Mitigating the Threat of Invasive Mosquito Species Expansion: A Comprehensive Entomological Surveillance Study on Kastellorizo, a Remote Greek Island.

The expansion of the tiger mosquito, a vector that can transmit diseases such as dengue, chikungunya, and Zika virus, poses a growing threat to global health. This study focuses on the entomological surveillance of Kastellorizo, a remote Greek island affected by its expansion. This research employs a multifaceted approach, combining KAP survey (knowledge, attitude, practices), mosquito collection using adult traps and human landing catches, and morphological and molecular identification methods. Results from questionnaires reveal community awareness and preparedness gaps, emphasizing the need for targeted education. Mosquito collections confirm the presence of the Aedes albopictus, Aedes cretinus, and Culex pipiens mosquitoes, highlighting the importance of surveillance. This study underscores the significance of community engagement in entomological efforts and proposes a citizen science initiative for sustained monitoring. Overall, this research provides essential insights for developing effective mosquito control programs in remote island settings, thereby emphasizing the importance of adopting a One Health approach to mitigate the spread of vector-borne diseases.

Comparison of Inter-Rater and Intra-Rater Reliability of Raters with Different Levels of Experience When Using Landing Error Scoring System (LESS) in Field-Based Screening of Professional Football Players.

It is essential for physical sports therapists to use reliable field-based tests to identify potential injury risk factors in athletes. The purpose of this study was to compare the inter- and intra-rater reliability of experienced and novice raters during use of the Landing Error Scoring System (LESS) in a field-based examination of professional football athletes. Thirty-seven male football athletes underwent pre-season LESS assessment. Two raters independently evaluated the recorded landing techniques at two separate intervals, two months apart, following the LESS standard protocol. Inter-and intra-rater values were calculated for the LESS total scores and individual scoring items. The overall LESS scores had excellent intra-rater reliability values for both the experienced (interclass correlation coefficient (ICC) = 0.95, 95% CI, 0.89-0.97; p < 0.001) and novice rater (ICC = 0.95, 95% CI, 0.90-0.97; p < 0.001), and very good to excellent inter-rater values for the first (ICC = 0.90, 95% CI, 0.77-0.95; p < 0.001) and second (ICC = 0.86, 95% CI, 0.71-0.93; p < 0.001) evaluation. Most of the individual scoring items ranged from moderate to perfect agreement. In conclusion, sports physical therapists, regardless of experience, can reliably use the LESS's total score, through video analysis of the regime. Individual scoring items can inform clinicians about impairments in the landing mechanism but data should be interpreted cautiously.

Research and application on modeling and landing point prediction technology for water jet trajectory of fire trucks under large-scale scenarios.

To let water jets land at the fire, pitch angle of the fire monitor has to be adjusted manually with successive rounds, which seriously affects the efficiency of fire extinguishing. To improve the efficiency, this paper proposes a technology for water jet trajectory modeling and landing point prediction to help with extinguishing automatically. Considering fragmentation and atomization of water jets, trajectories are analyzed and the predicted trajectory is closer to the real situation. Secondly, a compensation method for the prediction is proposed to further reduce the deviation between the predicted and the actual landing point, taking into account the combined effects of high altitude, initial jet velocity, and wind. On this basis, considering the difficulty of directly solving the analytical solution to the target initial pitch angle of the jets, a searching method is also proposed, which greatly improves the solving efficiency. Finally, through practical experiments and verification, the proposed model takes an average time of 0.00292 s, which is far less compared with other methods. The prediction error is improved by at least 45.3%, and the average deviation is less than 2 m.

Validity and Reliability of OpenPose-Based Motion Analysis in Measuring Knee Valgus during Drop Vertical Jump Test.

