J. Paulo Vilas-Boas

University of Porto | UP · Biomechanics

Runners achieve forward locomotion through diverse techniques. However, understanding the behavior of the involved kinematical variables remains incomplete, particularly when running overground and along an intensity spectrum. We aimed to characterize the biomechanical and physiological adaptations while running at low, moderate, heavy and severe i...

This study proposes a method for analysing decomposed electromyographic signals to enhance the characterization of motor units (MU). It involves two steps: (i) clustering groups of motor units based on firing rate (FR), recruitment threshold, and MU action potential amplitude, and (ii) segmentation of data at the time of interest. Such method, capa...

Strength programmes have shown good results in preventing swimmer’s shoulder. However, there aren’t studies based on electromyographic (EMG) analysis in these programmes. This study aims to compare an EMG activity of the middle trapezius (MT), lower trapezius (LT), infraspinatus (IS), serratus anterior (SA), and pectoralis major (PM) in two swimmer...

This study aimed (a) to evaluate the spatiotemporal gait variables of total knee arthroplasty (TKA) before (pre-) and after the procedure (post-), and (b) to investigate the influence of the surgical side on these variables. Twenty-one volunteers (13 females and 8 males) participated, undergoing assessments pre-surgery and nine to 12 months post-su...

Cardoso, F, Costa, MJ, Colaço, P, Vilas-Boas, JP, Pinho, JC, Pyne, DB, and Fernandes, RJ. Ventilatory and perceived ergogenic effects of mandibular forward repositioning during running at maximal oxygen uptake intensity. J Strength Cond Res XX(X): 000-000, 2024-Wearing an intraoral dental splint may enhance ventilatory function and exercise perform...

The effects of occlusal splints on sport performance have already been studied, although their biomechanical impacts are often overlooked. We investigated the kinematical changes during running until exhaustion at severe intensity while wearing a mandibular advancement occlusal splint. Twelve trained runners completed (i) an incremental protocol on...

Purpose: This study aimed to translate and cross-culturally adapt the Mini-BESTest into European Portuguese and to evaluate its psychometric properties in individuals with sensorimotor impairments. Material and methods: A cross-sectional cross-cultural adaptation and validation study was conducted according to the COSMIN guidelines and the STROB...

We aimed to conduct a biophysical comparison of angular (Biorower) and linear (Concept2) rowing ergometers across a wide spectrum of exercise intensities. Sixteen (eleven male) skilled rowers, aged 29.8 ± 8.6 and 23.6 ± 1.5 years, with international competitive experience, performed 7 × 3 min bouts with 30 W increments and 60 s intervals, plus 1 mi...

We investigated the acute biophysical responses of changing the mandibular position during a rowing incremental protocol. A World-class 37-year-old male rower performed two 7 × 3 min ergometer rowing trials, once with no intraoral splint (control) and the other with a mandibular forward repositioning splint (splint condition). Ventilatory, kinemati...

A cross-sectional study was conducted to biomechanically characterize Isabel's workout (30 snatch repetitions with 61 kg fixed weight), focusing on eventual changes in knee, hip and shoulder angles. A three-dimensional markerless motion capture system was used to collect data from 11 highly trained male crossfitters along the Isabel workout perform...

The study of gestures in music performance provides valuable insights for instrumental learning. However, gestural vocabularies vary depending on the instrument being played, according to its postural and technical specificities. The goals of this study were twofold: first, to create a gesture categorization system for saxophone players, and second...

Despite its limitations, 2D kinematical analysis remains a simple and valid alternative for swimming analysis. This analysis is limited by the length of the field of view, and the reconstruction errors are proportional to the calibrated area. A possible solution for these problems is the usage of moving cameras that allow for tracking an object acr...

The speedometer is widely used to evaluate swimming velocity but has some constraints. With the constant development of inertial units (IMUs), it is expected that they will become a good alternative to the speedometer. This study aimed to compare the data retrieved by an IMU and a speedometer when breaststroke is performed at maximum speed. Sixteen...

