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One of the difficulties in studying the concept of ability as it relates to motor skill performance is that the term ability is used in so many different ways. For example, physical and occupational therapists refer to "functional ability"; a baseball coach might refer to a player's "running ability"; educators often refer to students' "cognitive ability" or "intellectual ability." The list of examples could go on, but these few examples illustrate the problem. As a result, it is important to specify the precise manner in which the term will be used.
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For this discussion, the term ability will be used according to its meaning in the area of psychology that involves the study of individual differences. People who study individual differences are concerned with the identification and measurement of abilities that characterize and differentiate individuals. Individual-difference psychologists also investigate the relationship between abilities and the performance and learning of skills. In this context, the term ability means a general trait or capacity of the individual that is a relatively enduring characteristic that serves as a determinant of a person's achievement potential for the performance of specific skills. When the term motor ability is used in this context, it refers to an ability that is specifically related to the performance of a motor skill. It is important to note that some researchers and practitioners use terms such as "psychomotor ability" and "perceptual motor ability" to refer to what we will call motor ability.1
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The identification of specific motor abilities is not an easy task. As a result, few researchers have ventured into this area of study. However, those who have undertaken this challenge have provided us with useful information that helps us have a better understanding of an important factor related to determining why people differ in achievement levels of motor skill performance.
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Abilities as Individual-Difference Variables
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The individual differences we observe in the amount of success that people achieve in the performance of a motor skill depends in large part on the degree to which the person has the motor abilities that are important for the performance of that skill. For example, people with differing levels of the motor abilities important for playing tennis will have differing achievement potentials in tennis. This example indicates that various motor abilities underlie the performance of a complex motor skill such as tennis and that people have different levels of these abilities. It also indicates that if two people have the same training experiences and amount of practice, but differ in their levels of the motor abilities important for playing tennis, the one with the higher levels of the appropriate abilities has the potential to perform at a higher level. Although researchers generally agree with this view, they debated for many years, especially in the 1950s and 1960s, how motor abilities relate to one another within the same person.
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General versus specific motor abilities. In the debate about the relationship of motor abilities, one viewpoint holds that motor abilities are highly related to each other. The opposite view is that they are relatively independent of one another. This debate is not commonly pursued in the current research literature. However, an understanding of the different points of view will help you apply the concept of motor abilities to motor skill performance achievement.
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The general motor ability hypothesis maintains that although many different motor abilities can be identified within an individual, they are highly related and can be characterized in terms of a singular, global motor ability. It holds that the level of that ability in an individual influences the ultimate success that person can expect in performing any motor skill. This viewpoint has been in existence since the early part of the last century (e.g., Brace, 1927; McCloy, 1934), having been developed as the motor ability analogue to the then popular cognitive ability concept of a general intelligence (IQ). The hypothesis predicts that if a person is highly skilled in one motor skill, then he or she would be expected to be or become highly skilled in all motor skills. The reasoning behind this prediction is that there is one general motor ability. In fact, one proponent of this view developed a motor ability test battery that he proposed could be used to classify students into one of five homogeneous motor ability subgroups for purposes of teaching and engaging in physical activities (Barrow, 1957).
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ability a general trait or capacity of an individual that is a determinant of a person's achievement potential for the performance of specific skills.
motor ability an ability that is specifically related to the performance of a motor skill.
general motor ability hypothesis a hypothesis that maintains that the many different motor abilities that exist in an individual are highly related and can be characterized in terms of a singular, global motor ability.
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But contrary to the expectations of proponents of the general motor ability hypothesis, very little research evidence supports this viewpoint. One suspects that the basis for the continued existence of this hypothesis is its intuitive appeal. Tests of general motor ability are convenient, appealing to those who seek an easy explanation for why certain people are successful or unsuccessful at performing motor skills. The fact that these tests are poor predictors of specific motor skill performance has not diminished the appeal of the general motor ability hypothesis.
