Effect of goalkeepers' offensive participation on team performance in the women Spanish La Liga: a multinomial logistic regression analysis.

This study aimed to examine the effect of goalkeeper distribution on offensive team performance, during the 2018/2019 and 2019-2020 seasons of the Women Spanish La Liga. A total of 10,868 distributions, during 376 matches were analyzed by systematic observation. Two UEFA PRO coaches designed an ad hoc observation instrument "GOALDFOOT" and one observer coded the data after a training process. An intra-observer reliability kappa index of 0.94 was established. Results show how the offensive effectiveness of the goalkeepers was similar to outfield players, with 0.4% of possessions ending in a goal, 2.2% ending in an attempt on goal, with 79.4% ending unsuccessfully. The goalkeeper lost possession from their distribution 32.5% of the time. Multivariate analysis identified several predictors of goalkeepers' distributions. The results show that teams classified in the middle zone of the final classification of the regular league had 1.2 times more probability of being successful compared with the lowest ranked teams (p < 0.05). Goalkeeper's distribution beginning during Open play after a transition, represented an increase success rate of almost 3 times compared to being performed from a free kick (p < 0.05). Passes from outfield players to a goalkeeper made from distant zones to the own goal, decreased the probability of success (p < 0.001). The pitch location of the distribution outcome near to the opponent goal offered the best probability of success. In conclusion, the most effective offensive sequences occur with dynamic transitions initiated with short passes. This information can provide coaches and players with insights to improve the offensive performance of goalkeepers.

Using video docuseries to explore male professional football head coaches' well-being experiences throughout a season.

Football coaches have disclosed how their work environment is unpredictable and demanding, comprising a multitude of stressors which can impede well-being. Additionally, the masculine culture within football often promotes suppression of voice, causing internalisation of thoughts and isolation. Due to professional football head coaches being a seldom-heard group, little is known about how they experience well-being within their given context (i.e., ecological niche). The present study utilised football docuseries and a bioecological framework to explore how four male professional head coaches experienced well-being whilst working in one of the top European football leagues (Premier League, La Liga). Four docuseries were sampled and resulted in the analysis of 31 episodes (Mduration = 46.6 min, SD = 4.5 min). The study implemented an adapted interpretative phenomenological analysis approach to illuminate convergences and divergences in contextual accounts. These accounts resulted in five group experiential themes: 'I belong to the game'; 'he belongs to the game'; 'you need the right people around you'; 'it's difficult to describe the manager without describing the person'; and 'people are trying to stab you'. The findings indicate that football coaches may experience identity conflicts and become deeply absorbed in their work. This impacts not only their well-being but also their family's, who they often turn to for social support. Consequently, by unveiling nuanced challenges to coaches' well-being, organisations may be better informed to offer more aligned and bespoke well-being support systems.

Joint moments and power in the acceleration phase of bend sprinting.

Joint kinetics of the lower limb (hip, knee, ankle, midfoot and metatarsophalangeal joints) were investigated during the acceleration phase of bend sprinting and straight-line sprinting. Within the bend sprinting literature, it is generally accepted that sprint performance on the bend is restricted by moments in the non-sagittal plane preventing the production of force in the sagittal plane. However, there is limited evidence in conditions representative of elite athletics performance that supports this hypothesis. Three-dimensional kinematic and ground reaction force data were collected from seven participants during sprinting on the bend (36.5 m radius) and straight, allowing calculation of joint moment, power and energy. No changes in extensor moment were observed at the hip and knee joints. Large effect sizes (g = 1.07) suggest a trend towards an increase in left step peak ankle plantarflexion moment. This could be due to a greater need for stabilisation of the ankle joint as a consequence of non-sagittal plane adaptations of the lower limb. In addition, the observed increase in peak MTP joint plantar-flexor moment might have implications for injury risk of the fifth metatarsal. Energy generation, indicated by positive power, in the sagittal plane at the MTP and ankle joints was moderately lower on the bend than straight, whilst increases in non-sagittal plane energy absorption were observed at the ankle joint. Therefore, energy absorption at the foot and ankle may be a key consideration in improving bend sprinting performance.

Measurement of bend sprinting kinematics with three-dimensional motion capture: a test-retest reliability study.

