Ballistic Skill Research Articles

Gross Motor Functions Assessed Through The Tgmd-3 In Down Syndrome Individuals And Related Gender Differences

PURPOSE: Down Syndrome (DS) individuals show a markedly reduced general coordination, resulting in an overall reduced motor proficiency which limits their participation and, consequently, inclusion in sport activities. In this work we aim to characterize gross motor functions in DS, assessed by means of the Test of Gross Motor Development (TGMD 3), and assess possible gender-related differences. METHODS: Thirty-six age- and gender-matched DS individuals (Age: 29.1±7.5 years; Stature: 1.53±0.09 m; Mass: 67±14 kg; BMI: 28.6±14.1 kg/m2; n = 18 females (FE), 18 males (MA)), recruited in 5 European countries, performed the TGMD version 3 (TGMD-3). Participants were matched also for their daily physical activity (p = 0.6) as assessed by the international physical activity questionnaire (IPAQ). TGMD-3 includes 13 skills classified as Locomotor Skills (Running, Galloping, Hopping, Skipping, Horizontal jumping, and Sliding) or Ballistic Skills (Two-hand and One-hand striking, Dribbling, Overhand throwing, Underhand throwing, Catching, and Kicking). For each skill, two attempts were performed. A video analysis was performed to assess if the performance criteria were respected. For each criterion, the participant scored 1 if the performance criterion was respected and 0 if not. Individual scores of the two attempts for each skill classified as Locomotor or Ballistic were separately summed. The total gross motor functions score was the sum of Locomotor and Ballistic skills. All scores were computed as a percentage of the maximum achievable score. MA and FE scores were compared using RM-ANOVAs (α=0.05). RESULTS. The participants had a total gross motor function score of 51% on average, similar for MA and FE (F1,34 = 1.39; p = 0.24; M = 54%; F= 48%). No significant differences between MA and FE were observed for the total scores of Locomotor or Ballistic skills (F1,34 = 1.45; p = 0.23). At single skill level, MA outperformed FE in the kicking skill (F1,34= 8.14; p = 0.007; M = 47%; F = 22%). CONCLUSION. These results highlight gross motor functions limitations in this population, showing a similar impairment of MA and FE, especially for locomotor functions. The different score obtained between MA and FE in the kicking skill may reflect an European cultural bias. Co-funded by the Erasmus + Programme of the European Union, GA 2018-2512.

Quantitative assessment of developmental levels in overarm throwing using wearable inertial sensing technology

ABSTRACTMotor proficiency in childhood has been recently recognised as a public health determinant, having a potential impact on the physical activity level and possible sedentary behaviour of the child later in life. Among fundamental motor skills, ballistic skills assessment based on in-field quantitative observations is progressively needed in the motor development community. The aim of this study was to propose an in-field quantitative approach to identify different developmental levels in overarm throwing. Fifty-eight children aged 5–10 years performed an overarm throwing task while wearing three inertial sensors located at the wrist, trunk and pelvis level and were then categorised using a developmental sequence of overarm throwing. A set of biomechanical parameters were defined and analysed using multivariate statistics to evaluate whether they can be used as developmental indicators. Trunk and pelvis angular velocities and time durations before the ball release showed increasing/decreasing trends with increasing developmental level. Significant differences between developmental level pairs were observed for selected biomechanical parameters. The results support the suitability and feasibility of objective developmental measures in ecological learning contexts, suggesting their potential supportiveness to motor learning experiences in educational and youth sports training settings.

Examining Impulse-Variability in Kicking.

This study examined variability in kicking speed and spatial accuracy to test the impulse-variability theory prediction of an inverted-U function and the speed-accuracy trade-off. Twenty-eight 18- to 25-year-old adults kicked a playground ball at various percentages (50-100%) of their maximum speed at a wall target. Speed variability and spatial error were analyzed using repeated-measures ANOVA with built-in polynomial contrasts. Results indicated a significant inverse linear trajectory for speed variability (p < .001, η2= .345) where 50% and 60% maximum speed had significantly higher variability than the 100% condition. A significant quadratic fit was found for spatial error scores of mean radial error (p < .0001, η2 = .474) and subject-centroid radial error (p < .0001, η2 = .453). Findings suggest variability and accuracy of multijoint, ballistic skill performance may not follow the general principles of impulse-variability theory or the speed-accuracy trade-off.

Examining Impulse-Variability in Overarm Throwing

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.

Kinematic Motion of the Windmill Softball Pitch in Prepubescent and Pubescent Girls

This study examined the joint motions and movement patterns of the kinetic chain in the ballistic skill of performing the windmill pitch. Seventeen healthy girls who were currently playing competitive fast-pitch softball volunteered for the study. Subjects were instructed to perform 5 successful fastball windmill style deliveries. We selected 1 pitch for analysis based on the velocity, accuracy, and subjects' input. Kwon3D motion analysis package (Visol., Inc., Seoul, Korea), with 6 digital camcorders placed at 60 degrees apart was used for analysis. Raw data were interpolated using a frequency of 60 Hz and then smoothed using Butterworth low-pass second-order filter with a fixed cut-off frequency of 6 Hz. The subjects were divided into groups based on skill level: novice, intermediate, and advanced. Sequential progression of kinematic variables that resulted in increased throwing velocity and the contribution each segment (upper arm, forearm, and hand) possessed toward ball velocity with descriptive statistics and path analysis were assessed. There was evidence of sequentiality among the arm segments in the intermediate and advanced groups. The patterns of the shared positive contributions made by each of the limb segments were similar among the 3 groups of participants. The novice group tended to rely on more of the upper arm and forearm than the other 2 groups. From this study, it is evident that all emphasis should not be placed on the shoulder, but training and conditioning methods should focus on the entire kinetic chain including the torso and the full arm segment, not just the shoulder in an attempt to gain the greatest velocity while performing the 360 degrees arc of the windmill softball pitch.