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The alternative perspective, for which there has been substantial support, is the specificity of motor abilities hypothesis. Franklin Henry is generally credited with deriving the specificity hypothesis to explain results from his research that the general motor ability hypothesis could not explain. This specificity view states that individuals have many motor abilities, and these abilities are relatively independent. This means, for example, that if a person exhibited a high degree of balancing ability, we could not predict how well that person would do on a test of reaction time.
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Support for the specificity hypothesis has come from experiments that were reported primarily in the 1960s. These experiments were based on the common assumption that if motor abilities are specific and independent, then there will be little, if any, relationship between any two abilities. Thus, in the simplest of cases, there would be little, if any, relationship between abilities such as balance and reaction time, or between reaction time and speed of movement, or between static and dynamic balance.
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The research evidence that provided most of the initial support for the specificity hypothesis, and became an impetus for further research, came from Franklin Henry's laboratory at the University of California, Berkeley. This research was based on the premise that motor abilities are relatively independent. Henry and his colleagues reasoned that they could demonstrate this independence rather simply by investigating the relationship between reaction time and arm movement speed. Recall from the discussion in chapter 2 that reaction time is the amount of time to see, hear, or feel a stimulus (i.e., a "go" signal) and then initiate the required movement; movement time is the amount of time from the initiation of the movement to its completion. The common result from many experiments from Henry's laboratory (e.g., Henry, 1961a, 1961b) was that reaction time and movement speed are uncorrelated,2 which means that each is an independent motor ability.
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Balance and Timing Abilities
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Although researchers now generally accept the specificity of motor abilities hypothesis, some have raised questions about the generality of certain specific motor abilities. That is, do certain motor abilities represent one ability, or are there several variations of these abilities, each of which is task specific and relatively independent of the other(s)? Two examples of these motor abilities, which are especially relevant to our discussions in this book, are balance and timing.
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Balance. When used in reference to motor skill performance, the term balance refers to postural stability (see Shumway-Cook & Wollacott, 2011), which involves maintaining equilibrium while stationary or while moving. In other words, balance concerns our capability to stand, sit, or move without falling. Although sometimes regarded as a single motor ability, balance should be viewed as comprised of at least two types: static and dynamic. Static balance is the maintenance of equilibrium while stationary, such as while standing, sitting, or kneeling. Dynamic balance, on the other hand, is the maintenance of equilibrium while in motion, such as while walking or running. Static balance is sometimes considered to be a simpler variation of dynamic balance. This viewpoint is seen, for example, when rehabilitation protocols specify that a person should develop static postural balance capabilities before engaging in activities requiring dynamic postural balance, such as walking. However, research evidence consistently indicates that static and dynamic balance are relatively independent motor abilities. For example, Rose et al. (2002) reported that fourteen of twenty-three children with gait disorders related to cerebral palsy showed normal standing balance characteristics.
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Research evidence also indicates that several relatively independent variations of static and dynamic balance exist. Drowatzky and Zuccato (1967) reported an excellent example of this research many years ago. In this experiment, participants performed six different balancing tasks that generally have been regarded as measures of either static or dynamic balancing ability. The results of the correlations among all the tests (table 3.1) showed that the highest correlation (.31) was between two dynamic balance tests, the sideward leap and the Bass stepping stone test. The highest correlation between a static and dynamic balance test was .26 (between the stork stand and sideward leap). Most of the correlations ranged between .12 and .19. The Drowatzky and Zuccato results are not unique. Other researchers have found similar results. For example, a study by Tsiglis, Zachopoulou, and Mavridis (2001) supported the Drowatsky and Zucatto results for various types of dynamic balance. The highest correlation between two of three different types of dynamic balance tests was .22. The two other correlations between the tests were .05 and .13. Similar results were more recently reported by Sell (2012) for comparisons between several static and dynamic balance tests, which involved single-leg standing and dynamic postural stability tests of varying degrees of difficulty. Even highly related static and dynamic balance tests, standing on one leg and stabilizing the body after landing on one leg, are not highly correlated with each other (Pau et al., 2015).
