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1.
Brain Sci ; 11(8)2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34439610

RESUMO

This study aimed to examine the neural responses of children using prostheses and prosthetic simulators to better elucidate the emulation abilities of the simulators. We utilized functional near-infrared spectroscopy (fNIRS) to evaluate the neural response in five children with a congenital upper limb reduction (ULR) using a body-powered prosthesis to complete a 60 s gross motor dexterity task. The ULR group was matched with five typically developing children (TD) using their non-preferred hand and a prosthetic simulator on the same hand. The ULR group had lower activation within the primary motor cortex (M1) and supplementary motor area (SMA) compared to the TD group, but nonsignificant differences in the primary somatosensory area (S1). Compared to using their non-preferred hand, the TD group exhibited significantly higher action in S1 when using the simulator, but nonsignificant differences in M1 and SMA. The non-significant differences in S1 activation between groups and the increased activation evoked by the simulator's use may suggest rapid changes in feedback prioritization during tool use. We suggest that prosthetic simulators may elicit increased reliance on proprioceptive and tactile feedback during motor tasks. This knowledge may help to develop future prosthesis rehabilitative training or the improvement of tool-based skills.

2.
Front Neurosci ; 15: 693138, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34177460

RESUMO

The purpose of the current case study was to determine the influence of an 8-week home intervention training utilizing a partial hand prosthesis on hemodynamic responses of the brain and gross dexterity in a case participant with congenital unilateral upper-limb reduction deficiency (ULD). The case participant (female, 19 years of age) performed a gross manual dexterity task (Box and Block Test) while measuring brain activity (functional near-infrared spectroscopy; fNIRS) before and after an 8-weeks home intervention training. During baseline, there was a broad cortical activation in the ipsilateral sensorimotor cortex and a non-focalized cortical activation in the contralateral hemisphere, which was non-focalized, while performing a gross manual dexterity task using a prosthesis. After the 8-week home intervention training, however, cortical activation shifted to the contralateral motor cortex while cortical activation was diminished in the ipsilateral hemisphere. Specifically, the oxygenated hemodynamics (HbO) responses increased in the medial aspects of the contralateral primary motor and somatosensory cortices. Thus, these results suggest that an 8-week prosthetic home intervention was able to strengthen contralateral connections in this young adult with congenital partial hand reduction. This was supported by the case participant showing after training an increased flexor tone, increased range of motion of the wrist, and decreased times to complete various gross dexterity tasks. Changes in HbO responses due to the home intervention training follow the mechanisms of use-dependent plasticity and further guide the use of prostheses as a rehabilitation strategy for individuals with ULD.

3.
J Neuroeng Rehabil ; 18(1): 24, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33536034

RESUMO

BACKGROUND: The purpose of the current study was to determine the influence of upper-limb prostheses on brain activity and gross dexterity in children with congenital unilateral upper-limb reduction deficiencies (ULD) compared to typically developing children (TD). METHODS: Five children with ULD (3 boys, 2 girls, 8.76 ± 3.37 years of age) and five age- and sex-matched TD children (3 boys, 2 girls, 8.96 ± 3.23 years of age) performed a gross manual dexterity task (Box and Block Test) while measuring brain activity (functional near-infrared spectroscopy; fNIRS). RESULTS: There were no significant differences (p = 0.948) in gross dexterity performance between the ULD group with prosthesis (7.23 ± 3.37 blocks per minute) and TD group with the prosthetic simulator (7.63 ± 5.61 blocks per minute). However, there was a significant (p = 0.001) difference in Laterality Index (LI) between the ULD group with prosthesis (LI = - 0.2888 ± 0.0205) and TD group with simulator (LI = 0.0504 ± 0.0296) showing in a significant ipsilateral control for the ULD group. Thus, the major finding of the present investigation was that children with ULD, unlike the control group, showed significant activation in the ipsilateral motor cortex on the non-preferred side using a prosthesis during a gross manual dexterity task. CONCLUSIONS: This ipsilateral response may be a compensation strategy in which the existing cortical representations of the non-affected (preferred) side are been used by the affected (non-preferred) side to operate the prosthesis. This study is the first to report altered lateralization in children with ULD while using a prosthesis. Trial registration The clinical trial (ClinicalTrial.gov ID: NCT04110730 and unique protocol ID: IRB # 614-16-FB) was registered on October 1, 2019 ( https://clinicaltrials.gov/ct2/show/NCT04110730 ) and posted on October 1, 2019. The study start date was January 10, 2020. The first participant was enrolled on January 14, 2020, and the trial is scheduled to be completed by August 23, 2023. The trial was updated January 18, 2020 and is currently recruiting.