OpenPose-based motion analysis (OpenPose-MA), utilizing deep learning methods, has emerged as a compelling technique for estimating human motion. It addresses the drawbacks associated with conventional three-dimensional motion analysis (3D-MA) and human visual detection-based motion analysis (Human-MA), including costly equipment, time-consuming analysis, and restricted experimental settings. This study aims to assess the precision of OpenPose-MA in comparison to Human-MA, using 3D-MA as the reference standard. The study involved a cohort of 21 young and healthy adults. OpenPose-MA employed the OpenPose algorithm, a deep learning-based open-source two-dimensional (2D) pose estimation method. Human-MA was conducted by a skilled physiotherapist. The knee valgus angle during a drop vertical jump task was computed by OpenPose-MA and Human-MA using the same frontal-plane video image, with 3D-MA serving as the reference standard. Various metrics were utilized to assess the reproducibility, accuracy and similarity of the knee valgus angle between the different methods, including the intraclass correlation coefficient (ICC) (1, 3), mean absolute error (MAE), coefficient of multiple correlation (CMC) for waveform pattern similarity, and Pearson's correlation coefficients (OpenPose-MA vs. 3D-MA, Human-MA vs. 3D-MA). Unpaired t-tests were conducted to compare MAEs and CMCs between OpenPose-MA and Human-MA. The ICCs (1,3) for OpenPose-MA, Human-MA, and 3D-MA demonstrated excellent reproducibility in the DVJ trial. No significant difference between OpenPose-MA and Human-MA was observed in terms of the MAEs (OpenPose: 2.4° [95%CI: 1.9-3.0°], Human: 3.2° [95%CI: 2.1-4.4°]) or CMCs (OpenPose: 0.83 [range: 0.99-0.53], Human: 0.87 [range: 0.24-0.98]) of knee valgus angles. The Pearson's correlation coefficients of OpenPose-MA and Human-MA relative to that of 3D-MA were 0.97 and 0.98, respectively. This study demonstrated that OpenPose-MA achieved satisfactory reproducibility, accuracy and exhibited waveform similarity comparable to 3D-MA, similar to Human-MA. Both OpenPose-MA and Human-MA showed a strong correlation with 3D-MA in terms of knee valgus angle excursion.

Reliability and validity of knee valgus angle calculation at single-leg drop landing by posture estimation using machine learning.

Background: The consensus on anterior cruciate ligament (ACL) injury prevention involves the suppression of dynamic knee valgus (DKV). The gold standard for evaluating the DKV includes three-dimensional motion analysis systems; however, these are expensive and cannot be used to evaluate all athletes. Markerless motion-capture systems and joint angle calculations using posture estimation have been reported. However, there have been no reports on the reliability and validity of DKV calculations using posture estimation. Research question: This study aimed to clarify the reliability and validity of DKV calculation using posture estimation. Methods: Fifteen participants performed 10 single-leg jump landings from a height of 20 cm, and the knee joint angle was calculated using joint points measured using machine learning (MediaPipe Pose) and motion-capture systems (VICON MX). Two types of angle calculation methods were used: absolute value and change from the initial ground contact (IC). Intra- and inter-rater reliabilities were examined using intraclass correlation coefficients, and concurrent validity was examined using Pearson's correlation coefficients. To examine intra-examiner reliability, we performed single-leg jump landings at intervals of ≥3 days. Results: The calculation by MediaPipe Pose was significantly higher than that by the 3-D motion analysis systems (p < 0.05, error range 18.83-19.68°), and there was no main effect of knee valgus angle or time on the excursion angle from IC (p > 0.05). No significant concurrent validity was found in the absolute value, which was significantly correlated with the change in IC. Although the inter-rater reliability of the absolute value was low, the change in IC showed good reliability and concurrent validity. Significance: The results of this research suggest that the DKV calculation by pose estimation using machine learning is practical, with normalization by the angle at IC.

Tree Frogs Alter Their Behavioral Strategies While Landing On Vertical Perches.

