and low noise make the creation of daily wear assist devices challenging, but once such devices appear they will present new opportunities for clinical treatment of gait abnormalities.

Download or read book Core Topics in Foot and Ankle Surgery written by Andrew Robinson and published by Cambridge University Press. This book was released on 2018-04-19 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: This concise guide offers an ideal overview of both the practical and theoretical aspects of foot and ankle surgery for trainees and junior consultants. Easy to read chapters cover all areas of surgery, from examination, imaging, and the biomechanics of the foot and ankle, to specific conditions including amputations and prostheses, deformities, arthritis, cavus and flat foot, sports injuries, Achilles tendon, benign and malignant tumors and heel pain. Fractures and dislocations of the ankle, hind-, mid- and forefoot are also covered, as are the foot in diabetes and pediatrics. Written by a team of international experts, the text is an accessible way to prepare for postgraduate examinations and manage patients successfully.

Download or read book Cerebral Palsy written by Christos P. Panteliadis and published by Springer. This book was released on 2018-03-06 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: This third edition systematically reviews recent developments in the diagnosis and evidence-based treatment of cerebral palsy, a consequence of foetal and early infant brain damage resulting in lifelong disabilities with a range of clinical characteristics. The first part discusses the definition, aetiology, classification, imaging and neuropathology, while the second focuses on the management of the individual challenges that children with cerebral palsy face, such as spasticity, dyskinesia, feeding problems and scoliosis. Based on the diverse characteristics of cerebral palsy, children require care from various specialists, including neuro-paediatricians, orthopaedists, psychologists, epidemiologists, physiotherapists and occupational therapists. This work was written by an international team of such specialists, providing a comprehensive mix of perspectives and expertise.

Download or read book Cerebral Palsy written by Bernard Dan and published by Mac Keith Press. This book was released on 2015-01-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The only complete, scientifically rigorous, fully integrated reference giving a wide ranging and in-depth perspective on cerebral palsy and related neurodevelopment disabilities. It considers all aspects of cerebral palsy from the causes to clinical problems and their implications for individuals. Leading scientists present the evidence on the role of pre-term birth, inflammation, hypoxia, endocrinological and other pathways. They explore opportunities for neuroprotection leading to clinical applications. An international team of experts provides clinicians and researchers with key information on the mechanisms underlying impairments in movement, development, cognition, communication, vision, feeding, behaviour, sexuality, and musculoskeletal deformities. They present a wide range of person-centred assessment approaches, including clinical evaluation, measurement scales, neuroimaging and gait analysis. The principles of multi-disciplinary management are presented, in terms of therapist intervention, medication and surgery. The perspective of the book spans the lifelong course of cerebral palsy, taking into account worldwide differences in socio-economic and cultural factors. Many chapters are illustrated with clinical vignettes enabling direct translation into practice. Full integrated colour, with extensive cross-referencing make this a highly attractive and useful reference.

