DC motor proportional control system for orthotic devices

Multi-channel proportional control system for operation of dc motors for use with externally-powered orthotic arm braces is described. Components of circuitry and principles of operation are described. Schematic diagram of control circuit is provided

Orthotic management of instability of the knee related to neuromuscular and central nervous system disorders: qualitative interview study of patient perspectives

Objectives: Adults with knee instability related to neuromuscular disorders or central nervous conditions often experience mobility problems and rely on orthoses to improve function and mobility. Patient views of device effectiveness and acceptability are underexplored. Our study aimed to elicit device users’ perspectives regarding fitting, acceptability, effectiveness and use of orthoses, and identify important treatment outcomes. / Design: Qualitative descriptive study using in-depth semistructured interviews. Interview transcriptions were coded and thematically analysed, using ‘Framework’. / Setting and participants: A purposive sample of 24 adult users of orthotic devices. Nineteen patients were recruited across three National Health Service sites, and five people through charities/patient support groups in England. Half of the participants had been diagnosed with poliomyelitis, and the remainder with multiple sclerosis, Charcot-Marie-Tooth disease, spinal injury or spina bifida, and stroke. The median age of participants was 64.5 years (range 36–80 years). / Results: Patients’ medical condition impacted significantly on daily life. Participants relied on orthotic devices to enable engagement in daily activities. Patient goals for mobility were linked to individual circumstances. Desired treatment outcomes included reduction in pain, trips and falls, with improved balance and stability. Effectiveness, reliability, comfort and durability were the most valued features of orthoses and associated with reported use. Obtaining suitable footwear alongside orthotic devices was a significant concern. Time pressures during device fitting were viewed negatively. / Conclusions: Orthotic devices for knee instability play a crucial role in promoting, maintaining and enhancing physical and psychological health and well-being, enabling patients to work, engage in family life and enjoy social activities. Future research should consider how best to measure the impact of orthotic devices on patient quality of life and daily functioning outside the clinic setting, as well as device use and any adverse effects. / Trial registration number: This qualitative study was retrospectively registered as Current Controlled Trials ISRCTN65240228

Effects of foot orthoses on patellofemoral load in recreational runners

The most common chronic injury in recreational runners is patellofemoral pain. Whilst there is evidence to suggest that orthotic intervention may reduce symptoms in runners who experience patellofemoral pain the mechanism by which their clinical effects are mediated is currently poorly understood. The aim of the current investigation was to determine whether foot orthoses reduce the loads experienced by the patellofemoral joint during running. Patellofemoral loads were obtained from fifteen male runners who ran at 4.0 m·s-1. Patellofemoral loads with and without orthotics were contrasted using paired t-tests. The results showed that patellofemoral joint loads were significantly reduced as a function of running with the orthotic device. The current investigation indicates that through reductions in patellofemoral loads, foot orthoses may serve to reduce the incidence of chronic running injuries at this joint

Multi-segment foot biomechanics with varying foot orthotic postings

Foot orthotic devices are often used to treat overuse injuries, over- or under- pronation of the foot, knee pain, and other foot disorders. Clinical documentation shows the effectiveness of foot orthoses but there is little understanding of the mechanisms behind these outcomes. Existing studies of foot orthoses focus on rearfoot biomechanics, yet these devices are aimed at changing whole-foot mechanics. Additional research on the mechanical effects of orthoses is often suggested.The main goal of this study was to evaluate the effects of different foot orthotic devices on foot mechanics. In order to assess the effects foot orthoses have on the midfoot, we placed reflective markers on the participant’s lower limbs and right foot and recorded the leg mechanics as the participant walked across a 75 ft walkway.We expected directional movement patterns based on the location and type of orthotic posting or lift. It is possible that a better understanding of the effects of orthotic devices can lead to more effective treatments for patients with foot disorders.https://ecommons.udayton.edu/stander_posters/1666/thumbnail.jp

Use of MMG signals for the control of powered orthotic devices: Development of a rectus femoris measurement protocol