Assuntos
Membros Artificiais , Lateralidade Funcional/fisiologia , Córtex Motor/fisiologia , Córtex Motor/fisiopatologia , Destreza Motora/fisiologia , Deformidades Congênitas das Extremidades Superiores/fisiopatologia , Criança , Feminino , Humanos , Masculino
4.
Disabil Rehabil Assist Technol ; 16(2): 209-213, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-31385727

RESUMO

INTRODUCTION: Many individuals with stroke still have functional difficulties with their affected hand after going through a rehabilitation program. A 3D printed upper limb exoskeleton was designed for an individual who had a stroke. Functional and neuromuscular outcomes were measured using his affected hand with and without a 3D printed passive exoskeleton. The goal of this study was to determine the functional and neuromuscular changes induced by the 3D printed exoskeleton in a participant with stroke. MATERIALS AND METHODS: The functional ability of the exoskeleton was assessed using the Fugl-Meyer Assessment and the Box and Block Test. Strength testing and muscle activation of the participant's forearms were measured during maximal voluntary contractions. Furthermore, EMG was measured during the Box and Block Test and satisfaction and usability of the 3D printed exoskeleton were assessed using standardized questionnaires. RESULTS: The exoskeleton improved both the participant's Fugl-Meyer Assessment scores and Box and Block test scores compared to not wearing the device. The subject had increased EMG activation in his extensor when wearing the exoskeleton. CONCLUSION: The inexpensive 3D printed exoskeleton was effective in assisting the participant with stroke during the functional assessments and has the potential to be used to help regain function of the hand in the home setting of an individual with stroke.IMPLICATIONS FOR REHABILITATIONA 3D printed passive hand exoskeleton may assist to accomplish rehabilitation outcomes by increasing function of the affected hand of patients with stroke.The use of this hand exoskeleton may be used to improve gross hand dexterity and assist with functional grasps during rehabilitation sessions with a lower patient's level of perceived exertion.The use of new antimicrobial 3D printing polymers can be effectively implemented to manufacture assistive devices to prevent skin infections during rehabilitation.


Assuntos
Desenho Assistido por Computador , Exoesqueleto Energizado , Mãos/fisiopatologia , Impressão Tridimensional , Reabilitação do Acidente Vascular Cerebral/instrumentação , Atividades Cotidianas , Idoso , Humanos , Masculino
5.
Diagn Microbiol Infect Dis ; 98(4): 115176, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33069048

RESUMO

The SARS-CoV-2 is the causative agent of the COVID-19 disease, a severe acute respiratory syndrome-coronavirus (SARS-CoV). Its main transmission pathway is through large respiratory droplets, as well as direct and indirect contact. Copper in different formats has been used in research and clinical settings to reduce the risk of bacterial and viral contamination. Therefore, this review aims to search for evidence about the biocidal properties of copper over the Coronaviridae family. A literature review was performed using PubMed and Ovid servers without date or language restrictions. The search was carried out on March 7, 2020, using the following search terms: [Copper] Coronavirus OR CoV OR SARS OR MERS OR Influenza. Copper destroys the replication and propagation abilities of SARS-CoV, influenza, and other respiratory viruses, having high potential disinfection in hospitals, communities, and households. Copper can eliminate pathogenic organisms such as coronavirus bacterial strains, influenza virus, HIV, and fungi after a short period of exposure. Copper seems to be an effective and low-cost complementary strategy to help reduce the transmission of several infectious diseases by limiting nosocomial infectious transmission. Copper oxide or nanocompounds may be used as filters, face masks, clothing, and hospital common surfaces to reduce viruses and bacterial incubation.