As an arboreal animal, tree frogs face diverse challenges when landing on perches, including variations in substrate shape, diameter, flexibility, and angular distribution, with potentially significant consequences for failed landings. Research on tree frog landing behavior on perches, especially concerning landing on vertical substrates, remains limited. This study investigated the landing strategies (forelimb, abdomen, and hindlimb) of tree frogs on vertical perches, considering perch diameter. Although all three strategies were observed across perches of different diameters, their frequencies differed. Forelimb landing was most common across all perch diameters, with its frequency increasing with perch diameter, while abdomen and hindlimb landing strategies were more prevalent on smaller diameter perches. During the process from take-off to landing, the body axis underwent some deviation owing to the asymmetric movement of the left and right limbs; however, these deviations did not significantly differ among landing strategies. Additionally, different landing strategies led to variations in the landing forces, with abdominal landings generating significantly higher impact forces than the other two strategies. These findings provide insights into the biomechanics and biological adaptations of tree frogs when landing on challenging substrates, such as leaves or branches.

Relationship Between the Results of the Landing Error Scoring System and Trunk Muscle Thickness.

Background: A landing error scoring system (LESS) is widely used to evaluate landing maneuvers. Poor landing maneuvers, such as lateral bending of the trunk, are thought to be associated with a risk of lower-extremity injury. However, no studies have examined the association between landing and trunk muscle function, which is associated with a high risk of lower-extremity injury. Hypothesis/Purpose: This study examined whether an association exists between landing movements and a high risk of lower-extremity injury and trunk muscle function. It was hypothesized that athletes with poor activation of deep trunk muscle (transversus abdominis and internal oblique) would have lower LESS scores. Study Design: Cross-sectional study. Methods: The trunk muscle thickness at rest and during the plank was measured using ultrasonography. The percent of change in muscle thickness (during plank/at rest) was calculated. The LESS was measured using the Physimax. Based on the LESS scores, patients were divided into high- (LESS > 6) and low-risk (5 > LESS) groups for lower extremity injury. The relationship between the high-risk group and trunk muscle thickness was examined using a stepwise regression analysis. Results: The high-risk group had significantly lower muscle thicknesses of the transversus abdominis (p=0.02) and transversus abdominis plus internal oblique abdominis (p=0.03) muscles during the plank. Additionally, the high-risk group showed significantly lower percent of change in muscle thickness of the internal oblique (p=0.02) and transversus abdominis plus internal oblique (p=0.01) muscles. Only the percentage of change in the thickness of the internal oblique and transverse abdominal muscles was extracted from the regression as a factor. Conclusion: The findings indicated that athletes with landing movements and a high risk of injury, as determined based on the LESS results, had low trunk muscle function, and a relationship was observed between the change in thickness of transversus abdominis and internal oblique abdominis muscles. Level of Evidence: 3B.

Effects of attentional focus strategies in drop landing biomechanics of individuals with unilateral functional ankle instability.