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LAB LINKS
Lab 3 in the Online Learning Center Lab Manual for chapter 3 provides an opportunity for you to experience several different types of balance tests and compare your results to the predictions of the general motor ability and specificity of motor abilities hypotheses.
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On the basis of results such as these, it would be difficult to conclude that only one test could be considered a valid measure of balancing ability. At the most basic level, we need to consider static balance and dynamic balance as two independent types of balance ability. The application of the relative independence of static and dynamic balance to professional practice can be seen in several of the balance tests commonly used in physical rehabilitation contexts. For example, the Berg Balance Scale (BBS), which is one of the most commonly used balance tests, involves fourteen types of static and dynamic tests of balance. Research evidence has shown that the BBS is a useful assessment tool in a variety of contexts, such as determining the risk of falling by the elderly and evaluating treatment effects for post-stroke patients (see Blum & Korner-Bitensky, 2008). Many other balance tests have been developed that also include the use of multiple static and dynamic activities. Research has shown that these tests are for use with specific populations and for specific purposes (e.g., Cattaneo, Jonsdottir, & Repetti, 2007; Haines et al. 2007; Rose, Lucchese, & Wiersma, 2006; Verbecque, Da Costa, Vereeck, & Hallemans, 2015). The important conclusion to draw from the research on balance tests is that balance is a multidimensional ability that is specific to the task or skill in which balance is involved, with static and dynamic balance viewed as general categories of types of balance.
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specificity of motor abilities hypothesis a hypothesis that maintains that the many motor abilities in an individual are relatively independent.
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Timing. As a motor ability, timing is an important component of the performance of many motor skills. For some skills we need to precisely time our movement initiation with the movement of an external object, such as hitting a moving baseball or starting a sprint in track. This type of timing is commonly referred to as external, or anticipation, timing. For other skills, we time our movements according to our knowledge of time, which occurs when we walk or jog at a desired pace or when a dancer performs without music but must maintain a specific rhythm and tempo. This type of timing is known as internal timing. In the study of individual differences, researchers have held different views about internal timing as a motor ability. One view proposes that timing is controlled by a common timing process, much like an internal clock, that provides the musculature with the rhythmic information needed to produce the continuous timing requirements of a skill (e.g., Ivry & Hazeltine, 1995). An alternate view argues that the precise rhythmic timing we observe for the skills described as examples of internal timing results from task-specific characteristics related to the interaction between the person and the performance environment.
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One of the ways researchers have tested views about the control of internal timing is to follow the approach used to test the specificity of motor abilities hypothesis that we discussed earlier. If an "internal clock" controls timing, we would expect a general ability for timing, and therefore people should perform similarly across a variety of tasks that require timing. On the other hand, if timing is task specific, performance on one type of task should not predict how well we would perform on a different task. These two possibilities were first tested in a series of experiments by Robertson and her colleagues (Robertson et al., 1999). Included in these experiments was a comparison of the performance of two tasks that included the same timing requirement, a series of 800 msec simple movements. One task required participants to repetitively tap an index finger on a tabletop at a speed of 800 msec per tap; the other required repetitive circle drawing at 800 msec per circle. Participants were initially provided a metronome as a guide so they could become familiar with the 800 msec rate of movement. Then the metronome stopped, and participants continued to tap or draw circles as a test of their timing ability. The results showed a low correlation between the two tasks, which indicated that performance on either of the two tasks did not predict how well participants would perform on the other task. Additional research by Zelaznik and his colleagues has shown similar results for repetitive movements performed at the participants' preferred rate of speed (e.g., Zelaznik, Spencer, & Doffin, 2000).
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Looking at results based on statistical correlation analysis is not the only way to determine whether timing is a general or task-specific ability. Spencer and Zelaznik (2003) compared timing accuracy for several tasks that required a common timing of several simple movements. If timing is a general ability, we would expect timing accuracy to be similar across these tasks. But, as figure 3.1 shows, the participants varied greatly in how accurately they could time a 500 msec (i.e., 0.5 sec) movement for repetitive finger tapping, line drawing (horizontal and vertical lines of the same length), and circle drawing. Although they very accurately timed their finger tapping, their timing accuracy for the other tasks was notably poorer.