The contextual interference effect in applied settings

This paper analyses the research literature that approaches the contextual interference effect in applied settings. In contrast to the laboratory settings, in which high interference conditions depress acquisition and promote learning evaluated in retention and transfer tests, in applied settings most of the studies (60%) fail to observe positive effects after manipulation of the contextual interference. Some possible explanations for the fact are hypothesized regarding the characteristics of the task, with serial tasks doing best, shor t inter trial intervals rare in applied settings, interference produced by the use of different motor programmes and the possible interference of concurrent feedback in slow tasks in contrast to ballistic skills. It seems that there is a more evident contextual interference effect in an applied setting, when subject learns a serial task with high degree of complexity.

Consolidation of Dynamic Motor Learning Is Not Disrupted by rTMS of Primary Motor Cortex

Motor skills, once learned, are often retained over a long period of time. However, such learning first undergoes a period of consolidation after practice. During this time, the motor memory is susceptible to being disrupted by the performance of another motor-learning task. Recently, it was shown that repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex could disrupt the retention of a newly learned ballistic task in which subjects had to oppose their index finger and thumb as rapidly as possible. Here we investigate whether the motor cortex is similarly involved during the consolidation that follows learning novel dynamics. We applied rTMS to primary motor cortex shortly after subjects had either learned to compensate for a dynamic force field applied to their index finger or learned a ballistic finger abduction task. rTMS severely degraded the retention of the learning for the ballistic task but had no effect on retention of the dynamic force-field learning. This suggests that, unlike learning of simple ballistic skills, learning of dynamics may be stored in a more distributed manner, possibly outside the primary motor cortex.

Life span motor development

Chapter 1. Fundamental Concepts Chapter 2. Theoretical Perspectives in Motor Development Chapter 3. Principles of Motion and Stability Chapter 4. Physical Growth, Maturation, and Aging Chapter 5. Development and Aging of Body Systems Chapter 6. Early Motor Development Chapter 7. Development of Human Locomotion Chapter 8. Development of Ballistic Skills Chapter 9. Development of Manipulative Skills Chapter 10. Sensory-Perceptual Development Chapter 11. Perception and Action in Development Chapter 12. Social and Cultural Constraints in Motor Development Chapter 13. Psychosocial Constraints in Motor Development Chapter 14. Knowledge As Functional Constraint in Motor Development Chapter 15. Development of Cardiorespiratory Chapter 16. Development of Strength and Flexibility Chapter 17. Development of Body Composition Chapter 18. Conclusion: Interactions Among Constraints.

The role of verbal estimates of movement error in ballistic skill acquisition.

The role of verbal estimates of movement error in a ballistic movement task was investigated. Two groups performed a rapid linear movement timing task for 50 trials with KR followed by 50 trials without KR. Group I was required to give a verbal estimate of movement time immediately after the task, while Group II was not. Verbal labeling of movement error did not augment performance when KR was present. When KR was withdrawn, however, Group I maintained performance, but Group II's response accuracy declined. Implications for current motor learning theories are discussed.

Role of feedback in the development and maintenance of complex skill.

Three experiments examined the role of various sources of feedback in the development and maintenance of a complex ballistic skill, dart throwing, using extended practice. Even a brief delay of visual feedback initially affected accuracy and consistency adversely, though with practice performance gradually recovered. A total absence of visual feedback impelled subjects to use subtle cues such as crude auditory localization. When these cues were available, accuracy suffered to the same extent as with delayed visual feedback, but consistency in this case was unaffected. When all external feedback was removed, with subjects throwing in the dark at a luminous dot without hearing the dart land, consistency remained unimpaired, but accuracy suffered. However, on returning to full visual feedback both accuracy and consistency were found to have improved when compared to a control group. The independence of accuracy and consistency is discussed in terms of fixed and variable parameters of the skill. The effect of delayed visual feedback is attributed to the failure to integrate visual information with the fading proprioceptive trace. Central importance is attached to improvement in compentence when no external feedback is available, and possible underlying mechanisms for this improvement are described.

The Development of a Simple Ballistic Skill with and Without Visual Control

80 randomly selected male Ss discriminated the "effort" required to perform a simple 1-handed ballistic aiming task: aligning a Fletcher's Trolley with a pointer placed at varying distances adjacent to an inclined wooden track. Groups were aged 5-6, 10-11, 15-16, and 18 or more yr., with 10 Ss able to see both hands and target while the other 10 could see neither. A split-plot factorial design was used. On excluding the 5-6 yr.-old "Nonvision" children, the remaining 7 sub-groups were shown to be homogeneous. Mean absolute error scores increased with Distance, and also with a decrease in Age. In the "Non-vision" condition accuracy was reduced still further for all Ss. Age, Vision, and Distance and the interaction of Age with Vision were all significant, p<.01.