Journal of Functional Morphology and Kinesiology最新文献

Background: Nordic walking (NW) is a physical sports activity that has been sufficiently studied from the point of view of health, but physiological and performance analyses have not been so much. Objectives: With this study, we intend to analyse the physical work areas, according to ventilatory thresholds, that occur during a NW competition. Methods: Four participants of different characteristics anthropometrics (weight 57.6-85.6 kg; height 165.8-178 cm; and fat percentage 14.5-21.5%) gender (3 males and 1 female) and age (15-57 years) who participated in the NW regional championship have been chosen, and their electrocardiographic tracing was recorded using a NUUBO^® device throughout the race, obtaining average and maximum heart rates (HR) in eight sections of the circuit. Previously, in the laboratory, a maximal stress test was performed to determine the maximum oxygen consumption (VO₂max), the first (VT1) and second (VT2) ventilatory threshold (VT). With these data, four work areas were obtained. Results: Most of the sections of the circuit were conducted with average HRs in zone 2a (above average between VT1 and VT2 but below VT2) and peak HRs in zone 3 (between VT2 and VO₂max). Conclusions: We conclude that, with the data collected on HR, VO₂max, and VT, the training zones obtained can be related to the heart rates in the different sections of the circuit. This can be used to improve the sports performance of the walkers.

Background: The COVID-19 pandemic has led to reduced physical activity and increased sedentary behaviors, negatively impacting mental and physical health. Engaging in physical activity at home during quarantine became essential to counteracting these adverse effects. To develop appropriate physical activity programs, assessing individuals' fitness levels and the impact of inactivity is crucial. This study aims to compare motor abilities-including flexibility, balance, reaction time, cardiovascular endurance, and lower and upper limb strength-assessed both in-person and remotely, to determine the accuracy and repeatability of self-administered tests. Methods: A total of 35 young subjects (age 24.2 ± 1.97 years, BMI 22.4 ± 2.61 kg/m²) participated in this study. Each participant underwent a battery of motor ability tests designed to assess various fitness components. The tests were administered twice for each subject: once in a laboratory setting and once remotely at home. The sequence of tests was randomly assigned to ensure unbiased results. Both the in-person and remote assessments were used to evaluate the accuracy and reliability of self-administered tests. Results: The comparison of test results between the laboratory and remote settings revealed percentage differences ranging from 5% to 10%. This variation is considered an acceptable margin of error, suggesting that the tests conducted remotely were relatively accurate when compared to those performed in a controlled laboratory environment. Conclusions: The findings indicate that remote fitness testing is a promising method for evaluating motor abilities. With an acceptable margin of error, remote assessments can be effectively used to personalize training programs based on individuals' physiological characteristics. This approach may be particularly beneficial during times of limited access to fitness facilities, such as during quarantine, or for individuals seeking more flexible fitness evaluation methods.

Background/Objectives: Previous evidence has shown that American football headgear (e.g., facemasks, visors/eye shields) differentially impairs reaction time (RT) to visual stimuli, most notably in peripheral fields of view. However, this has only been established with stationary RT testing, which may not translate to gameplay situations that require gross motor skills. Therefore, the purpose of this study was to build upon previous findings to elucidate the effects of various American football headgear on gross motor visuomotor drill performance. Methods: Division 1 NCAA football players (n = 16) with normal/corrected-to-normal vision participated and completed two experiments (EXP), each with differing conditions: EXP1- Varying facemask reinforcement and EXP2- Varying visor/eye shield light transmittance. In EXP1, participants completed an agility test for the following conditions: baseline/no helmet (BL), helmet + light (HL), helmet + medium (HM), and helmet + heavy (HH) face mask reinforcement. In EXP2, participants completed an agility test for the following conditions: baseline/no helmet (BL), helmet + clear visor (HCV), helmet + smoke-tinted visor (HSV), and helmet + mirrored visor (HMV). For each condition in EXP1 and EXP2, participants completed a reactive agility task using a FITLIGHT trainer system where five poles were equipped with a total of ten LED sensors and were placed in a semi-circle 1 m around a center point. Participants were asked to step and reach with their hands to hit each ten lights individually as fast as possible upon illumination. Each reactive agility test was repeated for a total of three attempts. Results: Average reaction time was analyzed and compared between conditions and according to visual fields of interest (e.g., central vs. peripheral). Results from EXP1 showed that compared to BL, reactive agility was worsened by HL (p = 0.030), HM (p = 0.034), and HH (p = 0.003) conditions. No differences between facemask conditions existed for overall performance (p > 0.05). For EXP2, HCV (p < 0.001), HSV (p < 0.001), and HMV (p < 0.001) conditions resulted in worsened reactive agility performance compared to BL. No differences between visor conditions existed for overall performance (p > 0.05). Conclusions: Overall, these findings suggest that American football headgear impairs reactive agility, which could result in worsened game performance and safety. Future studies investigating training strategies to overcome impairments are warranted.

