Cristiano De Marchis

Università degli Studi di Messina | UNIME · Dipartimento di Ingegneria

This study examined the efficacy of an optimized DeepLabCut (DLC) model in motion capture, with a particular focus on the sit-to-stand (STS) movement, which is crucial for assessing the functional capacity in elderly and postoperative patients. This research uniquely compared the performance of this optimized DLC model, which was trained using ’fil...

This article presents a systematic review aimed at mapping the literature published in the last decade on the use of machine learning (ML) for clinical decision-making through wearable inertial sensors. The review aims to analyze the trends, perspectives, strengths, and limitations of current literature in integrating ML and inertial measurements f...

Introduction: Virtual reality (VR) is an advanced technology that creates simulated environments and conditions. By offering the possibility of combining motor, cognitive, and well-being in conjunction with the potential to manipulate multi-sensorial features in a safe environment, VR has emerged as a promising powerful rehabilitation tool. Among...

The aim of this study is to develop a modeling procedure based on using artificial neural networks (ANNs) for predicting the frequency-dependent behavior of a microwave split-ring resonator (SRR) used for the dielectric characterization of liquid samples. The SRR device was designed and fabricated using the inkjet printing technology and, then, cal...

Driven by the fast-expanding market, wearable technologies have rapidly evolved [...]

Objective: This study presents the walking abilities of participants fitted with transfemoral bone-anchored prostheses using a total of 14 gait parameters. Design: Two-centre retrospective cross-sectional comparative study. Setting: Research facilities equipped with tridimensional motion capture systems. Participants: Two control arms includ...

The characterization of both limbs’ behaviour in prosthetic gait is of key importance for improving the prosthetic components and increasing the biomechanical capability of trans-femoral amputees. When characterizing human gait, modular motor control theories have been proven to be powerful in providing a compact description of the gait patterns. I...

italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Goal: The goal of this manuscript is to investigate the optimal methods for extracting muscle synergies from a sit-to-stand test; in particular, the performance in identifying the modular structures from signals of different length is characterized. M...

Thanks to the development of additive manufacturing techniques, prosthetic surgery has reached increasingly advanced levels, revolutionizing the clinical course of patients with joint arthritis. 3D printing has made it possible to obtain customized prostheses based on patient needs, using high-performance materials. However, wear caused by regular...

Sit-to-stand can be defined as a set of movements that allow humans to rise from a sitting position to a bipedal standing pose. These movements, often categorized as four distinct kinematic phases, must be coordinated for assuring personal autonomy and can be compromised by ageing or physical impairments. To solve this, rehabilitation techniques an...

Muscle synergy analysis has been widely adopted in the literature for the analysis of upper limb surface electromyographic signals during reaching tasks and for the prediction of movement direction for myoelectric control purposes. However, previous studies have characterized movements in constrained or semi-constrained scenarios, in which the subj...

The estimation of the sEMG–force relationship is an open problem in the scientific literature; current methods show different limitations and can achieve good performance only on limited scenarios, failing to identify a general solution to the optimization of this kind of analysis. In this work, this relationship has been estimated on two different...

Prosthetic gait implies the use of compensatory motor strategies, including alterations in gait biomechanics and adaptations in the neural control mechanisms adopted by the central nervous system. Despite the constant technological advancements in prostheses design that led to a reduction in compensatory movements and an increased acceptance by the...

The development of technology that can assist people during movements such as sit to stand can benefit from simulations that can estimate the effect of different assistance patterns. These simulations need to be based on frameworks that can replicate the neuromechanical features of non-pathological sit-to-stand movements. In this study, we present...

Muscle synergy analysis is a useful tool for the evaluation of the motor control strategies and for the quantification of motor performance. Among the parameters that can be extracted, most of the information is included in the rank of the modular control model (i.e. the number of muscle synergies that can be used to describe the overall muscle coo...

Amputation of a lower limb implies a re-organization in the strategies used to reach a stable walking pattern. The planar covariation law of elevation angles is a well-defined low-dimensional description of the kinematics of movement; according to this law, thigh, shank and foot elevation angle co-vary on a plane, defining a typical gait loop. Howe...

The hypothesis of modular control, which stands on the existence of muscle synergies as building blocks of muscle coordination, has been investigated in a great variety of motor tasks and species. Yet, its role during learning processes is still largely unexplored. To what extent is such modular control flexible, in terms of spatial structure and t...

Background Subjects with transfemoral amputation (TFA) show an asymmetric gait pattern associated with a decreased ability to recover mechanical energy and an increased metabolic cost of walking. Research question This study aimed to identify the spatio-temporal and kinematic gait variables correlated with mechanical energy values in subjects with...

The aim of this study was to analyze the effect of the level of amputation and various prosthetic devices on the muscle activation of the sound limb in people with unilateral transfemoral and transtibial amputation. We calculated the global coactivation of 12 muscles using the time-varying multimuscle coactivation function method in 37 subjects wit...

