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1.
Pain Res Manag ; 2021: 2706731, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34938379

RESUMO

Introduction: There is no diagnosis for phantom limb pain (PLP), and its investigation is based on anamnesis, which is subject to several biases. Therefore, it is important to describe and standardize the diagnostic methodology for PLP. Objective: To characterise PLP and, secondarily, to determine predictors for its diagnosis. Methodology. This is a cross-sectional study involving patients with unilateral traumatic lower-limb amputation aged over 18 years. Those with clinical decompensation or evidence of disease, trauma, or surgery in the central or peripheral nervous system were excluded. Sociodemographic and rehabilitative data were collected; PLP was characterised using the visual analogue scale (VAS), pain descriptors, and weekly frequency. Results: A total of 55 eligible patients participated in the study; most were male, young, above-knee amputees in the preprosthetic phase of the rehabilitation. The median PLP VAS was 60 (50-79.3) mm characterised by 13 (6-20) different descriptors in the same patient, which coexist, alternate, and add up to a frequency of 3.94 (2.5-4.38) times per week. The most frequent descriptor was movement of the phantom limb (70.91%). Tingling, numbness, flushing, itchiness, spasm, tremor, and throbbing are statistically significant PLP descriptor numbers per patient predicted by above-knee amputation, prosthetic phase, higher education level, and greater PLP intensity by VAS (p < 0.05). Conclusion: PLP is not a single symptom, but a set with different sensations and perceptions that need directed and guided anamnesis for proper diagnosis.


Assuntos
Amputados , Membro Fantasma , Adulto , Amputação , Estudos Transversais , Humanos , Extremidade Inferior , Masculino , Pessoa de Meia-Idade , Membro Fantasma/diagnóstico , Membro Fantasma/etiologia
2.
Sensors (Basel) ; 21(22)2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34833534

RESUMO

There are currently limited data on how prosthetic devices are used to support lower-limb prosthesis users in their free-living environment. Possessing the ability to monitor a patient's physical behaviour while using these devices would enhance our understanding of the impact of different prosthetic products. The current approaches for monitoring human physical behaviour use a single thigh or wrist-worn accelerometer, but in a lower-limb amputee population, we have the unique opportunity to embed a device within the prosthesis, eliminating compliance issues. This study aimed to develop a model capable of accurately classifying postures (sitting, standing, stepping, and lying) by using data from a single shank-worn accelerometer. Free-living posture data were collected from 14 anatomically intact participants and one amputee over three days. A thigh worn activity monitor collected labelled posture data, while a shank worn accelerometer collected 3-axis acceleration data. Postures and the corresponding shank accelerations were extracted in window lengths of 5-180 s and used to train several machine learning classifiers which were assessed by using stratified cross-validation. A random forest classifier with a 15 s window length provided the highest classification accuracy of 93% weighted average F-score and between 88 and 98% classification accuracy across all four posture classes, which is the best performance achieved to date with a shank-worn device. The results of this study show that data from a single shank-worn accelerometer with a machine learning classification model can be used to accurately identify postures that make up an individual's daily physical behaviour. This opens up the possibility of embedding an accelerometer-based activity monitor into the shank component of a prosthesis to capture physical behaviour information in both above and below-knee amputees. The models and software used in this study have been made open source in order to overcome the current restrictions of applying activity monitoring methods to lower-limb prosthesis users.


Assuntos
Amputados , Acelerometria , Monitores de Aptidão Física , Humanos , Aprendizado de Máquina , Postura Sentada
3.
Sensors (Basel) ; 21(22)2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34833573

RESUMO

One major challenge limiting the use of dexterous robotic hand prostheses controlled via electromyography and pattern recognition relates to the important efforts required to train complex models from scratch. To overcome this problem, several studies in recent years proposed to use transfer learning, combining pre-trained models (obtained from prior subjects) with training sessions performed on a specific user. Although a few promising results were reported in the past, it was recently shown that the use of conventional transfer learning algorithms does not increase performance if proper hyperparameter optimization is performed on the standard approach that does not exploit transfer learning. The objective of this paper is to introduce novel analyses on this topic by using a random forest classifier without hyperparameter optimization and to extend them with experiments performed on data recorded from the same patient, but in different data acquisition sessions. Two domain adaptation techniques were tested on the random forest classifier, allowing us to conduct experiments on healthy subjects and amputees. Differently from several previous papers, our results show that there are no appreciable improvements in terms of accuracy, regardless of the transfer learning techniques tested. The lack of adaptive learning is also demonstrated for the first time in an intra-subject experimental setting when using as a source ten data acquisitions recorded from the same subject but on five different days.