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A considerable amount of evidence now exists to support the conclusion that although people are capable of precise timing when performing motor skills, timing ability is specific to the requirements of the skill being performed rather than a general timing ability.
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The "All-Around Athlete"
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You have undoubtedly read about professional athletes who could have become a professional in several sports. Or perhaps you know people who seem to be "good at" many different physical activities. If motor abilities are numerous and independent, then how can we explain these people whom we often hear referred to as an "all-around athlete," the person who is very proficient at a variety of physical activities? According to the specificity view, abilities fall somewhere along a range containing low, average, and high amounts within individuals. Because people differ in a way that is consistent with a normal distribution scale, we would expect that some people have a large number of abilities at an average level, and other people have a majority of abilities at either the high or the low end of the scale.
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A CLOSER LOOK The Relationship between Falls among the Elderly and Balance
A common problem for the elderly is falling. Both clinicians and researchers have determined that among the many reasons for why the elderly fall, difficulty maintaining balance is one of the primary causes. Thus it is not surprising that the assessment of balance is important for identifying people who may be more at risk for falling than others. At the forefront of developing falls prevention programs is the Center for Successful Aging at California State University at Fullerton (http://hdcs.fullerton.edu/csa/). A publication in 2006 by a group from this center (Rose, Lucchese, & Wiersma, 2006) discussed the development of a balance test the center has successfully used as part of its programs. The following is a summary of some of the information they reported concerning the incidence of falling among the elderly and the test they developed. One of the noteworthy features of the test is that it is based on a multidimensional view of balance, which has been emphasized in this chapter.
Falling Incidence among the Elderly The Fullerton Advanced Balance Scale (FAB) Although many tests are available to assess a person's risk of falling, the Center for Successful Aging determined that a new test was needed to overcome specific problems associated with available tests. The result was the development of a multidimensional test designed to "identify balance problems of varying severity in functionally independent older adults and also evaluate more of the system(s) (e.g., sensory, musculoskeletal, neuromuscular) that might be contributing to balance problems" (p. 1478). The FAB consists of 10 items that require approximately 10 to 12 min to administer. Table 3.2 summarizes the items and the primary physiological systems or mechanisms each item assesses. A complete description of the test items, the scoring for each item, and the psychometric evaluations of the test are presented in the article.
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According to the specificity hypothesis, the person who excels in a large number of physical activities has high levels of a large number of abilities. We would expect that a person would do very well in those activities for which the underlying abilities required for successful performance matched the abilities for which the person was at the high end of the scale.
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In actual fact, the true all-around athlete is a rare individual. Typically, when a person shows high performance levels in a variety of physical activities, a close inspection of those activities reveals they involve many foundational motor abilities in common. We would expect a person exhibiting high levels for a variety of abilities to do well in activities for which those abilities were foundational to performance. However, we would expect average performance if this person engaged in activities for which those abilities were less important, activities based on other abilities, of which the person possessed only average levels.
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Identifying Motor Abilities
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As a general trait or capacity, an ability is a relatively enduring attribute of an individual. Researchers who study individual differences assume that we can describe the skills involved in complex motor activities in terms of the abilities that underlie their performance. For example, the ability called spatial visualization is related to the performance of such diverse tasks as aerial navigation, blueprint reading, and dentistry. An important step in understanding how abilities and skill performance are related is identifying abilities and matching them with the skills involved.
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When researchers and practitioners identify specific motor abilities, they usually refer to the work of Edwin Fleishman (see Fleishman & Quaintance, 1984, for a description of this work). His pioneering research, which was carried out for four decades beginning in the 1950s, continues to influence our understanding and study of motor abilities and how they relate to motor skill performance. Perhaps the most significant achievement of Fleishman's work was the development of a taxonomy of abilities that includes a taxonomy of motor abilities.