Work-related low-back disorders (WLBDs) can be caused by manual lifting tasks. Wearable devices used to monitor these tasks can be one possible way to assess the main risk factors for WLBDs. This study aims at analyzing the sensitivity of kinematic data to the risk level changes, and to define an instrument-based tool for risk classification by usi...

Background: Muscle synergies analysis can provide a deep understanding of motor impairment after stroke and of changes after rehabilitation. In this study, the neuro-mechanical analysis of leg cycling was used to longitudinally investigate the motor recovery process coupled with cycling training augmented by Functional Electrical Stimulation (FES)...

Background: The above-knee amputation of a lower limb is a severe impairment that affects significantly the ability to walk; considering this, a complex adaptation strategy at the neuromuscular level is needed in order to be able to move safely with a prosthetic knee. In literature, it has been demonstrated that muscle activity during walking can...

The present study’s aim was to identify the kinematic and kinetic gait patterns and to measure the energy consumption in people with amputation according to both the anatomical level of amputation and the type of prosthetic components in comparison with a control group matched for the gait speed. Fifteen subjects with unilateral transtibial amputat...

12 young adults were requested to walk along a circuitous path including turns, slaloms, stair ascending and descending, while wearing an inertial sensor placed on the back at the lumbar level. The path was completed under two conditions: with no additive cognitive task, and while performing a cognitive task and texting on a smartphone. Different t...

Smartphone use is one of the most common activities performed while walking: recent studies showed how this behaviour affected spatio-temporal, smoothness, symmetry and regularity gait parameters. In this study, we investigated a subset of additional gait parameters, potentially indicative of gait instability, to check whether concurrent smartphone...

The accurate and reliable extraction of specific gait events from a single inertial sensor at waist level has been shown to be challenging. Among several techniques, a wavelet-based method for initial contact (IC) and final contact (FC) estimation was shown to be the most accurate in healthy subjects. In this study, we evaluated the sensitivity of...

Cycling induced by Functional electrical stimulation (FES) was proposed as a method to improve motor recovery after stroke. This study aimed at assessing the effects of this training on motor patterns of muscle co-activations, referred as muscle synergies. Seven post-acute patients underwent 15 sessions of FES-cycling training. Outcome measures wer...

The purpose of this work was to analyze the variation of some gait descriptors when additional tasks (motor and cognitive with low and high load levels) were performed during walking, in 10 young healthy subjects. From one inertial sensor located at lumbar level, spatio-temporal parameters and measures of acceleration and jerk root mean square were...

Humans can adapt their motor commands in response to alterations in the movement environment. This is achieved by tuning different motor primitives, generating adaptations that can be generalized also to relevant untrained scenarios. A theory of motor primitives has shown that natural movements can be described as combinations of muscle synergies....

Humans have a remarkable ability to modify their motor commands in response to alterations in the environment. These motor commands are thought to be adaptively tuned by combining different motor primitives, a characteristic that allows for adaptations to be generalized also to relevant untrained scenarios. A complementary theory of motor primitive...

The surface electromyographic (sEMG) data of 12 trunk muscles of 10 workers during the execution of lifting tasks using three lifting indices (LI) were recorded. The aims of this work were to: 1) identify the most sensitive trunk muscles with respect to changes in lifting conditions based on the selected sEMG features and 2) test whether machine-le...

Surface ElectroMyography (sEMG) is widely used as a non-invasive tool for the assessment of motor control strategies. However, the standardization of the methods used for the estimation of sEMG amplitude is a problem yet to be solved; in most cases, sEMG amplitude is estimated through the extraction of the envelope of the signal via different low-p...

The term “task failure” describes the point when a person is not able to maintain the level of force required by a task. As task failure approaches, the corticospinal command to the muscles increases to maintain the required level of force in the face of a decreased mechanical efficacy. Nevertheless, most motor tasks require the synergistic recruit...

The main goal of this work was to assess the performance of different initializations of matrix factorization algorithms for an accurate identification of muscle synergies. Currently, nonnegative matrix factorization (NNMF) is the most commonly used method to identify muscle synergies. However, it has been shown that NNMF performance might be affec...

[This corrects the article DOI: 10.1371/journal.pone.0185825.].

Segmentation is an essential and crucial step in interpreting medical images for possible treatment. Medical image segmentation is very chaotic procedure as medical image may have different structures of same organ in different image modalities and may also have different features in different image slices of same modality. In this work, we present...

The widespread and pervasive use of smartphones for sending messages, calling, and entertainment purposes, mainly among young adults, is often accompanied by the concurrent execution of other tasks. Recent studies have analyzed how texting, reading or calling while walking–in some specific conditions–might significantly influence gait parameters. T...