Assuntos
Cobre/farmacologia , Infecções por Coronavirus/prevenção & controle , Desinfetantes/farmacologia , Influenza Humana/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Betacoronavirus/efeitos dos fármacos , COVID-19 , Infecções por Coronavirus/transmissão , Humanos , Influenza Humana/transmissão , Orthomyxoviridae/efeitos dos fármacos , Pneumonia Viral/transmissão , SARS-CoV-2
7.
J Musculoskelet Neuronal Interact ; 20(1): 77-87, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32131371

RESUMO

OBJECTIVES: This study examined the time course of changes and patterns of responses in electromyographic amplitude (EMG AMP) and EMG mean power frequency (MPF) for the superficial quadriceps muscles during exhaustive treadmill runs within the severe exercise intensity zones (SIZ1 and SIZ2). METHODS: The EMG signals for the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) as well as times to exhaustion (Tlim) were recorded in ten runners during two exhaustive treadmill runs (SIZ1 and SIZ2). The composite and individual responses were compared among muscles and between intensities. RESULTS: The composite patterns of responses in EMG AMP (linear, quadratic, and cubic increases; r2/R2=0.684-0.848) and EMG MPF (linear, quadratic, and cubic decreases; r2/R2=0.648 - 0.852) for the VL and RF were consistent with neuromuscular fatigue in both zones, but those for the VM were not (quadratic, cubic, and non-significant relationships with responses near baseline). The RF tended to demonstrate greater fatigue (EMG MPF decreased from 80-100% Tlim). There was large inter-individual variability (only 10-60% of responses consistent with composite) in response to fatiguing treadmill running. CONCLUSIONS: The current findings support the examination and characterization of neuromuscular fatigue on an intensity, muscle, and subject-by-subject basis.


Assuntos
Teste de Esforço/métodos , Fadiga Muscular/fisiologia , Junção Neuromuscular/fisiologia , Músculo Quadríceps/fisiologia , Corrida/fisiologia , Adulto , Eletromiografia/métodos , Feminino , Humanos , Masculino , Adulto Jovem
8.
3D Print Med ; 5(1): 7, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31049828

RESUMO

BACKGROUND: Traditional prosthetic fabrication relies heavily on plaster casting and 3D models for the accurate production of prosthetics to allow patients to begin rehabilitation and participate in daily activities. Recent technological advancements allow for the use of 2D photographs to fabricate individualized prosthetics based on patient anthropometrics. Additive manufacturing (i.e. 3D printing) enhances the capability of prosthesis manufacturing by significantly increasing production speed and decreasing production cost. Existing literature has extensively described the validity of using computer-aided design and 3D printing for fabrication of upper limb prostheses. The present investigation provides a detailed description of the development of a patient specific body-powered 3D printed partial finger prosthesis and compares its qualitative and functional characteristics to a commercially available finger prosthesis. CASE PRESENTATION: A 72-year old white male with a partial finger amputation at the proximal interphalangeal joint of the left hand performed a simple gross motor task with two partial finger prostheses and completed two self-reported surveys (QUEST & OPUS). Remote fitting of the 3D printed partial finger began after receipt of 2D photographs of the patient's affected and non-affected limbs. Prosthetic fitting when using 3D printable materials permitted the use of thermoforming around the patient's residual limb, allowing for a comfortable but tight-fitting socket. Results of the investigation show improved performance in the Box and Block Test when using both prostheses (22 blocks per minute) as compared to when not using a prosthesis (18 blocks per minute). Both body-powered prostheses demonstrated slightly lower task-efficiency when compared to the non-affected limb (30 blocks per minute) for the gross motor task. Results of the QUEST and OPUS describe specific aspects of both prostheses that are highly relevant to quality of life and functional performance when using partial finger prostheses. CONCLUSION: The use of 3D printing exhibits great potential for the fabrication of functional partial finger prostheses that improve function in amputees. In addition, 3D printing provides an alternative means for patients located in underdeveloped or low-income areas to procure a functional finger prosthesis.

