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Force and Accuracy Throws by Older Adult Performers

Kathleen Williams, Kathleen Haywood, and Ann VanSant

Older adults threw tennis balls for force and accuracy to examine their adaptability to different task demands. Twenty-one (13 women, 8 men) participants were videotaped as they performed five force and five accuracy throws. The developmental level of each throw was determined; resultant ball velocities also were examined. Roberton’s (1977, 1978) movement components were used in the former analysis. The typical pattern of gender differences occurred for both movement component and velocity measures. Men performed at higher levels than women. Only minor force versus accuracy differences were found in the movement patterns used by either men or women; none of these differences were significant. Clear task differences occurred for ball velocities. Men’s forceful throws were faster than those for accuracy; women’s throws did not differ for the two tasks. The generally lower developmental level of women’s throws accounted for gender differences in velocity. Insufficient task differences may explain the lack of clear contrast in movement patterns.

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Force and Accuracy Throws by Older Adults: II

Kathleen Williams, Kathleen Haywood, and Ann VanSant

Older adults were tested to clarify findings of an earlier examination of movement responses to shifting task requirements (Williams et al., 1993). Eleven participants (average age = 77 years) were evaluated on form and velocity as they performed overarm throws for force and accuracy. Significant gender and force-accuracy differences occurred for resultant velocity. Although no statistically significant differences occurred for force-accuracy comparisons of movement form, there were trends toward change in most movement components. Additionally, many individuals displayed change in one or more components as they shifted from force to accuracy throws. Results of this study point to the importance of examining developmental status and task requirements simultaneously.

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Age, Gender, and Flexibility Differences in Tennis Serving among Experienced Older Adults

Kathleen M. Haywood and Kathleen Williams

This study examined tennis serving in older adult tennis players. Twenty-two older adults, divided into younger and older halves, were videotaped serving five “first” serves. Dominant shoulder flexibility also was measured. From the videotape, servers were classified into developmental levels and their resultant ball impact velocity was calculated. An Age × Gender (2 × 2) mixed model MANOVA yielded no significant differences between the age groups or between men and women in flexibility, ball impact velocity, or movement pattern. A few combinations of the developmental levels of elbow and forearm/racket action were used by the majority of servers. Regular practice might consolidate older adults in these attractor movement patterns, making them more resilient to change than with less practiced skills. These results suggest practice in older adulthood favorably affects performance by resulting in consistency of movement pattern and maintenance of movement pattern, flexibility, and ball impact speed.

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Stair Climbing in Young Boys: A Longitudinal Study

Kathleen Williams, Lavon Williams, and H. Scott Strohmeyer

This longitudinal investigation examined the shift from use of a marking time to an alternating stepping pattern by young children. A set of twin males was videotaped between ages 37 and 46 months climbing stairs of 3.8-17.8 cm height. One boy began to alternate consistently on the highest steps at 41 months, the other at 46 months. Anthropometries (leg lengths) and a measure of foot overshoot (maximum height of the foot over the stair) were used to investigate the timing of the shift for the 2 boys. Magnitude of overshoot decreased with age and with increased use of the more advanced pattern. Immature balance and an initial need to visually guide the foot to the next step may be important factors in the timing of the pattern shift.

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Environmental versus Biological Influences on Gender Differences in the Overarm Throw for Force: Dominant and Nondominant Arm Throws

Kathleen Williams, Kathleen M. Haywood, and Mary A. Painter

Both environmental and biological factors have been cited to explain large gender differences in throwing. Because differences are observed as early as three years, some researchers have suggested biological differences may be a primary factor (Nelson et al., 1986). To explore the contribution of these factors more carefully, three groups of children, 7-8 years, 9-10 years, and 11-12 years, were videotaped performing ten forceful overarm throws each with their dominant and nondominant hands. Resultant ball velocities were computed across all trials for each hand. Five trials for each arm, for each participant were categorized using Roberton’s (Roberton & Halverson, 1984) movement components for the overarm throw. Overall significant age differences were obtained for ball velocities for both dominant and nondominant arms, but gender differences were demonstrated only for the dominant arm. Ball velocity differences for the nondominant arm were not evident. Minimal differences in form occurred for the nondominant arm. When the nondominant arm exhibited coordination patterns and performances typical of an unpracticed performer, we suggest that nonbiological factors are important in explaining the large gender differences in throwing widely noted in the literature.

