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2.
PLoS One ; 14(12): e0218644, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31860669

RESUMO

Changes to arm swing and gait symmetry are symptomatic of several pathological gaits associated with reduced stability. The purpose of this study was to examine the relative contributions of arm swing and gait symmetry towards gait stability. We theorized that actively increasing arm swing would increase gait stability, while asymmetric walking would decrease gait stability. Fifteen healthy, young adults (23.4 ± 2.8 yrs) walked on a split-belt treadmill under symmetric (1.2 m/s) and asymmetric walking (left/right, 5:4 speed ratio) with three different arm swings: held, normal, and active. Trunk local dynamic stability, inter-limb coordination, and spatiotemporal gait variability and symmetry were measured. Active arm swing resulted in improved local trunk stability, increased gait variability, and decreased inter-limb coordination (p < .013). The changes in local trunk stability and gait variability during active arm swing suggests that these metrics quantify fundamentally different aspects of stability and are not always comparable. Split-belt walking caused reduced local trunk stability, increased gait variability, and increased lower limb asymmetry (p < .003). However, the arm swing symmetry was unaffected by gait asymmetry, this suggests that the decreases in gait stability are linked to the increases in gait asymmetry rather than increases in arm swing asymmetry.


Assuntos
Marcha/fisiologia , Movimento/fisiologia , Caminhada/fisiologia , Braço/fisiologia , Fenômenos Biomecânicos , Feminino , Voluntários Saudáveis , Humanos , Perna (Membro)/fisiologia , Masculino , Tronco , Adulto Jovem
3.
Hum Mov Sci ; 67: 102516, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31539754

RESUMO

This study investigated motor responses of force release during isometric elbow flexion by comparing effects of different ramp durations and step-down magnitudes. Twelve right-handed participants (age: 23.1 ±â€¯1.1) performed trajectory tracking tasks. Participants were instructed to release their force from the reference magnitude (REF; 40% of maximal voluntary contraction force) to a step-down magnitude of 67% REF or 33% REF and maintain the released magnitude. Force release was guided by ramp durations of either 1 s or 5 s. Electromyography of the biceps brachii and triceps brachii was performed during the experimental task, and the co-contraction ratio was evaluated. Force output was recorded to evaluate the parameters of motor performance, such as force variability and overshoot ratio. Although a longer ramp duration of 5 s decreased the force variability and overshoot ratio than did shorter ramp duration of 1 s, higher perceived exertion and co-contraction ratio were followed. Force variability was greater when force was released to the step-down magnitude of 33% REF than that when the magnitude was 67% REF, however, the overshoot ratio showed opposite results. This study provided evidence proving that motor control strategies adopted for force release were affected by both duration and step-down magnitude. In particular, it implies that different control strategies are required according to the level of step-down magnitude with a relatively short ramp duration.


Assuntos
Articulação do Cotovelo/fisiologia , Contração Isométrica/fisiologia , Músculo Esquelético/fisiologia , Braço/fisiologia , Eletromiografia , Humanos , Masculino , Desempenho Psicomotor/fisiologia , Amplitude de Movimento Articular/fisiologia , Fatores de Tempo , Adulto Jovem
4.
Sports Biomech ; 18(6): 663-685, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31543063

RESUMO

The golfer's body (trunk/arms/club) can be modeled as an inclined axle-chain system and the rotations of its parts observed on the functional swing plane (FSP) can represent the actual angular motions closely. The purpose of this study was to investigate the effects of pelvis-shoulders torsional separation style on the kinematic sequences employed by the axle-chain system in golf driving. Seventy-four male skilled golfers (handicap ≤ 3) were assigned to five groups based on their shoulder girdle motion and X-factor stretch characteristics: Late Shoulder Acceleration, Large Downswing Stretch, Large Backswing Stretch, Medium Total Stretch, and Small Total Stretch. Swing trials were captured by an optical system and the hip-line, thorax, shoulder-line, upper-lever, club, and wrist angular positions/velocities were calculated on the FSP. Kinematic sequences were established based on the timings of the peak angular velocities (backswing and downswing sequences) and the backswing-to-downswing transition time points (transition sequence). The backswing and transition sequences were somewhat consistent across the groups, showing full or partial proximal-to-distal sequences with minor variations. The downswing sequence was inconsistent across the groups and the angular velocity peaks of the body segments were not significantly separated. Various swing characteristics associated with the separation styles influenced the motion sequences.


