A prospective comparison of lower extremity kinematics and kinetics between injured and non-injured collegiate cross country runners

Collegiate cross country runners are at risk for running related injuries (RRI) due to high training volume and the potential for aberrant lower extremity biomechanics. However, there is a need for prospective research to determine biomechanical risk factors for RRI. The purpose of this study was to prospectively compare ankle, knee, and hip kinematics and kinetics and ground reaction force characteristics between injured and non-injured cross country runners over a 14-week season. Biomechanical running analyses were conducted on 31 collegiate-cross country runners using a 3-dimensional motion capture system and force plate prior to the start of the season. Twelve runners were injured and 19 remained healthy during the course of the season. Peak external knee adduction moment (KAM), a surrogate for frontal plane knee loading, and peak ankle eversion velocity were greater in runners who sustained an injury compared to those who did not, and no differences were noted in ground reaction force characteristics, or hip kinematics and kinetics. Reducing the KAM and ankle eversion velocity may be an important aspect of preventing RRI.     

A new Bayesian procedure for the estimation of the referees' decision thresholds and agreement. The case of professional handball refereeing

In double refereeing, agreement between referees is fundamental for the achievement of a flawless and smooth refereeing activity. Nonetheless, the agreeement can be affected by several external and internal factors, with a negative impact on the consistency of the refereeing and the fluidity of the game. The referee’s Decision Threshold (DT) is the limit above which the evidence of a foul results in the call of an infraction by the referee. It represents the individual refereeing style, and it is one of the factors that can contribute to low agreement between the referees. We present an application of a new Bayesian procedure to estimate referee’s DT in a typical refereeing task. To this end, 56 italian professional handball (FIGH) referees were asked to evaluate 96 potential foul plays, belonging to four different infraction types: 7-m throw, passive play, offensive foul, disciplinary sanctions. The proposed method provides information about: (i) referee’s individual DT; (ii) the agreement between pairs of referees (i.e., one-to-one); (iii) the agreement between each referee and all the other referees (i.e., one-to-total); (iv) the agreement between each referee and a reference referee (i.e., one-to-expert); (v) the proportion of agreement between the referees and a reference referee for each potential foul play. Sport federations would profit by this procedure in different ways: by using the information about the DT to train referees, by detecting referees with a low agreement with their colleagues or with the reference referee, by focusing training on specific plays to improve the arbitration class internal consistency.     

Mobility and migration experiences of transnational coaches within the Israeli handball context

ObjectivesDespite a growing body of literature on athletes' migration, the mobility and migration experiences of coaches have received limited attention. In this study, we explored the mobility and migration experiences of transnational coaches operating within the Israeli handball context.DesignA qualitative study was conducted, underpinned by our relativist ontology and a constructionist epistemological position.MethodsEight male professionals (e.g., national team coaches, senior team coaches, youth coaches), working (currently, or most recently) in national teams and clubs, who migrated to Israeli handball within the past five years were interviewed. A thematic analysis, integrating inductive and deductive reasoning, was applied in data analysis. Meticulousness was enhanced by focusing on a worthy topic, maintaining credibility, critical friends, producing generalization, and making a significant contribution.ResultsThe analysis yielded raw-data codes, further organized into lower-order themes and three higher-order themes reflecting transnational coaches' migration and mobility experiences within the Israeli handball context, including (a) cultural transition, (b) cultural adaption, and (c) coaches' personal insights about mobility and migration. The findings are conceptually analyzed and discussed in relation to the previous research on coaches' career migration.Discussion and conclusionThe findings emphasize the complexity of the migration process, accompanied by varying motivations, demands and barriers, active decision-making; all within the framework of cultural adaptation. The participants endorsed a transnational coaching career, driven by their open-mind mentality and personal-professional growth.     

Effect of stride length on overarm throwing delivery: A linear momentum response

Changing stride length during overhand throwing delivery is thought to alter total body and throwing arm linear momentums, thereby altering the proportion of throwing arm momentum relative to the total body. Using a randomized cross-over design, nineteen pitchers (15 collegiate and 4 high school) were assigned to pitch two simulated 80-pitch games at ±25% of their desired stride length. An 8-camera motion capture system (240 Hz) integrated with two force plates (960 Hz) and radar gun tracked each throw. Segmental linear momentums in each plane of motion were summed yielding throwing arm and total body momentums, from which compensation ratio’s (relative contribution between the two) were derived. Pairwise comparisons at hallmark events and phases identified significantly different linear momentum profiles, in particular, anteriorly directed total body, throwing arm, and momentum compensation ratios (P ⩽ .05) as a result of manipulating stride length. Pitchers with shorter strides generated lower forward (anterior) momentum before stride foot contact, whereas greater upward and lateral momentum (toward third base) were evident during the acceleration phase. The evidence suggests insufficient total body momentum in the intended throwing direction may potentially influence performance (velocity and accuracy) and perhaps precipitate throwing arm injuries.     