Background: Functional Ankle Instability (FAI) is a pervasive condition that can emerge following inadequate management of lateral ankle sprains. It is hallmarked by chronic joint instability and a subsequent deterioration in physical performance. The modulation of motor patterns through attentional focus is a well-established concept in the realm of motor learning and performance optimization. However, the precise manner in which attentional focus can rehabilitate or refine movement patterns in individuals with FAI remains to be fully elucidated. Objective: The primary aim of this study was to evaluate the impact of attentional focus strategies on the biomechanics of single-leg drop landing movements among individuals with FAI. Methods: Eighteen males with unilateral FAI were recruited. Kinematic and kinetic data were collected using an infrared three-dimensional motion capture system and force plates. Participants performed single-leg drop landing tasks under no focus (baseline), internal focus (IF), and external focus (EF) conditions. Biomechanical characteristics, including joint angles, ground reaction forces, and leg stiffness, were assessed. A 2 × 3 [side (unstable and stable) × focus (baseline, IF, and EF)] Repeated Measures Analysis of Variance (RM-ANOVA) analyzed the effects of attentional focus on biomechanical variables in individuals with FAI. Results: No significant interaction effects were observed in this study. At peak vertical ground reaction force (vGRF), the knee flexion angle was significantly influenced by attentional focus, with a markedly greater angle under EF compared to IF (p < 0.001). Additionally, at peak vGRF, the ankle joint plantarflexion angle was significantly smaller with EF than with IF (p < 0.001). Significant main effects of focus were found for peak vGRF and the time to reach peak vGRF, with higher peak vGRF values observed under baseline and IF conditions compared to EF (p < 0.001). Participants reached peak vGRF more quickly under IF (p < 0.001). Leg Stiffness (kleg) was significantly higher under IF compared to EF (p = 0.001). Conclusion: IF enhances joint stability in FAI, whereas EF promotes a conservative landing strategy with increased knee flexion, dispersing impact and minimizing joint stress. Integrating these strategies into FAI rehabilitation programs can optimize lower limb biomechanics and reduce the risk of reinjury.

Writing with Mass-Selected Ions Using a Dynamic Field Wien Filter.

We have designed and constructed a low-cost Wien filter based on strong permanent magnets and integrated it into an ion soft-landing instrument to enable parallel deposition as well as one- and two-dimensional surface patterning of mass-selected ions using dynamic fields. We show the capabilities of this device for separating ions from a multicomponent high-flux continuous ion beam and simultaneous deposition of ions of different mass-to-charge ratios onto discrete locations on a surface. When a dynamic electric field is applied parallel to the magnetic field, ions are deposited in one-dimensional arrays, laterally separated by mass. The field's strength, frequency, and waveform type determine both the lengths of the arrays and the density of ions across the 1-D pattern. Additionally, a second dynamic field from user-defined waveforms orthogonal to the magnetic field enables two-dimensional surface patterning of ions while maintaining mass separation. These experiments demonstrate the practical utility of a Wien filter for the controlled fabrication of interfaces with arbitrary patterns of mass-selected ions.

Dynamic Functional Ability in Lacrosse Players in Relation to Development of Sport-Related Onset of Musculoskeletal Pain.

Background: Unlike other sports, the relationship between performance deficits and pain/injury in lacrosse players has not been well-investigated. Purpose: The purposes of this study were to: 1) determine whether age and sex differences exist in dynamic physical function tests and drop jump performance among lacrosse players, and 2) determine whether pre-seasonal physical function scores predict onset of either lower extremity or low back pain over time. Study Design: Prospective observational study. Methods: Lacrosse players (N=128) were stratified into three groups: 12-14.9 yrs, 15-18 yrs and >18 yrs. Thomas test (hip flexibility), Ober's test (iliotibial band tightness), and Ely's test (rectus femoris tightness) were performed. Landing Error Scoring System (LESS) scores were collected while players performed drop jumps. Sagittal and frontal plane movement from 2D video during single and double legged squats was assessed. Musculoskeletal pain symptoms or injury were tracked for six months. Age bracket, sex and physical function scores were entered into logistic regression models to determine risk factors that predicted onset of lower extremity pain and low back pain onset. Results: LESS scores and single-leg squat movement quality test scores were lowest in the 12-14.9 yr groups and highest in the >18 yr group (all p<0.05). Single leg squat performance score increased the odds risk (OR) for lower extremity pain (OR=2.62 [95% CI 1.06-6.48], p=.038) and LESS scores elevated risk for low back pain onset over six months (OR = 2.09 [95% CI 1.07- 4.06], p= .031). Conclusions: LESS scores and single legged squat performance may help identify lacrosse players at risk for musculoskeletal pain or injury onset. Detecting these pertinent biomechanical errors and subsequently developing proper training programs could help prevent lower extremity and low back pain onset. Level of Evidence: III.

Different strategies for landing from different heights among people with chronic ankle instability.