Chronic spinal pain (CSP) is a prevalent condition, and prolonged sitting at work can contribute to it. Ergonomic factors like this can cause changes in motor variability. Variability analysis is a useful method to measure changes in motor performance over time. When performing the same task multiple times, different performance patterns can be obs...

The electrical stimulation of pedicle screws is a technique used to ensure its correct placement within the vertebrae pedicle. Several authors have studied these screws’ electrical properties with the objective of understanding if they are a potential source of false negatives. As titanium screws are anodized with different thicknesses of a high el...

Purpose: To compare the kinematic profile of 2 underwater pullout breaststroke techniques. Methods: Sixteen swimmers (9 men, 20.67 [2.71] y old; 7 women, 18.86 [0.83] y old) performed 3 × 25-m breaststroke using 2 pullout breaststroke techniques: Fly-Kick first and Combined. A speedometer was used to assess the peak and the mean velocity during...

Explainable artificial intelligence (XAI) models with Shapley additive explanation (SHAP) values allows multidimensional representation of movement performance interpreted on both global and local levels in terms understandable to human intuition. We aimed to evaluate the swimming performance (World Aquatics points) predictability of a combination...

This study aimed to systematically review and summarise the evidence about the effect of muscle fatigue on the knee proprioception of trained and non-trained individuals. A search in PubMed, Scopus, Web of Science and EBSCO databases and Google Scholar was conducted using the expression: “fatigue” AND (“proprioception” OR “position sense” OR “repos...

Lower limb exoskeletons have the potential to mitigate work-related musculoskeletal disorders; however, they often lack user-oriented control strategies. Human-in-the-loop (HITL) controls adapt an exoskeleton’s assistance in real time, to optimize the user–exoskeleton interaction. This study presents a HITL control for a knee exoskeleton using a CM...

In this study, we quantified relevant biophysical characteristics of two elite rowers across a wide range of intensities. Two <40-year-old male and female Olympic and World Championship finalists performed a 7 × 3 min protocol plus 1 min maximal effort on a rowing ergometer. The intensity increase resulted in maximum values of 79.4 ± 2.4 and 69.7 ±...

In everyday life, we recurrently perform two tasks simultaneously, which is called dual-tasking. A common dual task is smartphone use while standing or walking. According to previous studies, this task can compromise postural stability. However, few studies have analyzed lower limb muscle activity during dual-tasking using smartphones. This study a...

Purpose: Neural and peripheral effects of induced muscle pain on explosive force production were investigated. Methods: Nine participants performed two maximal, six explosive, and six electrical stimulations induced (twitches and octets) isometric knee extensions before and after (15 min of rest) receiving an intramuscular injection of hypertonic s...

Despite the existence of several studies about the scapula’s position and motion, in shoulder pain conditions, there are still conflicting findings regarding scapular adaptations and reduced research about the scapula’s role during functional tasks. The present study aimed to compare scapular-related kinematic and electromyographic outcomes during...

Jumping performance is considered an overall indicator of gymnastics ability. Acrobatic Gymnastics involves base and top gymnasts, considering the type of training that is performed and the distinct anthropometric traits of each gymnast. This work aims to investigate a hierarchy of variables that influence the force–velocity (F-V) profile of top an...

Non-linear and dynamic systems analysis of human movement has recently become increasingly widespread with the intention of better reflecting how complexity affects the adaptability of motor systems, especially after a stroke. The main objective of this scoping review was to summarize the non-linear measures used in the analysis of kinetic, kinemat...

Lower limb exoskeletons have the potential to reduce the prevalence of work-related musculoskeletal disorders; however, they often lack user-oriented control strategies. Human-in-the-loop (HITL) controls can adapt an exoskeleton’s assistance in real-time, to optimize the user-exoskeleton interaction. This study presents a HITL control for a knee ex...

Background: Strength programs with few exercises, performed out of the water and in an open kinetic chain have shown good results in minimizing some musculoskeletal risk factors related to swimmer’s shoulder. However, there is no information about the epidemiology of this injury after its implementation. Objective: To evaluate the effect of two 12...

