Adapting activities for all children: considering constraints can make planning simple and effective.

Too often in society, persons with disabilities are considered in terms of what they cannot do, and how they differ from people without disabilities (Silvers 2003). Disabilities are thought of as restraints. In many college-level physical education programs, this focus is reflected in the curricular distinction between physical education (generally the bulk of physical education courses) and adapted physical education (a much smaller, specialty area). This lays the groundwork for physical educators and others to focus their thinking on movement differences, and what physical activities students with disabilities cannot accomplish within an inclusive physical education setting. This teaching mindset may cause students with disabilities to become isolated and their differences accentuated within a movement-based setting, which could lead to negative feelings and attitudes about physical education.

It is important to see the notion of disabilities in a more inclusive conceptual environment, disabilities as constraints. Constraints, for many, bring an image of negative conditions. Within motor development, constraints describe the status quo, merely conditions existing at any time marker. There is no value judgment about whether those conditions are positive or negative. Avoid any past negative meaning you may have attributed to the word constraints; the concept referenced here was applied to physical education in the work of Karl Newell (1984, 1986). In brief, Newell described constraints as the characteristics of the individual, environment, or task that work together to encourage certain movements and make others more difficult or impossible. Difference between restraints and constraints is not simply a matter of semantics, but of philosophy. When one envisions a disability as a restraint or a limitation, focus is placed on negative aspects of performance (he cannot run; she cannot swim). Alternatively, when one envisions disabilities as constraints, disabilities are viewed as neither positive nor negative, but simply as conditions encouraging different kinds of movements by the performer. By learning about disabilities as constraints (but not restraints), physical education students can build a knowledge base that begins, by definition, with inclusion and focuses on abilities. By considering disabilities more positively as constraints, current physical educators can empower students with disabilities to explore what they can do. In addition, by identifying the most important constraints acting on students with or without disabilities, physical educators can construct a learning environment both challenging and rewarding to all children.

The Theory of Constraints as Applied to Movement

The theory of constraints comes from a theoretical perspective known as the Ecological perspective. In recent years, various researchers in different areas of motor behavior have found the Ecological perspective valuable in understanding human movement (e.g., Hamilton, 2000; Langendorfer & Roberton, 2002). At the same time, others have discovered useful principles that spring directly from the perspective (e.g., Chen, Rovegno, Todorovich, & Babiarz, 2003; Gagen, 2003). The theory of constraints offers many practical ideas that can be directly applied in a physical education setting to help teachers plan activities allowing all students to become more proficient movers (Gagen & Getchell, 2004).

Briefly, the theory of constraints suggests, in order to understand why movement patterns exist, one must consider not only characteristics of the mover (individual constraints), but also characteristics of the environment and task, as well (Gagen & Getchell, 2004; Newell, 2000). In short, everything matters. It's easy to focus on the characteristics of the performer, particularly when he or she is a person with a disability, and forget that many other factors may influence movement--the presence or absence of other people, gymnasium space, the surface of the floor or ground, the lighting conditions, and the equipment size, shape, and fit, to name a few.

In fact, the individual, environment, and task are always dynamically interacting, and characteristics of each change can also be influenced by other changes taking place (see Figure 1). So, in addition to rule one, everything matters, a second important consideration is the world is not static--it changes over time and context. Consider a young basketball player who is a wheelchair user. When this player is shooting a free throw during a practice session, with a coach and fellow teammates providing encouragement, she might easily master the shot. If the social environment changes slightly, and it's the county finals instead of regular practice, or her parents are at a game for the first time, her ability to make the shot may change. So, not only does everything matter, but everything changes. The goal of adapted physical educators is to manipulate relevant task and environmental constraints to improve chances of success. For typically developing children, physical educators can more easily group students using certain age-related or skill-related individual constraints, since constraints may be more similar between students within the group. Physical educators must take different individual constraints into consideration when working with students with disabilities. However, according to the Newell model, physical educators can modify the environmental and task constraints to improve skill proficiency in an equally effective way for students with any combination of constraints.

