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BACKGROUND: Relative motion between the residual limb and socket in individuals with transtibial limb loss can lead to substantial consequences that limit mobility. Although assessments of the relative motion between the residual limb and socket have been performed, there remains a substantial gap in understanding the complex mechanics of the residual limb-socket interface during dynamic activities that limits the ability to improve socket design. However, dynamic stereo x-ray (DSX) is an advanced imaging technology that can quantify 3D bone movement and skin deformation inside a socket during dynamic activities. OBJECTIVE: This study aims to develop analytical tools using DSX to quantify the dynamic, in vivo kinematics between the residual limb and socket and the mechanism of residual tissue deformation. METHODS: A lower limb cadaver study will first be performed to optimize the placement of an array of radiopaque beads and markers on the socket, liner, and skin to simultaneously assess dynamic tibial movement and residual tissue and liner deformation. Five cadaver limbs will be used in an iterative process to develop an optimal marker setup. Stance phase gait will be simulated during each session to induce bone movement and skin and liner deformation. The number, shape, size, and placement of each marker will be evaluated after each session to refine the marker set. Once an optimal marker setup is identified, 21 participants with transtibial limb loss will be fitted with a socket capable of being suspended via both elevated vacuum and traditional suction. Participants will undergo a 4-week acclimation period and then be tested in the DSX system to track tibial, skin, and liner motion under both suspension techniques during 3 activities: treadmill walking at a self-selected speed, at a walking speed 10% faster, and during a step-down movement. The performance of the 2 suspension techniques will be evaluated by quantifying the 3D bone movement of the residual tibia with respect to the socket and quantifying liner and skin deformation at the socket-residuum interface. RESULTS: This study was funded in October 2021. Cadaver testing began in January 2023. Enrollment began in February 2024. Data collection is expected to conclude in December 2025. The initial dissemination of results is expected in November 2026. CONCLUSIONS: The successful completion of this study will help develop analytical methods for the accurate assessment of residual limb-socket motion. The results will significantly advance the understanding of the complex biomechanical interactions between the residual limb and the socket, which can aid in evidence-based clinical practice and socket prescription guidelines. This critical foundational information can aid in the development of future socket technology that has the potential to reduce secondary comorbidities that result from complications of poor prosthesis load transmission. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/57329.
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Extremidade Inferior , Pele , Tíbia , Humanos , Cotos de Amputação/diagnóstico por imagem , Cotos de Amputação/fisiopatologia , Membros Artificiais , Fenômenos Biomecânicos/fisiologia , Cadáver , Extremidade Inferior/diagnóstico por imagem , Extremidade Inferior/cirurgia , Extremidade Inferior/fisiologia , Movimento/fisiologia , Pele/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Tíbia/cirurgiaRESUMO
BACKGROUND: Powered ankle-foot prosthetic devices can generate net positive mechanical work during gait, which mimics the physiological ankle. However, gait deviations can persist in individuals with transfemoral limb loss because of habit or lack of rehabilitation. Prosthetic research efforts favor the design or evaluation of prosthetic componentry and rarely incorporate any type of rehabilitation, despite evidence suggesting that it is critical for minimizing gait imbalances. Given the accelerated rate of innovation in prosthetics, there is a fundamental knowledge gap concerning how individuals with transfemoral limb loss should learn to correctly use powered ankle-foot devices for maximum functional benefit. Because of the recent advances in prosthetic technology, there is also a critical unmet need to develop guidelines for the prescription of advanced prosthetic devices that incorporate both physical and psychological components to identify appropriate candidates for advanced technology. OBJECTIVE: The primary goal of this investigation is to examine the roles of advanced prosthetic technology and a device-specific rehabilitative intervention on gait biomechanics, functional efficacy, and pain in individuals with transfemoral limb loss. The secondary goal is to develop preliminary rehabilitation guidelines for advanced lower limb prosthetic devices to minimize gait imbalances and maximize function and to establish preliminary guidelines for powered ankle-foot prosthetic prescription. METHODS: This prospective, multisite study will enroll 30 individuals with