Developing Fundamental Object-Control Skills

1. Developing Fundamental Object-Control Skills

2. When the child is able to ambulate freely, the hands are free to use in a new fundamental skill ~ object-control

3. Overarm Throwing One of the most complex fundamental movements Can be divided into 3 phases • Preparatory phase • All movements directed away from the intended line of projection • Execution phase • All movements performed in the direction of the throw • Follow-through • All movements following the release of the projectile

4. Developmental Stages of Throwing Monica Wild (1938) • Four developmental stages of throwing • Set standards for developmental throwing stages • Studied age and gender characteristics of throwing in 32 boys and girls • Ages 2-12 years old

5. Developmental Stages of Throwing Trends • Movement progresses from an anterior-posterior plane to a horizontal plane • The base of support changes from a stationary to a shifting position

6. Developmental Stages of Throwing • Roberton (1978) presents longitudinal evidence for developmental stages within the humerus, forearm, and trunk components for the overarm throw • “Development within component parts may proceed at different rates in the same individual or at different rates in different individuals.” Roberton, 1977, p.55

7. Developmental Stages of Throwing • Throwing motion is posterior-anterior in direction • Feet do not move • Little trunk rotation • Force for projecting the ball comes from hip flexion, shoulder protraction, and elbow extension Stage 1

8. Developmental Stages of Throwing • More rotation of the body • Performer may step forward (ipsilateral or contralateral pattern) • Arm brought forward in transverse plane • Form resembles a sling Stage 2

9. Developmental Stages of Throwing • Note the ipsilateral arm-leg action • Ball is placed into throwing position above the shoulder by a vertical and posterior motion of the arm at the time that the ipsilateral leg is moving forward • Little or no rotation of the spine and hips • Follow-through includes flexion at the hips and some trunk rotation Stage 3

10. Developmental Stages of Throwing • Movement is contralateral • Little or no rotation of the hips and spine during wind-up • Motion of trunk and arms resembles stages 1 and 3 • Stride forward with contralateral leg provides a wide base of support and stability Stage 4

11. Developmental Stages of Throwing • Mature movement pattern Stage 5 Age at which 60% of boys and girls are able to perform at a specific level

12. Developmental Performance Trends for Overarm Throwing • Study techniques for performance • Throw for distance • Throw for accuracy • Measurement of throwing velocity • Annual improvement regardless of study technique • Boys and men outperform girls and women at all ages

13. Factors that Influence Overarm Throwing Performance • Instruction • Knowledge • Instructional cues • Ball size • Angle of ball release

14. Factors that Influence Overarm Throwing Performance Instruction • Does instruction facilitate development or is improvement due to the year-to-year improvement of the fundamental skill? • Instruction significantly affects changes in throwing technique, but not greater horizontal ball velocities • Velocity should not be used as the sole index in the evaluation of the over-arm throw

15. Factors that Influence Overarm Throwing Performance Instruction • An “increased range of motion instruction” program can increase the stride length component of the overarm throw • Stride length • Arm retraction • Side facing • Trunk rotation • Preparatory leg recoil • Arm patterns • Stride opposition

16. Factors that Influence Overarm Throwing Performance • A training program designed to improve throwing pattern can be effective in improving girls’ foot action and pelvic-spine rotation, but not arm action, throwing distance, or ball velocity

17. Factors that Influence Overarm Throwing Performance Knowledge • Awkward throwers possess significantly less declarative knowledge than more talented throwers • Awkward throwers lack knowledge in • Ball size • Stepping forward with the opposite foot • Throwing low • Ability to recognize correct form from a side view • Knowledge of throwing influences performance

18. Factors that Influence Overarm Throwing Performance Instructional cues • Identification of critical cues facilitates throwing performance • Critical cues • “Take a long step toward the target with the opposite foot of your throwing arm” • “Take your arm straight down, then stretch it way back to make an ‘L’ with the arm” • “Watch the target and release the ball when you see your fingers”

19. Factors that Influence Overarm Throwing Performance Ball size • When ball diameter is scaled up, a transitional point is reached where the performer resorts to a less mature throwing pattern in the backswing and forearm components • As diameter increases, there is a transition from one-handed grasping to two-handed grasping • Ball size and hand width are important in throwing performance

20. Factors that Influence Overarm Throwing Performance Angle of ball release • In those using an “arm-dominated” throwing pattern, the ball is released too early resulting in an upward trajectory (49o) • May be linked to poor grasp, ball weight, and ball size • A more mature throwing pattern observed at a 15o angle of release • Older children release the ball at an angle between 25-28o

21. Factors that Influence Overarm Throwing Performance Working with small children • Control for ball weight and size • With help child with more mature ball release Does improvement in technique affect performance?

