Decision-Making Time and Neuromuscular Coordination in Youth and Senior Soccer Goalkeepers.

The aim of this study was to compare soccer goalkeepers' decision-making times following a shot on goal and to determine goalkeepers' movement pattern structures using EMG in a typical game situation (two-on-one). Two groups of goalkeepers (n = 60) took part in the study: Group A, the senior group (22.00 ± 2.35 years of age), and Group B, the youth group (15.38 ± 1.32 years of age). The goalkeepers' decision-making times were measured by using EMG from the moment the attacker struck the ball until the completion of the saving action by the goalkeeper. Subsequently, the goalkeepers' movement pattern structure was determined (for both Groups A and B), and the values of muscle bioelectrical tension during a typical defensive situation in training conditions were revealed. The findings clearly indicate a significantly (p = 0.001) shorter decision-making time in experienced goalkeepers (250-260 ms) than in novices (300-320 ms). In addition, the movement pattern structure confirmed the hypotheses on the economization of effort and the visual-muscular coordination of the postural muscles (calf muscles) that affect soccer goalkeepers. The study also demonstrated a lower bioelectric tension of the gastrocnemius muscle (GAS.MED. RT-p = 0.008; GAS.LAT. RT-p = 0.030) in the expert goalkeepers.

Movement Patterns of Polish National Paralympic Team Wheelchair Fencers with Regard To Muscle Activity and Co-Activation Time.

The aim of this study was to determine muscle co-activation and muscle activity time using EMG in Paralympic wheelchair fencers categorized into two disability-level groups: A (n= 7) and B (n= 9). The study was carried out with the use of a 16-channel EMG system. The surface EMG electrodes were placed on the fencer's body along nine channels: arm muscles - deltoideus middle head (DEL), triceps brachii (TRI) and biceps brachii (BC); forearm muscles - extensor carpi radialis longus (ECR), flexor carpi radialis (FCR); postural (abdominal and back) muscles - the right and the left external oblique abdominal (EOA RT and LT) and latissimus dorsi (LD RT and LT). To assess the relative level of co-activation (simultaneous contraction of both muscles) for the TRI-BC, ECR-FCR, LD RT-EDA RT and LD LT-EDA LT muscle pairs, the co-activation index (CI) was calculated. The collected data were processed using Jamovi. The study hypotheses were verified at the level of significance of p≤0.05 (Welch's t-test). The normal distribution of analyzed statistical features was checked with the Shapiro-Wilk test. The analysis of muscle activation time, as a percent ratio of three attempts executed in a series, confirmed the study assumptions. Fencers from Group A had a shorter activation time in all tested muscles, with the exception of the ECR (58.24), than fencers from Group B. This confirms that the activation of antagonist muscles representing a centrally programmed anticipatory mechanism stabilizing technical actions was particularly intensified in Group A fencers. The study results indicate that the standard co-activation index (CI) of key muscles involved in wheelchair fencing ranges from 48 to 51%.

The Impact of Four High-Altitude Training Camps on the Aerobic Capacity of a Short Track PyeongChang 2018 Olympian: A Case Study.

This study characterizes high-altitude training camps and their effect on the aerobic capacity of a Polish national team member (M.W.), who was a participant in the PyeongChang 2018 Winter Olympic Games (body weight: 59.6 kg, body height: 161.0 cm, fat mass: 10.9 kg and 18.3% of fat tissue, fat-free mass: 48.7 kg, muscle mass: 46.3 kg, and BMI = 23.0 kg/m2). The tests were conducted in the periods from April 2018 to September 2018 and April 2019 to September 2019 (period of general and special preparation). The study evaluated aerobic and anaerobic capacity determined by laboratory tests, a cardiopulmonary graded exercise test to exhaustion performed on a cycle ergometer (CPET), and the Wingate anaerobic test. Based on the research, training in hypobaric conditions translated into significant improvements in the skater's exercise capacity recorded after participating in the Olympic Winter Games in Korea (February 2018). In the analyzed period (2018-2019), there was a significant increase in key parameters of aerobic fitness such as anaerobic threshold power output (AT-PO) [W]-223; power output POmax [W]-299 and AT-PO [W/kg]-3.50; (POmax) [W/kg]-4.69; and AT-VO2 [mL/kg/min]-51.3; VO2max [mL/kg/min]-61.0. The athlete showed high-exercise-induced adaptations and improvements in the aerobic metabolic potential after two seasons, in which four training camps were held in altitude conditions.