Assuntos
Golfe/fisiologia , Destreza Motora/fisiologia , Pelve/fisiologia , Ombro/fisiologia , Adulto , Braço/fisiologia , Fenômenos Biomecânicos , Humanos , Masculino , Movimento , Tórax/fisiologia , Estudos de Tempo e Movimento
5.
Sports Health ; 11(6): 535-542, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31478791

RESUMO

BACKGROUND: The variability of throwing metrics, particularly elbow torque and ball velocity, during structured long-toss programs is unknown. HYPOTHESES: (1) Elbow torque and ball velocity would increase as throwers progressed through a structured long-toss program and (2) intrathrower reliability would be high while interthrower reliability would be variable. STUDY DESIGN: Descriptive laboratory study. LEVEL OF EVIDENCE: Level 3. METHODS: Sixty healthy high school and collegiate pitchers participated in a structured long-toss program while wearing a validated inertial measurement unit, which measured arm slot, arm velocity, shoulder rotation, and elbow varus torque. Ball velocity was assessed by radar gun. These metrics were compared within and between all pitchers at 90, 120, 150, and 180 ft and maximum effort mound pitching. Intra- and interthrower reliabilities were calculated for each metric at every stage of the program. RESULTS: Ball velocity significantly changed at each progressive throwing distance, but elbow torque did not. Pitching from the mound did not place more torque on the elbow than long-toss throwing from 120 ft and beyond. Intrathrower reliability was excellent (intraclass correlation coefficient >0.75) throughout the progressive long-toss program, especially on the mound. Ninety-one percent of throwers had acceptable interthrower reliability (coefficient of variation <5%) for ball velocity, whereas only 79% of throwers had acceptable interthrower reliability for elbow torque. CONCLUSION: Based on trends in elbow torque, it may be practical to incorporate pitching from the mound earlier in the program (once a player is comfortable throwing from 120 ft). Ball velocity and elbow torque do not necessarily correlate with one another, so a degree of caution should be exercised when using radar guns to estimate elbow torque. Given the variability in elbow torque between throwers, some athletes would likely benefit from an individualized throwing program. CLINICAL RELEVANCE: Increased ball velocity does not necessarily equate to increased elbow torque in long-toss. Some individuals would likely benefit from individualized long-toss programs for rehabilitation.


Assuntos
Beisebol/fisiologia , Cotovelo/fisiologia , Condicionamento Físico Humano/métodos , Braço/fisiologia , Traumatismos em Atletas/reabilitação , Beisebol/lesões , Fenômenos Biomecânicos , Monitores de Aptidão Física , Humanos , Rotação , Ombro/fisiologia , Equipamentos Esportivos , Torque , Exercício de Aquecimento , Dispositivos Eletrônicos Vestíveis , Adulto Jovem
6.
Gait Posture ; 74: 71-75, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31473585

RESUMO

BACKGROUND: There is growing evidence that arm movements make a substantial and functionally relevant contribution to dynamic balance. Additional insight of the important role of arm movements may be gained by quantifying the effects of arm restriction on the performance of commonly recommended static balance tasks of increasing difficulty. RESEARCH QUESTION: The purpose of the present study was to determine whether restricting/permitting arm movements influences postural sway during tasks of various levels of difficulty. METHODS: A total of 20 healthy and physically active adults (females; n = 10; age, 20.7 ±â€¯1.3 years) randomly completed (a) quiet standing postural control tasks of increasing difficulty (bipedal, tandem, unipedal) on a fixed and foam surface, and (b) a dynamic postural control task (Y balance test), under two different verbally conveyed instructions of arm position; (1) restricted arm movement and (2) free arm movement. Centre of pressure outcomes measured during quiet standing served as a measure of static balance performance. RESULTS: The results showed that restricting movements of the arms elicited large magnitude (Cohen's d = 0.97 - 1.28) increases in mediolateral postural sway (P < 0.05) but not anteroposterior (P > 0.05) sway. These effects were only observed during challenging (tandem and unipedal) standing balance tasks. Restricting arm movements elicited a marked reduction in the Y Balance reach distance (all directions, P < 0.001, d = -0.53 to -1.15). SIGNIFICANCE: The findings from the present study suggest that the contribution of the arms only become relevant when frontal plane balance is challenged. Moreover, the data indicate that arm movements are vital for the control of mediolateral postural sway.