Assuntos
Amputados , Membros Artificiais , Algoritmos , Eletromiografia , Mãos , Humanos , Reconhecimento Automatizado de Padrão
4.
Sensors (Basel) ; 21(21)2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34770281

RESUMO

Foot strike detection is important when evaluating a person's gait characteristics. Accelerometer and gyroscope signals from smartphones have been used to train artificial intelligence (AI) models for automated foot strike detection in able-bodied and elderly populations. However, there is limited research on foot strike detection in lower limb amputees, who have a more variable and asymmetric gait. A novel method for automated foot strike detection in lower limb amputees was developed using raw accelerometer and gyroscope signals collected from a smartphone positioned at the posterior pelvis. Raw signals were used to train a decision tree model and long short-term memory (LSTM) model for automated foot strike detection. These models were developed using retrospective data (n = 72) collected with the TOHRC Walk Test app during a 6-min walk test (6MWT). An Android smartphone was placed on a posterior belt for each participant during the 6MWT to collect accelerometer and gyroscope signals at 50 Hz. The best model for foot strike identification was the LSTM with 100 hidden nodes in the LSTM layer, 50 hidden nodes in the dense layer, and a batch size of 64 (99.0% accuracy, 86.4% sensitivity, 99.4% specificity, and 83.7% precision). This research created a novel method for automated foot strike identification in lower extremity amputee populations that is equivalent to manual labelling and accessible for clinical use. Automated foot strike detection is required for stride analysis and to enable other AI applications, such as fall detection.


Assuntos
Amputados , Idoso , Inteligência Artificial , Árvores de Decisões , Humanos , Extremidade Inferior , Memória de Curto Prazo , Estudos Retrospectivos
5.
Sensors (Basel) ; 21(21)2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34770393

RESUMO

The complexity of the user interfaces and the operating modes present in numerous assistive devices, such as intelligent prostheses, influence patients to shed them from their daily living activities. A methodology to evaluate how diverse aspects impact the workload evoked when using an upper-limb bionic prosthesis for unilateral transradial amputees is proposed and thus able to determine how user-friendly an interface is. The evaluation process consists of adapting the same 3D-printed terminal device to the different user-prosthesis-interface schemes to facilitate running the tests and avoid any possible bias. Moreover, a study comparing the results gathered by both limb-impaired and healthy subjects was carried out to contrast the subjective opinions of both types of volunteers and determines if their reactions have a significant discrepancy, as done in several other studies.


Assuntos
Amputados , Membros Artificiais , Atividades Cotidianas , Eletromiografia , Mãos , Humanos , Desenho de Prótese
6.
Sensors (Basel) ; 21(21)2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34770512

RESUMO

In the current study, our research group proposed an asymmetric lower extremity exoskeleton to enable above-knee amputees to walk with a load. Due to the absence of shank and foot, the knee and ankle joint at the amputation side of the exoskeleton lack tracking targets, so it is difficult to realize the function of assisted walking when going up and downstairs. Currently, the use of lower-limb electromyography to predict the angles of lower limb joints has achieved remarkable results. However, the prediction effect was poor when only using electromyography from the thigh. Therefore, this paper introduces hip-angle and plantar pressure signals for improving prediction effect and puts forward a joint prediction method of knee- and ankle-joint angles by electromyography of the thigh, hip-joint angle, and plantar pressure signals. The generalized regression neural network optimized by the golden section method is used to predict the joint angles. Finally, the parameters (the maximum error, the Root-Mean-Square error (RMSE), and correlation coefficient (γ)) were calculated to verify the feasibility of the prediction method.