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A taxonomy of motor abilities. From the results of extensive batteries of perceptual motor tests given to many people, Fleishman developed a "taxonomy of human perceptual motor abilities" (Fleishman, 1972; Fleishman & Quaintance, 1984). The goal of the taxonomy was "to define the fewest independent ability categories which might be most useful and meaningful in describing performance in the widest variety of tasks" (Fleishman, 1967, p. 352). The taxonomy included two broad categories of human abilities in the perceptual motor and physical domains: perceptual motor abilities and physical proficiency abilities. Table 3.3 presents and defines the eleven perceptual motor ability categories Fleishman proposed. Note that table 3.3 also includes an example of one of the tests he used to assess each ability and an example of a motor skill whose performance would be associated with the ability category.
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In addition to perceptual motor abilities, Fleishman also identified nine abilities that he designated as physical proficiency abilities. These abilities differ from the perceptual motor abilities in that they are more generally related to gross motor skill performance, which most people would consider as physical fitness abilities. The physical proficiency abilities identified by Fleishman are as follows: (1) static strength, the maximum force that a person can exert against external objects; (2) dynamic strength, the muscular endurance used in exerting force repeatedly; (3) explosive strength, the ability to mobilize energy effectively for bursts of muscular effort; (4) trunk strength, the strength of the trunk muscles; (5) extent flexibility, the ability to flex or stretch the trunk and back muscles; (6) dynamic flexibility, the ability to make repeated, rapid trunk-flexing movements; (7) gross body coordination, the ability to coordinate the action of several parts of the body while the body is in motion; (8) gross body equilibrium, the ability to maintain balance without visual cues; and (9) stamina, the capacity to sustain maximum effort requiring cardiovascular effort.
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We should not consider Fleishman's lists to be exhaustive inventories of all the abilities related to motor skill performance, because Fleishman wanted to identify the smallest number of abilities that would describe the tasks performed in the test battery. Although he used hundreds of tasks to identify those abilities, the inclusion of additional types of tasks besides those Fleishman used could lead to the identification of other motor abilities. For example, Fleishman did not include the following abilities in his two lists:
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Static balance—The ability to maintain postural stability on a stable surface or when not engaging in locomotor activities (e.g., standing on the floor while reading a book)
Dynamic balance—The ability to maintain postural stability on a moving surface or when engaging in locomotor activities (e.g., walking on a sidewalk)
Visual acuity—The ability to see clearly and precisely (e.g., reading a street sign)
Visual tracking—The ability to visually follow a moving object (e.g., watching the flight of a ball that is thrown to you to catch)
Eye-hand or eye-foot coordination—The ability to perform skills requiring vision and the precise use of the hands (e.g., correctly typing a sentence on a keyboard) or feet (e.g., kicking a penalty kick in soccer)
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A CLOSER LOOK The Relationship between Perceptual Motor Abilities and Handwriting Speed: Implications for Occupational Therapists' Interventions
Slow handwriting speed can affect children's school performance by preventing them from completing handwritten work that must meet time constraints. To investigate factors that are associated with slow handwriting, Tseng and Chow (2000) administered three perceptual or motor abilities tests and a vigilance test to 7- to 11-year-old Chinese schoolchildren whose handwriting was slow or at normal speed.
Handwriting speed: The amount of time required for the children to copy in pencil a previously studied text (speed = the number of Chinese characters written per minute).
The abilities tests measured:
arm movement speed and hand dexterity
nonmotor visual perception (including discrimination, sequential memory, figure closure, etc.)
visual-motor integration (which required the copying in sequence of a set of geometric forms)
focusing and maintaining attention over time
Results: The following abilities were predictors of slow handwriting:
Authors' conclusion: These results suggest that "intervention for slow handwriting should focus on facilitating visual processing, including memory and visual-motor integration, rather than the fine motor training so often emphasized in occupational therapy programs" (p. 87).