Correlations between the EMG Structure of Movement Patterns and Activity of Postural Muscles in Able-Bodied and Wheelchair Fencers.

The study involved Paralympic wheelchair fencers (N = 7) in two disability categories, and able-bodied female epee fencers (N = 7), members of the polish paralympic fencing teams. The performance of postural muscles and sword arm muscles in both groups of fencers, and of the front and rear leg muscles in the able-bodied fencers, was examined using surface electromyography with an accelerometer and the OptiTrack motion analysis system, as well as ground force reaction platforms. The activation sequence of individual muscles was determined and the structure of movement patterns in able-bodied and wheelchair fencers was formulated. A statistically significant correlation was found between the complex motor reaction time and latissimus dorsi muscle activation (p = 0.039, Z = -2.062) in wheelchair fencers. High correlations between the vertical force and EMG signal values of the gastrocnemius caput laterale muscle (0.85 for p = 0.022) were found in able-bodied fencers. A heuristic analysis indicated the significance of postural muscles in the movement patterns of wheelchair and able-bodied fencers. These muscles play a crucial role in the anticipatory postural adjustment of the trunk during technical fencing actions, including attacks on the opponent's body.

Expectations of Patients Recovering from SARS-CoV-2 towards New Forms of Pulmonary Rehabilitation.

The purpose of this study was to explore the experiences of patients attending an innovative technology-enhanced pulmonary rehabilitation program of National Health Found Program in Poland. The study included two groups of patients participating in post-COVID-19 stationary rehabilitation. Patients from group I (127 individuals) contracted COVID-19 in 2020, while patients from group II fell ill in 2021 (68 individuals). The study used a self-administered questionnaire. This study was designed as an acceptability study. In the experience related to COVID-19 in both groups of the respondents, the possibility of undertaking inpatient rehabilitation in a hospital ward played an important and positive role. Patients who experienced COVID-19 symptomatically expected that rehabilitation would eliminate the related dysfunctions, such as reduced respiratory efficiency of the lungs, disorders of the nervous system, and cognitive disorders (the so-called brain fog). All respondents who experienced symptomatic COVID-19 positively assessed the rehabilitation program offered. Among the highest-rated rehabilitation, elements were identified: exercise on a cycle ergometer implemented with video stimulation, group fitness exercises, and breathing exercises. Other innovative forms of rehabilitation were positively evaluated by 10% to 25% of patients.

Wavelet coherence as a measure of trunk stabilizer muscle activation in wheelchair fencers.

BACKGROUND: Intermuscular synchronization constitutes one of the key aspects of effective sport performance and activities of daily living. The aim of the study was to assess the synchronization of trunk stabilizer muscles in wheelchair fencers with the use of wavelet analysis. METHODS: Intermuscular synchronization and antagonistic EMG-EMG coherence were evaluated in the pairs of the right and the left latissimus dorsi/external oblique abdominal (LD/EOA) muscles. The study group consisted of 16 wheelchair fencers, members of the Polish Paralympic Team, divided into two categories of disability (A and B). Data analysis was carried out in three stages: (1) muscle activation recording using sEMG; (2) wavelet coherence analysis; and (3) coherence density analysis. RESULTS: In the Paralympic wheelchair fencers, regardless of their disability category, the muscles were activated at low frequency levels: 8-20 Hz for category A fencers, and 5-15 Hz for category B fencers. CONCLUSIONS: The results demonstrated a clear activity of the trunk muscles in the wheelchair fencers, including those with spinal cord injury, which can be explained as an outcome of their intense training. EMG signal processing application have great potential for performance improvement and diagnosis of wheelchair athletes.

Neuromuscular, Perceptual, and Temporal Determinants of Movement Patterns in Wheelchair Fencing: Preliminary Study.

