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Purpose: Alpine ski racing is a complex sport where no single factor can exclusively account for performance. We assessed body composition, using bioelectrical impedance vector analysis (BIVA), and our purpose was to study its influence on the strength and power profile of young alpine skiers. Methods: Anthropometric measurements and advanced BIVA parameters were recorded on eighteen alpine ski racers (6 females/12 males; 17.0 ± 1.3 years; 172.2 ± 9.3 cm; 68.5 ± 9.8 kg). Dynamic force and power were assessed using countermovement jumps (CMJ), while maximal isometric strength was evaluated for hip flexion-extension and abduction-adduction movements. Stepwise regression models examined the relationship between BIVA-derived parameters and strength/power variables. Results: Body cellular mass (BCM) positively related to jump height (p =.021, R2 = 74%), jump momentum (p <.001, R2 = 89%), reactive strength index modified (p =.026, R2 = 75%) and peak concentric power (p <.001, R2 = 82%), while intracellular water (ICW) related to peak eccentric (p <.001, R2 = 76%) and concentric force (p <.001, R2 = 77%) as well as to concentric rate of force development together with the phase angle (PhA) (p =.008, R2 = 79% and R2 = 0.015). Regarding isometric assessment, ICW was a significant predictor for all four movement directions, and PhA contributed to hip adduction strength. Conclusions: Body composition, particularly BCM and ICW, significantly predict force- and power-related factors in young alpine skiers. [ABSTRACT FROM AUTHOR]

Alpine skiing performance depends on several qualities, including lower limb strength, power production and flexibility. However, how these physical skills, as well as their relationship, differ between sexes and evolve in growing skiing athletes is still unclear. We analysed sit-and-reach (SR) and three jump test (height and peak power) scores of over 200 alpine ski racers collected across 15 sports seasons. We stratified data among sex and age categories to assess differences and to interpret the relationships between flexibility and jump performance. The mixed models showed a significant age category and sex effect (p < 0.001) for all the flexibility and jump performance scores, with males having higher jump scores but lower SR scores than females, and all performance scores increasing significantly through the age categories. The regressions between SR and the jump scores performed on the whole database were positively significant for the three jump variations (p < 0.001, R 2 ranging from 8.9% to 15.9%), while when the relationship was reanalysed independently in each age–sex group, only some were significant. Both age and sex influenced the performance in the investigated lower limb power and flexibility qualities, along with their relationship. The presented results suggest that lower limb power and flexibility should be longitudinally assessed, as well as their relationship, for training and testing purposes, considering the sex and growth-related modifications. [ABSTRACT FROM AUTHOR]

The persistence of symptoms following COVID-19 infection represents a significant challenge in healthcare management. During the outbreak, tele-rehabilitation emerged as a new tool to support healthcare structures in providing rehabilitation services. This study assessed the effectiveness and the feasibility of a 3-week home-based motor and respiratory rehabilitation program for individuals with long COVID-19 after traditional rehabilitation. Twenty-three patients completed the program and underwent functional tests at different time points (i.e., baseline, at discharge from in-hospital rehabilitation and after tele-rehabilitation). Motor function was evaluated using the instrumented Six-Minutes Walking Test (i6MWT), with monitored heart rate and oxygen saturation. Additionally, respiratory function was measured via forced vital capacity (FVC) and maximal voluntary ventilation (MVV) tests. Significant improvements (p < 0.05) in motor and respiratory function were observed throughout the intervention, including an 18.3% increase in walked distance from the baseline. The findings suggest that the proposed home-based tele-rehabilitation shows potential in enhancing motor and respiratory function in patients with long COVID. Despite limitations such as the small sample size, lack of control group and the preliminary nature of the outcomes observed, the overall findings seem to support the feasibility of the proposed tele-rehabilitation program in managing long COVID symptoms and promoting functional recovery. Nevertheless, further research is needed to validate these findings and explore tele-rehabilitation's potential in broader and different patient populations [ABSTRACT FROM AUTHOR]