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An important assumption of this view of human abilities is that all individuals possess these motor abilities. Another is that because it is possible to measure these motor abilities, it is also possible to determine a quantified measure of the level of each ability in a person. People differ in the amount of each ability they possess. Their motor abilities indicate limits that influence a person's potential for achievement in motor skill performance.
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Relating Motor Abilities to Motor Skill Performance
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Figure 3.2 illustrates the view that motor abilities are underlying, foundational components of motor skill performance. This figure shows how we can analyze complex motor skills by a process known as task analysis in order to identify the abilities that underlie any motor skill. For example, to serve a tennis ball successfully, a player must perform certain components of that skill properly. Figure 3.2 identifies these components, which are the first level of analysis of the tennis serve, in the middle tier of the diagram. Identification of these components helps us identify more readily the underlying motor abilities that are involved in the successful performance of this task. The bottom tier of the diagram presents these abilities. Based on Fleishman's lists, they include such abilities as multilimb coordination, control precision, speed of arm movement, rate control, aiming, and static strength. You undoubtedly could add others. However, these few examples should serve to illustrate the foundational role perceptual motor and physical proficiency abilities play in the performance of motor skills.
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Uses for tests of motor abilities. Because of the foundational role played by motor abilities in the performance of motor skills, tests of motor abilities are used for a variety of purposes. We will consider two of the most common. One use is the prediction of future performance of a motor skill or physical activity. Tests used for this purpose are sometimes called aptitude tests. For example, the military and industry use tests of motor abilities in their batteries of tests to select people to train for or work in specific jobs (e.g., Chan, 2005). Medical and dental schools often include motor abilities tests in their selection of students for specialist training or admission into specific programs. And professional sports teams, and national and international sports agencies, typically give motor abilities tests as part of test batteries to select athletes for their teams.3
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A CLOSER LOOK The Assessment of Motor Abilities as Part of the Complex Process of "Talent Identification" in Sports: An Example from Gymnastics
In Belgium, the Flemish Gymnastics Federation conducts an annual selection day to determine which 7- to 8-year-old female gymnasts will be selected for the national talent development program for becoming an elite senior gymnast. In a research study reported by Barbara Vandorpe and colleagues at universities in Belgium (Vandorpe et al., 2012), 23 of the gymnasts were assessed with a multidimensional test battery, with its results compared to the gymnasts all-around competition results two years later, when the gymnasts were classified as either elite or subelite.
Assessment Included in the selection process was a multidimensional test battery that included an assessment of motor coordination, which is a non-gymnastics-specific test that includes the following four subtests:
Walking backward on balance beams of different widths
Moving sideways on wooden platforms for 20 sec
Jumping sideways with two feet over a wooden slat for 15 sec
Hopping on one leg over foam obstacles of different heights
The performance scores were transformed into one score for each gymnast, which the test reports as an index of a child's motor coordination. In addition, the test battery also included nine basic motor skills tests: running backwards, skipping, hopping, shuffle pass, cross steps, bouncing, jumping jacks, tuck jumps, and giant jumps. Also assessed were specific physical characteristics of the gymnasts. Finally, expert coaches evaluated their technical skills.
Results When these test results were compared to the outcome performances of the gymnasts at a competition two years later, the only meaningful predictor of competition result was the motor coordination score for the elite gymnasts; none of the initial test battery predicted competition outcomes for the gymnasts who were placed in the subelite category. Interestingly, the coaches' evaluations were not significant predictors of performance for either the elite or nonelite gymnasts.
Conclusion This study serves as an excellent example of how difficult it is to identify the critical factors that would predict performance two years into a young athlete's future.
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A second use of motor abilities tests is evaluation, which may include the evaluation of the causes of motor skill performance deficiencies or the assessment of the effectiveness of an intervention program, such as in physical rehabilitation. For example, therapists and athletic trainers use motor abilities tests to assess patients' rehabilitation progress and determine the types of functional activities the patient may be ready to undertake. Another common evaluation use of motor abilities tests involves the assessment of motor development in infants and young children. For both prediction and evaluation uses of motor abilities tests, the key to success is the development and use of valid and reliable tests.
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