Sprint velocity decreases on the bend when compared with the straight, therefore understanding technique during bend sprinting could have important implications for aiding race performance. Few bend sprinting studies have used optoelectronic cameras to investigate kinematic variables. Limited published evidence regarding the reliability of marker sets in conditions representative of elite bend sprinting makes model selection difficult. Therefore, a test-retest protocol was conducted to establish the reliability and minimum detectable difference of a lower limb and trunk marker set during bend sprinting (radius: 36.5 m). Six participants completed five, 60 m trials at maximum effort, with data collected at 38-45 m. This was repeated 2-7 days later. Spatio-temporal (e.g., contact time) and kinematic variables (e.g., peak joint angles) were evaluated. Intra-class correlation coefficients (ICC) were used to determine the between- and within-day reliability. Between-day reliability (ICC 3, k) was fair to excellent for all variables. Compared to between-day, within-day reliability demonstrated stronger agreement for the majority of variables. Thus, same-day data collection is preferable. It has been established that the marker set is reliable for future use. In addition, the minimal detectable difference was calculated which serves as useful reference for future research in bend sprinting.

Kinematic modifications of the lower limb during the acceleration phase of bend sprinting.

A decrease in speed when sprinting on the bend compared with the straight has been attributed to kinetic, kinematic and spatiotemporal modifications. Although maximal speed is dependent on an athlete's ability to accelerate, there is limited research investigating the acceleration phase of bend sprinting. This study used a lower limb and trunk marker set with 15 optoelectronic cameras to examine kinematic and spatiotemporal variables of the lower limb during sprinting on the bend and straight. Nine sprinters completed up to six 30 m maximal effort trials in bend (radius 36.5 m, lane one) and straight conditions. An increase in body lateral lean at touchdown resulted in a number of asymmetric kinematic modifications. Whilst the left limb demonstrated a greater peak hip adduction, peak hip internal rotation and peak ankle eversion on the bend compared with the straight, the right limb was characterised by an increase in peak hip abduction. These results demonstrate that kinematic modifications start early in the race and likely accumulate, resulting in greater modifications at maximal speed. It is recommended that strength and conditioning programmes target the hip, ankle and foot in the non-sagittal planes. In addition, sprint training should prioritise specificity by occurring on the bend.

Horizontal force production and multi-segment foot kinematics during the acceleration phase of bend sprinting.

This paper investigated horizontal force production, foot kinematics, and metatarsophalangeal (MTP) joint push-off axis use during acceleration in bend (anti-clockwise) and straight-line sprinting. It was hypothesized that bend sprinting would cause the left step push-off to occur about the oblique axis, resulting in a decrease in propulsive force. Three-dimensional kinematic and ground reaction force data were collected from nine participants during sprinting on the bend (36.5 m radius) and straight. Antero-posterior force was reduced at 38%-44% of stance during bend sprinting compared with the straight. This coincided with an increase in mediolateral force for the majority of the stance phase (3%-96%) on the bend compared with the straight. In addition, a lower propulsive impulse was reported on the bend compared with the straight. Analysis of multi-segment foot kinematics provides insight into the possible mechanisms behind these changes in force production. Mean mediolateral center of pressure position was more lateral in relation to the second metatarsal head in the left step on the bend compared with the straight, indicating the oblique axis was used for push-off at the MTP joint. Greater peak joint angles of the left foot were also reported, in particular, an increase in left step midfoot eversion and internal ankle rotation. It is possible these changes in joint kinematics are associated with the observed decrease in propulsive force. Therefore, practitioners should seek to strengthen muscles such as tibialis posterior in frontal and sagittal planes and ensure specificity of training which may aid in addressing these force reductions.

Emergency Department Time Course for Mild Traumatic Brain Injury Workup.

INTRODUCTION: Mild traumatic brain injury (mTBI) is a common cause for visits to the emergency department (ED). The actual time required for an ED workup of a patient with mTBI in the United States is not well known. National emergency medicine organizations have recommended reducing unnecessary testing, including head computed tomography (CT) for these patients.10. METHODS: To examine this issue, we developed a care map that included each step of evaluation of mTBI (Glasgow Coma Scale Score 13-15) - from initial presentation to the ED to discharge. Time spent at each step was estimated by a panel of United States emergency physicians and nurses. We subsequently validated time estimates using retrospectively collected, real-time data at two EDs. Length of stay (LOS) time differences between admission and discharged patients were calculated for patients being evaluated for mTBI. RESULTS: Evaluation for mTBI was estimated at 401 minutes (6.6 hours) in EDs. Time related to head CT comprised about one-half of the total LOS. Real-time data from two sites corroborated the estimate of median time difference between ED admission and discharge, at 6.3 hours for mTBI. CONCLUSION: Limiting use of head CT as part of the workup of mTBI to more serious cases may reduce time spent in the ED and potentially improve overall ED throughput.

Effects of scaling task constraints on emergent behaviours in children's racquet sports performance.

