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M.A. Urbin

Goal-directed movement is possible because the cortical regions regulating movement have continuous access to visual information. Extensive research from the various domains of motor control (i.e., neurophysiology, neuropsychology, and psychophysics) has documented the extent to which the unremitting availability of visual information enables the sensorimotor system to facilitate online control of goal-directed limb movement. However, the control mechanism guiding appreciably more complex movements characterized by ballistic, whole-body coordination is not well understood. In the overarm throw, for example, joint rotations must be optimally timed between body segments to exploit the passive flow of kinetic energy and, in turn, maximize projectile speed while maintaining accuracy. The purpose of this review is to draw from the various research domains in motor control and speculate on the nature of the sensorimotor control mechanism facilitating overarm throwing performance.

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Sergio L. Molina and David F. Stodden

statistically significant relationship between speed and the resultant spatial error across a range of speed percentages (40–100%) in overarm throwing. Chappell et al. ( 2016 ) also showed that 40–59% of maximum kicking speed actually resulted in greater spatial error than speeds approximately 70–79% of maximum

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M.A. Urbin, David Stodden, Rhonda Boros and David Shannon

The purpose of this study was to examine variability in overarm throwing velocity and spatial output error at various percentages of maximum to test the prediction of an inverted-U function as predicted by impulse-variability theory and a speed-accuracy trade-off as predicted by Fitts’ Law Thirty subjects (16 skilled, 14 unskilled) were instructed to throw a tennis ball at seven percentages of their maximum velocity (40–100%) in random order (9 trials per condition) at a target 30 feet away. Throwing velocity was measured with a radar gun and interpreted as an index of overall systemic power output. Within-subject throwing velocity variability was examined using within-subjects repeated-measures ANOVAs (7 repeated conditions) with built-in polynomial contrasts. Spatial error was analyzed using mixed model regression. Results indicated a quadratic fit with variability in throwing velocity increasing from 40% up to 60%, where it peaked, and then decreasing at each subsequent interval to maximum (p < .001, η2 = .555). There was no linear relationship between speed and accuracy. Overall, these data support the notion of an inverted-U function in overarm throwing velocity variability as both skilled and unskilled subjects approach maximum effort. However, these data do not support the notion of a speed-accuracy trade-off. The consistent demonstration of an inverted-U function associated with systemic power output variability indicates an enhanced capability to regulate aspects of force production and relative timing between segments as individuals approach maximum effort, even in a complex ballistic skill.

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Gertjan Ettema, Tommy Gløsen and Roland van den Tillaar

Purpose:

The main purpose of this study was to compare the effect of a specific resistance training program (throwing movement with a pulley device) with the effect of regular training (throwing with regular balls) on overarm throwing velocity under various conditions.

Methods:

The training forms were matched for total training load, ie, impulse generated on the ball or pulley device. Both training groups (resistance training n = 7 and regular training n = 6) consisted of women team handball players, and trained 3 times per week for 8 weeks, according to an assigned training program alongside their normal handball training.

Results:

An increase in throwing velocity with normal balls after the training period was observed for both groups (P = .014), as well as throwing with heavier balls and throwing like actions in the pulley device. Although the regular training group seemed to improve more (6.1%) in throwing velocity with normal balls than the resistance training group (1.4%), this difference was not statistically significant.

Conclusions:

These findings indicate that resistance training does not surpass standard throwing training in improvement of overarm throwing velocity.

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Jin H. Yan, Richard N. Hinrichs, V. Gregory Payne and Jerry R. Thomas

This study was designed to examine Ihe developmental differences in the speed and smoothness of arm movement during overarm throwing. The second purpose of this investigation was to evaluate whether jerk is a useful measure in understanding children's overarm throwing. Fifty-one girls, aged 3 to 6 years, voluntarily participated in the study. Each subject threw tennis balls as hard as she could toward a large target on the wall. A 2-camera video system was used to obtain 3-D coordinates of the hand and ball using the DLT algorithm. The variables of velocity and jerk (for the hand and ball) served as the movement outcome measures. The age-associated differences in velocity and normalized jerk (absolute jerk standardized relative to movement time and distance) were examined by ANOVAs. The results supported the hypothesis that the older subjects demonstrated faster and smoother hand movements than their younger counterparts during the forward acceleration phase (from the beginning of forward motion to ball release). In addition, the correlation results indicated thai increased hand movement speed was associated with decreased movement jerk in older subjects, whereas increased hand speed was associated with increased jerk in younger subjects. The findings suggest that examining the jerk parameter (normalized or absolute jerk) is a useful and alternative approach to capture the variance of hand movement execution for children's overarm throwing.

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Susan Wilkinson

Effects of a visual-discrimination training program on participants’ ability to analyze overarm throwing performances was studied. Also examined was the extent to which transfer occurred in analyzing three related overarm skills (the badminton overhand clear, tennis serve, and volleyball serve) and one unrelated skill (the standing long jump). After the pretest, the training group (n = 13) was shown the visual-discrimination program. The control group (n = 13) received no training. The two-way ANOVA, with repeated measures, showed no significant differences between the groups for any skills on the pretest, but statistically significant differences between groups’ posttest scores for all skills, except the standing long jump.

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Judith L. Oslin, Sandra Stroot and Daryl Siedentop

The purpose of this study was to examine the efficacy of a component-specific instruction (CSI) intervention to enhance overarm throw development in preschool children. The study also examined the sequence of components within the intervention, a force production sequence (FPS) versus a forward-chaining sequence (FCS). During daily inspection of the data, investigators noted changes in efficiency levels of nontargeted components. Therefore, a third research question emerged regarding the ancillary effects of CSI on efficiency levels of nontargeted components. For all participants, intervention was required on two or more of the following: step, rotation/backswing, elbow/backswing, forearm/forward, and rotation forward. CSI was found to be effective for improving the efficiency of the targeted component as well as overall throwing efficiency. Ancillary effects occurred repeatedly across nontargeted components during all but one condition of CSI. During follow-up, the degree to which efficiency levels were maintained varied from child to child.

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Roland van den Tillaar and Gertjan Ettema

The aim of this study was to compare the kinematics in throwing with a regular weighted handball with 20% lighter and heavier balls in female experienced handball players. In total, eight joint movements during the throw were analyzed. The analysis consisted of maximal angles, angles at ball release, and maximal angular velocities of the joint movements and their timings during the throw. Results on 24 experienced female team handball players (mean age 18.2 ± 2.1 years) showed that the difference in ball weight affected the maximal ball velocity. The difference in ball release velocity was probably a result of the significant differences in kinematics of the major contributors to overarm throwing: elbow extension and internal rotation of the shoulder. These were altered when changing the ball weight, which resulted in differences in ball release velocity.

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Roland van den Tillaar and Gertjan Ettema

The aim of this study was to investigate the contribution of upper extremity, trunk, and lower extremity movements in overarm throwing in team handball. In total, 11 joint movements during the throw were analyzed. The analysis consists of maximal angles, angles at ball release, and maximal angular velocities of the joint movements and their timing during the throw. Only the elbow angle (extension movement range) and the level of internal rotation velocity of the shoulder at ball release showed a significant relationship with the throwing performance. Also, a significant correlation was found for the timing of the maximal pelvis angle with ball velocity, indicating that better throwers started to rotate their pelvis forward earlier during the throw. No other significant correlations were found, indicating that the role of the trunk and lower limb are of minor importance for team handball players.

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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.