[FIGURE 1 OMITTED]

Disabilities as Individual Constraints

One way to understand the influence of individual constraints is to classify them as either structural or functional. These classifications serve two purposes. First, they provide boundaries or guidelines for selecting appropriate activities. Second, they provide a means by which physical educators can translate an Individualized Educational Plan (IEP) or medical diagnosis into a more functional assessment of ways in which the child is capable of moving.

Classification of individual Constraints

Again, individual constraints are characteristics of the individual, both structural and functional, encouraging certain movements and discouraging others. Structural individual constraints relate to specific body structures. Several examples include height, weight, visual acuity, and musculature. These constraints are often slow to change. Structural constraints can be short term (i.e., a sprained ankle or broken arm) or long term (i.e., a limb malformation or dwarfism). Examples of other structural constraints physical educators might encounter in inclusion classes include amputations, juvenile arthritis, or obesity.

Functional individual constraints, on the other hand, are related to specific functions, such as attention, memory, motivation, fear, or self-esteem. They may also include interrelated structures, such as coordination or balance. Children of all ages, from toddlers through adolescents, who have disabilities involving functional constraints, may not have clearly apparent movement differences from typically developing students. Some examples of disabilities as functional constraints physical educators might encounter in an inclusion classroom are attention deficit/hyperactivity disorder (AD/HD) or learning disabilities such as dyslexia.

In some cases, students with disabilities may have both structural and functional constraints. For example, a child with cerebral palsy may have muscular rigidity and spasticity (structural), as well as cognitive delays (functional). Another example is a child with Down syndrome, who may be cognitively, as well as physically challenged.

Adaptations for Teaching Using the Constraints Model

Good adapted physical education involves adapting, modifying, and changing a physical activity or purposefully selecting an alternative activity so it is appropriate for the person with a disability or anyone whose individual constraints do not interact with the task in its original form to allow the desired movement to occur. "Instruction in Adapted Physical Education provides the foundation for learning and performing psychomotor skills, so that students with disabilities can more fully, safely and with satisfaction participate in movement programs, recreation, sport and physical fitness activities" (CAHPERD, 2001).

Issues for physical educators are the same regardless of children or adolescents with whom they work: provide fitness activities promoting the development of strength, flexibility, and cardio respiratory endurance; provide skill development in manipulative, locomotor, and non-manipulative activities; help develop cognitive reasoning and problem solving skills: and promote the development of social skills such as cooperation and sportsmanship. Need for adaptation arises when these fitness and skill-development tasks cannot be completed as planned, due to constraints not allowing the performance of the specific, desired movements.

The job of physical educators, then, is to plan goals and rules of the task and select appropriate equipment, or a user-friendly environment, allowing the opportunity for successful learning experiences for all students. A focus of this planning should be to bridge any gap separating the child from successful completion of a task. This bridge represents the development of an interaction of constraints allowing a particular, desired movement to take place. For example, in a tagging game, students who are running have the capacity to reach out to tag by stretching to one side or the other, extending an arm and/or shifting the body's weight in the direction of the desired player. To participate in tagging, a child in a wheelchair, or standing with a walker or braces, needs to be able to reach across a greater distance, since stretching and extending as far as needed are somewhat restrained by the chair's structure or a need to retain balance. Working with structural constraints of available mobility and flexibility, how can we extend this child's ability to reach out to tag?

Many students in wheelchairs or in supported standing have good mobility in the upper body, so extension needed to reach out and tag should come from those body parts. An answer to this question might be to provide a piece of equipment that would extend his/her reach. This equipment would bridge the gap by extending the child's upper body reaching capacity, which would compensate for movement not provided by the lower body. Because this equipment must be integrated into the game, it has to perform as an extended hand and arm in much the same way as any hand and arm would. That limits equipment choices to something firm enough to extend over the distance, but soft enough not to cause injury to others during tagging. A composition foam noodle or pointer works fairly well for this and can be attached to the child's hand with Velcro[TM] or ties if grasping ability is an additional structural constraint. This allows the child to participate on a more equal basis with the class by providing only what help is needed and still leaving some appropriate level of challenge.

