Overhand Throw Research Articles

A laparoscopic knot-tying device for minimally invasive cardiac surgery☆

Intracorporeal suturing and knot tying can complicate, prolong or preclude minimally invasive surgical procedures, reducing their advantages over conventional approaches. An automated knot-tying device has been developed to speed suture fixation during minimally invasive cardiac surgery while retaining the desirable characteristics of conventional hand-tied surgeon's knots: holding strength and visual and haptic feedback. A rotating slotted disc (at the instrument's distal end) automates overhand throws, thereby eliminating the need to manually pass one suture end through a loop in the opposing end. The electronic actuation of this disc produces left or right overhand knots as desired by the operator. To evaluate the effectiveness of this technology, seven surgeons with varying laparoscopic experience tied knots within a simulated minimally invasive setting, using both the automated knot-tying tool and conventional laparoscopic tools. Suture types were 2/0 braided and 4/0 monofilament. Mean knot-tying times were 246+/-116 s and 102+/-46 s for conventional and automated methods, respectively, showing an average 56% reduction in time per surgeon (p=0.003, paired t-test). The peak holding strength of each knot (the force required to break the suture or loosen the knot) was measured using tensile-testing equipment. These peak holding strengths were normalised by the ultimate tensile strength of each suture type (57.5 N and 22.1N for 2/0 braided and 4/0 monofilament, respectively). Mean normalised holding strengths for all knots were 68.2% and 71.8% of ultimate tensile strength for conventional and automated methods, respectively (p=0.914, paired t-test). Experimental data reveal that the automated suturing device has great potential for advancing minimally invasive surgery: it significantly reduced knot-tying times while providing equivalent or greater holding strength than conventionally tied knots.

Methods of Upper Body Training to Increase Overhand Throwing Power

Abstract Those who have taught motor skills would most likely agree that the overhand throw may be the most difficult skill for students to master and for instructors or coaches to teach. The timing involved when generating power to performing the overhand throw begins in the toes/feet and moves up the leg, hip, thorax (core muscles), arm, and ends in the finger tips. The overhand throw requires the coordination of almost all of the joints in the human body. Another consideration related to the complexity of the overhand throw is that the dominant or throwing side of the body is performing almost a completely opposite movement than the non-throwing side. The overhand throw is analyzed joint by joint followed by methods of increasing power and strength in each area beginning with the fingers and ending in the muscles of the body’s core. This paper provides information that suggests various methods of training for increasing power in the overhand throw by developing the core and upper body muscles. Often the overhand throw is performed without the assistance of force generated in the lower body. The focus of this paper is directed towards developing upper body strength to compensate for situations where the lower body is in a situation where it cannot contribution in the processes of developing force in the overhand throw.

Relationship Between Gross Motor Skill And Social Behavior In Children With Autism

Significant deficits in social behaviors have been reported among children with autism spectrum disorders (ASD), and there is growing recognition that individuals with ASD experience motor difficulties (Berkely et al., 2001; Miyahara et al., 1997). Children with ASD experience early challenges in motor skills, which further correlate with social engagement skill deficits (Trevarthen & Daniel, 2005). However, ASD children with motor deficits were not more likely to receive service than those without the motor deficits, and research investigating the relationship between gross motor skill and social behavior of children with ASD has been limited. PURPOSE: To measure the relationship between gross motor skill and social behavior in children with ASD. METHODS: Sixteen (Asperger, n = 8; high-functioning autism, n = 8) boys with ASD aged 6-10 (7.23±1.05 yrs) participated. The Test of Gross Motor Development (TGMD-2; Ulrich, 1985) was used to assess six locomotor skills (run, gallop, hop, leap, horizontal jump, and slide) and six object control skills (striking a stationary ball, stationary dribble, catch, kick, overhand throw, and underhand roll). The School Social Behavior Scales (SSBS-2; Merrell, 2002) was rated by the child's school classroom teacher to assess social competence (peer relations, self-management/compliance, academic behavior) and antisocial behavior (hostile/irritable, antisocial/aggressive, defiant/disruptive). Data are reported as standard score and T-score. Pearson product-moment correlation coefficients were calculated to evaluate the relationship between gross motor skill and social behavior. Significance was set at p < 0.05. RESULTS: Findings indicate that (a) object control skills were positively correlated with peer relations (r16 = 0.65, p < 0.01), self-management (r16 = 0.58, p < 0.05), and social competence (r16 = 0.66, p < 0.01), (b) gross motor quotient was positively correlated with peer relations (r16 = 0.64, p < 0.01), self-management (r16 = 0.58, p < 0.05), and social competence (r16 = 0.61, p < 0.05), and (c) locomotor skills were not correlated with any social behavior variable. CONCLUSION: The better motor skill the child with ASD performed, the more likely the child was to be socially competent. Supported by grant NSC 96-2413-H-017-005, Taiwan.