9.
J Strength Cond Res ; 33(5): 1311-1319, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31033774

RESUMO

Noble, EB, Pilarski, JM, Vora, HK, Zuniga, JM, and Malek, MH. Log-transformed electromyography amplitude-power output relationship: single-leg knee-extensor versus single-leg cycle ergometry. J Strength Cond Res 33(5): 1311-1319, 2019-Comparing and contrasting motor unit recruitment and activation for the same muscles for multiple versus single-joint exercise may provide a better understanding of neuromuscular fatigue. The purpose of this study, therefore, is to compare the slope and y-intercept terms for the 3 superficial quadriceps femoris (QF) (vastus lateralis, rectus femoris, and vastus medialis) muscles derived from the log-transformed electromyography (EMG) amplitude-power output relationship between the single-leg knee-extensor ergometry (KE) and the single-leg cycle ergometry (CE). Ten healthy college-aged men who engaged in regular physical activity visited the laboratory on 2 occasions separated by 7 days to perform either single-leg CE or single-leg KE in a randomized order. For each visit, subjects performed incremental exercise until voluntary fatigue. Electromyography electrodes were placed on the superficial QF muscles. The slope and y-intercept terms, for each muscle, for the EMG amplitude versus power output relationship was examined using the log-transformed model for each subject's data. The results indicated no significant (p > 0.05) mean differences for either slope or y-intercept terms between exercise modes and across muscles. In addition, separate repeated-measures analyses of variance (ANOVAs) were used to determine mean differences for the slope and y-intercept values between the 3 muscles. In addition, separate 2 (mode: CE or KE) × intensity (intensity: 30, 60, and 90% of maximal workload) repeated-measures ANOVAs were conducted for each muscle. There was a significant (p < 0.05) mode × exercise intensity interaction for each muscle. Follow-up testing indicated that in most cases, the normalized EMG amplitude was significantly higher for single-leg KE than single-leg CE. These results indicated that incremental single-leg KE activates the superficial QF muscles significantly greater than single-leg CE.


Assuntos
Exercício Físico/fisiologia , Fadiga/fisiopatologia , Articulação do Joelho/fisiologia , Músculo Quadríceps/fisiologia , Adulto , Fenômenos Biomecânicos , Eletromiografia/métodos , Ergometria/métodos , Teste de Esforço/métodos , Humanos , Masculino , Músculo Esquelético/fisiologia , Adulto Jovem
10.
Expert Rev Med Devices ; 16(3): 257-266, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30661413

RESUMO

BACKGROUND: The objective of the current investigation was twofold: i) describe a remote fitting procedure for upper limb 3D printed prostheses and ii) assess patient satisfaction and comfort with 3D printed prostheses fitted remotely. METHODS: A qualitative study using content and score analysis to describe patient satisfaction after remote prosthetic fitting. Research participants reported QUEST and OPUS scores that allow for perceived rating of general aspects and functionality of upper limb prostheses. RESULTS: Six children (three girls & boys, 6-16 years of age) and 2 adult males (25 and 59 years of age) with congenital (n = 7) and acquired (n = 1) upper limb loss participated in this study. Highest device satisfaction items of the QUEST include weight (4.50 ± 0.76), safety (4.38 ± 0.52), and ease of use (4.13 ± 0.64). Functional tasks of the OPUS observe that prosthesis donning and doffing (1.5 ± 0.84) and drinking from a paper cup (1.75 ± 0.89) were the easiest functional tasks. CONCLUSION: The presented methodology for remote fitting of 3D printed upper-limb prostheses exhibits significant potential for rapid fabrication of functional prostheses to developing countries due to increased availability of digital devices in rural areas.