unilateral transfemoral limb loss. At baseline, participants will undergo a full gait analysis and assessment of function, neurocognition, cognitive load, subjective preferences, and pain using their current passive prosthesis. The participants will then be fitted with a powered ankle-foot device and randomized into 2 equal groups: a powered device with a device-specific rehabilitation intervention (group A) or a powered device with the current standard of practice (group B). Group A will undergo 4 weeks of device-specific rehabilitation. Group B will receive the current standard of practice, which includes basic device education but no further device-specific rehabilitation. Data collection procedures will then be repeated after 4 weeks and 8 weeks of powered ankle use. RESULTS: This study was funded in September 2017. Enrollment began in September 2018. Data collection will conclude by March 2024. The initial dissemination of results is expected in August 2024. CONCLUSIONS: The projected trends indicate that the number of individuals with limb loss will dramatically increase in the United States. The absence of effective, evidence-based interventions may make individuals with transfemoral limb loss more susceptible to increased secondary physical conditions and degenerative changes. With this expected growth, considerable resources will be required for prosthetic and rehabilitation services. Identifying potential mechanisms for correcting gait asymmetries, either through advanced prosthetic technology or rehabilitative interventions, can provide a benchmark for understanding the optimal treatment strategies for individuals with transfemoral limb loss. TRIAL REGISTRATION: ClinicalTrials.gov NCT03625921; https://clinicaltrials.gov/study/NCT03625921. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/53412.
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Introduction: Many military service members and civilians suffer from lower extremity trauma. Despite recent advancements in lower limb bracing technology, it remains unclear whether these newer advanced braces offer improved comfort and functionality compared to conventional options. The IDEO (Intrepid Dynamic Exoskeletal Orthosis), a type of "advanced" orthosis was developed to assist in maintaining high functional performance in patients who have experienced high-energy lower extremity trauma and underwent limb salvage surgeries. Methods: A cross-sector multi-site initiative was completed to study the efficacy of advanced ankle foot orthoses (AFO) for lower limb trauma and injury compared to a conventional AFO. Following fitting, training, and accommodation, the subjects were assessed in each AFO system for mobility, self-reported function, safety and pain, and preference. Results: They preferred the advanced over the conventional AFO and the mobility and exertion perception improved with the advanced AFO with no difference in pain or overall health status scores. Discussion: Thus, an advanced AFO is an option for trauma affecting the lower limb. Long-term studies are required to better understand the accommodation and learning process of using an advanced AFO.
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INTRODUCTION: The number of people with lower limb loss continues to grow, though most research to date has been non-committal and lacks the appropriate clinical guidance required for proper prosthetic prescription. Previous literature using traditional spatiotemporal and biomechanical measures has not accurately identified differences in gait patterns when using different prosthetic devices. Therefore, a knowledge gap remains. To aid in determining the impact of different devices on gait in individuals with lower limb loss, a more sensitive quantitative measure should be used to supplement traditional biomechanical analyses. Continuous measures of coordination and stability, evaluated using relative phase analysis, has been shown to detect changes in gait patterns when traditional variables cannot. However, these measures have yet to be fully assessed in this population. This investigation will fill the knowledge gap by using relative phase analysis to provide a comprehensive description of kinematic behaviour by evaluating continuous interlimb coordination and stability for individuals with lower limb loss. METHODS AND ANALYSIS: Biomechanical analysis of individuals with lower limb loss during walking activities will be evaluated using relative phase analysis to identify the continuous interlimb coordination and stability relationships between the upper and lower extremities of these individuals. Three-dimensional motion capture will enable kinematic properties of movement to be captured and analysed. Non-traditional measures of analysis will be used. ETHICS AND DISSEMINATION: This study was approved by the Veterans Affairs New York Harbor Healthcare System Institutional Review Board (IRBNet #1573135, MIRB #1775). Findings will be disseminated through peer-reviewed publications, academic conference presentations, invited workshops, webinars and seminars.
