Loading...
8 results
Search Results
Now showing 1 - 8 of 8
- Postural Control and Muscle Activity during Dual-Task in Young AdultsPublication . Saraiva, Marina; Vilas-Boas, João Paulo; Castro, Maria AntónioIn 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 aimed to assess the postural sway and muscle activity during dual-tasking in young adults. Thirty-six healthy young adults (23.08 ± 3.92 years) participated in this study. They performed a single task (ST: keeping a quiet standing posture) and a dual task (DT: keeping the ST while simultaneously performing a cognitive task on their smartphone). Postural sway was assessed through the center of pressure (CoP) analysis using a force platform: total CoP displacement, CoP displacement in the anterior–posterior and medial–lateral directions, mean total velocity of the CoP, mean velocity of the CoP in the anterior–posterior and medial–lateral directions, and 95% confidence ellipse sway area. A surface electromyography system recorded the muscle activity of the lumbar spinal erector and five muscles of the lower limb (bilaterally). The results showed an increase in postural sway from the ST to the DT in all CoP variables (p < 0.05), and muscle activity in most muscles analyzed decreased from the ST to the DT (p < 0.05). In conclusion, our results reflect a decentralization of attention from motor performance once postural sway increased and muscle activity decreased in dual-task conditions.
- The Effect of Acute Physical Fatigue on Information Processing, Pain Threshold and Muscular PerformancePublication . Clemente-Suárez, Vicente Javier; Fuentes-García, Juan Pedro; Castro, Maria António; Tornero-Aguilera, Jose Francisco; Martínez-Guardado, IsmaelThis study explores the multifaceted effects of acute physical fatigue on information processing, pain threshold, and muscular performance. Enrolling 28 recreational athletes, we used a high-intensity interval training (HIIT) protocol to induce fatigue and conducted pre- and post-intervention assessments. Our findings revealed significant physiological and performance adaptations following the HIIT sessions. Key observations included increased heart rate and rate of perceived exertion and an enhancement in horizontal jump performance and isometric hand strength but no significant change in cognitive processing speed. Remarkably, participants demonstrated a notable increase in pain threshold and blood lactate levels post-exercise. These results challenge traditional views of fatigue, indicating not only a physiological but also a psychological resilience to high-intensity stress. This study provides new insights into the complex interplay between physical fatigue, cognitive function, and pain perception, highlighting the comprehensive effects of HIIT on both physiological and psychological dimensions of human performance.
- Visual Fixations in Basketball Shooting: Differences between Shooting ConditionsPublication . Amaro, Catarina M.; Castro, Maria António; Mendes, Rui; Gomes, Beatriz B.Basketball is a sport where shooting is one of the most important factors that determines the success or failure of the teams. Therefore, basketball players need to shoot the ball accurately. The present study aimed to evaluate whether different shooting conditions influence the visual behavior of athletes. For this, the Tobbi Pro Glasses 3 equipment was used to evaluate the time of the first fixation, the number of fixations, and the total time of fixations in the basket, during the shooting movement. Different distances to the basket, simulated gym audience noise, and shooting with opposition were considered. A group of 18 athletes with an average age of 22 ± 3.72 years and an average basketball practice experience of 12.5 ± 4.52 years performed 10 valid shots from different distances and different shooting angles, with different restrictions, namely, shooting with simulated opposition and gym audience noise. Statistically significant differences between shooting with opposition and baseline, in terms of the number of fixations and the total time of fixation, were found. Regarding shooting with gym audience noise, differences only occur for the total time of fixations in one position. Despite this, in all variables and positions, the values were lower in shooting with constraints compared to the baseline.
- Comparative Analysis of Pressure Platform and Insole Devices for Plantar Pressure AssessmentPublication . Amaro, Catarina M.; Paulino, Maria F.; Valvez, Sara; Roseiro, Luis; Castro, Maria António; Amaro, Ana M.Foot plantar pressure refers to the pressure or force that the foot generates in contact with the ground, varying across different regions of the foot. This parameter is essential in static and dynamic analyses to access accurate diagnoses, study the human body biomechanics, create functional footwear designs, aid in rehabilitation and physiotherapy, and prevent injuries in athletes during sports practice. This study presents an experimental comparison between two different plantar pressure measurement devices, Pedar® (sensorized insoles) and Physiosensing® (pressure platform). The devices were selected based on their capacity to measure contact area and peak pressure points. Results showed that Physiosensing® provided a more uniform measurement of the contact area, proving its efficiency for weight distribution and stability analysis applications, particularly in posture assessment and balance studies. The Pedar® system showed higher capacity in peak pressure point detection. Therefore, the insole system is more suitable for applications requiring precise high-pressure zone localization. Comparative analysis highlights the strengths and limitations of each device and offers insights regarding its optimal usage in clinical, sports, and research settings.