BACKGROUND: Lateral ankle sprain (LAS) usually occurs during landing from heights among people with chronic ankle instability (CAI). Although the kinematics when landing on the flat surface has been reported, no studies have explored the effect of different heights on the landing strategies using a trapdoor device among people with CAI. RESEARCH QUESTION: Do people with CAI adopt different landing strategies when drop-landing on the trapdoor device from three heights? METHODS: Thirty-one participants with CAI (24 males and 7 females, age=21.1±1.8 years, height=176.9±7.4 cm, body mass=71.9±9.2 kg, injured side=18 R&13 L) were recruited. They dropped from three different heights (low height (16 cm), medium height (23 cm), high height (30 cm)) with their affected foot landing on a movable surface of a trapdoor device, which was tilted 24° inward and 15° forward to simulate LAS. Kinematic data was collected using a twelve-camera motion capture system. One-way analysis of variance with repeated measures was used to compare the differences between the three heights. RESULTS: Significant height effects were detected in the peak ankle inversion angle (p=0.009, η2p=0.280) and angular velocity (p<0.001, η2p=0.444), and the peak ankle plantarflexion (p=0.002, η2p=0.360), knee flexion (p<0.001, η2p=0.555), and hip flexion (p=0.030, η2p=0.215) angles at the time of peak ankle inversion. Post-hoc tests showed that all the angles and velocities were higher at a low height than at medium (p: 0.001-0.045, d: 0.14-0.44) and high heights (p: 0.001-0.023, d: 0.28-0.66), except for the ankle plantarflexion angle, which was lower at a low height than at medium (p<0.001, d=0.44) and high (p=0.021, d=0.38) heights. SIGNIFICANCE: People with CAI adopt a protective strategy during drop-landing at medium and high heights compared to a low height. This strategy involves increased ankle dorsiflexion angle as well as knee and hip flexion angles.

Does chronic ankle instability patients lead to changes in biomechanical parameters associated with anterior cruciate ligament injury during landing? A systematic review and meta-analysis.

Objective: This study aimed to determine if patients with chronic ankle instability (CAI) exhibit biomechanical changes associated with the increased risk of anterior cruciate ligament (ACL) injury during landing tasks. Study Design: This study was conducted through systematic review and meta-analysis. Data Sources: Searches were conducted in May 2024 across five electronic databases, including Web of Science, Scopus, PubMed, SPORTDiscus, and Cochrane Library. Eligibility Criteria: Studies were included if they (1) involved subjects with CAI and healthy controls and (2) assessed biomechanical variables such as ground reaction forces, joint angles, and joint torques. Results: Of the 675 identified studies, 171 were included in the review, and 13 were eligible for meta-analysis. The reviewed studies clearly defined research objectives, study populations, consistent participant recruitment, and exposures, and they used valid and reliable measures for outcomes. However, areas such as sample size calculation, study sample justification, blinding in assessments, and addressing confounders were not robust. This meta-analysis involved 542 participants (healthy group: n = 251; CAI group: n = 291). Compared with healthy individuals, patients with CAI exhibited a greater peak vertical ground reaction force (peak VGRF; SMD = 0.30, 95% CI: 0.07-0.53, p = 0.009), reduced hip flexion angles (SMD = -0.30, 95% CI: -0.51 to -0.17, p < 0.0001), increased trunk lateral flexion (SMD = 0.47, 95% CI: 0.05 to 0.9, p = 0.03), greater hip extension moments (SMD = 0.47, 95% CI: 0.09-0.84, p = 0.02), and increased knee extension moments (SMD = 0.39, 95% CI: 0.02-0.77, p = 0.04). Conclusion: During landing tasks, patients with CAI demonstrate increased hip extension moments and knee extension moments, decreased hip flexion angles, increased peak VGRF, and increased trunk lateral flexion angles. These biomechanical variables are associated with an elevated risk of ACL injuries.Systematic Review Registration: Identifier CRD42024529349.