Assuntos
Amputados , Fenômenos Biomecânicos , Marcha , Humanos , Articulação do Joelho/cirurgia , Redes Neurais de Computação
7.
J Indian Prosthodont Soc ; 21(4): 339-347, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34810361

RESUMO

This study aimed to perform an integrative review of the literature on the use of silicone finger prostheses in amputee patients. Searches were performed in the PubMed, EMBASE, Web of Science, Scielo, and Cochrane Library databases until July 2021. Descriptors used in this article were: Silicone, finger, rehabilitation, and prosthesis. Clinical research and clinical reports on silicone finger prostheses, available in full and in English were included. Initially, 152 articles were identified. After establishing the inclusion/exclusion criteria, 23 studies were identified and constituted the final sample. Regarding the publication date of the included studies, 17.2% of them were published between 2012 and 2016. Most of the rehabilitations occurred in India (69.9%; n = 16), and the mean age of patients who used prostheses was 38.1 years. The level of scientific evidence of the included studies was IV and VI. Therefore, patients rehabilitated with silicone finger prostheses highlighted significant improvements in functional range of motion, restoration of self-esteem, advantages in psychological therapy, more pleasant social interaction, and changes in their quality of life.


Assuntos
Amputados , Membros Artificiais , Adulto , Dedos , Humanos , Qualidade de Vida , Silicones
8.
Elife ; 102021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34605407

RESUMO

The study of artificial arms provides a unique opportunity to address long-standing questions on sensorimotor plasticity and development. Learning to use an artificial arm arguably depends on fundamental building blocks of body representation and would therefore be impacted by early life experience. We tested artificial arm motor-control in two adult populations with upper-limb deficiencies: a congenital group-individuals who were born with a partial arm, and an acquired group-who lost their arm following amputation in adulthood. Brain plasticity research teaches us that the earlier we train to acquire new skills (or use a new technology) the better we benefit from this practice as adults. Instead, we found that although the congenital group started using an artificial arm as toddlers, they produced increased error noise and directional errors when reaching to visual targets, relative to the acquired group who performed similarly to controls. However, the earlier an individual with a congenital limb difference was fitted with an artificial arm, the better their motor control was. Since we found no group differences when reaching without visual feedback, we suggest that the ability to perform efficient visual-based corrective movements is highly dependent on either biological or artificial arm experience at a very young age. Subsequently, opportunities for sensorimotor plasticity become more limited.


Assuntos
Amputados , Membros Artificiais , Desempenho Psicomotor , Deformidades Congênitas das Extremidades Superiores , Adulto , Fatores Etários , Braço , Retroalimentação Sensorial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Plasticidade Neuronal
9.
J Exp Biol ; 224(19)2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34605903

RESUMO

An ideal prosthesis should perform as well as or better than the missing limb it was designed to replace. Although this ideal is currently unattainable, recent advances in design have significantly improved the function of prosthetic devices. For the lower extremity, both passive prostheses (which provide no added power) and active prostheses (which add propulsive power) aim to emulate the dynamic function of the ankle joint, whose adaptive, time-varying resistance to applied forces is essential for walking and running. Passive prostheses fail to normalize energetics because they lack variable ankle impedance that is actively controlled within each gait cycle. By contrast, robotic prostheses can normalize energetics for some users under some conditions. However, the problem of adaptive and versatile control remains a significant issue. Current prosthesis-control algorithms fail to adapt to changes in gait required for walking on level ground at different speeds or on ramps and stairs. A new paradigm of 'muscle as a tunable material' versus 'muscle as a motor' offers insights into the adaptability and versatility of biological muscles, which may provide inspiration for prosthesis design and control. In this new paradigm, neural activation tunes muscle stiffness and damping, adapting the response to applied forces rather than instructing the timing and amplitude of muscle force. A mechanistic understanding of muscle function is incomplete and would benefit from collaboration between biologists and engineers. An improved understanding of the adaptability of muscle may yield better models as well as inspiration for developing prostheses that equal or surpass the functional capabilities of biological limbs across a wide range of conditions.