- Effect of Preventive Exercise Programs for Swimmer’s Shoulder Injury on Rotator Cuff Torque and Balance in Competitive Swimmers: A Randomized Controlled TrialPublication . Tavares, Nuno; Vilas-Boas, João Paulo; Castro, Maria AntónioBackground: Over the season, competitive swimmers experience a progressive imbalance in rotator cuff strength, predisposing them to a significant risk factor for a swimmer’s shoulder injury. Objectives: Verify the effectiveness of two 12-week preventive programs on the shoulder rotators’ peak torque and conventional/functional ratios. Design: A care provider- and participant-blinded, parallel, randomized controlled trial with three groups. Participants: Competitive swimmers aged 16 to 35 years with no prior clinical issues related to their shoulders. Interventions: Twice a week, over 12 weeks, the two experimental groups performed five exercises where the only difference was executing the program with weights or elastic bands, and the control group performed a sham intervention. Main outcome measures: The concentric and eccentric peak torque of the internal and external rotators of the dominant shoulder were assessed before and after the intervention using an isokinetic dynamometer Biodex System 3, at 60°/s, 120°/s, and 180°/s. Results: Among the experimental groups, only one test indicated a reduction (p ≤ 0.05) in rotator peak torque, while the control group showed a decrease (p ≤ 0.05) in five tests. Swimmers who completed the prevention programs demonstrated less imbalance in conventional/functional ratios than controls. Conclusions: Implementing a 12-week preventive program minimizes the progressive shoulder rotational imbalance over the season in competitive swimmers. Clinical Trial Registration number: NCT06552585.
- Influence of Jump and Ball Release Parameters on Shooting Accuracy in Basketball Under Varying ConstraintsPublication . Amaro, Catarina M.; Castro, Maria António; Mendes, Rui; Rice, Hannah; Gomes, Beatriz B.Background: This study investigates how both jump-related (jump height and flight time) and ball-related parameters (release height, release angle, and velocity) influence shooting accuracy in basketball under different contextual constraints. Methods: Eighteen senior players competing in the national championship (11 females and 7 males; 22.0 ± 3.7 years) performed 90 shots each across three positions (left 45°, middle 90°, right 45°) and three shooting conditions (baseline, simulated gym audience noise, and simulated opposition). Jump variables were derived from force platforms, while ball kinematics were extracted using a high-speed Qualisys camera system. Results: A three-way ANOVA revealed no systematic effects of position or opposition, and only a small effect of noise on flight time (p = 0.019), which was not confirmed by the Linear Mixed Model. Comparisons between successful and missed shots indicated significantly higher flight time, jump height, and release height, and a tendency for higher release velocity in successful attempts, with no differences in release angle. Spearman correlation showed weak associations between biomechanical variables and shooting accuracy (R2 = 0.005–0.012). Conclusions: These findings suggest that while adaptive biomechanical changes occur under contextual constraints, their isolated impact on shot success is limited. Successful performance appears to rely more strongly on release-related parameters, emphasizing the need for a holistic approach to training that integrates technical, perceptual, and psychological dimensions.
- Electromyographic activity of shoulder muscles on two preventive exercise programmes for swimmer’s shoulder: elastic band versus weightPublication . Tavares, Nuno; Castro, Maria António; Vilas-Boas, João Paulo; Fong, DanielStrength 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’s shoulder preventive programmes – one performed with elastic band and the other with weights. Twenty competitive swimmers performed two strength programmes consisting of five exercises each, while the analysis of EMG activity in MT, LT, IS, SA, and PM for each exercise was recorded. The superficial EMG was used to collect data at a sampling frequency of 1000 hz. The Paired Sample T-test or the Wilcoxon test was applied to compare EMG activity between programmes. The internal rotation at 90º (p < 0.001) and external rotation at 90º (p ≤ 0.01) exercises produced high myoelectric shoulder muscle activity with an elastic band. Conversely, scapular punches (p < 0.001) exercise has high shoulder EMG activity when performed with weights. Performing the same preventive exercise programme with two different instruments produces great variability in the myoelectric activity of the shoulder muscles.
- Golf-Putting Performance in Skilled Golfers at Different Distances to the HolePublication . Dias, Gonçalo; Couceiro, Micael; Mendes, Pedro; Gomes, Ricardo; Mendes, Rui; Vaz, Vasco; Martins, Fernando; Gama, José; Castro, Maria AntónioGolf putting occurs under highly variable conditions. Therefore, adapting to different putting distances is a challenge that the golfer faces and understanding the variables underlying performance in this task is important. The main objective of this study was to analyse the golf-putting performance in skilled golfers at different distances to the hole. Fourteen highly skilled golfers, adult male and right-handed (41.5 ± 13.2 years with an average handicap of 2.3 ± 1.7) performed the golf putting on a natural grass green, completing a total of 120 randomly ordered trials, 30 trials at each of the four different practice conditions (1, 2, 3, and 4 m away from the hole). A smart engineered putter (InPutter) was used as the data acquisition instrument to record several process variables at 100 Hz. Results indicated that golf-putting distances constrained movement organisation variables in specific ways. For example, as the distance to the hole changes, so do the informational constraints, shaping how a golfer needs to regulate performance. We concluded that the effects of different golf-putting distances required the implementation of functional solutions uniquely adjusted to each player. Furthermore, the perception that the player withdrew from the properties of the context (e.g., distance to the hole) was important to adapt the golf-putting process variables (e.g., amplitude and duration of the movement, among others). All these factors led to a decisive influence on how the golfer hit the ball and adjusted his performance. A major implication of developing a better understanding of the role of performance in golf putting is that coaches and players should allow functional movement behaviours to emerge during practice.