Biceps Activity during Windmill Softball Pitching

Background Windmill pitching produces high forces and torques at the shoulder and elbow, making the biceps labrum complex susceptible to overuse injury. Little is known about the muscle firing patterns during a windmill pitch. Hypothesis Biceps muscle activity is greater during a windmill pitch than during an overhand throw. Study Design Descriptive laboratory study. Methods Seven female windmill pitchers underwent motion analysis and surface electromyography evaluation of their biceps muscles during windmill and overhand throwing. Marker motion analysis, muscle activity, and ball release were captured simultaneously. Surface electromyography trials were collected and related to the athletes’ phases of pitching and throwing, identified based on predefined softball and baseball pitching mechanics. Results Throws were of similar velocity (24 m/s, 53 mph, P =. 71), but peak biceps brachii muscle activation during the windmill pitch was significantly greater than during the overhand throw when normalized (38% vs 19% manual muscle test, P =. 02). The highest muscle activity occurred at the 9-o'clock phase of the windmill pitch, during which the biceps brachii undergoes eccentric contraction. In the overhand throw, the highest level of biceps activity occurred during arm cocking. Conclusion In female athletes, biceps brachii activity during the windmill pitch is higher than during an overhand throw and is most active during the 9-o'clock and follow-through phases of the pitch. Clinical Relevance Repetitive eccentric biceps contractions may help explain the high incidence of anterior shoulder pain clinically observed in elite windmill pitchers. Injury prevention and treatment mechanisms should focus on the phases with the highest muscle activity.

Perceived sports competence mediates the relationship between childhood motor skill proficiency and adolescent physical activity and fitness: a longitudinal assessment.

BackgroundThe purpose of this paper was to investigate whether perceived sports competence mediates the relationship between childhood motor skill proficiency and subsequent adolescent physical activity and fitness.MethodsIn 2000, children's motor skill proficiency was assessed as part of a school-based physical activity intervention. In 2006/07, participants were followed up as part of the Physical Activity and Skills Study and completed assessments for perceived sports competence (Physical Self-Perception Profile), physical activity (Adolescent Physical Activity Recall Questionnaire) and cardiorespiratory fitness (Multistage Fitness Test). Structural equation modelling techniques were used to determine whether perceived sports competence mediated between childhood object control skill proficiency (composite score of kick, catch and overhand throw), and subsequent adolescent self-reported time in moderate-to-vigorous physical activity and cardiorespiratory fitness.ResultsOf 928 original intervention participants, 481 were located in 28 schools and 276 (57%) were assessed with at least one follow-up measure. Slightly more than half were female (52.4%) with a mean age of 16.4 years (range 14.2 to 18.3 yrs). Relevant assessments were completed by 250 (90.6%) students for the Physical Activity Model and 227 (82.3%) for the Fitness Model. Both hypothesised mediation models had a good fit to the observed data, with the Physical Activity Model accounting for 18% (R2 = 0.18) of physical activity variance and the Fitness Model accounting for 30% (R2 = 0.30) of fitness variance. Sex did not act as a moderator in either model.ConclusionDeveloping a high perceived sports competence through object control skill development in childhood is important for both boys and girls in determining adolescent physical activity participation and fitness. Our findings highlight the need for interventions to target and improve the perceived sports competence of youth.