Coupling kinematics of memory and kinematics of movement: the conditions for a psychological relativity

The organization of spatial and temporal information relative to memory-movement interactions was studied in a recall task. Stimuli consisted of four different configurations of eight dots, presented sequentially. In two configurations, the stimuli were spatiotemporal congruent, with (constant or variable) inter-stimulus distances corresponding to (constant or variable) inter-stimulus time intervals. In the other two configurations, the stimuli were spatiotemporal incongruent, with (constant or variable) inter-stimulus distances not corresponding to (variable or constant) inter-stimulus time intervals. After a learning phase consisting of 20 presentations of the target configuration, participants performed a series of pointing movements to reproduce both spatial and temporal characteristics of the stimulus 60 times in succession without ever re-examining the target configuration. Classically, in incongruent spatiotemporal conditions, the reproduction of, respectively, constant distances or constant time intervals are strongly disturbed by the simultaneous perception of variable inter-stimulus time intervals (Tau effect) or variable distances (Kappa effect). We assume that these spatiotemporal dependencies, which occur when the response relates to one dimension only, crucially depend on the non-integration of motoric aspects in memory.     

Qualitative and quantitative measures of joint attention development in the first year of life: A scoping review

Joint attention (JA) is the purposeful coordination of an individual's focus of attention with that of another and begins to develop within the first year of life. Delayed, or atypically developing, JA is an early behavioural sign of many developmental disabilities and so assessing JA in infancy can improve our understanding of trajectories of typical and atypical development. This scoping review identified the most common methods for assessing JA in the first year of life. Methods of JA were divided into qualitative and quantitative categories. Out of an identified 13,898 articles, 106 were selected after a robust search of four databases. Frequent methods used were eye-tracking, electroencephalography, behavioural coding, and the Early Social Communication Scale (ECSC). These methods were used to assess JA in typically and atypically developing infants in the first year of life. This study provides a comprehensive review of the past and current state of measurement of JA in the literature, the strengths and limitations of the measures used, and the next steps to consider for researchers interested in investigating JA to strengthen this field going forwards.     

Real-time kinematic biofeedback improves scapulothoracic control and performance during scapular-focused exercises: A single-blind randomized controlled laboratory study

Emerging evidence suggests that scapular-focused therapeutic exercises hold promise for shoulder dynamic stability retraining. While recent findings show that therapeutic exercises can alter scapular neuromuscular function measured with muscle electromyography, no study has yet addressed the effects of kinematic biofeedback for improving scapulothoracic control and performance. The aim of this study was to assess the effectiveness of kinematic biofeedback on motor relearning transfer during shoulder flexion and a daily activity, on the quality of scapular-focused exercise performance, and on execution time. Thirty healthy young adults were randomly distributed into two groups. Skin mounted electromagnetic sensors were used to collect kinematic data of the thorax, scapula and humerus while subjects performed a shoulder flexion and a daily activity, prior to and after scapular-focused exercises. For both groups, the exercise execution error and the execution time determined the scapulothoracic control and performance. Significant statistical differences were found in the exercise execution error results within the experimental group (z = 5.313; p = 0.037) and between groups (u = 37.00; p = 0.001; u = 64.00; p = 0.024). This study’s results demonstrate that real-time kinematic biofeedback improves scapulothoracic control and performance during scapular-focused exercise execution.     