Assuntos
Amputados , Membros Artificiais , Procedimentos Cirúrgicos Robóticos , Fenômenos Biomecânicos , Marcha , Humanos , Músculos , Caminhada
10.
Nat Med ; 27(10): 1783-1788, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34635852

RESUMO

Above-knee amputation severely reduces the mobility and quality of life of millions of individuals. Walking with available leg prostheses is highly inefficient, and poor walking economy is a major problem limiting mobility. Here we show that an autonomous powered hip exoskeleton assisting the residual limb significantly improves metabolic walking economy by 15.6 ± 2.9% (mean ± s.e.m.; two-tailed paired t-test, P = 0.002) in six individuals with above-knee amputation walking on a treadmill. The observed metabolic cost improvement is equivalent to removing a 12-kg backpack from a nonamputee individual. All participants were able to walk overground with the exoskeleton, including starting and stopping, without notable changes in gait balance or stability. This study shows that assistance of the user's residual limb with a powered hip exoskeleton is a viable solution for improving amputee walking economy. By significantly reducing the metabolic cost of walking, the proposed hip exoskeleton may have a considerable positive impact on mobility, improving the quality of life of individuals with above-knee amputations.


Assuntos
Amputados/reabilitação , Exoesqueleto Energizado , Próteses e Implantes , Caminhada/fisiologia , Adulto , Amputação/tendências , Fenômenos Biomecânicos , Extremidades/fisiopatologia , Extremidades/cirurgia , Feminino , Marcha/fisiologia , Quadril/fisiopatologia , Quadril/cirurgia , Humanos , Joelho/fisiopatologia , Joelho/cirurgia , Masculino , Qualidade de Vida
11.
BMC Neurol ; 21(1): 416, 2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34706654

RESUMO

BACKGROUND: The objective of the current study is to evaluate the effects of phantom exercises on phantom limb pain, mobility status, and quality of life in lower limb amputees treated with mirror therapy and routine physiotherapy. METHODS: It is a randomized controlled trial in which 24 unilateral lower limb amputees (above and below the knee) were randomly assigned to two equal groups i.e., control group (mirror therapy and conventional physical therapy) and experimental group in which, phantom exercises were given, additionally. Physical therapy included conventional therapeutic exercises while phantom exercises include imagining the movement of the phantom limb and attempting to execute these movements Data were collected at baseline, after 2 and 4 weeks of intervention using VAS (pain), AMP (mobility) and RAND SF-36 Version 1.0 (QOL) questionnaires. All statistical analyses were done with IBM SPSS 25.0 with 95% CI. RESULTS: Twenty-four amputees (17 males and 7 females) participated in this trial. The Mean age of the participants in experimental and control groups was 45.3 ± 11.1 years and 40.5 ± 12.5 years respectively. After the intervention, the pain (VAS score) was significantly lower in the experimental group (p = 0.003). Similarly, the experimental group demonstrated a significantly better score in the "bodily pain" domain of SF-36 (p = 0.012). Both groups significantly (p < 0.05) improved in other domains of SF-36 and ambulatory potential with no significant (p > 0.05) between-group differences. CONCLUSIONS: The Addition of phantom exercises resulted in significantly better pain management in lower limb amputees treated with mirror therapy and routine physiotherapy. TRIAL REGISTRATION: This study is registered in the U.S National Library of Medicine. The clinical trials registration number for this study is NCT04285138 ( ClinicalTrials.gov Identifier) (Date: 26/02/2020).


Assuntos
Amputados , Membro Fantasma , Adulto , Feminino , Humanos , Extremidade Inferior , Masculino , Pessoa de Meia-Idade , Medição da Dor , Membro Fantasma/terapia , Qualidade de Vida
12.
Occup Ther Int ; 2021: 4357473, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34707468

RESUMO

Muscle fatigue is a decline in muscle maximum force during contraction and can influence the fall risk among people. This study is aimed at identifying the effect of fatigue on prospective fall risk in transfemoral amputees (TFA). Fourteen subjects were involved in this study with TFA (34.7 ± 8.1 yrs, n = 7) and normal subjects (31.1 ± 7.4 yrs, n = 7). Fatigue of lower limb muscles was induced with the fatigue protocol. Subjects were tested prefatigue and postfatigue using the standardized fall risk assessment. All results were calculated and compared between pre- and postfatigue to identify fatigue's effect on both groups of subjects. The results showed that the fall risk increased significantly during pre- and postfatigue for TFA (p = 0.018), while there were no significant differences in normal subjects (p = 0.149). Meanwhile, the fall risk between TFA and normal subjects for prefatigue (p = 0.082) and postfatigue (p = 0.084) also showed no significant differences. The percentage (%) of increased fall risk for TFA was 19.2% compared to normal subjects only 16.7%. However, 61.4% increased of % fall risk in TFA after fatigue by using the baseline of the normal subject as the normalized % of fall risk. The increasing fall risks for TFA after fatigue are three times higher than the potential fall risk in normal subjects. The result indicates that they need to perform more precautions while prolonging lower limb activities. These results showed the implications of fatigue that can increase the fall risk due to muscle fatigue from repetitive and prolonged activities. Therefore, rehabilitation programs can be done very safely and precisely so that therapists can pursue fitness without aggravating existing injuries.