Assuntos
Braço/fisiologia , Equilíbrio Postural/fisiologia , Adulto , Análise de Variância , Feminino , Humanos , Masculino , Adulto Jovem
7.
IEEE Int Conf Rehabil Robot ; 2019: 34-39, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374603

RESUMO

Task-oriented therapy consists of three stages: demonstration, observation and assistance. While demonstration using robots has been extensively studied, the other two stages rarely involve robots. This paper focuses on the transition between observation and assistance. More specifically, we tackle the robot's decision making problem of whether to assist a patient or not based on the observation. The proposed method is to train a discrete tunnel shape 3-D decision boundary through correct demonstration to classify motions. Additional conditions such as slow progress, self correction and overshot motions are taken into account of the decision making. Preliminary experiments have been performed on BAXTER robot for a cup reaching task. The BAXTER robot is programmed to react according to the decision boundary. It assists the patient when the patient's hand position is determined by the proposed algorithm to be unacceptable. Multiple cases including correct motion, continuous assistance, overshot, misaim and slow progress are tested. Results have confirmed the feasibility of the proposed method, which can reduce the current shortage of physical rehabilitation therapists.


Assuntos
Braço/fisiologia , Robótica/métodos , Reabilitação do Acidente Vascular Cerebral/instrumentação , Algoritmos , Estudos de Viabilidade , Humanos , Modalidades de Fisioterapia/instrumentação , Interface Usuário-Computador
8.
IEEE Int Conf Rehabil Robot ; 2019: 121-126, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374617

RESUMO

Proprioception, the ability to sense body position and limb movements in space without visual feedback, is one of the key factors in controlling body movements and performing activities of daily living. However, this capability might be affected after neural injuries such as stroke. Robotic platforms can be used to monitor and promote arm movements and, therefore, can assist in developing rehabilitation protocols that aim to improve proprioception through repetitive reaching motions without vision. The objective of this paper is to investigate if a robotic training protocol improves the end-position reaching proprioceptive sense in three-dimensional (3D) space. As an initial step towards clinical application, a robotic platform was employed to train the end-position proprioceptive sense in six healthy participants. During the training phase, volunteers used their dominant hand to reach without vision to two different targets in 3D space. Positions of these targets were carefully chosen to create a hand movement pattern similar to that used when self-feeding, which is an important activity of daily living. At the end of each training trial, participants were provided with visual feedback to help them move their hands to the exact locations confirmed through haptic feedback. Their performance was evaluated before and after the training in an assessment phase during which participants were asked to move from the start position to the same two targets as well as an additional third one without any visual or haptic feedback. The results from this study show significant improvements in overall reaching accuracy and trajectory smoothness, demonstrated by 41% decrease in the average end-position error and 13% reduction in the average index of curvature after the training. This research suggests the potential of designing robotic rehabilitation protocols for improving 3D proprioception.


Assuntos
Braço/fisiologia , Modalidades de Fisioterapia/instrumentação , Propriocepção/fisiologia , Robótica/instrumentação , Atividades Cotidianas , Adulto , Desenho de Equipamento , Retroalimentação , Retroalimentação Sensorial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Postura , Adulto Jovem
9.
IEEE Int Conf Rehabil Robot ; 2019: 264-269, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374640

RESUMO

The relationship between the smoothness of the upper limb endpoint movement and multi joint angular motion is a function of the individual joint angular velocities, accelerations, and jerks as well as the instantaneous arm configuration and its rate of change during movement execution. We compared the contribution of jerk components to the total endpoint jerk in able bodied participants who performed arm cranking movements on an arm cranking device where the two arms could crank independently. The results of this investigation suggest that the most dominant components of the end effector jerk are related to both the angular jerks and to the change of arm configuration pose. This jerk partitioning is much stronger as it was found previously for both reaching arm movements and single hand cranking. This shows the task specificity of the decomposition of endpoint jerk and the effect that bi-manual tasks can have on the smoothness of movements. The proposed decomposition may give useful information in why certain bi-manual rehabilitation processes are more useful than others.