One way to adjust how we think about this planning is to look at task revisions through a process called constraints-based task analysis (Haywood & Getchell, 2004), similar to the idea of developmental (Herkowitz, 1978) or ecological task analysis (Burton & Davis, 1999; Davis & Burton, 1991). Constraints-based task analysis (CTA) is a systematic way to consider adaptations or modifications to a task, while controlling resulting levels of difficulty for the mover. In CTA, all aspects of a task are defined in terms of the specific constraints influencing the skill. These are, then, defined as choices for modifying the constraint, and are rank ordered from the easiest modification to the most difficult (see Table 1). This produces a grid allowing many possible combinations of choices to vary the difficulty of the end task (see Table 2). By choosing more aspects from the easy end of the grid, a task can be defined that is easier to accomplish. Likewise, choosing the more difficult choices results in a more difficult task. In the case of a child needing a particular modification to interact with a particular individual constraint, task aspect(s) needing to be modified can be targeted more directly to provide the most desirable match up of activity with constraint.

Modifying Task Constraints

Equipment constraints

Adapting equipment is one of the most common modifications physical educators make to alter interactions of constraints to encourage a desired movement. Students with motor disorders such as cerebral palsy, muscular dystrophy, hemiplegia, or developmental coordination disorder, often need pieces of equipment that work with each child's individual abilities. Darrah and Bartlett (1995) proposed hold-ing a child to a gold standard movement behavior may be doing a disservice to the dynamical systems approach. When a child is moving in a natural way resulting from his/her own ability to self-organize with the equipment, the movement may look substantially different from movement we expect. If we allow the child to move naturally, but differently from other children, is this a positive practice that encourages activity, or does it hold the child back developmentally to move differently? Is completing the task a justification for accepting compromised movements, or should we be attempting to direct the movement into a particular, more uniform, pattern? As physical educators, if we value movement, we should value and nurture what movements are possible, given the specific interaction of constraints. Holding a child to an impossible standard of proficiency could discourage some children from moving at all.

Consider a child who is learning to bat. If a child has less ability to control the batting implement due to an individual constraint, such as less strength or smaller hand size, modifications could include a lighter-weight bat with a smaller grip to gain better control, or a larger striking surface, so control does not need to be so precise. We must be somewhat cautious, however, in choosing an implement with a larger striking surface if it makes the bat significantly heavier. This would discourage the desired movement pattern due to increased force production requirements without encouraging the striking pattern.

If the bat is too heavy for the child to manipulate, providing a lighter bat would be a logical solution. A consideration for a lighter bat would be that the striking surface remains an appropriate size for the degree of coordination, so the child can manipulate it successfully into the ball. Many commercially made, lighter plastic bats have very small barrels, and, therefore, are very difficult for beginning batters to connect with the ball. Others have larger surface areas in the barrels of the bats but have unmanageably large grips that might not match the size of the child's hands to allow effective grasping. Both equipment constraint modifications tend to discourage rather than encourage the appropriate striking pattern and can result in unsuccessful performances.

Another issue might be length of the bat. If the bat is disproportionately long, the striking surface is placed far from the hands that manipulate it. This creates need for more strength to create enough force in the swing, and more coordination to judge where the ball must be to strike it. If these constraints are present, a very short bat with the striking surface closer to the hands could create a better interaction. And, finally, if grasping is a constraint, use of Velcro[TM] straps or wrist loops on the bat can provide the means for a child to retain the bat to complete the swing.