Changes in motor skill and fitness measures among children with high and low motor competence: A five-year longitudinal study

Children with low motor competence (LMC) are less able to participate fully in many sports and recreational activities typically enjoyed by their well-coordinated peers. Poor fitness outcomes have been reported for these children, although previous studies have not tracked these outcomes over time. In this study, 19 children (8 girls and 11 boys) with LMC aged between 5 and 7years were matched by age and gender with 19 children with high motor competence (HMC). Six fitness (body composition and cardiovascular endurance) and motor skill (sprint run, standing broad jump and balance) measures were repeated for each group once a year for five years. For each year of the study, the LMC groups performed less well on all measures than the HMC groups. Changes over time were significantly different between groups for cardiovascular endurance, 50-m run and balance, but not for body composition, overhand throw or standing broad jump. Between the two groups, performances were significantly different for all measures, except body composition. These findings confirm the impact of LMC on fitness measures and skill performances over time.

A case study of the effect of skill training on the pitching motions of collegiate baseball pitchers

A three-dimensional (3D) videography study was performed to clarify the mechanical effects of a change of pitching motion from an overhand throw (OH style) to a three-quarter throw (TQ style). Two collegiate pitchers (subjects A and B) who normally used the OH style participated. They were requested to change their original OH style into the TQ style. To do this, they were subjected to a one-year skill training program based on biomechanical principles and on knowledge such as the stretch-shortening cycle theory, muscle force-velocity relationship, and the motions of skilled pitchers (e.g., shoulder positioning at 90 degrees of abduction-adduction during the acceleration phase). Four pitches for subject A (two in pre-training, one during training and one in post-training), and three for subject B (one each in pre-training, training and post-training) were videotaped with the 3D DLT procedure using two high-speed cameras, and then analyzed. We then examined the mechanical differences between pre- and post-training. The speed of the ball at release increased progressively with every successive pitch for both subjects (Subject A : 1st : 130.3km/h ; 2nd : 133.2km/h ; 3rd : 135.7km/h ; 4th : 142.2km/h. Subject B : 1st : 131.0km/h ; 2nd : 135.0km/h ; 3rd : 139.3km/h). The pitching styles of both subjects changed from their original OH style to the TQ style, both qualitatively and quantitatively. The time-dependent patterns and peak values of the angular velocities of shoulder internal-external rotation and elbow flexion-extension of the throwing arm did not change very much. However, the peak value of the angular velocity of shoulder internal rotation occurred immediately after ball release for the OH style, while for the TQ style it occurred at ball release. As a result, the angular velocity of elbow extension at ball release was larger in the OH style than in the TQ style. On the other hand, the angular velocity of shoulder internal rotation at ball release was larger in the TQ style than in the OH style. These findings suggest that the increase in the speed of the ball is dominated by elbow extension in the OH style, and by shoulder internal rotation in the TQ style.

Transfer of Training for Two Ball-Throwing Tasks

The effects of training overhand ball throws to enhance underhand ball-throwing accuracy were studied with 921 Italian high school pupils (575 girls, M age = 16.5 yr., SD = 1.3; 346 boys, M = 16.5 yr., SD = 1.2) ages 14 to 18 years. A standardized test (10 underhand tennis-ball throws into the floor area delimited by an 80-cm radius wooden hoop lying on the floor 9 m from the standing pupil) was performed and scored. An Experimental group (435 girls, M age = 16.5 yr., SD = 1.3; 204 boys, M age = 16.5 yr., SD = 1.2) was randomly selected to participate in 10 weekly training periods. The set included 10 overhand throws of a rubber bouncing ball (14.5 cm diameter, weight 240 g) into a basketball hoop from 5 standardized positions (in front of the basketball hoop; at 45 degrees, 90 degrees on the right and on the left of the basketball hoop) at a distance of 4.40 m. The underhand test was repeated for both groups. On the average, boys obtained higher test scores than girls of the same age. Older adolescents had higher mean scores than younger adolescents. After 10 weeks, boys and girls of all ages improved. Mean differences between sessions were significant for the Experimental group (Student t test, p < .01). In Session 2, consistent differences between Experimental and Control groups were also found (Student t test, p < .05).