Download or read book Effect of Quantitatively Matched Passive dynamic Ankle foot Orthoses on Post stroke Gait written by Corey A. Koller and published by . This book was released on 2018 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: The plantar flexors play a critical role in moving the body forward during gait by eccentrically contracting to control shank rotation. Insufficient control of shank rotation due to plantar flexor weakness, a common post-stroke impairment, may result in gait dysfunctions. Plantar flexor function during gait, or lack thereof, can be quantified by the peak plantar flexor moment. Passive-dynamic ankle-foot orthoses (PD-AFOs) can be prescribed to improve post-stroke gait. PD-AFO bending stiffness is a key orthosis characteristic that can replicate many functions of the plantar flexors. However, outcomes with ankle-foot orthoses (AFOs) are variable, likely because of the orthosis characteristics not being properly matched to each individual’s needs. We have developed a novel design and prescription process that quantitatively matches PD-AFOs based on each individual’s level of plantar flexor weakness. However, preliminary data collected by our lab showed that individuals post-stroke were unable to fully use the quantitatively matched PD-AFOs. We hypothesized that providing the individuals with real-time biofeedback on how to properly use the PD-AFO would help acclimate them to PD-AFO use and help them reap full benefits from the orthosis. Thus, the purpose of this study was to first evaluate if the quantitatively matched PD-AFOs improved gait biomechanics (peak plantar flexion moment) better than the originally prescribed AFO. Then, we developed and evaluated if a real-time biofeedback tool helped individuals post-stroke more effectively use the PD-AFO while walking. Eleven individuals with chronic stroke (> six months post-stroke) underwent an instrumented gait analysis to gather baseline data. Using our design and prescription process, a carbon fiber PD-AFO was then quantitatively matched for each subject. Once the PD-AFOs were manufactured, seven of the subjects visited the lab for one evaluation visit and underwent an instrumented gait analysis using his/her Original AFO and the quantitatively matched PD-AFO. The other four subjects visited the lab for two evaluation visits and underwent an instrumented gait analysis with his/her Original AFO and the quantitatively matched PD-AFO and used the biofeedback tool. A one-way repeated measures ANOVA was performed on the subject’s mean peak plantar flexion moment between his/her Original AFO and the quantitatively matched PD-AFO. If a significant difference was observed, simulation modeling analysis (SMA) was then performed to determine which subjects achieved a significant difference between the two conditions. The subject’s mean peak dorsiflexion angle was compared to the range assigned to each individual post-stroke to determine if the subject was able to reach that targeted dorsiflexion range. A one-way repeated measure ANOVA was performed on the subject’s mean peak plantar flexion moment between pre-biofeedback and post-biofeedback for both evaluation visits. SMA was also performed to determine if a significant increase in mean peak plantar flexion moment was achieved pre- and post-biofeedback for each subject individually for both evaluation visits. The subject’s change in mean step length (pre- vs. post-biofeedback) while walking with the quantitatively matched bending stiffness PD-AFO was compared to the pre-feedback step length variability for both visits. Results showed that 9 out of the 11 subjects had a significant increase in mean peak plantar flexion moment from the Original AFO to the quantitatively matched PD-AFO. Furthermore, two of the four subjects, on the second evaluation visit, were able to reach their targeted dorsiflexion range post-biofeedback. However, the individual post-stroke’s mean peak plantar flexion moment and mean step length did not improve from pre- to post-biofeedback for either evaluation visit. This study’s findings begin to lay the foundation of a novel quantitative prescription process to improve the gait of individuals post-stroke.

Download or read book Gait Analysis written by Jacquelin Perry and published by CRC Press. This book was released on 2024-06-01 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: The extensive and ground-breaking work of Dr. Jacquelin Perry is encompassed and detailed in the world renowned text, Gait Analysis: Normal and Pathological Function. The medical, healthcare, and rehabilitation professions key text for over 18 years on gait.... Now available in a much anticipated New Second Edition Dr. Jacquelin Perry is joined by Dr. Judith Burnfield to present today's latest research findings on human gait. Gait Analysis, Second Edition has been updated and expanded to focus on current research, more sophisticated methods, and the latest equipment available to analyze gait. What is New: • A new chapter covering running • Synergy of motion between the two limbs • A new chapter covering pediatrics • A new chapter covering stair negotiation • New and updated clinical examples • A section on power inside each chapter covering normal gait • New methods and equipment to analyze gait This Second Edition to Gait Analysis offers a re-organization of the chapters and presentation of material in a more user-friendly, yet comprehensive format. Essential information is provided describing gait functions, and clinical examples to identify and interpret gait deviations. Learning is further reinforced with images and photographs. Features: • Six sections cover the fundamentals, normal gait, pathological gait, clinical considerations, advanced locomotor functions, and gait analysis systems • Clinical significance of the most common pathological gait patterns • Over 470 illustrations and photographs, as well as 40 tables • Patient examples to illustrate elements of normal and pathological gait Tens of thousands of orthopedic, orthotic and prosthetic, physical therapy, and other rehabilitation professionals have kept a copy of Gait Analysis by their side for over 18 years...join the thousands more who will bring the Second Edition into their clinics, classrooms, and personal collections.

Download or read book Orthotics and Prosthetics in Rehabilitation written by Michelle M. Lusardi and published by Butterworth-Heinemann. This book was released on 2007 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt: Whether you are a student or a clinician, if you work with patients with neuromuscular and musculoskeletal impairments, you will find this text supplies a strong foundation in and appreciation for the field of orthotics and prosthetics that will give you the critical skills you need when working with this unique client population.