Striking with a racket or a paddle provides some similar issues to batting. The striking implement could be modified for weight, length, grip, or striking area to provide the best match to the individual constraints of the child. The easiest striking task, striking with the hand, can be modified to include the feeling of equipment by mounting a striking implement directly on the surface of the hand, eliminating the handle entirely (sliding a hand through two slits in a paper plate creates a pseudo racket surface that works well for this).

Varying equipment to be struck is also a way of modifying the batting or striking task. A larger ball provides more striking surface, therefore easier meeting of bat or paddle with ball. But a large ball may be too heavy for the child to apply enough force to move it when it is struck. A ball that is a solid texture, allowing it to fly straight, may be too heavy or dense for the child to strike it comfortably. Students with visual constraints need ball color to contrast as much as possible with background setting to track the ball movement most effectively. If visual acuity is limited, a well-lighted area could allow optimal vision.

If the ball is stationary, striking should be easier to accomplish, but in what manner do we present a stationary ball? A batting tee is often used; however, for many children, the structure of the batting tee under the ball creates a difficult situation, since the child is just as likely to strike the tee as the ball. Hanging the ball from a rope provides a stationary presentation, but the ball, kept in place by the length of the rope, flies around and might strike the child. This could develop a functional constraint of fear of the ball. An optimal presentation would be a ball on an angled, moveable post, with the ball closest to the child so the ball can be struck, but the post is not in the path of the striking implement. This is not an easy modification since the post would also have to be somewhat adjustable to the height of the child to place the ball in an optimal position to bat or strike. Batting tees do provide some of these desirable qualities and could be modified to provide most of them.

If the ball is not stationary, how and from where is it being propelled toward the child for striking? A slow, soft, and, therefore, easier to manage throw would force the pitcher to stand close to the bat and ball, in a more dangerous situation if the ball is struck firmly. A harder throw from a greater distance away is more difficult to place in an optimal striking place, and speed needed to get the ball there would make it more difficult for a child to judge, especially a child with visual or cognitive processing deficits. In this case, the type of ball used might work together with distance to allow pitching to be both safe and effective.

Other kinds of equipment modifications might include larger or more accessible targets. Rims for basketball can be both larger and lower to compensate for lesser abilities to produce force or accuracy by the shooter or thrower. Remember, interactions of pieces of equipment with each other might also adjust the task. Size of the rim interacts with size of the ball selected for the shooting task, and height of the rim interacts with weight of the ball.

Catching includes the same issues of ball size, weight, and color. While a ball fitting into the hand, like a tennis ball, is easier for throwing, a bit larger ball is better for catching (Payne & Isaacs, 1995). Ball texture can be an issue, as well. For students with grasping difficulties or small motor coordination deficits, the ball surface should be textured and not slippery to enhance grasping and retaining the ball. Optimal ball material would be heavy enough to fly straight, but light enough not to hurt if the child missed catching it in the hands. Other possible catching equipment could be something soft like a ball made of a pair of socks turned inside out, which would be small and very pliable in the hands. Pliable balls and bean bags conforming to configurations of the hand offer better opportunities to retain the object within the hands, even if the hands do not cradle the object as effectively as they might.

Baseball and softball gloves provide help for experienced catchers to diminish force on the ball, but are often difficult for inexperienced catchers to manage. Equipment interacting to simplify or enhance catching might be something like a flat surface worn over the hand and covered with Velcro[TM] to help capture the ball and stick it to the catching surface. A surface like this would compensate for a child's inability to configure the hands appropriately to cradle the ball, allowing some success in catching. A light, easy-to-manipulate plastic scoop with a handle that either fits the hand or can provide some attachment to the hand as with Velcro[TM] straps can provide a pocket into which a ball could fit. If this scoop is wide, such as one that might be made from cutting down a gallon milk jug, additional interior catching area allows for more successful catching, even with less accurate presentation of the catching object.