Assuntos
Amputados , Terapia Ocupacional , Fenômenos Biomecânicos , Humanos , Extremidade Inferior , Fadiga Muscular , Projetos Piloto , Estudos Prospectivos
13.
J Appl Biomech ; 37(5): 440-449, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34504044

RESUMO

Inertial measurement units and normative values enable clinicians to quantify clinical walking tests and set rehabilitation goals. Objectives of this study were (1) to compare time- and distance-based walking tests in individuals with lower limb amputation (iLLA) and normative values following rehabilitation discharge (T1) and 6 weeks after discharge (T2) and (2) to investigate spatiotemporal and foot kinematic parameters over a 6-minute walk test using inertial measurement units. Twelve iLLA participated in this study. Distance, cadence, stance ratio, loading rate ratio, push-up ratio, path length, and minimum toe clearance were analyzed during 6-minute walk test. Nonparametric repeated-measures analysis of variance tests, Bonferroni corrections, were performed. Time of distance-based walking tests diminished at T2 (P < .02). Compared with normative values, walking performance in iLLA was reduced. Cadence at T2 increased significantly (P = .026). Stance ratio increased in both legs at T2 (P < .05). Push-up ratio tended to decrease at T2 in the amputated leg (P = .0003). Variability of path length and minimum toe clearance at T2 were less than at T1 in the nonamputated leg (P < .05). Spatiotemporal improvement at T2 could be due to prosthesis adaptation in iLLA. The lower performance of the functional walk test compared with normative values could be due to amputation and pain-related fatigue.


Assuntos
Amputados , Membros Artificiais , Amputação , Seguimentos , Marcha , Humanos , Perna (Membro) , Teste de Caminhada , Caminhada
14.
Artigo em Inglês | MEDLINE | ID: mdl-34587090

RESUMO

This paper describes stair ambulation control and functionality of a semi-powered knee prosthesis that supplements nominally passive prosthesis behavior with swing-phase assistance. A set of stair ascent and descent controllers are described. The controllers were implemented in a semi-powered prosthesis prototype, and the prospective benefits of swing assist in stair ambulation were assessed on a group of three participants with unilateral, transfemoral amputation, relative to their respective daily-use prostheses. Results indicate that ambulation with the semi-powered knee resulted in improved stair ascent gait symmetry when compared to the participants' passive daily-use devices, and increased similitude to healthy stair ascent movement.


Assuntos
Amputados , Membros Artificiais , Prótese do Joelho , Fenômenos Biomecânicos , Marcha , Humanos , Articulação do Joelho , Estudos Prospectivos , Caminhada
15.
Comput Methods Programs Biomed ; 211: 106407, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34537492