The kinematics of belief and desire

Richard Jeffrey regarded the version of Bayesian decision theory he floated in ‘The Logic of Decision’ and the idea of a probability kinematics—a generalisation of Bayesian conditioning to contexts in which the evidence is ‘uncertain’—as his two most important contributions to philosophy. This paper aims to connect them by developing kinematical models for the study of preference change and practical deliberation. Preference change is treated in a manner analogous to Jeffrey’s handling of belief change: not as mechanical outputs of combinations of intrinsic desires plus information, but as a matter of judgement and of making up one’s mind. In the first section Jeffrey’s probability kinematics is motivated and extended to the treatment of changes in conditional belief. In the second, analogous kinematical models are developed for preference change and in particular belief-induced change that depends on an invariance condition for conditional preference. The two are the brought together in the last section in a tentative model of pratical deliberation. This paper is one of a pair dedicated to Richard Jeffrey and prepared for a workshop held in his memory at the 26th International Wittgenstein Symposium. My thanks to the organisers of, and the participants in, this workshop and to two anonymous referees for their comments.     

Situation Awareness in sports: A scoping review

Situation Awareness (SA) has been studied in many dynamic environments such as aviation.transportation, and medicine, but has not been extensively applied to sporting environments. Research from other areas suggests that SA is an important aspect of successful performance. The objectives of this scoping review were to identify what types of SA frameworks are used in sports, what methods are used to directly assess SA in sports, and what are the cognitive skills that have been linked to SA in sports. Seven databases were searched for peer-reviewed papers examining SA in a sporting context. The literature search revealed a scarcity of studies that directly describe SA within a sporting context. The most common frameworks described in the sporting literature were the three-level framework and Distributed Situation Awareness. The direct methods of measuring SA in sports varied and included the Situation Awareness Global Assessment Technique (SAGAT), Cognition Self-Assessment Tool (CSAT), and Random Number Cognition Test (RANCT) tools. Lastly, the cognitive skills linked to SA in sports included visual behaviours, anticipation, and decision-making. After evaluating the research, we argue there is potential benefit in applying SA to a sporting context but there are, currently, issues of validity and reliability in how SA is described and assessed in sports. Suggestions are made for how we might advance in this field of research.     

Effects of scapular retraction/protraction position and scapular elevation on shoulder girdle muscle activity during glenohumeral abduction

According to scapulohumeral rhythm, shoulder abduction is followed through scapular upward rotation to ensure joint mobility and stability. Of interest, the shoulder abduction can be performed holding the scapula in different positions and in association with scapular elevation, with possible effects on shoulder muscle activity. Therefore, the aim of the study was to analyze the activity of relevant shoulder muscles and the activity ratios between the scapulothoracic muscles, during shoulder abduction performed in different combinations of scapular position (neutral, retracted, protracted) and scapular elevation.The electromyographic activity of middle deltoid, serratus anterior, upper, middle and lower fibers of trapezius was recorded during shoulder abduction movements executed holding the scapula in neutral, retracted and protracted position, and subsequently a shoulder elevation movement. The activation of each muscle and the scapulothoracic muscles activity ratios were determined every 15 degrees, from 15° to 120° of abduction.Scapular retraction led to higher activation of the entire trapezius muscle, whereas protraction induced higher upper trapezius, middle deltoid and serratus anterior activity, along with lower activity of middle and lower trapezius. Shoulder elevation led to higher activity of the upper trapezius and middle deltoid. Moreover, it induced lower activation of the serratus anterior and middle and lower trapezius, thus leading to high ratios between the upper trapezius and the other scapulothoracic muscles, especially between 15 and 75 degrees of abduction.This study highlights that shoulder abduction performed with scapular protraction and in combination with scapular elevation leads to increased activity of the middle deltoid and upper trapezius, resulting in imbalances between the scapulothoracic muscles that could hamper the optimal scapulohumeral rhythm. The abduction performed in the aforementioned scapular conditions also induce potential reciprocal inhibition effects between the movers and stabilizers muscles of scapula, suggesting different motor control strategies of integrating a common shoulder movement with various modification of the scapular position.     

Behavior analysis in college classrooms: A scoping review

We conducted a scoping review of interventions that have been implemented classroom-wide in college classroom settings. We searched nine behavior-analytic journals from 2000 through 2020. We identified 59 studies that met our inclusion criteria and organized them into 13 categories: acceptance and commitment therapy (n = 1), equivalence-based instruction (n = 1), SAFMEDS (n = 4), guided notes (n = 4), response cards (n = 5), group contingencies (n = 5), interteaching (n = 6), programmed instruction, PSI, computer-aided (CA)PSI (n = 7), contingency arrangements (n = 15), feedback (n = 4), online delivery techniques (n = 4), game study sessions (n = 2), and peer-generated examples (n = 1). The interventions have been used with undergraduate and graduate students across various course topics and modalities. Most interventions produced positive results, commonly assessed via quiz and exam scores. This review presents the scope of interventions, their characteristics, and recommendations for future research.     

