Integra

Introduction
Motor learning involves stabilizing the coordination between information and movement in the perceptual-motor
workspace [1]. The issue of whether skill learning within the context of a specific sport is transferable to other
perceptual-motor tasks is questionable. Most studies indicate that specific balance modalities acquired by ballet dancers
[2] or expert gymnasts [3] do not imply better balance control in simplistic postural tasks. However, the influence of
motor expertise on postural coordination has not been addressed from the perception-action coupling perspective. The
present study examined whether expertise in soccer affects the performance and learning of a task requiring continuous
postural adjustments to dynamic visual information.

Method
A group of 10 soccer experts (mean age: 21.4±1.7, training years: 8.6±3) and 10 age-matched controls (mean age: 20.4,
±0.8) were trained in a visuo-motor postural coordination task. Performers were asked to stand on two adjacent force
platforms (ERBE BALANCE SYSTEM), while on-line visual feedback about each foot’s force vector was provided on
a computer screen ahead of them (1.5m ahead, eye-level, Fig.1). The aim of the task was to shift weight between sides
so as to always maintain each foot’s vector within the visually specified force constraints. Training consisted of 3
blocks of 5 trials separated by 1-minute intervals and followed by 5 retention trials (24 hours after training). Learning
was reflected in the mean movement time (MT) and number of errors (E) calculated over the 5-trial blocks.
Performance differences between the two groups were analyzed by means of a 2(group) x4 (block) repeated measures
ANOVA.

Results
Soccer experts exhibited significantly less number of left side errors and more stable performance compared to
untrained individuals [mean E: F (1,18) = 4.8 , p<0.05; SD of E: F(1,18) =3.85, p<0.05]. No significant between group
differences were noted in right side errors. A significant learning effect across trial blocks was noted for both groups
[mean E: F(3,54) =29.8, p<.001; SD of E :F(3,54) =16.36, p<.001; MT: F(3,54)= 37.8, P<.001]. However, a group x
block interaction for movement time [F (3, 54) = 3.53, p<0.05] suggests that soccer experts learned the specific visuomotor
coordination pattern faster than untrained individuals (Fig.2)

Discussion
The results of the present study suggest that soccer experts have developed a better visuomotor integration ability of
linking optical information to motor commands that modulate the weight distribution between the feet in accordance
with the dynamics specified by the visual patterns. It is concluded that specific soccer training reinforces perceptionaction
coupling in postural tasks requiring processing of visual information, continuously re-afferent update from the
periphery and subsequently implementation of the appropriate muscle torques.

References
[1]. Vereijken, B., Van Emmerik, Whiting, H.T.A and Newell, K.M. Free(z)ing degrees of freedom in skill acquisition.
Journal of Motor Behavior, 24, (1992) 133-142.
[2]. Hugel, F., Cadopi, M., Kohler, and Perrin, P., Postural control of ballet dancers: a specific use of visual input for
artistic purposes, Int Journal of Sports Medicine, 20(1999) 86-92 (Hugel et al., 1988).
[3]. Villerme et al., The effect of expertise in gymnasts on postural control, Neuroscience Letters, 303 (2001) 83-86.

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