Download or read book Understanding the Effects of Wearing a Quantitatively Prescribed Passive dynamic Ankle foot Orthosis on the Mechanical Cost of transport and Gait Velocity in Individuals Post stroke written by Corey A. Koller and published by . This book was released on 2022 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Individuals post-stroke are commonly prescribed passive-dynamic ankle-foot orthoses (PD-AFOs) to aid in the control of shank forward rotation during mid-to- terminal stance due to plantar flexor weakness. PD-AFO bending stiffness is a key orthotic characteristic that can assist the plantar flexor muscles by providing the resistance needed to control shank forward rotation. Controlling shank forward rotation can store and return mechanical energy that can potentially increase gait velocity and decrease total mechanical cost-of-transport (COT). We developed a prescription model that can quantitatively prescribe PD-AFO bending stiffness based on an individual's level of plantar flexor function deficit. The overall purpose of this dissertation was to quantify and compare post-stroke COT and gait velocity along with underlying joint-level mechanisms through a range of conditions over time while the participant wears their quantitatively prescribed PD-AFO and examine the relationships between COT and common clinical assessments. Ten individuals with chronic stroke (> six months post-stroke) participated and underwent five visits. A clinical evaluation and the data needed to prescribe and manufacture the PD-AFOs were captured at the first visit. The PD-AFOs were manufactured in carbon fiber material and then fitted to the participants. Data was collected as the participants walked on an instrumented treadmill while wearing the PD-AFO and then returned two weeks and four weeks later to complete the same analyses. Simulation modeling analysis was conducted to statistically test Aims 1-3. Results showed that the quantitatively prescribed PD-AFOs significantly decreased total mechanical COT and increased gait velocity, by at least one MDC, compared to not wearing an orthosis. When comparing wearing the PD-AFO to wearing the SOC AFO, seven out of the nine participants significantly decreased total mechanical COT and although all participants increased gait velocity, only two increased by at least one MDC. Despite these improvements, inconsistent results were seen in the joint-level parameters across the three orthoses conditions. While wearing the PD-AFO across a range of gait velocities, changes in total mechanical COT were seen. While wearing the PD-AFO over time, minimal to no changes were seen in the global and joint-level parameters. Lastly, three of the clinical assessments (Fugl-Meyer assessment, dorsiflexion ROM with the knee flexed to 90℗ʻ, and gait velocity) showed potential relationships to changes in total mechanical COT magnitudes while wearing the PD-AFO. In general, these results improved our understanding of how quantitatively prescribing PD-AFO bending stiffness effected gait biomechanics and energetics over a range of conditions.

Download or read book The Influence of Ankle foot Orthosis Stiffness on Gait Performance in Patients with Lower Limb Neuromuscular and Musculoskeletal Impairments written by Nicole Lynn Guckert and published by . This book was released on 2012 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Individuals with various lower-limb neuromuscular and musculoskeletal impairments are often prescribed passive-dynamic ankle-foot orthoses (PD-AFOs) to compensate for impaired ankle muscle weakness. Several studies have demonstrated the beneficial effects of PD-AFOs on pathological gait, but few studies have examined the influence of the AFO stiffness characteristics on gait performance. One challenge to performing such studies is the difficulty of manufacturing custom AFOs with a wide range of controlled stiffness levels. However, selective laser sintering (SLS) is a well-suited additive manufacturing technique for generating subject-specific PD-AFOs of varied stiffness. Therefore, the overall goal of this study was to use SLS manufactured PD-AFOs to identify the relationships between AFO stiffness and gait performance in patients with various lower-limb neuromuscular and musculoskeletal impairments. Six subjects with unilateral impairments were enrolled in this study. For each subject, one subject-specific PD-AFO equivalent to the subject's clinically prescribed carbon fiber PD-AFO (nominal), one 20% more compliant and one 20% more stiff were manufactured using SLS. Three-dimensional kinematic and kinetic data were collected from each subject while ambulating with each PD-AFO at two different speeds to allow a comprehensive biomechanical analysis to assess the influence of PD-AFO stiffness on gait performance. The results showed that in the compliant AFO condition, the AFO limb vertical ground reaction force (GRF) impulse during loading and the non-AFO limb medial GRF impulse during push-off decreased. In addition, the AFO limb braking GRF impulse during loading and the non-AFO limb braking GRF impulse in early single-limb stance decreased. Furthermore, in the compliant AFO condition, negative knee work during early single-limb stance increased while positive hip work in early swing decreased in the AFO limb. Overall, as AFO stiffness decreased, the AFO limb contributed less to body support and braking. In addition, a decreased medial GRF impulse coupled with an increased vertical GRF impulse during non-AFO single-limb stance suggests that walking stability may be compromised as AFO stiffness decreases. Thus, a tradeoff may exist between preserving stability and increasing net propulsion, which should be considered when assessing the mobility needs of individuals prescribed PD-AFOs as a result of various neuromuscular and musculoskeletal impairments.

