To successfully perform a variety of motor skills used in everyday life we must coordinate movements of different body parts. The number of combinations of movements we can perform with individual body parts is extremely high (Magill, 1998). Persons can successfully produce a remarkably accurate and consistent movement pattern in a variety of situations (Loosch, 1997), even in unfamiliar situations. The human effector system is capable of coordinating different movement actions at the same time, although the actions seem to be performed without interference by individual body parts. However, laboratory data clearly suggest that there is important interference between parts of the effector system when different, sometimes seemingly simple movements are performed (Heuer, 1996).
Turvey (1990) described coordination as a patterning of body and limb motions relative to the patterning of environmental objects and events. This definition contains two main characteristics. First, coordination involves patterns of body or limb movement, which means that we need to use the appropriate limb or body movement coordination patterns in order to be able to perform motor skills. The second characteristic is related to the fact that movement patterns of limb and body are in accordance with environmental objects and events. Aiming movements are performed within a time that is accurately set and often minimal, and they need to be spatially coordinated with maximum precision (Magill, 1998). Every motor action is performed according to exactly set patterns of neuromuscular activity (Schmidt & Lee, 1999). Motor control and therefore coordinated movement are assured by effective operation of the central nervous system (Pisot & Planinsec, 2005).
When performing complex motor tasks, cognitive functioning is important, and its influence rises with the increased complexity of the tasks (Planinsec, 2002a). The process of learning a complex motor task or relating individual elements into a motor unity is basically an intellectual process (Leithwood, 1971). Thomas and Chissom (1972) suggested a relationship between perceptive-motor abilities and intelligence, with eye-hand coordination having the closest relation to intelligence. The visual-motor integration test has a significant correlation with the verbal and non-verbal part of the Wechsler Intelligence Scale for Children III, where correlations with the non-verbal part of the test are higher (Graf & Hinton, 1997). This relationship is influenced mostly by abilities of speed and timing, and also partially visual memory. Tests of coordination of the whole body as well as the nonverbal part of the intelligence test have contributed most to the relationships between motor efficiency and intelligence (Zimmer, 1981). When a motor task includes no problem situations, the relation to intelligence can be explained by the speed of information flow in the nervous system, but when motor tasks present a problem, the relation can be explained by the influence of cognitive activities when solving a motor problem (Momirovic, Hosek, & Gredelj, 1987; Pisot & Planinsec, 2005). With increased complexity of motor tasks and higher demands for coordinated movement, the relationship to levels of intelligence rises (Mejovsek, 1977; Horga, 1993; Planinsec, 2001, 2002b). Success in performing motor tasks with high cognitive demands is highly conditioned by the processing of information and decision making; therefore, the performance of motor tasks with high cognitive demands depends on the use of cognitive potential (Kim, Singer, & Radlo, 1996). Different cognitive components, such as visual-processing, visuospatial processing, working memory, and also partially speed, influence successful motor coordination (Tirre, & Raouf, 1998). It has been determined that motor coordination is partly explained by cognitive factors. The nexus between high-order cognitive factors and psychomotor factors is higher than that between low order factors (Carretta & Ree, 1997). …