Muscle stiffness had a crucial role in joint stability, particularly, at the shoulder complex. Although changes in upper trapezius muscle stiffness have been described for shoulder pain, contradictory findings have been obtained. Also, existing data regarding scapular muscles are, majorly, about trapezius. Myotonometry is a method used to assess st...

Strength programs, with few exercises, performed out of the water and in an open kinetic chain seem to have better results in the swimmer’s shoulder prevention. On the other hand, the less activity of serratus anterior (SA) during swimming is an important musculoskeletal risk factor for swimmer’s shoulder. This study aimed to analyze the difference...

Rowing performance depends on the type and size of the rowing blade used. The blade ability to transfer the force between the rower and the water is decisive to increase the boat velocity during a rowing race. The rate of force development represents the muscle capacity to, powerfully, generate force, which is a relevant index neuromuscular functio...

This study was based on the dual-task paradigm to investigate the effects of two different cognitive tasks on the center of pressure (CoP) displacement and prefrontal cortex activity while simultaneously performing a static postural task in healthy young adults. Thirty-six young adults were recruited and divided into two groups to perform a cogniti...

Investigations of upper limb muscle activation during reach tasks available in the literature are not for rotator cuff injury. Yet, the small body of literature on upper limb muscle activation during these tasks does not include any systematic study on the influence of each shoulder test. Tests such as Belly press, Drop arm, Empty can, Full Can and...

Scapular punches are one of the most common exercises included in swimmer’s shoulder preventive programs. In previous electromyography (EMG) analyzes carried out in non-swimmers, it was verified that in this exercise there is a higher mean EMG activity in the serratus anterior (SA) compared to the remaining shoulder muscles. This study intends to c...

Previous studies reported that, in dual-task conditions, using a smartphone, the gait performance declines. Most of these studies assessed spatiotemporal gait parameters; however, few evaluated muscle activity. This study aimed to assess the effects of typing on a smartphone keyboard while simultaneously performing gait (motor dual-task: mot-DT) co...

Musicians’ body behaviour has a preponderant role in audience perception. We investigated how performers’ motion is perceived depending on the musical style and musical expertise. To further explore the effect of visual input, stimuli were presented in audio-only, audio–visual and visual-only conditions. We used motion and audio recordings of exper...

Background Therapeutic exercise has been considered a useful tool to rehabilitate shoulder pain, namely through its influence on scapular dynamics. Accordingly, the effectiveness of scapular therapeutic exercise needs to be explored. The present study aims to evaluate the effectiveness of scapular therapeutic exercises in shoulder pain and to ident...

Rowing performance depends on the design and building materials used for competition. Recently, attempting to improve rowing performance, the Randall foil has been attached to the top edge of a rowing Big blade, making it spoon shaped. The current study aimed to analyse the differences between Big blades with and without Randall foils in force-rela...

Introdução: A fisioterapia aquática (FA) parece ser uma forma eficaz de desenvolver força, equilíbrio, mobilidade, assim como promover o alívio da dor em indivíduos com diversas condições de saúde (Soto-Varela A, et al., 2016). A FA baseia-se na realização de movimentos e tarefas em meio aquático, nem sempre passíveis de realização em meio terrestr...

Lower limb exoskeletons and orthoses have been increasingly used to assist the user during gait rehabilitation through torque transmission and motor stability. However, the physical human-robot interface (HRi) has not been properly addressed. Current orthoses lead to spurious forces at the HRi that cause adverse effects and high abandonment rates....

INTRODUCTION: The complexity of open water swimming performance, particularly from an anthropometric, physical performance, propulsive swimming force and bioenergetics point of view, can be fully appreciated when considering and determining the correlation between these features. In the current study, we examined the relationships between the above...

INTRODUCTION The performance of open-water swimmers (OWS) is influenced by a complex process encompassing multiple factorial phenomenon, with recent research stating that anthropometric, bioenergetics, biomechanics, and propelling efficiency all play an important role in OWS performance (Vanheest et al., 2004; Baldassarre et al., 2017). Beside, evi...