Goals and rules for the activity

Often there are modifications physical educators can make to goals or rules of a task to assist a child with successful completion of the task. One of these modifications could be to disregard established time limits, or adjust number of attempts (number of strikes per player or number of outs per team), to allow each child a successful task completion. At times, this can become tedious when multiple attempts are needed to bat or strike a ball to put it in play, but using additional modifications in equipment or play spaces can often mitigate these difficulties. Playing a game where team groupings are small and each child bats once an inning, can make the game move along more effectively, with less debate than with more traditional rules. Perhaps, as an infrequent alternative, all batters could be seated in a chair to equalize experience and provide an awareness of these constraints for the class as a whole.

A partner system could be instituted for all students, allowing each pair to decide how to divide up responsibilities (e.g., you bat/I'll run). Frequent changes of partners and roles could make this method most effective. Partnering is one effective way to provide more assistance to a child who needs it. It allows the teacher to be freer to circulate throughout the class: being assured students needing more personal assistance can receive it from peers. Peer assignments can provide modeling of an activity, assistance retrieving the occasional escaped ball, and lots of affective involvement for both partners. Often you might find many students eager to provide this peer support for a classmate, and both partners benefiting from the experience. This should be approached from the assumption ALL students bring constraints to a partnership; some constraints are more easily recognized than others!

Environmental constraints

Adapting the environment to be more user-friendly comes from definitions of self-space and general space. While many games have boundaries (general play space) that are directed by the original rules, there is no reason that boundaries cannot be modified to provide a better match with the constraints of the child. A child with mobility constraints could benefit from a smaller space, or a well-defined space, in which s/he has control of that space. Dimensions of a playing field should be modified in ways that make sense. Perhaps the goalie area can be made smaller for a child with less mobility or enlarged to allow a partner-goalie to share the responsibility. Base paths are commonly shortened for smaller children. If a path to first base is standard size for all players, perhaps a count-of-three or -five head-start could make that play at first base more similar for a child with locomotor speed slowed by constraints.

Students with structural hardware, such as chairs, walkers, or crutches, need more self-space for several reasons. One important reason is for safety. There should be some thought as to how we can protect both the child who could be knocked off balance by other players, and other players from being injured by running into the chairs or tripping over walkers or crutches inadvertently during games. Well-defined boundary areas, which can be marked by colored cones or brightly colored floor tape, can help with this.

Another important reason for increased need for self-space is to allow the child space needed to maneuver, which could mean changing direction, or just becoming mobile from a stationary position. Adapted general space with the incorporation of well-marked safe zones can establish this concept so needed self-space can be granted to all. In many cases, marking off zones for game activities can be a positive step in teaching all the players appropriate position play, and lead to better game play in general, and the retention of appropriate sell-space for players who need it.

Teaching Techniques

Many techniques can be embedded into daily teaching to enable students with many different learning styles and different structural or functional constraints to perform effectively with no additional accommodations. Physical education teachers should routinely provide verbal instructions, as well as modeling or demonstrating an activity. It is not necessary to be able to demonstrate everything taught, but physical educators should be able to spot or manipulate a child through a demonstration so visual models are essentially correct. Consider using a child with cognitive constraints as the model, since moving this child through the activity could also provide him/her with kinesthetic modeling at the same time. During this modeling, inject your teaching keys as verbal prompts in appropriate places to provide a strong model for most differently-able learners in the class. Verbally walking the whole class through a demonstration is equally effective. When students are seeing, hearing, and moving through a skill at the same time, more students should be capable of reproducing that skill.

Structure within the classroom is an important element, particularly for students who might be AD/HD or ADD, even those who are not currently diagnosed. Minimizing transition times within your lesson by creating strong classroom routines is not only effective for eliminating wasted time, but also allows students to stay on task with fewer distractions. Each transition provides time and opportunity for children to be more readily drawn off task. Planning fewer transitions and standardizing them into routines is an effective classroom management technique for all students, particularly for students with behavioral constraints. These transitions and routines should be taught and practiced to be most effective.