Background: In volleyball, the upper limb dimensions and grip strength greatly influence offensive and defensive movements during a match. However, the relationship between these parameters remains underexplored in elite female volleyball players. Objective: This study aimed to contrast the upper limb anthropometric characteristics and handgrip strength (HGS) of female elite volleyball players against a control group. Methods: Selected upper limb anthropometric parameters and maximal HGS of 42 female volleyball players and 40 non-athletes were measured. Results: Players exhibited higher values in almost all variables studied than non-athletes. The differences were statistically significant (p < 0.001) except for body mass index and elbow and wrist diameters. Players showed a moderate correlation between dominant HGS and hand parameters (length r = 0.43 and breadth r = 0.63; p < 0.05). Weak correlations were identified with height, upper arm length, elbow diameter, and hand shape index (r = 0.32 to 0.38; p < 0.05). In the non-dominant hand, a moderate correlation with handbreadth (r = 0.55, p ≤ 0.01) and weak correlations with upper arm length, wrist diameter, hand length, and hand shape index (r = 0.32 to 0.35; p ≤ 0.05) was found. Conclusions: These findings underscore the importance of the upper limb anthropometric parameters as predictors of HGS and their utility in athlete selection. Future research should investigate biomechanical factors influencing HGS and injury prevention.

Background/objectives: Becoming an elite canoe slalom athlete requires thousands of hours of training, spread over many years. It is difficult to assess the correct balance between flatwater and whitewater training because differences in the paddle forces on these terrains are not known. The aim of this study was to describe paddle forces during canoe slalom training on flatwater and whitewater courses for the C1 canoe category.

Methods: Paddle forces for twenty C1 canoe slalom athletes were quantified during all-out figure-of-eight tests on a flatwater course and during race simulations on a whitewater course. Paddle forces were measured using strain gauges embedded in the paddle shaft and quantified by their force, impulse, and stroke durations.

Results: The mean force during the pull phase of the paddle strokes was not significantly different between the flatwater and whitewater courses; however, the longer pull phase durations led to a greater pull phase impulse when paddling on the whitewater course.

Conclusions: This study indicates that training for all-out runs on a whitewater course is more demanding for canoe slalom athletes than performing all-out trials on a flatwater figure-of-eight course. This evidence may help to develop effective training plans that are essential to reach the highest levels of the sport.

Background/objective: Soccer is a multifactorial sport, requiring physical, psychological, technical, and tactical skills to succeed. Monitoring and comparing physical characteristics over time is essential to assess players' development, customize training, and prevent injury. The use of wearable sensors is essential to provide accurate and objective physical data.

Methods: In this longitudinal study, 128 male adolescent soccer players (from Under 12 to Under 19) were evaluated at two time points (pre- and post-season). Participants completed the Euleria Lab test battery, including stability, countermovement and consecutive jumps, agility, and quick feet tests. A single Inertial Measurement Unit sensor provided quantitative data on fifteen performance metrics. Percentage changes were compared to the Smallest Worthwhile Changes to assess significant changes over time.

Results: The results showed significant improvements in most variables, including a 19.7% increase in quick feet, 10.9% in stability, and 9.6% in countermovement jumps. In principal component analysis, we identified four principal components-strength-power, balance, speed-agility, and stiffness-that explained over 80% of the variance.

Conclusions: These findings align with previous studies assessing seasonal changes in adolescent soccer players, showing that the proposed test battery seems to be adequate to highlight physical performance changes and provide coaches with meaningful data to customize training and reduce injury rates.

Background/objectives: This study examined the differences in participant force production and pain between a squat maximal voluntary isometric contraction (IMVIC) performed with either a waist belt (WB) or full-body harness (FBH) on the Desmotec D.EVO isoinertial device (D.EVO). Agreement between FBH IMVIC and a traditional force plate squat MVIC (TMVIC) was also assessed.

Methods: Twenty adults completed FBH, WB, and TMVIC assessments on two separate occasions. Two-way treatment x time ANOVAs were conducted to compare force outputs and pain between treatments (FBH vs. WB) across time. Test-retest reliability was assessed using intraclass correlation coefficients. Associations between outcomes were determined using Pearson's r. Standard error of estimate, constant error, total error, and Bland-Altman plots were used to assess agreement between IMVIC and TMVIC.

Results: FBH and WB IMVIC exhibited good to excellent reliability (ICC_2,1 = 0.889-0.994) and strong associations (r = 0.813 and 0.821, respectively) when compared to TMVIC. However, agreement between FBH and TMVIC was poor. No significant interaction or main effects were observed for pain. FBH maximum isometric force (MIF) was significantly higher than WB MIF. WB IMVIC was the only significant predictor of TMVIC (R² = 0.674).