Assuntos
Membros Artificiais , Impressão Tridimensional , Extremidade Superior/cirurgia , Adolescente , Adulto , Amputados , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Aparelhos Ortopédicos , Satisfação do Paciente , Desenho de Prótese , Autorrelato , Inquéritos e Questionários
11.
Disabil Rehabil Assist Technol ; 14(1): 68-74, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29116866

RESUMO

INTRODUCTION: There is limited knowledge on the use of 3 D-printed transitional prostheses, as they relate to changes in function and strength. Therefore, the purpose of this study was to identify functional and strength changes after usage of 3 D-printed transitional prostheses for multiple weeks for children with upper-limb differences. MATERIALS AND METHODS: Gross manual dexterity was assessed using the Box and Block Test and wrist strength was measured using a dynamometer. This testing was conducted before and after a period of 24 ± 2.61 weeks of using a 3 D-printed transitional prosthesis. The 11 children (five girls and six boys; 3-15 years of age) who participated in the study, were fitted with a 3 D-printed transitional partial hand (n = 9) or an arm (n = 2) prosthesis. RESULTS: Separate two-way repeated measures ANOVAs were performed to analyze function and strength data. There was a significant hand by time interaction for function, but not for strength. Conclusion and relevance to the study of disability and rehabilitation: The increase in manual gross dexterity suggests that the Cyborg Beast 2 3 D-printed prosthesis can be used as a transitional device to improve function in children with traumatic or congenital upper-limb differences. Implications for Rehabilitation Children's prosthetic needs are complex due to their small size, rapid growth, and psychosocial development. Advancements in computer-aided design and additive manufacturing offer the possibility of designing and printing transitional prostheses at a very low cost, but there is limited knowledge on the function of this type of devices. The use of 3D printed transitional prostheses may improve manual gross dexterity in children after several weeks of using it.


Assuntos
Membros Artificiais , Crianças com Deficiência/reabilitação , Impressão Tridimensional , Desenho de Prótese , Extremidade Superior , Atividades Cotidianas , Pré-Escolar , Feminino , Humanos , Masculino
12.
J Neuroeng Rehabil ; 15(1): 48, 2018 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-29884185

RESUMO

BACKGROUND: Co-contraction is the simultaneous activation of agonist and antagonist muscles that produces forces around a joint. It is unknown if the use of a wrist-driven 3D printed transitional prostheses has any influence on the neuromuscular motor control strategies of the affected hand of children with unilateral upper-limb reduction deficiencies. Thus, the purpose of the current investigation was to examine the coactivation index (CI) of children with congenital upper-limb reduction deficiencies before and after 6 months of using a wrist-driven 3D printed partial hand prosthesis. METHODS: Electromyographic activity of wrist flexors and extensors (flexor carpi ulnaris and extensor digitorum) was recorded during maximal voluntary contraction of the affected and non-affected wrists. Co-contraction was calculated using the coactivation index and was expressed as percent activation of antagonist over agonist. Nine children (two girls and seven boys, 6 to 16 years of age) with congenital upper-limb deficiencies participated in this study and were fitted with a wrist-driven 3D printed prosthetic hand. From the nine children, five (two girls and three boys, 7 to 10 years of age) completed a second visit after using the wrist-driven 3D printed partial hand prosthesis for 6 months. RESULTS: Separate two-way repeated measures ANOVAs were performed to analyze the coactivation index and strength data. There was a significant main effect for hand with the affected hand resulting in a higher coactivation index for flexion and extension than the non-affected hand. For wrist flexion there was a significant main effect for time indicating that the affected and non-affected hand had a significantly lower coactivation index after a period of 6 months. CONCLUSION: The use of a wrist-driven 3D printed hand prosthesis lowered the coactivation index by 70% in children with congenital upper limb reduction deficiencies. This reduction in coactivation and possible improvement in motor control strategies can potentially improve prosthetic rehabilitation outcomes.


