Canadian journal of applied sport sciences. Journal canadien des sciences appliquees au sport
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Can J Appl Sport Sci · Dec 1985
Individual differences in the mental practice and imagery of motor skill performance.
The role of mental practice in motor skill learning is briefly reviewed, and the relationship between mental practice and imagery discussed. A case is made for the importance of considering individual differences for imagery in motor studies investigating mental practice. ⋯ Finally, an approach for investigating imagery ability is suggested. This approach concentrates on the inclusion and interaction of three imagery related variables: the measurement of imagery ability, the task to be performed, and the imagery instructions that are given to the subjects.
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Seven brands of bicycle helmets were compared by means of a drop test using an instrumented Hodgson-WSU headform, on the front (F), rear (R) and left side (LS) locations from a height of 1.0m and on the right front boss (RFB) from either 1.0m or 1.75m. Acceleration signals from the headform were computer processed to yield peak acceleration and the Gadd Severity Index (GSI). Significant differences between helmets and within helmets at different locations were found. ⋯ The superiority of the polystyrene liners disappeared however when helmets were subjected to two consecutive drops to the same location (R). The results also indicated that for most cases the GSI was between 800-1200 but there were two helmets that had values in excess of 1500. Clearly not all bicycle helmets provide equivalent levels of protection and some are much superior to others.
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The paper describes a multidimensional model of leadership which specifies three states of leader behavior: leader behavior required by the situation, leader behavior preferred by the members, and the actual leader behavior. These three states of leader behavior are defined respectively by the situational characteristics such as the goals, size and structure of the organization and the nature of the work group and its norms; the characteristics of the members such as their personality and ability; and the leader's characteristics such as his personality and ability. ⋯ Based on the model and on Blau and Scott's (1969) typology of organizations, the paper suggests specific leadership styles appropriate to the various types of sports organizations. Further, leadership styles appropriate to recreational sport and to different levels of athletic teams are also suggested.