Conclusions: Our findings indicate that the D.EVO should not be utilized as a replacement for a traditional MVIC setup.

Background: The effect of tibial fixation on the movement of the talus during the tibiotarsal axial traction technique (TATT) is unknown. The aim was to evaluate the effect on the tibiotarsus when applying three different intensities of TATT force with or without tibial fixation in healthy subjects, and to assess the reliability of detecting the different forces applied. Also, the discomfort generated during the technique would be analysed. Methods: A cross-sectional study was conducted in thirty lower limbs. Three magnitudes of TATT force in an open-packed position were applied in tibial fixation and non-fixation conditions. The axial traction movement was measured by ultrasound, and the magnitudes of the force applied during low-medium and high TATT force were recorded in both conditions. Patients were asked about the level of discomfort perceived during the technique. Results: The most significant distance increase (mm) was observed in the tibial fixation condition at all magnitudes of the TATT (F = 102.693, p < 0.001). The discomfort sensation (numeric rating scale, "NRS") was higher in the non-fixation condition (p > 0.05). The application of the technique showed good reliability (>0.75 ICC) for the detection of the applied force. Conclusions: The TATT in the tibial fixation condition produced more significant axial movement of the talus (mm) relative to the tibia than the non-tibial fixation condition did. The detection of the magnitudes of movement showed good reliability (ICC: 0.75 to 0.92). The technique was well tolerated at all force magnitudes, with the tibial fixation condition being the most tolerable.

Objectives: To identify typical patterns of abdominal wall muscle activation in patients with diastasis recti and inguinal hernias compared to controls during the Valsalva maneuver, voluntary coughing, and physical activity.

Methods: The study included 15 subjects: 5 with diastasis recti, 4 with inguinal hernias, and 6 healthy controls. The functions of rectus abdominis (RA) and external oblique (OE) muscles were measured by surface electromyography (sEMG). Using ultrasound, the thicknesses of the RA, OE, internal oblique (IO), and transversus abdominis (TA) muscles were assessed as well as the echo intensity (EI) of RA and OE.

Results: We found a significant effect of the type of abdominal wall pathology on the maximum sEMG amplitude (p = 0.005). There was a reliable trend in maximum sEMG amplitude, with the highest one in diastasis recti and a significantly lower one in inguinal hernias. Duncan's test showed a significant difference in muscle thickness, both on the right and left sides, between patients with diastasis and controls, but only on the left side between patients with diastasis and those with inguinal hernia (p < 0.05).

Conclusions: The abdominal wall pathology results in a change in the function and structure of the abdominal muscles, which can be detected using electromyography and ultrasound examination. The presence of diastasis recti is accompanied by an increase in bioelectrical activity and a decrease in thickness.

Background: This study contributes to expanding the existing literature on learning technical skills in youth soccer by comparing the effectiveness of different training approaches in the development of passing skills. The ecological-dynamic approach, which emphasizes the continuous and adaptive interaction between the athlete and the environment, is analyzed in comparison to the traditional prescriptive approach, which relies on predefined techniques and exercises. The aim of the study is to determine which of the two approaches is more effective in improving the performance of young soccer players. Methods: Thirty players (age 12 ± 1.2 years) were randomly assigned to two groups: the ecological-dynamic group (ECG) and a control group (CON). Both groups underwent an eight-week training program with equal sessions. The ECG group's training focused on adjusting constraints like the learning environment, game rules, and visual restrictions to boost adaptability and problem-solving skills. The CON group followed a traditional prescriptive approach with specific instructions, goal setting, immediate feedback, and structured exercise progression. Passing abilities were evaluated before and after the program using the Loughborough Soccer Passing Test, with a retention test administered five weeks later. Descriptive statistics, including mean values and percentage improvements, were used. A repeated measures ANOVA compared differences between the groups. Results: The analysis revealed a significant Occasion × Group interaction for all performance variables, indicating that the ECG group experienced greater improvements than the CON group. Specifically, the ECG group showed significant reductions in Trial Time (p = 0.001, η_p² = 0.6), Penalty Time (p = 0.016, η_p² = 0.4), and Overall Performance (p = 0.011, η_p² = 0.8) from pre-test to post-test. However, these improvements did not persist into the retention test (p = 0.131, p = 0.792, and p = 0.192, respectively). The CON group also improved significantly in Trial Time (p = 0.003), Penalty Time (p = 0.002), and Overall Performance (p = 0.001) from pre-test to post-test, but with smaller effect sizes and no sustained gains at retention. Conclusions: The ecological-dynamic approach (EDG) has proven to be more effective in enhancing passing skills compared to the traditional prescriptive approach (CON). Although both methods led to performance improvements, the EDG group achieved more significant progress.