Our aim was to investigate if using a warm-up routine that included parachute-resisted sprints with large hand-paddles improves 50 m freestyle performance in trained collegiate swimmers. Twelve swimmers (23.9 ± 2.2 years, 179 ± 7 cm, 77.1 ± 10.6 kg) participated in the study and completed two 50-m freestyle races, each preceded by a different warm-...

Robotic assistive devices have emerged as a potential complement for repetitive and user-centered gait rehabilitation. In this field, the development of electromyography (EMG)-based torque controls has played a crucial role in improving the user experience with robotic assistive devices. However, most existing approaches for EMG-based joint torque...

Assessing scapular position and motion during functional arm movement patterns may add relevant information to the evaluation of the clinical status and athletic performance of overhead sports athletes’ shoulders. This study aimed to examine the three-dimensional scapular kinematics of elite volleyball players with (n = 11) and without scapular dys...

TO OUR READERS: An error appeared in the following article: Zacca R, de Souza Castro FA, Mottini Monteiro AS, Pyne DB, Vilas-Boas JP, Pinto Fernandes RJ. Swimming with the COSMED AquaTrainer and K5 wearable metabolic system in breath-by-breath mode: accuracy, precision, and repeatability. Int J Sports Physiol Perform. 2023;18(10):1152–1160. https:/...

The analysis of the external forces of swimming starts has revealed how swimmers propel themselves out of the block, but data should be properly interpreted to fully understand force-generation mechanisms. This study aimed to assess horizontal and vertical forces in the backstroke start based on swimmers’ structural and propulsive actions. Firstly,...

This study aimed to investigate and compare the performance, perceptual and reaction skills and neuromuscular control indicators of sub-elite (SEG) and elite (EG) karate athletes during the execution of a Gyaku Tsuki punch. The study included 14 male athletes, equally divided into two subgroups according to their current competitive level. We analy...

Citation: Silva, G.; Goethel, M.; Machado, L.; Sousa, F.; Costa, M.J.; Magalhães, P.; Silva, C.; Midão, M.; Leite, A.; Couto, S.; et al. Acute Recovery after a Fatigue Protocol Using a Recovery Sports Legging: An Experimental Study. Sensors 2023, 23, 7634. https://doi.org/10.3390/ s23177634 Academic Editors: Abstract: Enhancing recovery is a fundam...

It has been suggested that sex distinctions in physiology may affect the swimming performance of each sex differently. Yet, sex-based performance dependency has not been taken into consideration by most of the researchers evaluating swimming start. Therefore, the purpose of this research was to determine the effect of sex heterogeneity on the spati...

The swimming pool experience is a fertile ground to challenge current knowledge and catalyse research into factors governing swimming performance that may inform individualised swimming training. This paper discusses the perspective and contributions of a swimming scientist, analyst, and coach on the main current trends of scientific and technologi...

Swimming performance is likely influenced by strength, but differences between butterfly, backstroke, breaststroke and front crawl, as well as between novice and expert swimmers, are unclear. We have examined the associations between sprint performances, upper and lower limb strength, and anthropometric characteristics in 14 (six males and eight fe...

Low back pain is one of the main causes of motor disabilities and psychological stress, with the painful process encompassing sensory and affective components. Noxious stimuli originate on the periphery; however, the stimuli are recombined in the brain and therefore processed differently due to the emotional environment. To better understand this p...

Purpose: To evaluate the balance in patients with total knee arthroplasty (TKA) and knee osteoarthrosis (KOA), measured by postural stability computerized evaluation (PSCE), and to evaluate the effect of post-TKA patients' characteristics in their performance on PSCE. Materials and methods: An observational cross-sectional study was conducted in...

Music performance requires high levels of motor control. Professional musicians use body movements not only to accomplish and help technical efficiency, but to shape expressive interpretation. Here, we recorded motion and audio data of twenty participants performing four musical fragments varying in the degree of technical difficulty to analyze how...