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Marcha , Caminhada , Humanos , Estudos Retrospectivos , Extremidade Inferior , Modalidades de Fisioterapia , Fenômenos BiomecânicosRESUMO
OBJECTIVE: The purpose of this study was to assess the weight shift and X-Factor values of golfers with lower limb loss. DESIGN: Veterans with above or below knee limb loss participated in a 3-day adaptive golf event hosted by the Department of Veterans Affairs. Professional golf instructors educated participants on proper golf swing mechanics, after which kinematic analysis of trunk rotation and kinetic analysis of weight transfer between the legs during the golf swing were evaluated using three-dimensional motion capture and force platforms. RESULTS: Golfers with a trail leg amputation, regardless of level of limb loss, demonstrated superior weight shift, whereas golfers with lead limb amputation showed greater X-Factor values (all P < 0.05). Golfers with below knee limb loss demonstrated better weight shift strategies compared to those with above knee limb loss, regardless of which leg was amputated (i.e., lead or trail limb, all P < 0.05). CONCLUSIONS: Sports rehabilitation programs should focus on increased weight bearing on the prosthetic limb to achieve appropriate weight shift and increased flexibility to increase X-Factor values. Participation in such programs can offer both physical and psychosocial benefits and may be a valid tool to increase the overall quality of life of veterans with lower limb loss.
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Golfe , Veteranos , Humanos , Cinética , Qualidade de Vida , Fenômenos Biomecânicos , Extremidade Inferior/cirurgia , MovimentoRESUMO
INTRODUCTION: There is a growing population of women with limb loss, yet limited research is available to provide evidentiary support for clinical decision-making in this demographic. As such, there is a critical gap in knowledge of evidence-based healthcare practices aimed to maximise the physical and psychosocial needs of women with limb loss. The objective of this study is to develop a comprehensive, survey-based needs assessment to determine the unique impact of limb loss on women, including physical and psychosocial needs. METHODS AND ANALYSIS: A bank of existing limb loss-specific and non-limb loss-specific surveys were arranged around domains of general health, quality of life, prosthetic use and needs, psychosocial health and behaviours and body image. These surveys were supplemented with written items to ensure coverage of relevant domains. Written items were iteratively refined with a multidisciplinary expert panel. The interpretability of items and relevance to limb loss were then internally tested on a small group of rehabilitation, engineering and research professionals. A diverse sample of 12 individuals with various levels of limb loss piloted the instrument and participated in cognitive interviews. Items from existing surveys were evaluated for relevance and inclusion in the survey, but not solicited for content feedback. Pilot testing resulted in the removal of 13 items from an existing survey due to redundancy. Additionally, 13 written items were deleted, 42 written items were revised and 17 written items were added. The survey-based needs assessment has been crafted to comprehensively assess the wide spectrum of issues facing women with limb loss. The final version of the survey-based needs assessment included 15 subsections. ETHICS AND DISSEMINATION: This study was approved by the Veterans Affairs Central Institutional Review Board. The results will be disseminated through national and international conferences, as well as through manuscripts in leading peer-reviewed journals. TRIAL REGISTRATION NUMBER: No healthcare intervention on human participants was conducted.
