Long-axis rotation: The missing link in proximal-to-distal segmental sequencing

Most assessments of segmental sequencing in throwing, striking or kicking have indicated a proximal-to-distal sequencing of end-point linear speeds, joint angular velocities, segment angular velocities and resultant joint moments. However, the role of long-axis rotations has not been adequately quantified and located in the proximal-to-distal sequence. The timing and importance of pronation-supination in the development of racquet head speed have been examined in the tennis serve and squash forehand drive and considered in relation to conventional concepts of proximal-to-distal sequencing. Both long-axis rotations reached their peak angular speeds late in both strokes, typically after shoulder flexion-extension, shoulder abduction-adduction and elbow extension. These results clarify and confirm the importance of upper limb long-axis rotations in the production of racquet head speed. It appears that traditional proximal-to-distal sequencing concepts are inadequate to describe accurately the complexity of the tennis serve or squash forehand drive. It is essential to consider upper arm and forearm longitudinal axis rotations in explaining the mechanics of these movements and in developing coaching emphases, strength training schedules and injury prevention programmes.     

The penalty throw in water polo: A cinematographic analysis

Three‐dimensional (3‐D) high‐speed cinematography was used to record the penalty throw in water polo by six elite male (M) and six elite female (F) players. The direct linear transformation technique (DLT) was used in the 3‐D space reconstruction from 2‐D images recorded via laterally placed phase‐locked cameras operating at 200 Hz. Five of the twelve subjects lifted the ball from underneath at the start of the throw whilst the remaining subjects opted for a rotation lift. As the ball was brought behind the head the females used very little hip and shoulder rotation compared to the male players so that four of the six female subjects were square on to the target at the rear point. At the completion of the backswing the wrist was flexed to a similar angle (M‐162°; F‐158°); the elbow angle showed significantly greater flexion for females (85°) than males (107°).

During the forward swing, from rear point to release, the wrist joint of the female players flexed from a rear point angle of 158° to 148° at release. The wrist movement for male subjects was different from the females in that it flexed from 162° to 147°, 0.10 s prior to release and then extended to 159° at palmar release before again flexing to 156° at release. The amount of elbow extension during the forward swing was 48° for both groups; however, the females actually released the ball with the forearm vertical (89°) compared to the male forearm angle of 78°. Maximum angular velocity of the wrist and elbow occurred at release for 9 of the 12 subjects. Both the wrist and elbow joints (F‐148°; M‐156° at wrist and F‐126°; M‐148° at elbow) demonstrated greater flexion at release in female subjects, compared with males. Maximum linear endpoint velocities for the forearm and hand segments occurred at ball release resulting in mean ball velocities of 19.1 m s ^‐1 and 14.7 m s^{‐ 1} for male and female subjects respectively.     

Only Familiar Information is a “Curse”: Children’s Ability to Predict What Their Peers Know

The ability to make inferences about what one’s peers know is critical for social interaction and communication. Three experiments (n = 309) examined the curse of knowledge, the tendency to be biased by one’s knowledge when reasoning about others’ knowledge, in children’s estimates of their peers’ knowledge. Four- to 7-year-olds were taught the answers to factual questions and estimated how many peers would know the answers. When children learned familiar answers, they showed a curse of knowledge in their peer estimates. But, when children learned unfamiliar answers to the same questions, they did not show a curse of knowledge. These data shed light on the mechanisms underlying perspective taking, supporting a fluency misattribution account of the curse of knowledge.     

Perceived parental stress in face of kindergarten children’s academic setback: roles of parents’ goals and education

European Journal of Psychology of Education - Previous research studies have demonstrated the link between parents’ education and parental stress level. However, these studies have not taken...     