The effectiveness of penalty takers' deception: A scoping review

Attackers are supposed to take advantage of producing deceptive actions in competitive ball sports, particularly in penalty situations. We conducted a scoping review of the experimental literature to scrutinize whether penalty takers do indeed benefit from using deceptive actions in penalty situations, especially by increasing the likelihood to score a goal. Studies using video-based and in-situ tasks in which soccer and handball goalkeepers try to save a penalty were evaluated. Results showed that penalty takers' manipulation of spatial information available to the goalkeeper during deception (i.e., by using misleading and/or disguising actions) is less effective in in-situ than video-based studies. We argue that this difference occurs because goalkeepers adapt differently to the spatiotemporal constraints in the video-based and in-situ tasks. Goalkeepers appear to prioritize picking up spatial information in video-based tasks while prioritizing temporal information in-situ tasks. Therefore, the manipulation of spatial information appears to be less effective in the more representative in-situ studies than in video-based studies. In order to deceive, penalty takers are advised to manipulate temporal information during on-field penalty situations.     

Effect of stride length on overarm throwing delivery: Part II: An angular momentum response

This is the second component of a two-part series investigating 3D momentum profiles specific to overhand throwing, where altering stride reportedly influences throwing mechanics resulting in significantly different physiologic outcomes and linear momentum profiles. Using a randomized cross-over design, nineteen pitchers (15 collegiate and 4 high school) were assigned to pitch two simulated 80-pitch games at ±25% of their desired stride length. An 8-camera motion capture system (240 Hz) integrated with two force plates (960 Hz) and radar gun tracked each overhand throw. Segmental angular momentums were summed yielding throwing arm and total body momentums, from which compensation ratio’s (relative contribution between the two) were derived. Pairwise comparisons at hallmark events and phases identified significantly different angular momentum profiles, in particular total body, throwing arm, and momentum compensation ratios (P ⩽ 0.05) as a result of manipulating stride length. Sagittal, frontal, and transverse angular momentums were affected by stride length changes. Transverse magnitudes showed greatest effects for total body, throwing arm, and momentum compensation ratios. Since the trunk is the main contributor to linear and angular momentum, longer strides appear to better regulate transverse trunk momentum in double support, whereas shorter strides show increased momentum prior to throwing arm acceleration.     

Caregiver involvement in applied behavior-analytic research: A scoping review and discussion

We conducted a scoping review to characterize the role of caregiver involvement in behavior-analytic research. We reviewed eight behavioral-learning journals from 2011–2022 for works that included children or caregivers as participants and characterized caregiver involvement as passive (implications for caregivers, input, social validity) and active (implementation, caregiver behavior, training, caregiver-collected data). The review identified 228 studies, and almost all (96.1%; n = 219) involved caregivers in some capacity; 94.3% (n = 215) had passive involvement (26.8% had only passive involvement; n = 61), 69.3% (n = 158) had active involvement (1.8% had only active involvement; n = 4), and 3.9% (n = 9) had neither passive nor active involvement. Involvement generally increased over publication years. The most common types of involvement were implications for caregivers, implementation, and input; caregiver-collected data were rare. We propose considerations when engaging caregivers in research and suggest new avenues of inquiry related to caregivers' treatment objectives and social validity, treatment implementers, and caregiver-collected data.     

The effect of variable rest intervals and chronic ankle instability on triplanar ankle motion during performance of the Star Excursion Balance Test

Inadequate rest intervals may contribute to impaired performance during functional tests. However, the effect of different rest intervals on performance of the SEBT in individuals with and without CAI is not known. Our purposes were to determine whether different rest intervals impact ankle kinematics during the SEBT and whether there differences between those two populations. 24 controls and 24 CAI completed 3 trials in 3 reach directions (anteromedial; AM, medial; M, posteromedial; PM). The order of rest intervals and reach distance were randomized and counterbalanced. Three visits were required to complete the 3 rest interval conditions (10, 20, 40 s). Rest interval did not impact ankle kinematics between controls and CAI during the SEBT. Dorsiflexion (DF) (AM:partial η² = 0.18; M:partial η² = 0.23; PM:partial η² = 0.23) for all directions and tibial internal rotation (TIR) excursions (AM:partial η² = 0.20) for AM direction were greater in individuals with CAI regardless of rest interval length. Rest intervals ranging from 10 to 40 s did not influence ankle kinematics. Differences exist in DF and TIR between controls and CAI during the SEBT. These findings suggest that clinicians can use any rest interval between 10 and 40 s when administrating the SEBT. However, triplanar motion differs during a complex functional movement in controls compared to CAI.     