Assuntos
Braço/fisiologia , Articulação da Mão/fisiologia , Modelos Biológicos , Movimento/fisiologia , Adulto , Feminino , Humanos , Masculino
10.
IEEE Int Conf Rehabil Robot ; 2019: 1121-1126, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374780

RESUMO

Functional impairment of the hand, for example after a stroke, can be partially improved by intensive training. This is currently done by physiotherapy and the optimal intensity of hand rehabilitation programs is usually not reached due to a lack in human resources (high costs) and patients fatigue. In this work a cost-effective soft exosuit to support the hand's grasping function is presented. The system is based on tendon-like wires and all fingers except the little finger are actuated. Each of the remaining four fingers is bidirectionally controlled by an electrical motor. This allows a variety of gripping situations, e.g. a power or precision grip. Our prototype weighs 435g, including the battery and can be worn on the upper arm. The force applicable for a power grip exceeds 20N with a maximum gripping frequency of 4Hz. Furthermore, a force control is implemented, giving the wearer the opportunity to grab sensitive objects. All components used are available in different sizes, allowing a quick and individual preparation per patient. Therefore, our prototype can be used for rehabilitation while doing activities of daily living (ADL) starting on the day of the injury.


Assuntos
Mãos/fisiologia , Dispositivos Eletrônicos Vestíveis , Atividades Cotidianas , Braço/fisiologia , Eletromiografia , Dedos/fisiologia , Força da Mão , Humanos , Reabilitação
11.
IEEE Int Conf Rehabil Robot ; 2019: 1153-1158, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31374785

RESUMO

Individuals with paralyzed limbs due to spinal cord injuries lack the ability to perform the reaching motions necessary to every day life. Functional electrical stimulation (FES) is a promising technology for restoring reaching movements to these individuals by reanimating their paralyzed muscles. We have proposed using a quasi-static model-based control strategy to achieve reaching controlled by FES. This method uses a series of static positions to connect the starting wrist position to the goal. As a first step to implementing this controller, we have completed a simulated study using a MATLAB based dynamic model of the arm in order to determine the suitable parameters for the quasi-static controller. The selected distance between static positions in the path was 6 cm, and the amount of time between switching target positions was 1.3 s. The final controller can complete reaches of over 30 cm with a median accuracy of 6.8 cm.


Assuntos
Braço/fisiologia , Paralisia/terapia , Punho/fisiologia , Terapia por Estimulação Elétrica , Humanos , Músculo Esquelético/fisiologia , Traumatismos da Medula Espinal/fisiopatologia
12.
Eur J Appl Physiol ; 119(10): 2275-2286, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31435767

RESUMO

PURPOSE: To examine the effects of stage duration on power output (PO), oxygen uptake (VO2), and heart rate (HR) at peak level and ventilatory thresholds during synchronous arm crank ergometry. METHODS: Nineteen healthy participants completed a ramp, 1-min stepwise, and 3-min stepwise graded arm crank exercise test. PO, VO2, and HR at the first and second ventilatory threshold (VT1, VT2) and peak level were compared among the protocols: a repeated measures analysis of variance was performed to test for systematic differences, while intraclass correlation coefficients (ICC) and Bland-Altman plots were calculated to determine relative and absolute agreement. RESULTS: Systematic differences among the protocols were found for PO at VT1, VT2, and peak level. At peak level, PO differed significantly among all protocols (ramp: 115 ± 37 W; 1-min stepwise: 108 ± 34 W; 3-min stepwise: 94 ± 31 W, p ≤ 0.01). No systematic differences for HR or VO2 were found among the protocols. VT1 and VT2 were identified at 52% and 74% of VO2peak, respectively. The relative agreement among protocols varied (ICC 0.02-0.97), while absolute agreement was low with small-to-large systematic error and large random error. CONCLUSIONS: PO at VTs and peak level was significantly higher in short-stage protocols compared with the 3-min stepwise protocol, whereas HR and VO2 showed no differences. Therefore, training zones based on PO determined in short-stage protocols might give an overestimation. Moreover, due to large random error in HR at VTs between the protocols, it is recommended that different protocols should not be used interchangeably within individuals.