Prevalence and psychological sequelae of self-reported childhood physical and sexual abuse in a general population sample of men and women

OBJECTIVE: This study examined the prevalence and psychological sequelae of childhood sexual and physical abuse in adults from the general population. METHOD: A national sampling service generated a geographically stratified, random sample of 1,442 subjects from the United States. Subjects were mailed a questionnaire that included the Traumatic Events Survey (TES) [Traumatic Events Survey, Unpublished Psychological Test, Harbor-UCLA Medical Center, Los Angeles] and the Trauma Symptom Inventory (TSI) [Trauma Symptom Inventory Professional Manual, Psychological Assessment Resources, Odessa, FL]. Of all potential subjects, 935 (64.8%) returned substantially completed surveys. RESULTS: Sixty-six men and 152 women (14.2% and 32.3%, respectively) reported childhood experiences that satisfied criteria for sexual abuse, and 103 males and 92 females (22.2% and 19.5%, respectively) met criteria for physical abuse. Twenty-one percent of subjects with one type of abuse also had experienced the other type, and both types were associated with subsequent adult victimization. After controlling for demographics, adult history of interpersonal violence, and other child abuse, childhood sexual abuse was associated with all 10 scales of the TSI, and physical abuse was related to all TSI scales except those tapping sexual issues. Sexual abuse predicted more symptom variance than did physical abuse or adult interpersonal victimization. Various aspects of both physical and sexual abuse experiences were predictive of TSI scores. Abuser sex, however, both alone and in interaction with victim sex, was not associated with additional TSI symptomatology. CONCLUSIONS: Childhood sexual and physical abuse is relatively common in the general population, and is associated with a wide variety of psychological symptoms. These relationships remain even after controlling for relevant background variables.     

Goal orientations in Russian university students: from mastery to performance?

Research in the UK has shown that students start their university career with the goal of mastering their subject, but this focus shifts as they progress through their degree program. Studies have suggested that unlike students in the UK, Russian students continue to take a strong mastery approach to their work. The main aim of this study was to assess whether the effects observed in UK studies could be found in a Russian context. In a cross‐sectional study, 618 students across four years of a degree program in a Russian university completed an achievement‐goal questionnaire. Results revealed patterns similar to the studies in the UK; Russian students’ levels of mastery were significantly lower after Year 1. The results are discussed in terms of potential changes in Russian culture. Methodological issues relating to the relative failure of some questionnaire items to validate fully within their hypothesised constructs are also discussed.     

Differential Ability Scales – Second Edition (neuro)psychological predictors of math performance for typical children and Children with Math Disabilities

Concerns about the ability‐achievement discrepancy method for specific learning disability (SLD) determination led to alternative research‐based methods, such as failure to respond to intervention. Neither of these regulatory methods address the statutory SLD definition, which explicitly includes a deficit in basic psychological processes. Examining neuropsychological processing differences among typical children and children with math SLD, commonality analyses revealed that Differential Ability Scales – Second Edition (DAS‐II) predictors accounted for more achievement variance in typical children (46% to 58%) than in children with math SLD (33% to 50%), with substantial loss of predictive validity when General Conceptual Ability was used instead of subcomponent scores. Results suggest that differences in typical predictor‐outcome relationships may provide a foundation for developing specific cognitive and academic interventions for children with math SLD. © 2008 Wiley Periodicals, Inc.     

Evaluating the validity of the Automated Working Memory Assessment

The aim of the present study was to investigate the construct stability and diagnostic validity of a standardised computerised tool for assessing working memory: the Automated Working Memory Assessment (AWMA). The purpose of the AWMA is to provide educators with a quick and effective tool to screen for and support those with memory impairments. Findings indicate that working memory skills in children with memory impairments are relatively stable over the course of the school year. There was also a high degree of convergence in performance between the AWMA and the WISC‐IV Working Memory Index. The educational implications are discussed.     

Out-group value incongruence and intergroup attitude: The roles of common identity and multiculturalism

This research was designed to examine the moderation roles of common social identity and multiculturalism on the established relationship between Mainland Chinese's perceived value incongruence with Hong Kong Chinese and their negative attitude towards Hong Kong Chinese. A survey study was conducted among 202 college students in Mainland China and the results showed Mainland Chinese's value incongruence with Hong Kong Chinese significantly predicted their negative intergroup attitude. In addition, the results also revealed that among participants with high identification with the super-ordinate Chinese national group, this negative relation was significantly weaker than those with low Chinese identification. In addition, among participants with high multiculturalism endorsement, the relation between value incongruence and intergroup attitude was significantly weaker than those with low level of multiculturalism. Implications of this research and future directions were discussed based on these findings.