Another effective technique is use of very specific task directions, rather than allowing a great deal of free exploration for a child with any behavioral constraints. Specific directions on which a child can focus allow best opportunities to remain engaged with the task. When behavior overwhelms the task, regrouping from a stationary (sitting) position to recreate a structure of directions for a new task can often allow the student(s) to get back on task with a minimum of disruption to the class.

Task sheets are a good way to accommodate for any student. If you are using portfolios as a structure in your classes, partners can be assigned, and differently designed tasks inserted into each set of partners' portfolios to be worked through as partners during class. This allows some students to work at a more elementary level while some can move ahead more quickly. If you are not using portfolios, task sheets can be given out individually to each set of partners as you choose.

In many cases, safety issues must be considered. All students must move in a safe, protected environment. To ensure this, it is often easier for a teacher to have a child who needs extra consideration to be physically nearer to where the teacher is working. In this situation, close proximity can allow the teacher to jump in and assist only when help is needed and monitor when the child might need help or more direction. Monitoring a child's frustration level is often a positive way to allow him/her some time to work at a challenge and then assist in a timely manner, well before frustration becomes unmanageable.

Arranging proximity should be a two-way responsibility. The child should also accept the responsibility of making accommodations to allow him/her to be most productive. For example, a child who is reading lips should be sure s/he moves to a position to be able to see the teacher when directions are being given, and the teacher should ensure the student is in that relative position, as well. Often students have a good sense of what modifications make movement possible. They should have opportunities to discuss those suggestions with you, as well as opportunities to explore movement patterns to find the most workable methods for them.

While many physical educators have some training in making appropriate accommodations, it really is a matter of using knowledge of motor development, biomechanics, and exercise science to visualize how constraints work under activity conditions. This is, after all, one of the reasons physical education students take those courses. Accommodations based on constraints for all students in physical education classes should optimize each student's movement capabilities. This should always be the primary objective, as well as a legal, moral, and ethical responsibility, to teach every child as effectively as possible (APENS 2001). It is sad for all concerned when one can walk into a gymnasium full of activity and see a child in a wheelchair parked next to the bleachers, participating by watching and cheering. If physical educators take time to see the child (and not only the chair), then recognizing individual abilities and capabilities--by identifying constraints should help define appropriate interactions to identify movement possibilities. When we provide more appropriate activities by manipulating constraints, all students should have better opportunities to learn movement skills more effectively.

Selected References

Adapted Physical Education National Standards (APENS) (2001). Found on-line at: http://www.cortland.edu/apens/15standards.htm. Retrieved January 17, 2006.

Burton, A.W., & Davis, W.E. (1996). Ecological task analysis: Utilizing intrinsic measures in research and practice. Human Movement Science 15, 285-314.

California Association for Health, Physical Education, Recreation, and Dance (CAHPERD). (2001). Position paper for adapted physical education. Found on-line at: http://sc-ape.org/PositionPaper/Position%20Paper.pdf. Retrieved: January 17, 2006.

Chen, W., Rovegno, I., Todorovich, J., & Babiarz, M. (2003). Third grade children's movement responses to dribbling tasks presented by accomplished teachers. Journal of Teaching in Physical Education, 22, (4). 429-449.

Darrah, J., & Bartlett, D. (1995). Dynamic systems theory and management of children with cerebral palsy: Unresolved issues. Infants and Young Children, 8 (1), 52-55.

Davis, W.E., & Burton, A.W. (1991). Ecological task analysis: Translating movement behavior theory into practice. Adapted Physical Activity Quarterly, 8, 154-177.

Gagen, L.M. (2003). Choosing a racket for striking tasks in elementary school. Journal of Physical Education, Recreation and Dance. 74(7). 39-40.

Gagen, L., & Getchell, N. (2004). Combining theory and practice in the gymnasium: 'Constraints' within an ecological perspective. Journal of Physical Education, Recreation and Dance, 75, 25-30.