Preliminary Study on Gross Motor Performance of Hong Kong Children Aged 6-8 Years

LANGUAGE NOTE | Document text in English; abstract also in Chinese.Gross motor development is a critical component of elementary school physical education programs. This is also the foundation for active participation in later childhood and adult physical activities. This study aims to: (1) collect preliminary data on Hong Kong children's gross motor performance; (2) analyze Hong Kong Children's gross motor proficiency; and (3) introduce a gross motor test instrument to Hong Kong PE teachers. The Test of Gross Motor Development (Second Edition) (TGMD-2) (Ulrich, 2000) was chosen as the test instrument in this project. There were 15 girls and 15 boys selected for each age interval: 6-6 to 6-11, 7-6 to 7-11 and 8-0 to 8-11. Only 27.6% of the participants achieved the average level. 27.6% and 40% of them were below average and poor, respectively. No significant sex differences in the level of fundamental gross motor skills development. However, age differences were found in stationary dribble and overhand throw, 8 years old children got higher successful rate in the mature form of the two skills.大肌肉運動能力發展是小學體育課程的主要元素，這亦是青少年及成年時期積極參與體力活動的基石。本研究的目的是：(1)搜集香港兒童大肌肉運動能力數據；(2)分析香港兒童大肌肉運動能力表現；(3)介紹一套測試大肌肉運動能力的工具給香港體育老師。本研究選用了 '第二代大肌肉運動能力(TGMD-2)' 作測試工具。每一個年齡組別，即6-6至6-11，7-6至7-11及8-6至8-11均選取15男及15女作為研究樣本。總樣本為90人。研究發現，樣本中祗有27.6%在一般水平，另外27.6%及40%分別在低於及差的水平。在大肌肉運動能力的表現中，性別差異方面並不明顯。原地運球及擲球動作，年齡差異較明顯，八歲兒童成功掌握這兩個技能的百份比較年幼的兒童為高。

QUALITATIVE ANALYSIS OF THE OVERHAND THROW BY UNDERGRADUATES IN EDUCATION USING A DISTANCE LEARNING COMPUTER PROGRAM

The purpose was to (a) examine whether computer-based distance learning could enhance the qualitative analysis skills (error detection in the overhand throw) of undergraduates in education and (b) examine the effectiveness of several methods of information presentation (video file and text) on distance learning. Participants were randomly assigned to 1 of 4 groups, to detect errors in an incorrect throwing motion of a model on the computer screen. Group 1 (n = 13) was the control; Group 2 (n = 13) viewed a video of the appropriate throwing mechanics; Group 3 (n = 13) viewed text information describing the appropriate mechanics of the overhand throw; and Group 4 (n = 16) received a combination of video and text information. On Day 1 participants took a pretest. Treatment and testing occurred on Days 2 through 8. Then 5 days later participants took a retention test. One-way analysis of variance confirmed no significant differences between groups at Pretest (Day 1). An analysis of variance with repeated measures indicated learning over practice. Paired-sample t tests between Days 1 and 8 showed the video plus text group without significant change.

Change in Throwing Pattern: Critical Values for Control Parameter of Velocity

The purpose of this study was to determine the critical values at which throwing patterns change when scaling up on the control parameter of velocity. Thirty-six participants (ages: 6–12 years) were categorized into four throwing levels according to patterns represented by temporal joint lag. Each participant was required to complete 5 overhand throws at each of 10 relative velocities for a total of 50 trials per participant. The lowest velocity was 10% of maximum, with increases in increments of 10% up to a maximum effort. Quantitative and qualitative analyses indicated that critical values varied according to throwing category and joint. Generally, lower skilled throwers (Levels 1 and 2) had less stable joint lag and changed patterns at lower velocities than higher skilled (levels 3 and 4) throwers.

Relationship of physical activity to fundamental movement skills among adolescents.

To determine the relationship of participation in organized and nonorganized physical activity with fundamental movement skills among adolescents. Male and female children in Grade 8 (mean age, 13.3 yr) and Grade 10 (mean age, 15.3 yr) were assessed on six fundamental movement skills (run, vertical jump, catch, overhand throw, forehand strike, and kick). Physical activity was assessed using a self-report recall measure where students reported the type, duration, and frequency of participation in organized physical activity and nonorganized physical activity during a usual week. Multiple regression analysis indicated that fundamental movement skills significantly predicted time in organized physical activity, although the percentage of variance it could explain was small. This prediction was stronger for girls than for boys. Multiple regression analysis showed no relationship between time in nonorganized physical activity and fundamental movement skills. Fundamental movement skills are significantly associated with adolescents' participation in organized physical activity, but predict only a small portion of it.