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Imagem Corporal , Qualidade de Vida , Humanos , Feminino , Avaliação das Necessidades , Tomada de Decisão Clínica , Suplementos NutricionaisRESUMO
BACKGROUND: The prescription of prosthetic ankle-foot devices is often based on the professional judgment of the limb loss care team or limited evidentiary research. Current prosthetic research efforts have focused on the design and development of prosthetic devices rather than on understanding which devices are the most appropriate to prescribe. This investigation will evaluate biomechanical, functional, and subjective outcome measures to help determine the optimal prescription parameters of prosthetic ankle-foot devices. OBJECTIVE: This study aims to develop evidence-based guidelines for limb loss care teams for the appropriate prescription of commercially available prosthetic ankle-foot devices to improve function and satisfaction. METHODS: This investigation will be a multisite, randomized, crossover clinical trial targeting the enrollment of 100 participants. Participants will use 3 different types of prosthetic devices (energy storing and returning, articulating, and powered) in random order. Participants will be fitted and trained with each device and then separately use each device for a 1-week acclimation period. Following each 1-week acclimation period, participants will be evaluated using several functional measures and subjective surveys. A random subset of participants (30/100, 30%) will also undergo full-body gait analysis, following each 1-week acclimation period, to collect biomechanical data during level ground and incline and decline walking. After all individual device evaluations, participants will be given all 3 prostheses concurrently for 4 weeks of home and community use to capture user preference. Activity monitoring and a guided interview will be used to determine overall user preference. RESULTS: The study was funded in August 2017, and data collection began in 2018. Data collection is expected to be completed before July 2023. Initial dissemination of results is expected to occur in the winter of 2023. CONCLUSIONS: By identifying biomechanical, functional, and subjective outcomes that are sensitive to differences in prosthetic ankle-foot devices, a benchmark of evidence can be developed to guide effective prosthetic prescription. TRIAL REGISTRATION: ClinicalTrials.gov NCT03505983; https://clinicaltrials.gov/ct2/show/NCT03505983. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/45612.
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Veterans with disabilities can experience poor quality of life following military service due to the associated negative physical and psychological ramifications. However, participation in physical activities has shown to induce both physical and mental benefits and improve the quality of life of this population. Adaptive sports, an innovative approach to address the unique physical and psychosocial needs of veterans with disabilities, are becoming more widely used as a rehabilitation tool to improve the quality of life for these veterans. This study aimed to determine the acute influence of participation in a single-day, veteran-based, adaptive kayaking and sailing event on the perceived overall health, quality of life, and quality of social life of veterans with varying disabilities. It was hypothesized that all three categories and the sum score of quality of life would reflect a positive acute response after participation in the community-based physical activity event. Veterans responded to three quality of life-related questions using a 5-point Likert scale before and directly after participating in the event. Findings indicated that an adaptive sporting event can have an acute positive influence on the quality of life of veteran participants, with improvements observed in all three categories of perceived quality of life. Therefore, it is advantageous for the whole-health rehabilitation of veterans with disabilities for the Department of Veterans Affairs to continue to provide opportunities for veterans to participate in non-traditional, community-based activities.
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Pessoas com Deficiência , Esportes , Veteranos , Estados Unidos , Humanos , Qualidade de Vida , Exercício FísicoRESUMO
Individuals with transfemoral amputation experience relative motion between their residual limb and prosthetic socket, which can cause inefficient dynamic load transmission and secondary comorbidities that limit mobility. Accurately measuring the relative position and orientation of the residual limb relative to the prosthetic socket during dynamic activities can provide great insight into the complex mechanics of the socket/limb interface. Five participants with transfemoral amputation were recruited for this study. All participants had a well-fitting, ischial containment socket and were also fit with a compression/release stabilization socket. Participants underwent an 8-wk, randomized crossover trial to compare differences between socket types. Dynamic stereo x-ray was used to quantify three-dimensional residual bone kinematics relative to the prosthetic socket during treadmill walking at self-selected speed. Comfort, satisfaction, and utility were also assessed. There were no significant differences in relative femur kinematics between socket types in the three rotational degrees of freedom, as well as anterior-posterior and medial-lateral translation (p > 0.05). The ischial containment socket demonstrated significantly less proximal-distal translation (pistoning) of the femur compared to the compression/release stabilization socket during the gait cycle (p < 0.05), suggesting that the compression/release stabilization socket provided less control of the residual femur during distal translation. No significant differences in comfort and utility were found between socket types (p > 0.05). The quantitative, dynamic analytical tools used in the study were sensitive to distinguish differences in three-dimensional residual femur motion between two socket types, which can serve as a platform for future comparative effectiveness studies of socket technology.