The objective of the present study was to determine the structure of the movement pattern performed during a wheelchair fencing lunge that is executed in response to visual and sensory stimuli. In addition, a comparison was made between fencers in the categories A and B of disability. In addition, the analysis involved the correlation between the duration of the sensorimotor response and the value of the bioelectric signal recorded in selected muscles. Seven Paralympic team athletes specializing in wheelchair fencing (3 in category A and 4 in category B) participated in the research. The fencers perform at international level competitions and are multiple medalists of the Paralympic Games. In the study, a wireless system for sEMG and accelerometer signal measurement was employed to test the intervals between the initiation of the lunge attack and its termination defined by the touch of the weapon on the coach's torso. The electrodes were placed on 9 key muscles responsible for the effectiveness of the executed attack: DEL, TRI, BC, ECR FCR, LD, and EAO. The significant intergroup difference in the muscle activation was found to be 0.333 s for category A fencers and 0.522 s for category A fencers at p = 0.039 applies to the latissimus dorsi (LD LT) muscle, which demonstrates its significance as a postural muscle in the structure of the examined movement pattern. In terms of the values of EMG, a tendency for higher MVC (%) values in most muscles for category A competitors was recorded. The latissimus dorsi (DL RT) muscle with an intergroup difference of MVC-114.63 for cat. A and 67.50 for cat. B at p = 0.039 turned out to play a significant role. The results prove the role of postural muscles: external abdominal oblique and latissimus dorsi on the effectiveness of the attacks executed in wheelchair fencing.

sEMG Activation of the Flexor Muscles in the Foot during Balance Tasks by Young and Older Women: A Pilot Study.

OBJECTIVE: In this publication, we suggest that young adults and seniors use various defense mechanisms to counteract loss of balance. One of the hypotheses is the change in the coordination of antagonistic muscle groups, especially within the ankles. In this study, we tried to determine if there is a relationship between the condition from resilient, to pre-frail, to frail and the ability to maintain balance during free standing and balance tasks. The aim of the study was to define the importance of muscle activity in the ankle joint, dorsal flexor of the foot for the following: tibialis anterior (TA), plantar flexor of the foot gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and peroneus longus (PER), during balance tasks with eyes open (EO) and closed (EC). We hypothesized that there are differences in the activity and co-activation of the tested muscles in young and older women, which may indicate an increased risk of falls and walking disorders. MATERIALS AND METHODS: A group of 20 women qualified for the study. The group was divided into two subgroups, young (G1) and elderly women (G2). The aim of the study was to define the importance of muscle activity in the ankle joint, dorsal flexor of the foot for the following: tibialis anterior (TA), plantar flexor of the foot gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and peroneus longus (PER), during balance tasks with eyes open (EO) and closed (EC). RESULTS: In this study, we observed significant differences between groups in the maximum and mean values of electromyography activity (EMG) activation of the examined muscles on different types of surfaces and with open and closed eyes. Older women generated higher values of EMG activation in all muscles except the gastrocnemius medialis muscle. The results were significant for co-activation at rest for muscles as follows: tibialis anterior and gastrocnemius medialis with eyes closed (p = 0.01) and peroneus and gastrocnemius lateralis at rest with eyes open (p = 0.03), eyes closed (p = 0.04), and on a foam (p = 0.02). The sEMG amplitude of the tested muscles means that agonist muscle activity changed relative to antagonistic muscle activity. CONCLUSIONS: Activation of sEMG and coordination of ankle muscles during balance tasks change with age. It can be hypothesized that assessment of balance during free standing and equivalent tasks can predict the state of frailty, after taking into account other physiological variables that are believed to affect balance control.

Coordination Aspects of an Effective Sprint Start.

The aim of the present study was to examine differences in the movement structure and the coordination aspects expressed by bioelectrical tension indicators between a group of experts/sprinters and a group of novices/students. A group consisted of 20 sprinters and a control group consisted of 35 master's physical education students. A 16-channel surface electromyography (14 muscles) and two cameras with recording speed of 250 frames/per second were used. Significant differences were found between reaction time (p < 0.005) and time at 30 m of the covered sprinting distance (p < 0.001) between the students and advance athletes. Furthermore, the sprinters activated the back foot (taking off the starting blocks) and the front foot (first ground contact) earlier, which correlated with the attained times at 5 (r = 0.66) and 10 m (r = 0.62) of the covered sprinting distance. The most important component of the sprint start, apart from the muscle strength of the legs, is the appropriate motor coordination, which greatly affects the generation of power in the legs at the right time and optimal duration.