Significance of the internal locking mechanism for loop security enhancement in the arthroscopic knot

Purpose: Secure tissue fixation of an arthroscopic knot depends on the security of the initial loop and additional locking half-hitches. The purpose of this report is to evaluate the loop and knot security relative to the internal locking mechanism of arthroscopic slip knot. Type of Study: This is an experimental study designed for knot and loop security on a material testing system. The measurements were carried out in a blinded fashion in which the tester was not aware of the type of knot being tested. Methods: Five configurations of arthroscopic knots (overhand throw, Duncan loop, Revo knot, Tennessee slider, and SMC knot) were created around a 5-mm diameter metal bar using a No. 2 braided suture. For each knot configuration, 10 knots were tested for displacement at cyclic loading, load to clinical failure (3-mm displacement), ultimate failure load, and mode of failure on the servo-hydraulic material testing system (MTS 858 MiniBionix test system; NITS, Minneapolis, MN). A 1-way analysis of variance was used to determine the statistical difference in displacement at cyclic loading, load to clinical failure, and ultimate failure load between each knot configuration. Results: In the cyclic loading test, the average displacement of all knots was clinically insignificant, with the average being less than 0.24 mm. The overhand throw had the worst characteristic in the load to failure test. The other 4 knots had an optimal load to failure. The SMC knot, which has an internal locking mechanism, had good loop and knot security in the load to clinical failure and ultimate failure load (P < .05). The SMC and the Revo knots failed by knot breakage (material failure) whereas the other knots failed by knot slippage (loop failure). Conclusions: The internal locking mechanism flips the post strand to convert the loop strand into a new post strand while rerouting the original post strand around a new post. An arthroscopic knot with an internal locking mechanism can enhance loop security.

Verbal instruction for correcting errors versus such instructions plus videotape replay on learning the overhand throw.

The influence of two methods of providing information to women, ages 19 to 22 years who were novices and learning the overhand throw with the nondominant arm, was examined. One group received verbal information on correcting errors, and a second group received the same information immediately prior to viewing a videotaped replay of a just completed throw. Performance was assessed quantitatively with respect to outcome (distance thrown) and qualitatively with respect to throwing form as measured on a 7-point rating scale by judges with a working knowledge of the overhand throw and with respect to throwing mechanics rated by a panel of experts in biomechanics using a scale of Leme and Shambes. Although the treatments led to better learning and performance, there was no significant difference between groups for distance thrown on the Leme and Shambes scale in Sessions 1-6 of 10 trials each on Session 7. The mean rating also indicated increased scores for both groups and better retention at posttest by the group receiving only verbal corrections. These results suggest that information provided by adding videotaped replay may be redundant and unnecessary for those in Sessions 1-6.

VERBAL INSTRUCTION FOR CORRECTING ERRORS VERSUS SUCH INSTRUCTIONS PLUS VIDEOTAPE REPLAY ON LEARNING THE OVERHAND THROW

The influence of two methods of providing information to women, ages 19 to 22 years who were novices and learning the overhand throw with the non-dominant arm, was examined. One group received verbal information on correcting errors, and a second group received the same information immediately prior to viewing a videotaped replay of a just-completed throw. Performance was assessed quantitatively with respect to outcome (distance thrown) and qualitatively with respect to throwing form as measured on a 7-point rating scale by judges with a working knowledge of the overhand throw and with respect to throwing mechanics rated by a panel of experts in biomechanics using a scale of Leme and Shambes. Although the treatments led to better learning and performance, there was no significant difference between groups for distance thrown on the Leme and Shambes scale in Sessions 1–6 of 10 trials each on Session 7. The mean rating also indicated increased scores for both groups and better retention at posttest by the group receiving only verbal corrections. These results suggest that information provided by adding videotaped replay may be redundant and unnecessary for those in Sessions 1–6.