RESUMO

BACKGROUND AND OBJECTIVES: Magnetic tracking involves the use of magnetic sensors to localize one or more magnetic objectives, in those applications in which a free line-of-sight between them and the operator is hampered. We applied this concept to prosthetic hands, which could be controlled by tracking permanent magnets implanted in the forearm muscles of amputees (the myokinetic control interface). Concerning the system design, the definition of a sensor distribution which maximizes the information, while minimizing the computational cost of localization, is still an open problem. We present a simple yet effective strategy to define an optimal sensor set for tracking multiple magnets, which we called the Peaks method. METHODS: We simulated a proximal amputation using a 3D CAD model of a human forearm, and the implantation of 11 magnets in the residual muscles. The Peaks method was applied to select a subset of sensors from an initial grid of 480 elements. The approach involves setting an appropriate threshold to select those sensors associated with the peaks in the magnetic flux density and its gradient distributions. Selected sensors were used to track the magnets during muscle contraction. For validating our strategy, an alternative method based on state-of-the-art solutions was implemented. We finally proposed a calibration phase to customize the sensor distribution on the specific patient's anatomy. RESULTS: 80 sensors were selected with the Peaks method, and 101 with the alternative one. A localization accuracy below 0.22 mm and 1.86° for position and orientation, respectively, was always achieved. Unlike alternative methods from the literature, neither iterative or analytical solution, nor a-priori knowledge on the magnet positions or trajectories were required, and yet the outcomes achieved with the two strategies proved statistically comparable. The calibration phase proved useful to adapt the sensors to the patient's stump and to increase the signal-to-noise ratio against intrinsic noise. CONCLUSIONS: We demonstrated an efficient and general solution for solving the design optimization problem (i.e. identifying an optimal sensor set) and reducing the computational cost of localization. The optimal sensor distribution mirrors the field shape traced by the magnets on the sensing surface, being an intuitive and fast way of achieving the same results of more complex and application-specific methods. Several applications in the (bio)medical field involving magnetic tracking will benefit from the outcomes of this work.


Assuntos
Amputados , Mãos , Humanos , Fenômenos Magnéticos , Magnetismo , Imãs
16.
Artigo em Inglês | MEDLINE | ID: mdl-34516377

RESUMO

Sensory feedback from body-powered and myoelectric prostheses are limited, but in different ways. Currently, there are no empirical studies on how incidental feedback differs between body-powered and myoelectric prostheses, or how these differences impact grasping. Thus, the purpose of this study was to quantify differences in grasping performance between body-powered and myoelectric prosthesis users when presented with different forms of feedback. Nine adults with upper limb loss and nine without (acting as controls) completed two tasks in a virtual environment. In the first task, participants used visual, vibration, or force feedback to assist in matching target grasp apertures. In the second task, participants used either visual or force feedback to identify the stiffness of a virtual object. Participants using either prosthesis type improved their accuracy and reduced their variability compared to the no feedback condition when provided with any form of feedback (p < 0.001). However, participants using body-powered prostheses were significantly more accurate and less variable at matching grasp apertures than those using myoelectric prostheses across all feedback conditions. When identifying stiffness, body-powered prosthesis users were more accurate using force feedback (64% compared to myoelectric users' 39%) while myoelectric users were more accurate using visual feedback (65% compared to body-powered users' 53%). This study supports previous findings that body-powered prosthesis users receive limited force and proprioceptive feedback, while myoelectric prosthesis users receive almost no force or proprioceptive feedback from their device. This work can inform future supplemental feedback that enhances rather than reproduces existing incidental feedback.


Assuntos
Amputados , Membros Artificiais , Adulto , Eletromiografia , Retroalimentação , Retroalimentação Sensorial , Força da Mão , Humanos , Desenho de Prótese
17.
Med Biol Eng Comput ; 59(10): 2115-2126, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34467446

RESUMO

The kinematics of the body center of mass (bCoM) may provide crucial information supporting the rehabilitation process of people with transfemoral amputation. The use of magneto-inertial measurement units (MIMUs) is promising as it may allow in-the-field bCoM motion monitoring. Indeed, bCoM acceleration might be obtained by fusing the estimated accelerations of body segments' centers of mass (sCoM), the formers being computed from the measured accelerations by segment-mounted MIMUs and the known relative position between each pair of MIMU and underlying sCoM. This paper investigates how erroneous identifications of MIMUs positions impact the accuracy of estimated 3D sCoM and bCoM accelerations in transfemoral amputee gait. Using an experimental design approach, 215 simulations of erroneous identifications of MIMUs positions (up to 0.02 m in each direction) were simulated over seven recorded gait cycles of one participant. MIMUs located on the trunk and sound lower limbs were shown to explain up to 77% of the variance in the accuracy of the estimated bCoM acceleration, presumably due to the higher mass and/or angular velocity of these segments during gait of lower-limb amputees. Therefore, a special attention should be paid when identifying the positions of MIMUs located on segments contributing the most to the investigated motion. Sensitivity of the estimated vertical body center of mass acceleration to erroneous identifications of MIMU positions in the anteroposterior (AP), mediolateral (ML), and vertical (V) directions, expressed in percentage of the total variance of the estimation accuracy.