Landing error scoring system: A scoping review about variants, reference values and differences according to sex and sport.

OBJECTIVE: The Landing Error Scoring System (LESS) is a movement analysis tool proposed to identify the risk of anterior cruciate ligament injuries, very useful for injury prevention. The aim of this study is to review the variants of the LESS, their normative scores and the differences according to sex and sport practiced. METHODS: PubMed, Scopus and ScienceDirect databases were searched from inception to October 19, 2023. Studies were eligible if the objective was finding normative or reference scores for the LESS, analyze the differences between sexes or sports, or used some variant of the test. Results were limited to available full-text articles published in English in peer-reviewed journals. RESULTS: Of the 360 articles identified, 20 were included for a full analysis (18,093 participants, age = 8-30 years, males = 70.6%). The military population was the most frequently analyzed (7 studies, n = 16,603). Results showed six variants of the LESS and average values ranged from 2.56 to 7.1. Males and females showed different pattern landing with errors in different planes. CONCLUSIONS: Our findings highlight the need for more field studies on LESS reference scores, particularly for females and basketball or hockey players. Further research is required before conducting a systematic review and meta-analysis.

Abundance of Marine Macrodebris on the Northern Coast of Jaffna Peninsula, Sri Lanka.

Marine plastic debris has emerged as a pressing concern along the northern coast of Jaffna, Sri Lanka, posing a significant threat to marine resources. A preliminary study was conducted to investigate the abundance and characteristics of marine plastic debris at four major fish landing sites in the northern coast of Jaffna, using the Clean Coast Index (CCI) and Plastic Abundance Index (PAI). The results revealed that the average abundance of marine debris and plastic debris were 1.71 ± 0.42 items/m2 and 1.66 ± 0.57 items/m2, respectively. The most common types of plastic debris represented plastic rope and net pieces (23.2%), followed by unidentified weathered plastic fragments (16.7%), beverage bottles (16.2%), bottle caps and lids (13%), and styrofoam (14.1%). The recognized sources of plastic debris were mainly fishing-based activities, recreation activities, transboundary sources, and unidentified sources. The fish landing sites were classified as exceptionally polluted, with a CCI exceeding 10 and a PAI value exceeding 8. Myliddy had the highest debris density, indicating substantial pollution levels, followed by Point Pedro, Mathagal, and Valveddithurai. These findings underscore the urgency of establishing a comprehensive plastic waste management framework for the northern coast of Jaffna and devising strategies to address buoyant debris within the northern Indian Ocean. Furthermore, this study carries significant implications for the local marine ecosystem, coastal communities, and Sri Lanka's broader environmental policies and practices.

Effects of 6-Week Weighted-Jump-Squat Training With and Without Eccentric Load Reduction on Explosive Performance.

PURPOSE: To compare the effects of 6-week barbell weighted-jump-squat (WJS) training with and without eccentric load reduction on explosive performance. METHODS: Twenty well-trained male athletes were randomly assigned to either an experimental group (n = 10) or a control group (n = 10). Participants completed 12 WJS training sessions (6 sets of 5 repetitions of barbell back squat at 30% of 1-repetition maximum [1RM]) twice a week over a 6-week period. While the control group used 0% eccentric loading (ie, traditional WJS), the experimental group utilized a 50% eccentric loading reduction with a mechanical braking unit (ie, eccentric load set at 15% of 1RM). Performance assessments, including countermovement jump, 20-m sprint, standing long jump, and 1RM barbell back squat, were conducted both before (pretests) and after (posttests) the intervention. RESULTS: Both the experimental group and the control group demonstrated a significant increase in countermovement-jump height (+6.4% [4.0%] vs +4.9% [5.7%]; P < .001) and peak power output (+2.3% [2.7%] vs +1.9% [5.1%]; P = .017), faster 20-m sprint times (+9.4% [4.8%] vs +9.2% [5.5%]; P < .001), longer standing long jump (+3.1% [2.5%] vs +3.0% [3.3%]; P < .001), and higher 1RM back squat (+6.4% [4.0%] vs +4.9% [5.7%]; P < .001) from pretests to posttests. However, there was no significant condition × time interaction for any variable (all P ≥ .294). CONCLUSIONS: Both WJS training methods, with and without load reduction in the eccentric phase, effectively enhance explosive performance. Nevertheless, athletes in later stages of injury rehabilitation or intense training may find reducing eccentric load a more tolerable strategy for achieving similar performance gains compared with traditional isoinertial loading.