Download or read book Study of Mechanical Characteristics of Ankle foot Orthoses Using Finite Element Analysis Method written by Khandhar Previn Chendra Kaushal and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ankle-foot orthoses (AFOs) are external devices applied to the lower leg segment in patients with ankle joint impairment due to neuromusculoskeletal disorders resulting in abnormal gait. In the last three decades, plastic AFOs have superseded conventional metal AFOs. Prescriptions of AFOs by orthotists are usually based on trial and error and if gone wrong, cost time, money and increases the patients' rehabilitation treatment time. This is due to lack of understanding of the mechanical characteristics (i.e. stiffness) and stress distribution of AFOs. There is evidence indicating an optimal match exists between AFOs stiffness and successful rehabilitation. To date, most investigations on AFOs to determine mechanical characteristics are mechanical based. In this investigation an attempt to validate the use of finite element analyses (FEA) in order to predict stiffness and stress distribution of an AFO. Abaqus was used to conduct FEA. The AFO model was subjected to range of loads from 100N to 700N to dorsiflex and plantarflex the AFO. The resulting analysed change in ankle angle, change in length of foot and shank segments, stress distributions were analysed. A linear relationship was found to exist between ankle angle and moment of up to 24.9 Nm and 3.4° during dorsiflexion and moment of 23.9 Nm and 2.7° during plantarflexion and above which, non-linear behaviour is seen. FEA showed asymmetry in buckling displacements at the malleoli in medial and lateral surfaces of the AFO, where the lateral surface was found to be stiffer compared to the medial. However, this result may be inaccurate due to imprecise geometry of the AFO model. High stress concentrations were mainly around the Achilles tendon and malleoli region of the AFO during tension (plantarflexion) and compression (dorsiflexion). It is thought that FEA may be reliable method of studying mechanical characteristics and stress distribution on AFOs but further work is needed to validate the model at its and its accuracy under various conditions of use.

Download or read book The Effect of Ankle foot Orthosis on Gait and the Procedures Used to Assess Bi articular Muscle Length and Spasticity in Subjects with Diplegic Cerebral Palsy written by Fatma Mohsin and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ankle-foot orthoses are commonly prescribed amongst subjects with diplegic cerebral palsy as a conservative orthotic intervention. Multi-articular and bi-articular muscles are more severely involved in subjects with diplegic cerebral palsy. Appropriate clinical assessment including assessment of these muscles enables optimum ankle-foot orthosis footwear combination (AFO-FC) prescription and any required adjunct therapy.The overarching aim of this thesis was to investigate the effect of optimisation of the temporal midstance shank kinematics with the use of an AFO- FC on several variables including shank kinematics, thigh kinematics, vertical component of ground reaction force (FZ2) and ground reaction force (GRF) alignment in relation to hip and knee joint in temporal midstance to late stance. The understanding of the implication of, and the tools used to conduct assessment procedures and measurement processes were tested in the assessment of bi-articular muscles (specifically rectus femoris), to ascertain if results were predictive of presenting gait deviations and hence provide information to optimise treatment.The results of initial study suggested that a positive influence on the shank kinematics, thigh kinematics, FZ2 and GRF alignment in relation to hip and knee joint in temporal midstance to late stance was observed with the use of an AFO-FC. The results of a further study illustrated that a dominance relationship of the catch angle/length of rectus femoris (RF) measured using the Duncan-Ely with the knee or the hip joints varies at different gait points/periods. Additionally, the effect of dynamic shortness of4the RF differed on gait from the effect of true shortness. The results of series of studies testing the feasibility of using a 2-dimensional analysis system (PnO Clinical Movement Data) for hip, knee and ankle sagittal plane passive joint range of motion measurement during physical assessment confirmed the reliability and accuracy of this system.