22. Accounting for Gender Differences in Overarm Throwing The greatest gender differences for all fundamental skills is found with throwing • Success in distance throwing of boys is associated with • Heredity • Arm muscle mass • Sociocultural factors • Male adult in the home

23. Accounting for Gender Differences in Overarm Throwing • Success in distance throwing for girls is associated with…. • Greater body weight • More body fat • Large joint diameter • Greater arm and leg mass …..compared to smaller and weaker female counterparts

24. Accounting for Gender Differences in Overarm Throwing • By age 9, girls throw only 49% as far as boys due to differences in • Grip strength • Height • Upper-body strength

25. Accounting for Gender Differences in Overarm Throwing • The best predictors of throwing development in girls are • Participation in sport • Presence of an older brother in the household • TV watching is negatively correlated with throwing performance • The best predictors of throwing development in boys are • Father’s sport involvement • Father-son skill play

26. Accounting for Gender Differences in Overarm Throwing • Can gender differences in throwing be accounted for by factors involving human evolution? • Perhaps • Throwing behaviors were more prevalent among men in our early history • Defense • Hunting

27. Catching • The action of bringing an airborne object under control by using the hands and arms

28. Developmental Aspects: Two-handed Catching • First attempt to stop a rolling object is to sit on floor with legs spread apart • Legs trap ball • Hands trap ball • First attempt at an airborne object is passive • Tosser throws ball so the child can use the outstretched arms and body to catch

29. Developmental Aspects: Two-handed Catching (Kay, 1970)

30. Developmental Aspects: Two-handed Catching • This 6-year old child is showing fear in reaction to a thrown ball • Seefeldt speculates that fear of a projectile is learned from earlier failures

31. Stage 1 Developmental Sequences for Two-Handed Catching • Arms are directly in front with elbows extended; palms facing upward and inward • Arms and hands attempt to secure the ball by holding it against the chest

32. Stage 2 Developmental Sequences for Two-Handed Catching • Elbows are slightly flexed • Arms encircle the ball against the chest • Arm action initiated before ball contact

33. Developmental Sequences for Two-Handed Catching • Child prepares to receive ball with arms flexed and extended • Substage 1: child uses chest as first contact point • Substage 2: child attempts to catch ball with hands Stage 3

34. Developmental Sequences for Two-Handed Catching • Child prepares to receive the ball by flexing the elbows and presenting the arms ahead of the frontal plane • Ball is caught with the hands alone Stage 4

35. Stage 5 Developmental Sequences for Two-Handed Catching • Many children encounter difficulty when they are required to move toward the object • Mature catcher “gives” with the catch Age at which 60% of boys and girls are able to perform at a specific level

36. Developmental Aspects: One-handed Catching • Little scientific evidence exists regarding a child’s ability to catch with one hand • Boys typically outperform girls • Ball location is a factor • Young children can orient hands in all directions for a catch, but lack experience in finger closure • One-handed catching is less successful than two-handed

37. Factors That Influence Catching Performance • Ball size • Ball and background color • Ball velocity • Trajectory angel • Vision and viewing time • Instruction • Knowledge and experience • Catching on the run • Catching with a glove

38. Factors That Influence Catching Performance Ball size • Product oriented evaluation: Larger balls improve young children’s catching performance • Not concerned with level of maturation in catching technique • Process oriented evaluation: Smaller balls are more conducive to successful catching (Isaacs, 1980) • More mature catch

39. Factors That Influence Catching Performance Ball and background color • Blue and yellow balls are caught successfully more often then white balls • Blue balls against white background elicit the highest success • For both boys and girls, using preferred color of ball results in greater catching success • Child can obtain more information concerning ball’s flight

40. Factors That Influence Catching Performance Ball velocity • Important in predicting direction of projectile • Catching performance decreases as ball velocity increases (25 ft/s to 33 ft/s)

41. Factors That Influence Catching Performance Trajectory angle • Angle of projection does not significantly affect a child's catching ability • On average, 44o projection angle elicits success in catching • Unskilled children are more successful when ball is projected at 34o angle

42. Factors That Influence Catching Performance Vision and viewing time • A slowly moving ball through space is preferred when working with inexperienced catchers • Beach ball • Whiffle ball • Sponge ball

43. Factors That Influence Catching Performance Instruction • Only one study has examined catching instruction on one-handed catching • 8-year-old child trained over 7 days • Catching ability improved to the level of a child 2 years older

44. Factors That Influence Catching Performance Knowledge and experience • Knowledge of catching can influence performance • Procedural knowledge is higher in nondisabled children; higher in ambulatory disabled vs. nonambulatory disabled peers • Declarative knowledge does not differ significantly among the various groups

45. Factors That Influence Catching Performance Knowledge and experience • “…declarative and procedural knowledge do not develop at the same rate …… catching experience may foster the acquisition of procedural knowledge, even though a deficit in declarative knowledge may be evident.”

46. Factors That Influence Catching Performance Catching on the run • It is easier to catch a ball when directed toward the child • Teachers/coaches should use caution when paring up inexperienced and experienced catchers

47. Factors That Influence Catching Performance Catching with a glove • A glove can alter the nature of errors typically observed in bare-handed catching • Reduces the precision of limb-hand positioning • Alters the temporal grasping component of the hand closure • Glove catching is easier as ball moves toward a larger target and is caught over a larger surface area • Hand strength is important • To squeeze glove

48. Striking • A fundamental movement in which a designated body part or some implement is used to project an object • Bare hand against volleyball • Baseball ball • Tennis racquet

49. Developmental Aspects of One-and Two-handed Striking • The initial patterns in striking are similar to those observed in throwing • Child faces the object to be struck • May or may not take a forward step with homolateral leg • Striking movements occur in anterior-posterior plane

50. Inexperienced striker No steps taken or step taken with homolateral leg Up-down striking motion Little backswing No rotation of trunk or hip Rigid arm; little wrist snap Experienced striker Forward step with opposite foot taken Full backswing Swings implement horizontally Trunk and hip rotation Coordinated wrist snap Developmental Aspects of One-and Two-handed Striking