Assuntos
Membros Artificiais , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Impressão Tridimensional , Criança , Feminino , Humanos , Masculino , Extremidade Superior
13.
Expert Rev Med Devices ; 15(5): 349-356, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29723481

RESUMO

INTRODUCTION: 3D-printed anatomical models play an important role in medical and research settings. The recent successes of 3D anatomical models in healthcare have led many institutions to adopt the technology. However, there remain several issues that must be addressed before it can become more wide-spread. Of importance are the problems of cost and time of manufacturing. Machine learning (ML) could be utilized to solve these issues by streamlining the 3D modeling process through rapid medical image segmentation and improved patient selection and image acquisition. The current challenges, potential solutions, and future directions for ML and 3D anatomical modeling in healthcare are discussed. AREAS COVERED: This review covers research articles in the field of machine learning as related to 3D anatomical modeling. Topics discussed include automated image segmentation, cost reduction, and related time constraints. EXPERT COMMENTARY: ML-based segmentation of medical images could potentially improve the process of 3D anatomical modeling. However, until more research is done to validate these technologies in clinical practice, their impact on patient outcomes will remain unknown. We have the necessary computational tools to tackle the problems discussed. The difficulty now lies in our ability to collect sufficient data.


Assuntos
Algoritmos , Aprendizado de Máquina , Impressão Tridimensional , Procedimentos Cirúrgicos Operatórios , Humanos , Modelos Anatômicos , Fatores de Tempo
14.
J Tissue Eng ; 9: 2041731418769863, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29686829

RESUMO

An insufficiency of accessible allograft tissue for corneal transplantation leaves many impaired by untreated corneal disease. There is promise in the field of regenerative medicine for the development of autologous corneal tissue grafts or collagen-based scaffolds. Another approach is to create a suitable corneal implant that meets the refractive needs of the cornea and is integrated into the surrounding tissue but does not attempt to perfectly mimic the native cornea on a cellular level. Materials that have been investigated for use in the latter concept include natural polymers such as gelatin, semisynthetic polymers like gelatin methacrylate, and synthetic polymers. There are advantages and disadvantages inherent in natural and synthetic polymers: natural polymers are generally more biodegradable and biocompatible, while synthetic polymers typically provide greater control over the characteristics or property adjustment of the materials. Additive manufacturing could aid in the precision production of keratoprostheses and the personalization of implants.

15.
J Electromyogr Kinesiol ; 40: 88-94, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29704787

RESUMO

The selection of epoch lengths affects the time and frequency resolution of electromyographic (EMG) and mechanomyographic (MMG) signals, as well as decisions regarding the signal processing techniques to use for determining the power density spectrum. No previous studies, however, have examined the effects of epoch length on parameters of the MMG signal. The purpose of this study was to examine the differences between epoch lengths for EMG amplitude, EMG mean power frequency (MPF), MMG amplitude, and MMG MPF from the VL and VM muscles during MVIC muscle actions as well as at each 10% of the time to exhaustion (TTE) during a continuous isometric muscle action of the leg extensors at 50% of MVIC. During the MVIC trial, there were no significant (p > 0.05) differences between epoch lengths (0.25, 0.50, 1.00, and 2.00-s) for mean absolute values for any of the EMG or MMG parameters. During the submaximal, sustained muscle action, however, absolute MMG amplitude and MMG MPF were affected by the length of epoch. All epoch related differences were eliminated by normalizing the absolute values to MVIC. These findings supported normalizing EMG and MMG parameter values to MVIC and utilizing epoch lengths that ranged from 0.25 to 2.00-s.