It remains unknown if hip joint forces during squat tasks are altered in people with femoroacetabular impingement syndrome (FAIS). The aim of this study is to compare hip joint forces between people with FAIS and healthy controls during double leg squat and single leg squat tasks and within limbs during a single leg squat task in people with FAIS. Kinematic and kinetic data were collected in eight people with FAIS and eight healthy matched controls using 3D motion capture and force plates. AnyBody Modeling System was used to perform musculoskeletal simulations to estimate hip joint angles, forces, and moments for all participants. Estimates were postprocessed with AnyPyTools and converted into normalized time series to be compared using a 1D statistical nonparametric mapping (SnPM) approach. SnPM with an independent samples t‐test model was used to compare people with FAIS to controls, while a paired samples model was used to compare involved to uninvolved limb in people with FAIS. Patients demonstrated lower proximodistal force compared to controls (p < 0.01) and compared to the uninvolved side (p = 0.01) for single leg squat. The smaller joint contact forces in people with FAIS compared to controls could represent a strategy of reduced muscle forces to avoid pain and symptoms during this high demand task. These findings when combined with imaging data could help assess the severity of FAIS on hip related function during higher demand tasks. [ABSTRACT FROM AUTHOR]

Individuals with Down syndrome (DS) require more time to develop motor and/or cognitive skills. Neuromodulation is used to assist in this development. However, there is a gap in the literature on neurophysiological changes that may occur in the primary motor cortex in individuals with DS following neuromodulation. Our objective was to investigate possible neurophysiological changes in brain wave behavior of the primary motor cortex following the administration of anodal transcranial direct current stimulation combined with sensorimotor training. The study involved 12 participants with DS. EEG equipment was used to investigate brain activity. The participants received neuromodulation involving anodal tDCS for 20 minutes with a current of 1 mA combined with virtual reality (VR) training three times a week for a total of ten sessions. We analyzed EGG signals and 3D movement during a reaching movement of the dominant upper limb before and after the ten-session protocol. Significant differences in event-related desynchronization and event-related synchronization of the alpha and beta rhythms were found throughout the evaluations. Brain mapping revealed reductions in power and frequency, demonstrating changes in the patterns of these rhythms in the cerebral cortex. Revealed reorganization of the behavior of alpha and beta waves, as demonstrated by distribution of synchronization and desynchronization of these waves among the regions of the brain. The results suggest that anodal tDCS promotes the reorganization of brain impulses, redirecting these impulses to the required regions more efficiently and contributing to better motor planning. [ABSTRACT FROM AUTHOR]

This work addresses the lack of reliable wearable methods to assess walking gaits in underwater environments by evaluating the lateral hydrodynamic pressure exerted on lower limbs. Sixteen healthy adults were outfitted with waterproof wearable inertial and pressure sensors. Gait analysis was conducted on land in a motion analysis laboratory using an optoelectronic system as reference, and subsequently underwater in a rehabilitation swimming pool. Differences between the normalized land and underwater gaits were evaluated using temporal gait parameters, knee joint angles and the total water pressure on the lower limbs. The proposed method was validated against the optoelectronic system on land; gait events were identified with low bias (0.01s) using Bland-Altman plots for the stride time, and an acceptable error was observed when estimating the knee angle (10.96° RMSE, Bland-Altman bias -2.94°). The kinematic differences between the land and underwater environments were quantified, where it was observed that the temporal parameters increased by more than a factor of two underwater (p<0.001). The subdivision of swing and stance phases remained consistent between land and water trials. A higher variability of the knee angle was observed in water (CV = 60.75%) as compared to land (CV = 31.02%). The intra-subject variability of the hydrodynamic pressure on the foot (CVzfoot = 39.65%) was found to be substantially lower than that of the knee angle (CVz = 67.69%). The major finding of this work is that the hydrodynamic pressure on the lower limbs may offer a new and more reliable parameter for underwater motion analysis as it provided a reduced intra-subject variability as compared to conventional gait parameters applied in land-based studies. [ABSTRACT FROM AUTHOR]