Assuntos
Limiar Anaeróbio , Ergometria/normas , Contração Muscular , Adulto , Braço/fisiologia , Ergometria/métodos , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Esforço Físico
13.
J Am Soc Mass Spectrom ; 30(10): 2082-2091, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31407158

RESUMO

Keratinocyte organization and biochemistry are important in forming the skin's protective barrier. Intrinsic and extrinsic factors can affect skin barrier function at the cellular and molecular levels. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometric imaging, a technique which combines both molecular aspects and histological details, has proven to be a valuable method in various disciplines including pharmacology, dermatology and cosmetology. It typically requires ex vivo samples, prepared following frozen tissue sectioning. This paper demonstrates the feasibility of performing MALDI analysis on tape strips collected non-invasively on skin. The aim is to obtain molecular imaging of corneocytes on tapes towards novel biological insights. Tapes were collected from two skin sites (volar forearm and cheek) of human volunteers. Ten molecules relating to skin barrier function were detected with a single mode of acquisition at high spatial resolution with a 7 T MALDI-Fourier transform ion cyclotron resonance (FTICR) instrument. The method sensitivity was adequate to create molecular maps which could be overlaid on transmission microscopy images of the same area of the tape. Analysis of the molecular distributions from tapes at the two skin sites was consistent with the known skin properties of the two sites, confirming the validity of the observations. Hierarchical clustering analysis was used to differentiate corneocyte populations based on their molecular profiles. Furthermore, morphological analysis provided a new way of considering statistical populations of corneocytes on the same tape, rather than measuring a single averaged value, providing additional useful information relating to their structure-function relationship.


Assuntos
Biomarcadores/análise , Imagem Molecular/métodos , Pele , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Fita Cirúrgica , Braço/fisiologia , Face/fisiologia , Humanos , Pele/química , Pele/citologia
14.
Med Sci Monit ; 25: 5683-5689, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31365521

RESUMO

BACKGROUND Due to lack of normal reference values of forward and lateral reach tests for Saudi young adults, this study aimed to formulate normative values of the forward reach test and lateral reach test and to assess the correlation between the demographic variables and the reach test results. MATERIAL AND METHODS We randomly assigned 240 normal young Saudi adults ages 20-23 years to assess reach test scores in forward and lateral directions. All the subjects had been measured for distance reached in forward and lateral direction on graph paper fixed to a white board. RESULTS The mean and standard deviation of forward and lateral reach distances were 25±8.14 cm and 19.78±5.70 cm, respectively. Significant differences were found between males and females for forward reach and lateral reach scores (p<0.001). Forward reach and lateral reach values showed a moderate correlation with height, lower limb length, and upper limb length. The intra-rater reliability assessed by intra-class correlation coefficient was 0.91 and 0.92 for the forward and lateral reach test scores, respectively. CONCLUSIONS This study established reference values of forward and lateral reach scores for Saudi young adults ages 20-23 years. Height, upper limb length, and lower limb length were moderately correlated with the reach distances in forward and lateral directions. Males performed longer reach distances than females.


Assuntos
Braço/fisiologia , Pesos e Medidas Corporais/métodos , Antropometria/métodos , Fenômenos Biomecânicos , Teste de Esforço/métodos , Feminino , Humanos , Masculino , Equilíbrio Postural/fisiologia , Psicometria , Valores de Referência , Reprodutibilidade dos Testes , Arábia Saudita , Adulto Jovem
15.
J Sports Sci Med ; 18(3): 438-447, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31427865