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The dura mater is the outermost and most substantial meningial layer of central nervous system (CNS) tissue that acts as a protective membrane for the brain and spinal cord. In animal models of traumatic brain injury and spinal cord injury, mechanical insults are often delivered directly to the dura to injure the underlying tissue. As such, including a description of the mechanical properties of dura mater is critical for biomechanical analyses of these models. We have characterized the mechanical response of dura mater from the rat brain and spinal cord in uniaxial tension. Testing was performed at low (0.0014 sec(-1)) and high (19.42 sec(-1)) strain rates. Both rat cranial dura and spinal dura demonstrated non-linear stress-strain responses characteristic of collagenous soft tissues. The non-linear increase in stress lagged in the spinal dura compared to the cranial dura. The slow rate data was fit to a one-term Ogden hyperelastic constitutive law, and significant differences were observed for the stiffness, G, and the parameter, alpha, which nominally introduces non-linearity. High strain rate stress-relaxation tests were performed to 10% strain, which was held for 10 sec. The relaxation was fit to a four-term Prony series exponential decay. Cranial dura and spinal dura demonstrated similar overall relaxation, but significant differences were identified in the distribution of the relaxation over the Prony series parameters, which demonstrated that cranial dura tended to relax faster. Polarized light microscopy revealed that the structural entities of spinal dura were aligned in the axial direction, whereas cranial dura did not demonstrate a preferential alignment. This was confirmed qualitatively with Masson's Tri-chrome and Verhoeff's Van Gieson staining for collagen and elastin, which also indicated greater elastin content for the spinal dura than for the cranial dura.
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Encéfalo/fisiologia , Dura-Máter/fisiologia , Medula Espinal/fisiologia , Animais , Fenômenos Biomecânicos , Encéfalo/anatomia & histologia , Lesões Encefálicas/fisiopatologia , Colágeno/fisiologia , Tecido Conjuntivo/fisiologia , Dura-Máter/anatomia & histologia , Elasticidade , Elastina , Microscopia de Polarização , Modelos Biológicos , Dinâmica não Linear , Ratos , Ratos Long-Evans , Medula Espinal/anatomia & histologia , Coloração e Rotulagem/métodos , Estresse Mecânico , ViscosidadeRESUMO
A three-dimensional (3D) finite element model (FEM) that simulates the Impactor weight-drop experimental model of traumatic spinal cord injury (SCI) was developed. The model consists of the rat spinal cord, with distinct element sets for the gray and white matter, the cerebrospinal fluid (CSF), the dura mater, a rigid rat spinal column, and a rigid impactor. Loading conditions were taken from the average impact velocities determined from previous parallel weight-drop experiments employing a 2.5-mm-diameter, 10-g rod dropped from either 12.5 or 25 mm. The mechanical properties were calibrated by comparing the predicted displacement of the spinal cord at the impact site to that measured experimentally. Parametric studies were performed to determine the sensitivity of the model to the relevant material properties, loading conditions, and essential boundary conditions, and it was determined that the shear modulus had the greatest influence on spinal cord displacement. Additional simulations were performed where gray and white matter were prescribed different material properties. These simulations generated similar drop trajectories to the homogeneous model, but the stress and strain distributions better matched patterns of acute albumin extravasation across the blood-spinal cord barrier following weight-drop SCI, as judged by a logit analysis. A final simulation was performed where the impact site was shifted laterally by 0.35 mm. The off-center impact had little effect on the rod trajectory, but caused marked shifts in the location of stress and strain contours. Different combinations of parameter values could reproduce the impactor trajectory, which suggests that another experimental measure of the tissue response is required for validation. The FEM can be a valuable tool for understanding the injury biomechanics associated with experimental SCI to identify areas for improvement in animal models and future research to identify thresholds for injury.
