Percorrer por autor "Fonseca, Pedro"
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- Accuracy and repeatability of the gait analysis by the WalkinSense systemPublication . P. de Castro, Marcelo; Meucci, Marco; Soares, Denise P.; Fonseca, Pedro; Borgonovo-Santos, Márcio; Sousa, Filipa; Machado, Leandro; Villas-Boas, João PauloWalkinSense is a new device designed to monitor walking. The aim of this study was to measure the accuracy and repeatability of the gait analysis performed by the WalkinSense system. Descriptions of values recorded by WalkinSense depicting typical gait in adults are also presented. A bench experiment using the Trublu calibration device was conducted to statically test the WalkinSense. Following this, a dynamic test was carried out overlapping the WalkinSense and the Pedar insoles in 40 healthy participants during walking. Pressure peak, pressure peak time, pressure-time integral, and mean pressure at eight-foot regions were calculated. In the bench experiments, the repeatability (i) among the WalkinSense sensors (within), (ii) between two WalkinSense devices, and (iii) between the WalkinSense and the Trublu devices was excellent. In the dynamic tests, the repeatability of the WalkinSense (i) between stances in the same trial (within-trial) and (ii) between trials was also excellent (ICC > 0.90). When the eight-foot regions were analyzed separately, the within-trial and between-trials repeatability was good-to-excellent in 88% (ICC > 0.80) of the data and fair in 11%. In short, the data suggest that the WalkinSense has good-to-excellent levels of accuracy and repeatability for plantar pressure variables.
- Analysis and quantification of upper-limb movement in motor rehabilitation after strokePublication . Silva, R. Mariana; Sousa, Emanuel; Fonseca, Pedro; Pinheiro, Ana Rita; Silva, Cláudia; Correia, Miguel V.; Mouta, SandraIt is extremely difficult to reduce the relations between the several body parts that perform human motion to a simplified set of features. Therefore, the study of the upper-limb functionality is still in development, partly due to the wider range of actions and strategies for motor execution. This, in turn, leads to inconsistent upper-limb movement parameterization. We propose a methodology to assess and quantify the upper-limb motor execution. Extracting key variables from different sources, we intended to quantify healthy upper-limb movement and use these parameters to quantify motor execution during rehabilitation after stroke. In order to do so, we designed an experimental setup defining a workspace for the execution of the action recording kinematic data. Results reveal an effect of object and instruction on the timing of upper-limb movement, indicating that the spatiotemporal analysis of kinematic data can be used as a quantification parameter for motor rehabilitation stages and methods.
- Biomechanical Characterization of Comfort Footwear using Gait AnalysisPublication . Flores, Andreia; Marques, Maria Arcelina; Fonseca, Pedro; Machado, Leandro; Vaz, MárioComfort footwear has unique characteristics fundamental to people looking for this type of shoe, namely foot support, flexibility, stability, lightweight, cushioning, traction, etc. [1]. They are usually preferred mainly by elder, overweighed or people with feet problems [2]. It is known that the shoe can modify gait behavior [3]. The purpose of this study was to evaluate posture and gait by comparing barefoot and shoe wearing circumstances to assess the real effect of the comfort footwear under study.
- Influence of automation on biomechanical exposure of the upper-limbs in an industrial assembly line: a pilot studyPublication . Santos, Joana; Abreu, Ana Betty; Fonseca, Pedro; Alberto Alves Carvalhais, Carlos; Santos Baptista, João; Santos, Rubim; Vaz, MárioAutomation of assembly work was originally developed to increase operation efficiency and to reduce workload. However, a considerable number of unanticipated ergonomic problems have been observed such as the interaction between humans and automated systems. The aims of this study were to quantify joint angle positions (shoulder, elbow and wrist) of workers in two assembly lines with different mechanization levels and analyse the performance of an inertial motion capture system. Seven experienced female assemblers participated in this study. The measurements were performed in the workplace with a full-body inertial measurement system (Xsens MVN BIOMECH system). Maximum cross-correlation between angle-time courses was calculated to quantify the waveform similarities. In manual line, there are larger variations of joint angles than in the semi-automatic one. The analysis of cross correlation coefficients revealed that electromagnetic interferences are potential limitations to the use of these systems under field conditions.
- Kinematic and electromyographic features of upper-limb movement performed by healthy and post-stroke patientsPublication . Silva, Rosa Mariana; Fonseca, Pedro; Pinheiro, Ana Rita; Vila-Chã, Carolina; Silva, Cláudia; Correia, Miguel Velhote; Mouta, SandraIt is extremely difficult to simplify the relation between several body parts, which perform human motion, into one set of features. Mainly, the upper-limb is capable of a wider range of actions, going from fine manipulation to prehension and grasping. Aiming to describe its complexity, several studies have been conducted in order to better understand the upper-limb specificities. However, most of studies restrain the task to pointing, reaching, or grasping, which seems not enough to explain the wide range of tasks possible to be performed in a daily scenario.