Hamilton, M.L. (2000). Developmental comparisons of task constraints on the overhand throw. Journal of Sport & Exercise Psychology, 22, s48.

Haywood, K., & Getchell, N. (2004). Life Span Motor Development (4th ed). Champaign, IL: Human Kinetics.

Herkowitz, J. (1978). Developmental task analysis: The design of movement experiences and evaluation of motor development status. In M.V. Ridenour (Ed.), Motor Development (pp. 139-164). Princeton, NJ: Princeton Book.

Langendorfer, S.A., & Roberton, M.A. (2002). Individual pathways in the development of forceful throwing. Research Quarterly for Exercise and Sport, 73, 245-256.

Newell, K.M (2000). Constraints on the development of coordination revisited. Journal of Sport & Exercise Psychology, 22, s3.

Newell K.M. (1986). Constraints on the development of coordination. In M. Wade & HTA Whiting (Eds): Motor Development in Children: Aspects of Coordination and Control (pp. 341-360). Dordrecht, Germany: Martinus Nijhoff.

Newell, K.M (1984). Physical constraints to development of motor skills. In J. Thomas (Ed.). Motor Development during Childhood and Adolescence. Minneapolis, MN: Burgess Publishing Company.

Payne, V.G., & Isaacs, L.D. (1995). Human Motor Development: A Lifespan Approach. (6th ed.). Mountain View, CA: Mayfield.

Silvers, A. (November 2003). On the possibility and desirability of constructing a neutral conception of disability. Theoretical Medicine and Bioethics, 24(6). 471-487.

Table 1
Constraints Matrix: Catching
What constraints are operating in this skill?

Structural          Functional             Environmental
Constraints         Constraints            Constraints

Hand length         Motivation             Background

Arm length          Fear                   Gravity

Height              Self-esteem            Temperature

Visual acuity,      Focus                  Lighting
visual tracking

Flexibility         Anticipation

Hand strength       Experience

Arm strength        Social
                    pressure

Ability to          Hand-eye
configure hands     coordination

Structural
Constraints         Balance

Hand length         Task Goals             Task Rules
                    Constraints            Constraints

                    Catch with 1 hand      Catch while running
Arm length          (dominant or
                    non-dominant)

Height              Catch with 2 hands     Catch and keep feet
                                           in bounds

Visual acuity,      Catch over head        Catch and jump
visual tracking                            stop

Flexibility         Catch in front of      Catch from behind
                    body                   or over shoulder

                    Move to the ball       Catch while running
Hand strength       to dominant or         toward
                    non-dominant side

                    Move to the ball       Catch while running
                    front or back          away from

Arm strength

Ability to          Varied ball speed      Field a ground ball
configure hands
                                           Catch a fly ball

                                           Catch in a squat
                                           position

Structural          Equipment
Constraints         Constraints

Hand length         Object to catch

Arm length          Size

Height              Color

Visual acuity,      Texture--surface
visual tracking     or composition

Flexibility         Weight

Hand strength       Catching
                    equipment
                    (gloves, scoops,
                    Velcro[TM] pads,
                    lacrosse sticks)

Arm strength

Ability to
configure hands

Note: A Constraints-based Task Analysis matrix for catching. The first
column contains different categories of constraints that may influence
catching. Within each category is a list of specific constraints,
ordered from easiest to most difficult to modify. This matrix should
provide the categories for Table 2.

Table 2
Constraints-based Task Analysis: Interaction of Constraints in Catching
What are criteria involved in catching we can identify by interacting
constraints?