Download or read book Design and Simulation of a Single hinge and Adaptive Ankle Foot Orthoses Based on Superelasticity of Shape Memory Alloys written by Morteza Gorzinmataee and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this thesis is to propose and develop new designs of Ankle Foot Orthosis (AFO) based on superelastic characteristics of shape memory alloys (SMAs). The problem investigated in this research is a human gait abnormality called drop foot caused by the paralysis of the muscles which allow the ankle to dorsiflex. This neuromuscular disorder results in foot slap after heel strike and toe drag during leg swing. As the most common solution, drop foot patients use an orthotic device called AFO add support and improve their gait. However, development of a more compact assistive device, which could passively or actively secure the normal gait requirements, is still a need by both patients and clinicians. Based on investigations and experimentations performed in Dynamic and Smart Systems Laboratory at University of Toledo, SMA is a potential solution due to its unique stiffness behavior and hysteretic characteristics. In this work superelastic characteristics of SMAs is considered as an enabler in the development of new generation of AFOs. Within this work a passive AFO design is proposed which employs a superelastic SMA element as the hinge of the device. This SMA hinge controls the ankle motion by storing and releasing energy during walking. The superelastic element enables the AFO to provide sufficient torque during dorsiflexion to raise the foot in the swing phase of the gait. In order to evaluate the design performance a comprehensive gait analysis study is performed to extract the requirements of motion, understand the critical loads, and calibrate the desired stiffness profiles for the ankle and the superelastic element. A Finite Element Analysis is performed to realize an optimum design for the SMA hinge. Preliminary simulations are carried out in the sagittal plane of the body to verify the functionality of the design in providing the motion requirements. Unlike existing AFOs with two hinges, the proposed design uses only one hinge. The multi-axial loading of the ground reaction in 3D is then simulated to estimate lateral response of the hinge in preventing hypermobility and securing the walking stability. To maintain stability the hinge should limit the motion in directions other than rotation in the sagittal plane. In addition to this passive hinge, superelastic SMA is also envisioned to realize an active AFO. To this end, an active superelastic SMA element which is adjusted structurally and dynamically is used to reproduce the stiffness variation of a healthy ankle. This concept could produce a controlled stiffness profile desired for different walking conditions such as various speeds. Actuation mechanism design for this concept is also discussed. Although, the major contribution of this study is developing a reliable passive AFO design, experimental and numerical analyses confirm the functionality of both passive and active SMA AFOs.

Download or read book Management of Chronic Musculoskeletal Conditions in the Foot and Lower Leg E Book written by Keith Rome and published by Elsevier Health Sciences. This book was released on 2014-09-18 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridging the gap between undergraduate and postgraduate knowledge and experience, this new full colour resource uses an interdisciplinary approach to help manage chronic conditions – osteoarthritis, Achilles tendinopathy, gout, rheumatic diseases, forefoot/rearfoot entities, stress fractures/reactions, cerebral palsy – in the lower limb and foot. Each chapter includes sections on predisposing factors, diagnosis, impairments, function, quality of life and management strategies while highlighting any complex features of a condition which may present. The latest advances are discussed with suggestions for new paths of research – ‘future directions’. The text is further supported by additional commentaries from internationally renowned researchers who highlight the key elements of the work and provide a supplementary perspective of the particular clinical condition. A general view of the patient’s needs is offered throughout, connecting clinical realities to real-world patient experiences. Management of Chronic Conditions in the Foot and Lower Leg is a comprehensive, practical tool that can be used to inform daily decision making in practice as well as to support those who build policy and management strategies in the clinical areas covered. Clear content and structure supported by full colour illustrations Includes less discussed conditions such as gout and cerebral palsy Focus on pain, impairment, function, quality of life and management strategies Critical reflections by experts highlight current clinical practice and thinking in research Provides a sound interpretation of research findings Features patient-reported outcome measures and health related behaviour strategies

Download or read book A Pilot Study Investigating the Effect of Ankle foot Orthosis AFO Stiffness on Walking Patterns of Patients with Ankle Impairment written by Peeraya Ruthiraphong and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ankle- foot orthoses (AFO) are commonly utilized as one of the standard treatments to improve ambulation in stroke patients. However, AFOs are prescribed and customized to individual patient in a variety of designs by healthcare professionals because there is a lack of strong level of evidence-based studies. In addition, the influence of AFOs' mechanical properties on functional deficit or clinical impairment is still not well understood. Therefore, this study aims to evaluate the biomechanical effects of commonly used AFOs on the lower extremities during the gait cycle. A healthy subject volunteered to be tested walking firstly without an AFO as a control and then wearing a solid carbon fibre reinforced, a solid and two posterior leaf spring AFOs. Strain gauges were attached to each AFO at ankle level to allow the measurement of the moment generated by the orthosis in the sagittal plane. The subject, wearing each instrumented AFO walked in the gait analysis laboratory where kinematic and kinetic data were acquired. This method allows the contribution of the AFOs during walking to be determined, and this information in conjunction with the kinematic and kinetic data, the anatomical moments, which are the moments generated by the muscles and ligaments can be calculated. The results imply that an AFO that is stiffer than the optimal requirement could lead to restriction of ankle motion during the stance phase and have an indirect effect on the knee and hip joints. The findings suggest that the stiffness of AFO, applied in stroke patients should be tailored base on the clinical impairment to get the optimum benefit. It is planned to continue this investigation on stroke patients.