Mastery of fundamental motor skills among new south wales school students: Prevalence and sociodemographic distribution

Mastery of fundamental motor skills among children and adolescents is a potentially important contribution to satisfying participation in sports, games and other physical activities and may enhance the development of an active lifestyle. However, few attempts have been made to determine the prevalence of fundamental motor skill mastery among young Australians. The NSW Schools Fitness and Physical Activity Survey, 1997 (N = 5518) randomly selected schools proportionally from all three education sectors and selected students in Years 4, 6, 8 and 10. Performance on six fundamental motor skills (run, vertical jump, catch, overhand throw, forehand strike and kick) was assessed qualitatively. The prevalence of mastery and near mastery of each skill and mastery of each skill component is reported for boys and girls in each school year. The findings indicate that the prevalence of mastery and near mastery of each of the fundamental motor skills was generally low. There were no differences between students from urban or rural schools and the prevalence of skill mastery was directly associated with socioeconomic status more consistently among girls than among boys. Greater curriculum time and resourcing and training of teachers is required to increase the proportion of students who have mastered the skills fundamental to common sports, games and other physical activities.

Methods of the NSW schools fitness and physical activity survey, 1997

Physical fitness, participation in physical activity, fundamental motor skills and body composition are important contributors to the health and the development of a healthy lifestyle among children and youth. The New South Wales Schools Fitness and Physical Activity Survey, 1997, was conducted to fill some of the gaps in our knowledge of these aspects of the lives of young people in New South Wales. The survey was conducted in February and March, 1997 and collected data on a randomly-selected sample of students (n = 5518) in Years 2, 4, 6, 8 and 10. Measures were taken on body composition (height and weight, waist and hip girths, skinfolds), health-related fitness (aerobic capacity, muscular strength, muscular endurance, flexibility), fundamental motor skills (run, vertical jump, catch, overhand throw, forehand strike and kick), self-reported physical activity, time spent in sedentary recreation, and physical education (PE) classes. The methods are described to assist in the development of surveys of other populations and to provoke debate relevant to the development and dissemination of standard approaches to monitoring the fitness, physical activity habits and body composition of Australian children and youth. Finally, we offer comments on some of the strengths and limitations of the methods employed.

Relationships of physical activity and somatic characteristics with physical fitness and motor skill in prepubertal girls.

The purpose of this study was to examine the relationships between physical activity and somatic growth with motor skill and physical fitness in prepubertal girls. The subjects were 215, 7-10-year-old girls. Somatic characteristics included 15 dimensions. Physical fitness was assessed by the EUROFIT battery of 9 tests. Motor skill development was based on quantitative and qualitative assessment of the overhand throw. Physical activity was assessed by parental seven-day physical activity recall for the child. Sum of five skinfolds was significantly negatively related with motor fitness after controlling for the effects of physical activity (r = -0.27 to -0.39). Somatic characteristics were not significantly related with fitness items and throwing stage after controlling for physical activity. Age-specific partial correlations between physical activity, fitness items, quantitative, and qualitative characteristics of the overhand throw, were not significant. After controlling for body size and subcutaneous fatness, aerobic fitness was significantly related with physical activity of moderate to high intensity. Am. J. Hum. Biol. 9:513-521, 1997. © 1997 Wiley-Liss, Inc.

Use of Instructional Statements by Preservice Teachers for Overhand Throwing Performance of Children

The purpose of this study was to (a) determine preservice teachers’ ability to use component-specific feedback to influence student performance on the overhand throw and (b) to develop an instrument to record teachers’ verbal behaviors concurrent with student performance. Preservice teachers used a force-production sequence of overhand throw components (Siedentop, Herkowitz, &amp; Rink, 1984) to intervene upon sport-skill performance of elementary age children. Techniques for observing, recording, and accessing overhand throwing performance and the subsequent instructional statements of the preservice teachers were presented, using the sport skill process variable assessment instrument (SSPVA). Analyses of data suggested three major patterns of instructional feedback statements provided by preservice teachers: (a) Preservice teachers often provided feedback on a component that had been consistently demonstrated at a high level of efficiency; (b) some components were not demonstrated at consistently high efficiency levels, yet little or no specific feedback was directed toward these components; and (c) when preservice teachers were able to recognize errors and provide appropriate feedback, change did occur.

Teaching children with autism through task variation in physical education.

The purpose of the study was to determine whether the technique of task variation (with maintenance tasks interspersed) (TV) is more effective in the acquisition of gross motor skills for students with autism than a constant task (CT) condition in a physical education setting. Subjects were 12 male students with autism, ages 11 to 15 years. The study included pretest-posttest administration of the I CAN assessment of Gross Motor Skills to assess skills such as overhand throw, kick, and vertical jump. After a 6-week treatment period, the TV condition was significantly more effective than the CT condition, at the .05 level.