The effect of running on foot muscles and bones: A systematic review

Despite the widespread evidence of running as a health-preserving exercise, little is known concerning its effect on the foot musculature and bones. While running may influence anatomical foot adaptation, it remains unclear to what extent these adaptations occur. The aim of this paper is to provide a systematic review of the studies that investigated the effects of running and the adaptations that occur in foot muscles and bones. The search was performed following the PRISMA guidelines. Relevant keywords were used for the search through PubMed/MEDLINE, Scopus and SPORTDiscus. The methodological quality of intervention studies was assessed using the Downs and Black checklist. For cross-sectional studies, the Newcastle-Ottawa scale was used. Sixteen studies were found meeting the inclusion criteria. In general, the included studies were deemed to be of moderate methodological quality. Although results of relevant literature are limited and somewhat contradictory, the outcome suggests that running may increase foot muscle volume, muscle cross-sectional area and bone density, but this seems to depend on training volume and experience. Future studies conducted in this area should aim for a standard way of reporting foot muscle/bone characteristics. Also, herein, suggestions for future research are provided.     

The effect of shoe and floor characteristics on walking kinematics

It is common sense that walking on sand poses challenges to postural control. However, there are no studies quantifying the kinematics of sand walking compared to other types of postural perturbations such as unstable shoes. The aim of the study was to investigate differences in walking kinematics during walking on solid ground, in unstable shoes and on unstable surfaces. Nineteen healthy young adults (23.5 ± 1.5 years) performed three different walking tasks: 1) walking at preferred speed while wearing regular shoes; 2) Walking at preferred speed wearing Masai Barefoot Technology shoes and 3) barefoot walking at preferred speed on a large sand grave. Full-body kinematics were recorded during all conditions using an inertial motion capture system. Basic gait parameters (walking speed, stride length and duration), relative vertical center-of-mass position (rvCOM), and ankle, knee and hip joint angles in the sagittal plane were compared across the tasks through statistical parametric mapping over the course of full walking cycles. Participants presented similar walking speed, as well as stride length and duration across different conditions (p > 0.05). However, walking on sand reduced the rvCOM (p < 0.05), while also requiring greater ankle plantarflexion during stance phase (p < 0.05), as well as greater knee and hip flexion during leg swing and initial contact when compared to the other conditions (p < 0.05). It was concluded that walking on sand substantially changes walking kinematics, and may cause greater postural instability than unstable shoes. Therefore, walking on sand can be an alternative to improve postural control in patients undergoing walking rehabilitation.     

Regulate to facilitate: A scoping review of prefrontal asymmetry in sport and exercise

BackgroundPrefrontal asymmetry (PFA) describes the relative activity of the right PFC compared to the left PFC. It has been shown that PFA is associated with affective and motivational variables in several contexts, including sport and exercise. Considering the significant roles of affect and motivation in different performance settings, PFA might also be an important indicator of athletic performance. However, the relevance of PFA in the sport and exercise setting has not yet been addressed in its entirety. Instead, previous systematic reviews have solely focused on affective variables. Mapping out the complex interactions between PFA and affective, motivational as well as performance variables could help to understand what determines successful athletic performance as well as the positive psychological effects associated with exercise.ApproachScientific databases were searched for quantitative studies in English language published in international peer-reviewed journals. All 27 selected studies assessed physical activity and measured PFA in the brain locations F4-F3 and/or F8-F7 using electroencephalography.FindingsThe majority of the studies used a non-athlete sample (78%) and exercise types were diverse. While all studies focused on affective or motivational processes, 19% also reported associations with performance. Even though findings are inconsistent, they support the assumption that PFA plays a role in self-regulation.ConclusionThere is evidence for an involvement of PFA in affective, motivational and performance processes in the sport and exercise setting that can be interpreted as regulatory mechanisms. Future research on the underlying mechanisms is warranted, in particular, associations with motivational processes and performance need to be investigated more explicitly.