Oral health involves physiological functions related to mouth, teeth and orofacial structures, but also includes psychological and social dimensions. In this sense, oral health is an integrated part of human general health and well-being. Our aim was to access and evaluate the general oral health status of a high- and elite-level sample of Portugue...

The present study aimed to analyse the associations between force production and 100 m front crawl inter-lap pacing and kinematics. Eleven elite male swimmers performed a 100 m front crawl maximal effort to collect 50 m lap time (T50, s) and velocity (v, m·s-1) for pacing, stroke rate (SR), stroke length (SL) and stroke index (SI) as kinematic vari...

Purpose: To compare ventilatory and cardiorespiratory responses between the COSMED AquaTrainer coupled with the K4b2 and K5 wearable metabolic systems in breath-by-breath mode over a wide range of swimming speeds. Methods: Seventeen well-trained master swimmers performed 2 front-crawl 7 × 200-m incremental intermittent protocols (increments of 0...

We characterized the physical and physiological profiles of high-level female Portuguese handball players and examined the relationships between their anthropometric characteristics, general motor performance and cardiopulmonary fitness. Twenty-four high-level female handball players with an average age of 23.6 ± 5.5 years, height of 173.6 ± 5.1 cm...

Previous studies reported changes in spatiotemporal gait parameters during dual-task performance while walking using a smartphone compared to walking without a smartphone. However, studies that assess muscle activity while walking and simultaneously performing smartphone tasks are scarce. So, this study aimed to assess the effects of motor and cogn...

Epidemiological reports on physical inactivity (Guthold et al., 2020) and drowning accidents (WHO, 2014) show that the 6-12-year-old population are not protected to take advantage of the aquatic environment as an opportunity to practice in the water environment while they are lifelong activities (Chase et al., 2008). To carry this dual aquatic safe...

Objectives: Swimming intra-cycle velocity fluctuation has often been assessed using the coefficient of variation, which requires a mathematical assumption of a positive linear relationship between the velocity mean and standard deviation. As this assumption has never been tested, the current study aimed to investigate the within-participant relati...

In chronic shoulder pain, adaptations in the nervous system such as in motoneuron excitability, could contribute to impairments in scapular muscles, perpetuation and recurrence of pain and reduced improvements during rehabilitation. The present cross-sectional study aims to compare trapezius neural excitability between symptomatic and asymptomatic...

Free-swimming performance depends strongly on the ability to develop propulsive force and minimise resistive drag. Therefore, estimating resistive drag (passive or active) may be important to understand how free-swimming performance can be improved. The purpose of this narrative overview was to describe and discuss experimental methods of measuring...

Postural control depends on attentional resources besides automatic processes. The dual-task paradigm is a possible approach to analyzing the interference and performance between motor and/or cognitive tasks. Various studies showed that, when individuals simultaneously perform two tasks, the postural stability can decline during a dual-task compare...

Background Physical exercise is a source of stress to the human body, triggering different ventilatory responses through different regulatory mechanisms and the aquatic environment imposes several restrictions to the swimmer, particularly regarding the restricted ventilation. Thus, we aimed to assess the acute ventilatory responses and to character...

In investigating the influence of body movement in multimodal perception, human motion displays are frequently used as a means of visual standardization and control of external confounders. However, no principle is established regarding the selection of an adequate display for specific study purposes. The aim of this study was to evaluate the effec...

Background Physical exercise is essential to improve quality of life, with muscle recovery after exercise being crucial since it reduces the delayed sensation of muscle discomfort and fatigue. The present study aims to identify the methods used by physiotherapists to recover sports practitioners after physical exercise and presents a non-experiment...

Intracycle velocity variation is a swimming relevant research topic, focusing on understanding the interaction between hydrodynamic propulsive and drag forces. We have performed a systematic scoping review to map the main concepts, sources and types of evidence accomplished. Searches were conducted in the PubMed, Scopus and Web of Science databases...