The Influence of Induced Head Acceleration on Lower-Extremity Biomechanics during a Cutting Task.

Sports-related concussions are caused by one substantial impact or several smaller-magnitude impacts to the head or body that lead to an acceleration of the head, causing shaking of the brain. Athletes with a history of sports-related concussion demonstrate lower-extremity biomechanics during landing tasks that are conducive to elevated injury risk. However, the effect of head acceleration on lower-extremity biomechanics during landing tasks is unknown. Twenty participants were evenly separated into a vertical hopping group and a lateral hopping group. Participants performed several land-and-cut maneuvers before and after a hopping intervention. Vertical head acceleration (g) was measured via an accelerometer during the hopping interventions. Comparisons in head acceleration during the hopping tasks were made between groups. Additionally, kinematic and kinetic variables were compared pre- and post-intervention within groups as well as post-intervention between groups. The vertical hopping group demonstrated greater vertical head acceleration compared to the lateral hopping group (p = 0.04). Additionally, the vertical hopping group demonstrated greater knee abduction angles during landing post-intervention compared to the lateral hopping group (p < 0.000). Inducing head acceleration via continuous hopping had an influence on lower-extremity biomechanics during a landing task.

The effects of core muscle fatigue on lower limbs and trunk during single-leg drop landing: A comparison between recreational runners with and without dynamic knee valgus.

BACKGROUND: A deficit in neuromuscular trunk control can impact the lower limb motion, predisposing runners to injuries. This deficit may show a greater impact on runners with dynamic knee valgus. This study aimed to compare the effect of core fatigue on kinetic, kinematic, and electromyographic parameters of the trunk and lower limbs during single-leg drop landing between runners with and without dynamic knee valgus. METHODS: Twenty-seven recreational runners were allocated to the valgus (n = 14) and non-valgus groups (n = 13). They performed the test before and after a fatigue protocol, taking a step forward and landing on the force platform while maintaining balance. The fatigue protocol included isometric and dynamic exercises performed consecutively until voluntary exhaustion. The vertical ground reaction force, the sagittal and frontal plane angles, and the electromyographic activity were evaluated. The integral of electromyographic activity was calculated into three movement phases. ANOVA with repeated measures was used to verify the group, time, and interaction effects. RESULTS: After fatigue, both groups showed a significant reduction in the minimum (p = 0.01) and maximum (p = 0.02) knee angles in the frontal plane (more dynamic knee valgus) and greater gluteus medius activity (p = 0.05) from the peak of knee flexion to the end of the movement. The valgus group had a greater hip excursion (p = 0.01) and vertical linear shoulder displacement (p = 0.02) than the non-valgus. CONCLUSION: Our results suggest that core fatigue can impact the local muscle and the distal joint and that the groups presented different strategies to deal with the demand during landing.

Dual-loop control and state prediction analysis of QUAV trajectory tracking based on biological swarm intelligent optimization algorithm.