Assuntos
Eletromiografia/métodos , Contração Isométrica/fisiologia , Músculo Esquelético/fisiologia , Fenômenos Biomecânicos/fisiologia , Feminino , Humanos , Masculino , Processamento de Sinais Assistido por Computador , Fatores de Tempo , Torque , Adulto Jovem
16.
Int J Sports Med ; 38(2): 111-117, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28006829

RESUMO

The purpose of the present study was to examine the effects of electrode placements centered over and offset from the innervation zone (IZ) with different interelectrode distances (IED) on the time and frequency domain parameters of the electromyographic (EMG) signal during a fatiguing submaximal, isometric workout. 11 adults performed an isometric leg extension muscle action at 50% maximal voluntary isometric contraction (MVIC) to exhaustion. Electromyographic amplitude and frequency parameters were determined from electrode placements with different IED centered over, at proximal offset, at distal offset, and away from the IZ at 10, 50, and 100% of the time to exhaustion using an electrode array. There were greater absolute EMG amplitude and lower absolute EMG frequency for electrode placements over and offset from the IZ, but lower absolute EMG amplitude over than offset from the IZ regardless of IED at each time-point during the time to exhaustion. The absolute EMG frequency values were affected by the location relative to the IZ and IED of the electrode placements, and were greater for distal offset vs. proximal offset electrode placements at each time-point. Normalization of the EMG amplitude and EMG frequency values to MVIC eliminated differences due to IED and electrode placements during the fatiguing workout.


Assuntos
Eletromiografia , Contração Isométrica , Músculo Quadríceps/inervação , Músculo Quadríceps/fisiologia , Eletrodos , Feminino , Humanos , Masculino , Adulto Jovem
17.
Prosthet Orthot Int ; 41(2): 205-209, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27117013

RESUMO

BACKGROUND AND AIM: The prosthetic options for higher level amputees are limited and costly. Advancements in computer-aided design programs and three-dimensional printing offer the possibility of designing and manufacturing transitional prostheses at very low cost. The aim of this project was to describe an inexpensive three-dimensional printed mechanical shoulder prosthesis to assist a pre-selected subject in performing bi-manual activities. TECHNIQUE: The main function of the body-powered, manually adjusted three-dimensional printed shoulder prosthesis is to provide a cost-effective, highly customized transitional device to individuals with congenital or acquired forequarter amputations. DISCUSSION: After testing the prototype on a young research participant, a partial correction of the patient's spinal deviation was noted due to the counterweight of the device. The patient's family also reported improved balance and performance of some bimanual activities after 2 weeks of using the device. Limitations of the design include low grip strength and low durability. Clinical relevance The prosthetic options for higher level amputees are limited and costly. The low-cost three-dimensional printed shoulder prosthesis described in this study can be used as a transitional device in preparation for a more sophisticated shoulder prosthesis.


Assuntos
Membros Artificiais , Desenho Assistido por Computador/economia , Impressão Tridimensional , Desenho de Prótese/economia , Ajuste de Prótese/métodos , Amputados/reabilitação , Braço , Criança , Pré-Escolar , Análise Custo-Benefício , Estudos Transversais , Feminino , Mãos , Humanos , Masculino , Desenho de Prótese/métodos , Ombro , Estados Unidos
18.
Nutr Rev ; 74(11): 708-721, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27753625

RESUMO

CONTEXT: Dietary supplements are widely used by military personnel and civilians for promotion of health. OBJECTIVE: The objective of this evidence-based review was to examine whether supplementation with l-arginine, in combination with caffeine and/or creatine, is safe and whether it enhances athletic performance or improves recovery from exhaustion for military personnel. DATA SOURCES: Information from clinical trials and adverse event reports were collected from 17 databases and 5 adverse event report portals. STUDY SELECTION: Studies and reports were included if they evaluated the safety and the putative outcomes of enhanced performance or improved recovery from exhaustion associated with the intake of arginine alone or in combination with caffeine and/or creatine in healthy adults aged 19 to 50 years. DATA EXTRACTION: Information related to population, intervention, comparator, and outcomes was abstracted. Of the 2687 articles screened, 62 articles meeting the inclusion criteria were analyzed. Strength of evidence was assessed in terms of risk of bias, consistency, directness, and precision. RESULTS: Most studies had few participants and suggested risk of bias that could negatively affect the results. l-Arginine supplementation provided little enhancement of athletic performance or improvements in recovery. Short-term supplementation with arginine may result in adverse gastrointestinal and cardiovascular effects. No information about the effects of arginine on the performance of military personnel was available. CONCLUSIONS: The available information does not support the use of l-arginine, either alone or in combination with caffeine, creatine, or both, to enhance athletic performance or improve recovery from exhaustion. Given the information gaps, an evidence-based review to assess the safety or effectiveness of multi-ingredient dietary supplements was not feasible, and therefore the development of a computational model-based approach to predict the safety of multi-ingredient dietary supplements is recommended.