Cycling training is used in neurorehabilitation to promote motor recovery in people affected by neurological impairments, such as spinal cord injury and stroke. Visual biofeedback, normally based on cadence or load, can be used in combination with cycling exercise to inform the patient about his/her physical performance. We wanted to test the effec...

Haralick’s features have been extensively used in texture analysis of medical images. In this contribution, we have applied Haralick’s to T2-weighted colorectal MRI for a possible cancer evaluation. In particular, the T2-MRI images of 8 patients with colorectal pathology were identified as early stage malignant and later stage malignant using the w...

Wearable devices are able to capture movement-related characteristics from inertial sensors integrated in them. Many spatio-temporal parameters of gait can be estimated by the acquisition of inertial data, but their accuracy depends on the placement of the devices on the body, as well as on the numerical values chosen for the estimation techniques....

Cycling training is strongly applied in post-stroke rehabilitation, but how its modular control is altered soon after stroke has been not analyzed yet. EMG signals from 9 leg muscles and pedal forces were measured bilaterally during recumbent pedaling in 16 post-acute stroke patients and 12 age-matched healthy controls. Patients were asked to walk...

Background Functional Electrical Stimulation (FES) is increasingly applied in neurorehabilitation. Particularly, the use of electrode arrays may allow for selective muscle recruitment. However, detecting the best electrode configuration constitutes still a challenge. Methods A multi-contact set-up with thirty electrodes was applied for combined FE...

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method that can be used in cognitive and clinical protocols in order to modulate neural activity. Although some macro effects are known, the underlying mechanisms are still not clear. tDCS in combination with electroencephalography (EEG) could help to understand thes...

Motor impairment after stroke has been hypothesized to be related, among others, to impairments in the modular control of movement. In this study we analyzed muscle coordination and pedal forces during a recumbent pedaling exercise from a sample of post-acute stroke patients (n=5) and a population of age-matched healthy individuals (n=4). Healthy s...

The execution of rhythmical motor tasks requires the control of multiple skeletal muscles by the Central Nervous System (CNS), and the neural mechanisms according to which the CNS manages their coordination are not completely clear yet. In this study, we analyze the distribution of the neural drive shared across muscles that work synergistically du...

Several studies have showed the positive effect that real-time presentation of centre of pressure (COP) has on stability. Typically the COP position is depicted in real-time on the screen and it is required that the participant uses this additional information to regulate his/her postural sway. In order to perform the motor task, it requires an att...

The multi-action plan (MAP) model reflects the notion that different psychophysiological states underlie distinct performance-related experiences. Previous empirical evidence suggested that attentional focus, affective states, and psycho-physiological patterns differ among optimal-automatic (type 1), optimal-controlled (type 2), suboptimal-controll...

The aim of this study is to introduce a new parameter for fatigue investigations, which relies on a bi-dimensional analysis of sEMG signals in temporal and spectral domains. The new parameter, the Fatigue Vector, is defined in a space domain whose coordinates are the amplitude and the mean spectral frequency of the sEMG signal. The performance of t...

Dynamic posturography has been proposed as a valuable tool for the assessment of balance impairments. This paper compares the postural responses of healthy and hemiplegic children while keeping balance on a 3D robotic perturbed platform, addressed as Rotobit3D. Dynamic postural responses are assessed by using surface EMG, recorded from four muscles...

Recent studies have reported evidence that the motor system may rely on a modular organization, even if this behavior has yet to be confirmed during motor adaptation. The aim of the present study is to investigate the modular motor control mechanisms underlying the execution of pedaling by untrained subjects in different biomechanical conditions. W...

In this study we investigate the muscle coordination underlying the execution of a pedaling exercise across different biomechanical demands, by using the muscle synergies paradigm. 9 non professional subjects performed a cycling exercise using their preferred pedaling strategy (Preferred Strategy, PS) and then, through the use of a feedback based o...

This study aims at evaluating the neuromuscular adaptations occurring during submaximal prolonged cycling tasks. In particular, we want to assess changes in surface electromyographic (sEMG) signal recorded during a pedaling task, performed by six subjects on a cycle-simulator at a constant power output, until voluntary exhaustion. Task failure was...

In this study, the problem of detecting and tracking tremor from the surface myoelectric signal is addressed. A method based on the calculation of a Second Order Moment Function (SOMF) inside a window W sliding over the sEMG signal is here presented. An analytical formulation of the detector allows the extraction of the optimal parameters character...

The aim of this work is to propose an improvement to the double threshold algorithm for muscular activation intervals estimation developed by Bonato and his co-workers. The proposed method has been designed in order to be adaptive also when the Signal to Noise ratio (SNR) of the sEMG signal changes during the trial, by re-evaluating the parameters...

Two different detection techniques for EMG burst detection are here used to reveal tremor in both a set of synthetic data and in a small sample of experimental trials. An optimization procedure that employs the minimization of a cost function to provide the parameter set characterizing the two techniques is here presented and its performance assess...