Quadrotor unmanned aerial vehicles (QUAVs) have attracted significant research focus due to their outstanding Vertical Take-Off and Landing (VTOL) capabilities. This research addresses the challenge of maintaining precise trajectory tracking in QUAV systems when faced with external disturbances by introducing a robust, two-tier control system based on sliding mode technology. For position control, this approach utilizes a virtual sliding mode control signal to enhance tracking precision and includes adaptive mechanisms to adjust for changes in mass and external disruptions. In controlling the attitude subsystem, the method employs a sliding mode control framework that secures system stability and compliance with intermediate commands, eliminating the reliance on precise models of the inertia matrix. Furthermore, this study incorporates a deep learning approach that combines Particle Swarm Optimization (PSO) with the Long Short-Term Memory (LSTM) network to foresee and mitigate trajectory tracking errors, thereby significantly enhancing the reliability and safety of mission operations. The robustness and effectiveness of this innovative control strategy are validated through comprehensive numerical simulations.

Evaluating plantar biomechanics while descending a single step with different heights.

Objective: This study aims to investigate the plantar biomechanics of healthy young males as they descend a single transition step from varying heights. Methods: Thirty healthy young males participated the experiment using the F-scan insole plantar pressure system in which participants made single transition steps descent from four step heights (5, 15, 25, and 35 cm), leading with their dominant or non-dominant foot. Plantar pressure data were collected for 5 s during the period between landing touchdown and standing on the ground. Landing at each step height was repeated three times, with a five-minute rest between different height trials. Results: At 5 cm and 15 cm steps, participants demonstrated a rearfoot landing strategy on both sides. However, forefoot contact was observed at heights of 25 cm and 35 cm. Parameters related to center of plantar pressure (COP) of the leading foot were significantly larger compared to the trailing foot (P < 0.001), increased with higher step heights. Vertical ground reaction forces for the biped, leading and trailing feet decreased with increasing step height (all P < 0.05). The leading foot had a higher proportion of overall and forefoot loads, and a lower proportion of rearfoot load compared to the trailing foot (P < 0.001). The overall load on the dominant side was lower than that on the non-dominant side for both the leading and trailing feet (P < 0.001). For the trailing foot, forefoot load on the dominant side was lower than that on the non-dominant side, however, the opposite result appeared in rearfoot load (P < 0.001). Upon the leading foot landing, forefoot load exceeded the rearfoot load for the dominant (P < 0.001) and non-dominant sides (P < 0.001). Upon the trailing foot landing, forefoot load was lower than the rearfoot load for the dominant (P < 0.001) and non-dominant sides (P = 0.019). Conclusion: When the characteristics of biomechanical stability are compromised by step height, landing foot, and footedness factors - due to altered foot landing strategies, changing COP, or uneven force distribution - ability to control motion efficiently and respond adaptively to the forces experienced during movement is challenged, increasing the likelihood of loss of dynamic balance, with a consequent increased risk of ankle sprains and falls.

Analysing lower limb motion and muscle activation in athletes with ankle instability during dual-task drop-jump.

This study investigates the impact of chronic ankle instability (CAI) on athletes' lower extremity mechanics during bounce drop-jump landings with divided attention. Thirty Division I physical education voluntarily participated in the study. They performed two sets of bounce drop jumps: one set with a divided attention task and the other without. The obtained data were analysed using a paired t-test to compare the outcomes between the divided attention (DA) and non-divided attention (NDA) tasks. Athletes with CAI, during the DA task, displayed higher vertical landing forces, increased ankle inversion velocity, and greater range of motion of the ankle, knee, and hip in the frontal and transverse planes. They also exhibited insufficient neuromuscular preparation of the rectus femoris muscle. Notably, distinct kinematic alterations were observed in the ankle, knee, and hip joints regarding frontal and transverse lower-extremity kinematics. The findings suggest that athletes with CAI experience decreased activation of the rectus femoris muscle, which may impact their dynamic postural stability from pre-landing to ascending phases. Furthermore, the results indicate that individuals with CAI closely replicate the injury mechanisms encountered during a drop-jump landing task with divided attention. These insights offer valuable information about the real-time challenges faced by athletes with CAI.