Assuntos
Arginina/administração & dosagem , Arginina/efeitos adversos , Desempenho Atlético , Suplementos Nutricionais , Militares , Cafeína/administração & dosagem , Doenças Cardiovasculares/induzido quimicamente , Creatina/administração & dosagem , Suplementos Nutricionais/efeitos adversos , Gastroenteropatias/induzido quimicamente , Humanos
19.
Int J Exerc Sci ; 9(3): 376-383, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27766128

RESUMO

The purpose of this study was to determine if the amount of subcutaneous tissue over the quadriceps affects the assessment of mean power frequency at the fatigue threshold (MPFFT). It was hypothesized that greater skinfold values will result in lower power outputs associated to the MPFFT. Fourteen adults (Mean ± SD age = 20.7 ± 0.99; body weight = 72.8 ± 12.6 kg) performed an incremental cycle ergometry test to exhaustion while surface electromyographic (EMG) signals were measured from the vastus lateralis. The skinfold thickness of each leg was taken prior to the test, and skinfold thicknesses were separated into a larger and a smaller groups. The independent t-test showed a significant difference (p = 0.01) between the power outputs associated to the MPFFT of groups with high (Mean ± SD 130.4 ± 34.5 W) versus low skinfold (212.5 ± 61.2 W) values. The results suggested that higher subcutaneous fat may have affected the assessment of MPFFT during cycle ergometry.

20.
J Strength Cond Res ; 30(10): 2697-2702, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27658233

RESUMO

Smith, CM, Housh, TJ, Herda, TJ, Zuniga, JM, Camic, CL, Bergstrom, HC, Smith, DB, Weir, JP, Hill, EC, Cochrane, KC, Jenkins, NDM, Schmidt, RJ, and Johnson, GO. Time course of changes in neuromuscular parameters during sustained isometric muscle actions. J Strength Cond Res 30(10): 2697-2702, 2016-The objective of the present study was to identify the time course of changes in electromyographic (EMG) and mechanomyographic (MMG) time and frequency domain parameters during a sustained isometric muscle action of the leg extensors at 50% maximal voluntary isometric contraction. The EMG and MMG signals were measured from the vastus lateralis of 11 subjects to identify when motor unit activation strategies changed throughout the sustained isometric muscle action. The EMG amplitude (muscle activation) had a positive linear relationship (p = 0.018, r = 0.77) that began to increase at the initiation of the muscle action and continued until task failure. Electromyographic frequency (motor unit action potential conduction velocity) and MMG frequency (global motor unit firing rate) had negative quadratic relationships (p = 0.002, R = 0.99; p = 0.015, R = 0.94) that began to decrease at 30% of the time to exhaustion. The MMG amplitude (motor unit activation) had a cubic relationship (p = 0.001, R = 0.94) that increased from 10 to 30% of the time to exhaustion, then decreased from 40 to 70% of the time to exhaustion, and then markedly increased from 70% to task failure. The time course of changes in the neuromuscular parameters suggested that motor unit activation strategies changed at approximately 30 and 70% of the time to exhaustion during the sustained isometric muscle action. These findings indicate that the time course of changes in neuromuscular responses provide insight into the strategies used to delay the effects of fatigue and are valuable tools for quantifying changes in the fatiguing process during training programs or supplementation research.

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