Copyright © 2009 Rehabilitation Engineering and Assistive Technology Society (RESNA). This is an Author's Accepted Manuscript of an article published in Assistive Technology, 21(1), 1 - 12, 2009, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/10400430902945678.A test protocol is defined for the purpose of measuring rectus femoris mechanomyographic (MMG) signals. The protocol is specified in terms of the following: measurement equipment, signal processing requirements, human postural requirements, test rig, sensor placement, sensor dermal fixation, and test procedure. Preliminary tests of the statistical nature of rectus femoris MMG signals were performed, and Gaussianity was evaluated by means of a two-sided Kolmogorov-Smirnov test. For all 100 MMG data sets obtained from the testing of two volunteers, the null hypothesis of Gaussianity was rejected at the 1%, 5%, and 10% significance levels. Most skewness values were found to be greater than 0.0, while all kurtosis values were found to be greater than 3.0. A statistical convergence analysis also performed on the same 100 MMG data sets suggested that 25 MMG acquisitions should prove sufficient to statistically characterize rectus femoris MMG. This conclusion is supported by the qualitative characteristics of the mean rectus femoris MMG power spectral densities obtained using 25 averages

Fabrication of Custom Dynamic Pedorthoses for Clubfoot Correction via Additive-Based Technologies

Additive technologies have created many opportunities to improve the quality of life for patients in a range of medical applications. This paper provides an overview of how several of these technologies were leveraged to transform custom pedorthosis designs into physical, end-use, custom pedorthoses for clubfoot patients. The pedorthoses that were produced are currently being tested on the respective patients for their improvement in mobility and degree of clubfoot correction, and will continue through early 2010. The advantage of this approach is the reduction in labor and the increase in degrees of design freedom available, compared to conventional methods of fabricating orthotic devices. Several new approaches for fabricating custom orthotic devices that were explored, and the related results, are discussed.Mechanical Engineerin

Acute Orthotic Intervention Does Not Affect Muscular Response Times and Activation Patterns at the Knee

Objective: To evaluate the short-term effect of a semirigid foot orthotic device on response times and activation patterns of knee musculature in individuals with hyperpronation after a lower extremity perturbation in a single-leg, weight-bearing stance.Design and Setting: We used a lower extremity perturbation device designed to produce a forward and either internal or external rotation of the trunk and femur on the weight-bearing tibia to evoke a reflex response. Subjects were tested both with and without orthotic devices.Subjects: Seventeen (13 male, 4 female) volunteers (age, 20.6 ± 1.8 years; height, 181.0 ± 8.1 cm; weight, 87.4 ± 19.5 kg; navicular drop, 12.1 ± 1.8 mm) with a navicular drop greater than 10 mm volunteered for this study.Measurements: Long latency reflex times were recorded via surface electromyography for the medial and lateral hamstrings, gastrocnemius, and quadriceps muscles.Results: A dependent-sample t test revealed a significant decrease in navicular drop with orthotic intervention (P < .0001). With that confirmed, separate repeated-measures analyses of variance with 2 within factors (orthotic condition and muscle) revealed no significant difference in muscle response time between orthotic and nonorthotic conditions for either internal or external rotation perturbation. Although we found a main effect for muscle for both internal (P < .0001) and external (P < .0001) rotation, indicating a preferred muscle activation order, this activation order did not differ between orthotic and nonorthotic conditions (internal rotation P=.674, external rotation P=.829).Conclusions: Our findings suggest that a short-term application of a semirigid orthotic device does not alter muscle response times or activation patterns of the muscles that stabilize the knee. Further research is needed to determine whether changes in activation patterns may occur over time since mechanical adaptations occur with long-term wear

Orthotic devices using lightweight composite materials

Potential applications of high strength, lightweight composite technology in the orthotic field were studied. Several devices were designed and fabricated using graphite-epoxy composite technology. Devices included shoe plates, assistive walker devices, and a Simes prosthesis reinforcement. Several other projects having medical application were investigated and evaluations were made of the potential for use of composite technology. A seat assembly was fabricated using sandwich construction techniques for the Total Wheelchair Project

Southwest Research Institute assistance to NASA in biomedical areas of the technology

Significant applications of aerospace technology were achieved. These applications include: a miniaturized, noninvasive system to telemeter electrocardiographic signals of heart transplant patients during their recuperative period as graded situations are introduced; and economical vital signs monitor for use in nursing homes and rehabilitation hospitals to indicate the onset of respiratory arrest; an implantable telemetry system to indicate the onset of the rejection phenomenon in animals undergoing cardiac transplants; an exceptionally accurate current proportional temperature controller for pollution studies; an automatic, atraumatic blood pressure measurement device; materials for protecting burned areas in contact with joint bender splints; a detector to signal the passage of animals by a given point during ecology studies; and special cushioning for use with below-knee amputees to protect the integrity of the skin at the stump/prosthesis interface