RESUMO

Monitoring the upper arm propulsion is a crucial task for swimmer performance. The swimmer indeed can produce displacement of the body by modulating the upper limb kinematics. The present study proposes an approach for automatically recognize all stroke phases through three-dimensional (3D) wrist's trajectory estimated using inertial devices. Inertial data of 14 national-level male swimmer were collected while they performed 25 m front-crawl trial at intensity range from 75% to 100% of their 25 m maximal velocity. The 3D coordinates of the wrist were computed using the inertial sensors orientation and considering the kinematic chain of the upper arm biomechanical model. An algorithm that automatically estimates the duration of entry, pull, push, and recovery phases result from the 3D wrist's trajectory was tested using the bi-dimensional (2D) video-based systems as temporal reference system. A very large correlation (r = 0.87), low bias (0.8%), and reasonable Root Mean Square error (2.9%) for the stroke phases duration were observed using inertial devices versus 2D video-based system methods. The 95% limits of agreement (LoA) for each stroke phase duration were always lower than 7.7% of cycle duration. The mean values of entry, pull, push and recovery phases duration in percentage of the complete cycle detected using 3D wrist's trajectory using inertial devices were 34.7 (± 6.8)%, 22.4 (± 5.8)%, 14.2 (± 4.4)%, 28.4 (± 4.5)%. The swimmer's velocity and arm coordination model do not affect the performance of the algorithm in stroke phases detection. The 3D wrist trajectory can be used for an accurate and complete identification of the stroke phases in front crawl using inertial sensors. Results indicated the inertial sensor device technology as a viable option for swimming arm-stroke phase assessment.


Assuntos
Acelerometria/instrumentação , Braço/fisiologia , Destreza Motora/fisiologia , Natação/fisiologia , Algoritmos , Fenômenos Biomecânicos , Humanos , Masculino , Reprodutibilidade dos Testes , Estudos de Tempo e Movimento , Gravação em Vídeo , Dispositivos Eletrônicos Vestíveis , Punho , Adulto Jovem
16.
Sensors (Basel) ; 19(15)2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31382363

RESUMO

In this paper, the analysis of the intensity of muscle activations in different subjects when they perform an industrial task in a repetitive way assisted by a robotic upper-limb exoskeleton is presented. To do that, surface electromyography (EMG) signals were monitored with and without a robotic upper-limb exoskeleton for 10 subjects during a drilling task, a typical tedious maintenance or industrial task. Our results show that wearing the upper-limb exoskeleton substantially reduces muscle activity during a drilling task above head height. Specifically, there is statistically significant differences in the pectoralis major and rhomboids muscles between the groups wearing or not wearing the robotic upper-limb exoskeleton.


Assuntos
Braço/fisiologia , Eletromiografia/métodos , Adulto , Fenômenos Biomecânicos , Eletromiografia/instrumentação , Desenho de Equipamento , Exoesqueleto Energizado , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologia , Impressão Tridimensional , Adulto Jovem
17.
Appl Ergon ; 81: 102896, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31422263

RESUMO

Accurate estimations of manual arm strength (MAS) are crucial in the evaluation of occupational force demands relative to population capacity. Most current strength predictions assume force application with a vertically oriented handle, but it is unknown how uni-manual force capability changes as a function of handle orientation and hand location. This study evaluated the effect of handle orientation on MAS throughout the reach envelope. Fifteen female participants exerted maximum forces in six directions (i.e. superior, inferior, anterior, posterior, medial, lateral), at five different hand locations, and MAS was measured with the handle oriented at 0° (i.e. horizontal), 45°, 90° (i.e. vertical) and 135°. Handle orientation affected MAS in all but the anterior exertion direction, with significant interactions between hand location and grip orientation existing for the superior and inferior directions. These results suggest that handle orientation is important to consider in future predictive models of manual arm strength.


Assuntos
Braço/fisiologia , Ergonomia/métodos , Força Muscular/fisiologia , Orientação Espacial/fisiologia , Esforço Físico/fisiologia , Fenômenos Biomecânicos , Ergonomia/instrumentação , Feminino , Voluntários Saudáveis , Humanos , Adulto Jovem
18.
Sensors (Basel) ; 19(13)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31266252