Manipulating task constraints by scaling key features like space and equipment is considered an effective method for enhancing performance development and refining movement patterns in sport. Despite this, it is currently unclear whether scaled manipulation of task constraints would impact emergent movement behaviours in young children, affording learners opportunities to develop relevant skills. Here, we sought to investigate how scaling task constraints during 8 weeks of mini tennis training shaped backhand stroke development. Two groups, control (n = 8, age = 7.2 ±â€¯0.6 years) and experimental (n = 8, age 7.4 ±â€¯0.4 years), underwent practice using constraints-based manipulations, with a specific field of affordances designed for backhand strokes as the experimental treatment. To evaluate intervention effects, pre- and post-test match-play characteristics (e.g. forehand and backhand percentage strokes) and measures from a tennis-specific skills test (e.g. forehand and backhand technical proficiency), were evaluated. Post intervention, the experimental group performed a greater percentage of backhand strokes out of total number of shots played (46.7 ±â€¯3.3%). There was also a significantly greater percentage of backhand winners out of total backhand strokes observed (5.5 ±â€¯3.0%), compared to the control group during match-play (backhands = 22.4 ±â€¯6.5%; backhand winners = 1.0 ±â€¯3.6%). The experimental group also demonstrated improvements in forehand and backhand technical proficiency and the ability to maintain a rally with a coach, compared to the control group. In conclusion, scaled manipulations implemented here elicited more functional performance behaviours than standard Mini Tennis Red constraints. Results suggested how human movement scientists may scale task constraint manipulations to augment young athletes' performance development.

Development of expertise in elite and sub-elite British rugby league players: A comparison of practice experiences.

Previous studies have investigated how individuals reach an expert level by counting the number of hours engaged in specific practice types. Here we sought to understand and compare the microstructure (e.g. practice tasks undertaken) of these practice hours experienced by elite and sub-elite British rugby league players. Semi-structured interviews explored the practice experiences of eight international and eight domestic level players. A two-staged thematic analysis was used to interpret the data. The analysis revealed that both player groups experienced a rich and narrow landscape of affordances and were exposed to early diversification of sports experiences during childhood. Differences were identified in domestic level players' experiences of amateur and professional sports, where episodes of negative developmental environments were reported. International players' practice experiences revealed differences in their professional careers, where exposure to scenario-based practice and dynamic learning environments were reported. The findings suggest that insights from ecological dynamics provide a suitable theoretical framework to guide coaches in the design of practice environments that should consider the physical, psychological, emotional and social dimensions of expertise acquisition.

Physical and Emotional Benefits of Different Exercise Environments Designed for Treadmill Running.

(1) Background: Green physical activity promotes physical health and mental wellbeing and interesting questions concern effects of this information on designing indoor exercise environments. This study examined the physical and emotional effects of different nature-based environments designed for indoor treadmill running; (2) Methods: In a counterbalanced experimental design, 30 participants performed three, twenty-minute treadmill runs at a self-selected pace while viewing either a static nature image, a dynamic nature image or self-selected entertainment. Distance ran, heart rate (HR) and five pre-and post-exercise emotional states were measured; (3) Results: Participants ran farther, and with higher HRs, with self-selected entertainment compared to the two nature-based environment designs. Participants attained lowered anger, dejection, anxiety and increased excitement post exercise in all of the designed environments. Happiness increased during the two nature-based environment designs compared with self-selected entertainment; (4) Conclusions: Self-selected entertainment encouraged greater physical performances whereas running in nature-based exercise environments elicited greater happiness immediately after running.

Emergent perception-action couplings regulate postural adjustments during performance of externally-timed dynamic interceptive actions.

Studies of postural coordination during performance of externally-timed interceptive actions, such as catching a ball, have been infrequent, with advanced visual information from a thrower's actions towards a catcher, typically excluded in experimental task constraints. Yet previous research suggests that manipulating participant access to such information alters their hand movements and gaze behaviours when catching. In this study, we manipulated participant access to advanced information of a thrower's actions, and from ball flight, while recording whole body kinematic and kinetic data to investigate effects on postural control during performance of interceptive actions. Twelve participants attempted to make or simulate performance of one-handed catches in three experimental conditions: when facing integrated videos of advanced visual information and ball flight only, videos of a thrower's actions only, and of ball flight only. Findings revealed when integrating advanced visual information and ball flight, and when participants were provided with ball flight information only, lower limb adjustments were primarily used to regulate posture. However, movement was initiated earlier when advanced visual information was available prior to ball flight, resulting in more controlled action and superior catching performance in the integrated condition. When advanced visual information was presented without ball flight, smaller displacements were observed in lower limb joint angles, resulting in upward projection of the centre of mass, compared to a downward trajectory when ball flight information was available, in the integrated video and ball flight, and ball-flight only conditions. Results revealed how postural coordination behaviors are dependent on specific informational constraints designed into experiments, implying that integration of task constraints in studies of human perception and action needs careful consideration.