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Simulação por Computador , Análise de Elementos Finitos , Traumatismos da Medula Espinal/fisiopatologia , Medula Espinal/fisiopatologia , Animais , Fenômenos Biomecânicos/métodos , Barreira Hematoencefálica/lesões , Barreira Hematoencefálica/fisiopatologia , Modelos Animais de Doenças , Feminino , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Fibras Nervosas Mielinizadas/patologia , Ratos , Ratos Long-Evans , Reprodutibilidade dos Testes , Medula Espinal/irrigação sanguínea , Medula Espinal/patologia , Traumatismos da Medula Espinal/patologia , Estresse Mecânico , Ferimentos não PenetrantesRESUMO
Primary damage to the blood-spinal cord barrier (BSCB) is a nearly universal consequence of spinal cord injury that contributes significantly to the overall pathology, including the introduction of reactive species that induce cytotoxicity as well as secondary insults on the BSCB itself. We have characterized quantitatively the extent and severity of primary, physical disruption of the BSCB in adult rats 5 min after graded trauma induced with the Impactor weight-drop model of spinal cord contusion. Animals were injured by dropping a 10-g mass 12.5, 25, or 50 mm (n(level) = 8) on to the exposed mid-thoracic spinal cord. The volume of extravasation of three markers of distinct size--fluorescently labeled hydrazide ( approximately 730 Da), fluorescently labeled bovine serum albumin ( approximately 70 kDa), and immunohistochemically labeled red blood cells ( approximately 5 microm in diameter)--were quantified in both the gray and white matter. The results indicate that spinal cord trauma causes immediate, non-specific vascular changes that are well-predicted by mechanical parameters. Extravasation volume increased significantly with increasing drop height and decreasing marker size. Extravasation volumes for all three markers were greater in gray matter than in white matter, and were better correlated to the rate of spinal cord compression than to the depth of spinal cord compression, which suggests that tissue-level strain rate effects contribute to primary spinal cord microvasculature pathology. The relationship between the response of the spinal cord and the injury pattern points towards opportunities to control the distribution and extent of injury patterns in animal models of spinal cord injury through a precise understanding of model and tissue biomechanics, as well as potential improvements in means of preventing spinal cord injury.
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Traumatismos da Medula Espinal/patologia , Medula Espinal/patologia , Albuminas/metabolismo , Animais , Encéfalo/patologia , Permeabilidade Capilar/fisiologia , Eritrócitos/patologia , Feminino , Imuno-Histoquímica , Microcirculação/patologia , Proteínas do Tecido Nervoso/metabolismo , Ratos , Ratos Long-EvansRESUMO
High-energy lower extremity trauma is a consequence of modern war and it is unclear if limb amputation or limb salvage enables greater recovery. To improve function in the injured extremity, a passive dynamic ankle-foot orthosis, the Intrepid Dynamic Exoskeletal Orthosis (IDEO), was introduced with specialized return to run (RTR) therapy program. Recent research suggests, these interventions may improve function and return to duty rates. This systematic literature review sought to rate available evidence and formulate empirical evidence statements (EESs), regarding outcomes associated with IDEO utilization. PubMed, CINAHL, and Google Scholar were systematically searched for pertinent articles. Articles were screened and rated. EESs were formulated based upon data and conclusions from included studies. Twelve studies were identified and rated. Subjects (n = 487, 6 females, mean age 29.4 year) were studied following limb trauma and salvage. All included studies had high external validity, whereas internal validity was mixed because of reporting issues. Moderate evidence supported development of four EESs regarding IDEO use with specialized therapy. Following high-energy lower extremity trauma and limb salvage, use of IDEO with RTR therapy can enable return to duty, return to recreation and physical activity, and decrease pain in some high-functioning patients. In higher functioning patients following limb salvage or trauma, IDEO use improved agility, power and speed, compared with no-brace or conventional bracing alternatives.