RESUMO

Electrode reversal errors in standard 12-lead electrocardiograms (ECG) can produce significant ECG changes and, in turn, misleading diagnoses. Their detection is important but mostly limited to the design of criteria using ECG databases with simulated reversals, without Wilson's central terminal (WCT) potential change. This is, to the best of our knowledge, the first study that presents an algebraic transformation for simulation of all possible ECG cable reversals, including those with displaced WCT, where most of the leads appear with distorted morphology. The simulation model of ECG electrode swaps and the resultant WCT potential change is derived in the standard 12-lead ECG setup. The transformation formulas are theoretically compared to known limb lead reversals and experimentally proven for unknown limb-chest electrode swaps using a 12-lead ECG database from 25 healthy volunteers (recordings without electrode swaps and with 5 unicolor pairs swaps, including red (right arm-C1), yellow (left arm-C2), green (left leg (LL) -C3), black (right leg (RL)-C5), all unicolor pairs). Two applications of the transformation are shown to be feasible: 'Forward' (simulation of reordered leads from correct leads) and 'Inverse' (reconstruction of correct leads from an ECG recorded with known electrode reversals). Deficiencies are found only when the ground RL electrode is swapped as this case requires guessing the unknown RL electrode potential. We suggest assuming that potential to be equal to that of the LL electrode. The 'Forward' transformation is important for comprehensive training platforms of humans and machines to reliably recognize simulated electrode swaps using the available resources of correctly recorded ECG databases. The 'Inverse' transformation can save time and costs for repeated ECG recordings by reconstructing the correct lead set if a lead swap is detected after the end of the recording. In cases when the electrode reversal is unknown but a prior correct ECG recording of the same patient is available, the 'Inverse' transformation is tested to detect the exact swapping of the electrodes with an accuracy of (96% to 100%).


Assuntos
Eletrocardiografia/métodos , Eletrodos , Adulto , Idoso , Braço/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Sensors (Basel) ; 19(13)2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31284455

RESUMO

The consequences of falls, costs, and complexity of conventional evaluation protocols have motivated researchers to develop more effective balance assessments tools. Healthcare practitioners are incorporating the use of mobile phones and other gadgets (smartphones and tablets) to enhance accessibility in balance evaluations with reasonable sensitivity and good cost-benefit. The prospects are evident, as well as the need to identify weakness and highlight the strengths of the different approaches. In order to verify if mobile devices and other gadgets are able to assess balance, four electronic databases were searched from their inception to February 2019. Studies reporting the use of inertial sensors on mobile and other gadgets to assess balance in healthy adults, compared to other evaluation methods were included. The quality of the nine studies selected was assessed and the current protocols often used were summarized. Most studies did not provide enough information about their assessment protocols, limiting the reproducibility and the reliability of the results. Data gathered from the studies did not allow us to conclude if mobile devices and other gadgets have discriminatory power (accuracy) to assess postural balance. Although the approach is promising, the overall quality of the available studies is low to moderate.


Assuntos
Telefone Celular , Monitorização Fisiológica/métodos , Equilíbrio Postural/fisiologia , Smartphone , Adolescente , Adulto , Idoso , Braço/fisiologia , Estudos de Coortes , Estudos Transversais , Feminino , Pé/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/instrumentação , Processamento de Sinais Assistido por Computador , Dispositivos Eletrônicos Vestíveis
20.
Ann Hum Biol ; 46(4): 335-339, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31284770

RESUMO

Background: It remains unclear how past exercise habits can affect the skeletal muscle mass in adulthood in Japanese populations. Aim: The purpose of the present investigation was to examine the association of appendicular muscle mass (AMM) and skeletal muscle mass index (SMI) with the history of exercise and/or physical activity participation in Japanese women. Subjects and methods: One hundred and twenty females, aged between 18 and 28 years old, participated in the present investigation. Using a dual-energy X-ray absorptiometry scanner, the appendicular lean soft tissue, which is considered as a measure of AMM, was evaluated. Skeletal muscle mass index (SMI) was also assessed. Furthermore, all subjects answered a physical activity questionnaire. Results: Exercise habits at 7 years of age or older positively affected the AMM and SMI. The results of the multiple regression analysis showed that exercise history at 16-18 years of age as well as the current status of exercise and/or physical activity participation was a significant predictor of SMI and AMM. Conclusions: These results indicate that not only the past history of participation in physical and/or sports activities but also the current status of daily physical activity and sports activity play an important role in maintaining appropriate SMI and AMM in young women.


Assuntos
Braço/fisiologia , Extremidade Inferior/fisiologia , Músculo Esquelético/fisiologia , Absorciometria de Fóton , Adulto , Fatores Etários , Estudos Transversais , Exercício , Feminino , Humanos , Japão , Perna (Membro)/fisiologia , Adulto Jovem
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