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Validation of a Backswing Developmental Sequence for the Overarm Throw for Force

Bradley Beseler, Kathleen Williams, and Mandy S. Plumb

Background: Roberton’s movement components are used to assess fundamental motor skills as segmental developmental sequences. In 1991, Haywood, Williams and VanSant determined that original developmental sequences proposed for the backswing levels of the overarm throw did not encompass all ages. Their study of older throwers identified two new qualitatively different levels, with half the participants categorized at two new levels. This investigation extended the initial validation across a wider age range. Method: Two hundred and twenty-eight primary, high school, university students, and adults were instructed to make five throws for maximum force using their dominant hand. Throws were recorded with side and rear cameras synchronized for analysis. Prelongitudinal screening was used to analyze the Haywood et al. revisions of the Langendorfer developmental sequence. Results: Five of the six levels of Haywood’s sequence were suitable for assessing throwers 8 years of age through to adulthood. More study is needed of one less advanced pattern. Lower level throws corresponded to lower velocities; higher level throws were faster, suggesting the sequence was properly ordered. More males than females were classified at higher levels, demonstrating typical gender differences. Discussion: The categories hypothesized for the backswing action of the overarm throw were valid descriptors of differences observed across ages, from childhood to adulthood. Additional study of Levels 3 and 4 is warranted to clarify their order.

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Developmental Sequences for the Vertical Cradle in Lacrosse: An Exploratory Study

Kate R. Barrett, Kathleen Williams, Jill McLester, and Sara Ljungkvist

Developmental sequences for the vertical cradle were hypothesized and tested using a prelongitudinal screening technique to determine comprehensiveness and developmental accuracy. Fifty-one 10- to 13-year-old children were videotaped as they ran and cradled over a flat surface. A total of 150 trials were categorized for seven components: basic rhythm, hand and arm action, stick position, top hand grip, stick head and top arm action, position of hands, and bottom arm and hand action. Lack of developmental variability occurred for the basic rhythm, hand and arm action, and hand position components. For the stick position component, more younger children were classified at the highest level than older children. The developmental sequence for the stick head and top arm component was comprehensive and age related. The role various constraints play in hypothesizing sequences of sport specific skills needs to be considered along with the quality and amount of instruction.

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Athletic Aggression: Perceived Legitimacy and Behavioral Intentions in Girls’ High School Basketball

M. Kathleen Ryan, Jean M. Williams, and Beverly Wimer

The present study examined the stability of athletes' legitimacy judgments and behavioral intentions over the course of a basketball season and the relationship between these factors to actual behavior. The 49 female basketball players responded to a questionnaire that was derived from Bredemeier's (1985) Continuum of Injurious Acts. The preseason legitimacy rating of aggressive actions made by first-year basketball players were significantly higher than those made by more experienced players, but by the end of the season the first-year participants' ratings had dropped to a level comparable to their more experienced teammates. Preseason legitimacy judgments were found to predict player aggression during the season. Interpretation of the findings and recommendations for future direction in this area are discussed.

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PRESENT 2020: Text Expanding on the Checklist for Proper Reporting of Evidence in Sport and Exercise Nutrition Trials

James A. Betts, Javier T. Gonzalez, Louise M. Burke, Graeme L. Close, Ina Garthe, Lewis J. James, Asker E. Jeukendrup, James P. Morton, David C. Nieman, Peter Peeling, Stuart M. Phillips, Trent Stellingwerff, Luc J.C. van Loon, Clyde Williams, Kathleen Woolf, Ron Maughan, and Greg Atkinson