Assuntos
Amputados , Fenômenos Biomecânicos , Marcha , Aceleração , Humanos , Extremidade Inferior
18.
Prosthet Orthot Int ; 45(5): 384-392, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34469939

RESUMO

BACKGROUND: No previous studies have followed prosthesis users with upper limb loss or limb deficiency using their own prostheses to assess change over time. OBJECTIVES: (1) To describe prostheses and terminal device types used at baseline and 1-year follow-up; (2) to examine changes in functional outcomes and device satisfaction over time; and (3) to examine whether changes in outcomes varied across level of amputation and type of prosthesis used. STUDY DESIGN: Multisite, observational time series design with in-person functional performance and self-report data collected at baseline and 1-year follow-up. METHODS: Baseline and follow-up outcome scores were compared using Wilcoxon signed-rank tests. Analyses were stratified by amputation level, time since amputation, prosthesis type, and change in device type. Published minimal detectable change (MDC) values were used to determine whether detectable change in outcome measures occurred. RESULTS: The longitudinal cohort consisted of 64 participants (mean age 64 years, 56% body-powered users). The only significant differences in outcome measures between baseline and follow-up (after adjustment for false discovery) were hours/day of prosthesis use, which increased from 6.0 (4.4) to 7.3 (5.3) hours (P = 0.0022). Differences in prosthesis use intensity remained significant in analyses stratified by amputation level, time since amputation, prosthesis type, and change in device type. Between 14 and 20% of the sample had change in one or more outcome measures that was greater than the known MDC. CONCLUSIONS: Most participants had stable outcomes over a year's time, whereas 14-20% experienced either improvement or decline in one or more tests indicating the importance of annual follow-up visits.


Assuntos
Amputados , Membros Artificiais , Amputação , Estudos de Coortes , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Extremidade Superior
19.
Prosthet Orthot Int ; 45(5): 410-416, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34469940

RESUMO

BACKGROUND: Increased knee osteoarthritis risk in patients with unilateral lower extremity limb loss is attributed to increased intact limb loading. Modulating powered ankle prosthesis push-off power may be an effective way to modulate intact limb loading. We examined how changes in the parameter settings of a commercial prosthetic ankle affect power delivery during push-off and the resulting collisional work experienced by the intact limb in persons with unilateral lower extremity limb loss. METHODS: Five subjects with unilateral transtibial amputation were fitted with a commercially available powered ankle prosthesis (Ottobock Empower). Subjects walked on a treadmill in seven conditions, where ankle power delivery settings were adjusted using methods accessible to clinicians. Kinetics and kinematics data were collected. RESULTS: Standard adjustment of parameter settings within the prosthetic foot did not alter timing of peak prosthesis power or intact limb collisional work but did have a significant effect on the magnitude of positive prosthesis ankle work. Increased prosthesis work did not decrease intact limb collisional work as predicted. CONCLUSIONS: Altering the parameter settings on a commercial powered ankle prosthesis affected the magnitude, but not the timing, of power delivered. Increased prosthesis push-off power did not decrease intact limb loading.


Assuntos
Amputados , Membros Artificiais , Tornozelo , Fenômenos Biomecânicos , , Marcha , Humanos , Caminhada
20.
Med Eng Phys ; 95: 39-44, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34479691

RESUMO

RESEARCH QUESTION: Would there be differences in muscle activation between healthy subjects' (HS) dominant leg and transfemoral amputees' (TFA) intact-leg/contralateral-limb (IL) during normal transient-state walking speed? METHODS: The muscle activation patterns are obtained by calculating the linear envelope of the EMG signals for each group. The activation patterns/temporal changes are compared between-population using statistical parametric mapping (SPM). RESULTS: Individual muscle activity showed significant differences in all muscles except vastus lateralis (VL), semitendinosus (SEM) and tensor fascia latae (TFL) activities. SIGNIFICANCE: The information could be used by the therapists to prevent secondary physical conditions and prosthetic companies to improve the mobility of the amputees.


Assuntos
Amputados , Membros Artificiais , Fenômenos Biomecânicos , Marcha , Humanos , Perna (Membro) , Caminhada , Velocidade de Caminhada
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