SIMPLE TO COMPLEX

Catching            Catching            Location of
Object              Equipment           ball

* 6" contrasting    No                  Coming
  color play-       equipment           from
  ground ball       used                straight
* Nubby                                 ahead
  textured 6"-
  8" foam ball

Light weight,       Wide mouth
contrasting         scoop
colored             (gallon milk
beanbag             jug)

8.5" contrasting    Velcro pad          Coming
color play-         covering            from 45[degrees]
ground ball         hand                angle,
                                        dominant
                                        side

* Tennis ball       Soft textured
* Rubber chicken    baseball/
                    softball
                    glove

* Junior football   Plastic scoop       Coming
* Basketball                            from 45[degrees]
                                        angle,
                                        non-dominant
                                        side

* Deck tennis                           Coming
  ring                                  from 90[degrees],
* Large softball                        dominant
                                        side

* Large football                        Coming
  Regulation                            from
  softball                              90[degrees],
                                        non-dominant
                                        side

* Star-shaped or    Jai Alai            From rear,
  pointed           basket              over the
  catching obj.     (scoop)             shoulder,
* Regulation                            dominant
  baseball                              side

* Flat disk         Lacrosse            From rear,
  (Frisbee)         stick (cross)       over the
* Lacrosse ball                         shoulder,
* Golf ball                             non-dominant
                                        side

Catching            Movement of         Ball speed
Object              catcher

* 6" contrasting    Standing still,     Slow ball
  color play-       no movement         velocity
  ground ball
* Nubby
  textured 6"-
  8" foam ball

Light weight,       Moving
contrasting         slowly,
colored             stepping
beanbag             toward ball

8.5" contrasting    Moving              Moderate
color play-         slowly,             ball
ground ball         stepping to         velocity,
                    dominant side       no spin

* Tennis ball       Moving
* Rubber chicken    slowly, stepping
                    to non-dominant
                    side

* Junior football   Running
* Basketball        slowly toward
                    ball

* Deck tennis       Running             High ball
  ring              slowly away         velocity,
* Large softball    from ball           no spin

* Large football    Running at full
  Regulation        speed, toward
  softball          ball

* Star-shaped or    Running at full
  pointed           speed, away
  catching obj.     from ball
* Regulation
  baseball

* Flat disk         Running             High ball
  (Frisbee)         backwards           velocity,
* Lacrosse ball                         spin on
* Golf ball                             ball

Catching            Trajectory          Distance
Object              of ball             away of
                                        thrower

* 6" contrasting    Softly              Short
  color play-       arching             throw (3'-5')
  ground ball

* Nubby
  textured 6"-
  8" foam ball

Light weight,
contrasting
colored
beanbag

8.5" contrasting                        Moderate
color play-                             throw (6'-8')
ground ball

* Tennis ball       Flat
* Rubber chicken    trajectory

* Junior football                       Moderately
* Basketball                            long throw
                                        (10'-15')

* Deck tennis
  ring
* Large softball

* Large football    High arch
  Regulation
  softball

* Star-shaped or                        Long throw
  pointed                               (over 15')
  catching obj.
* Regulation
  baseball

* Flat disk         Straight
  (Frisbee)         overhead
* Lacrosse ball
* Golf ball

Catching            Kind of catch
Object

* 6" contrasting    2 hands at
  color play-       midline
  ground ball
* Nubby
  textured 6"-
  8" foam ball

Light weight,       Dominant
contrasting         hand reaching
colored
beanbag

8.5" contrasting    2 hands, high
color play-         at midline
ground ball

* Tennis ball       2 hands low
* Rubber chicken    at midline

* Junior football   Dominant
* Basketball        hand, high

* Deck tennis       Dominant
  ring              hand, low
* Large softball

* Large football    Non-
  Regulation        dominant
  softball          hand

* Star-shaped or    Non-
  pointed           dominant
  catching obj.     hand reaching
* Regulation
  baseball

* Flat disk
  (Frisbee)
* Lacrosse ball
* Golf ball

Note: A Constraints-based Task Analysis activity grid for catching
(based on Table 1). This grid aids in selecting appropriate
activities and progressions through the skill, from easier tasks
to more complex ones.