- Neurobiomechanical characterization of feedforward phase of gait initiation in chronic stroke: A linear and non-linear approachPublication . Freitas, Marta; Fonseca, Pedro; Alves, Leonel; Pinho, Liliana; Silva, Sandra; Figueira, Vânia; Félix, José; Pinho, Francisco; Vilas-Boas, João Paulo; Silva, Augusta; Ferreira Silva, Maria AugustaPostural control arises from the complex interplay of stability, adaptability, and dynamic adjustments, which are disrupted post-stroke, emphasizing the importance of examining these mechanisms during functional tasks. This study aimed to analyze the complexity and variability of postural control in post-stroke individuals during the feedforward phase of gait initiation. A cross-sectional study analyzed 17 post-stroke individuals and 16 matched controls. Participants had a unilateral ischemic stroke in the chronic phase and could walk independently. Exclusions included cognitive impairments, recent surgery, and neurological/orthopedic conditions. Kinematic and kinetic data were collected during 10 self-initiated gait trials to analyze centre of pressure (CoP) dynamics and joint angles (−600 ms to +50 ms). A 12-camera motion capture system (Qualisys, Gothenburg, Sweden) recorded full-body kinematics using 72 reflective markers placed on anatomical landmarks of the lower limbs, pelvis, trunk, and upper limbs. Ground reaction forces were measured via force plates (Bertec, Columbus, OH, USA) to compute CoP variables. Linear (displacement, amplitude, and velocity) and non-linear (Lyapunov exponent—LyE and multiscale entropy—MSE) measures were applied to assess postural control complexity and variability. Mann–Whitney U tests were applied (p < 0.05). The stroke group showed greater CoP displacement (p < 0.05) and reduced velocity (p = 0.021). Non-linear analysis indicated lower LyE values and reduced complexity and adaptability in CoP position and amplitude across scales (p < 0.05). In the sagittal plane, the stroke group had higher displacement and amplitude in the head, trunk, pelvis, and limbs, with reduced LyE and MSE values (p < 0.05). Frontal plane findings showed increased displacement and amplitude in the head, trunk, and ankle, with reduced LyE and MSE (p < 0.05). In the transverse plane, exaggerated rotational patterns were observed with increased displacement and amplitude in the head, trunk, pelvis, and hip, alongside reduced LyE convergence and MSE complexity (p < 0.05). Stroke survivors exhibit increased linear variability, indicating instability, and reduced non-linear complexity, reflecting limited adaptability. These results highlight the need for rehabilitation strategies that address both stability and adaptability across time scales.
- On the adequacy of SDN and TSN for Industry 4.0Publication . Silva, Luis; Pedreiras, Paulo; Fonseca, Pedro; Almeida, LuisIndustry 4.0, Industrial Internet of Things, Cyber-Physical Production Systems and Smart Factories are closely related emerging concepts expected to drive significant improvements in industrial production systems, with gains in efficiency, cost and customer satisfaction. These concepts are intimately associated with highly distributed and cooperative architectures that rely, naturally, on the network infrastructure. However, traditional industrial communication technologies hardly provide the required level of integration, flexibility and performance. Seeking a solution to this mismatch, we assess two technologies that appeared recently in the industrial realm, namely IEEE 802.1 Time-Sensitive Networking (TSN) and Software-Defined Networking (SDN). TSN and SDN are fundamentally different, thus having distinct strengths and weaknesses. This paper reviews their fundamental operation principles, evaluating them qualitatively against the specific requirements posed by Industry 4.0.
- Postural adaptations of saxophone players during music performancePublication . Moura, Nádia; Fonseca, Pedro; Magalhães, Bárbara; Vidal, Marc; Serra, Sofia; Vilas-Boas, João PauloMusic performance is one of the most refined forms of skilled human behaviour, combining high-level motor and cognitive demands with expressive intentions. We examined how musical features and movement expression affect postural sway in expert saxophone players. Twenty participants (nine female) performed excerpts varying in tempo, rhythmical density, articulation, and technical demands, in standing position, under movement-restricted and expressive-movement conditions. Generalised linear mixed models were used to assess the effects of these factors on centre-of-mass measurements. Results showed that participants swayed faster and travelled longer distances in music with faster tempo and increased rhythmical density, but slower and with reduced mediolateral range when performing tonguing technique (staccato). When limited to technical motion, participants still showed increased mediolateral sway during staccato passages, suggesting compensatory postural adjustments. Sway frequency was unaffected by movement condition, possibly reflecting an unconscious, task-related motor response. Performances were longer when movement was constrained, highlighting the role of body motion in temporal regulation. Our findings help understand how saxophone players accommodate technical and expressive goals, offering new insights into motor control and multisensory integration during performance.