Elsevier

Gait & Posture

Volume 27, Issue 1, January 2008, Pages 76-81
Gait & Posture

Are there specific conditions for which expertise in gymnastics could have an effect on postural control and performance?

https://doi.org/10.1016/j.gaitpost.2007.01.004Get rights and content

Abstract

The first aim of this study was to analyse the effect of elite training, linked to expertise, in gymnastics on postural performance and control. For this purpose, body sway of expert gymnasts was compared to other sportsmen, non-experts and non-gymnasts, in two different postures: bipedal (easy and unspecific to gymnasts) and unipedal (difficult and fairly specific). The second aim was to compare the groups in the same tasks but in a visual condition for which they were not trained, i.e. with eyes closed. Postural performance was assessed by centre of gravity motion, which was computed from centre of pressure motion, estimating postural control. A significant difference between the two groups was observed for postural performance in the unipedal posture and with eyes open only. Regardless of their posture, the groups were similarly affected by removal of vision. Expertise in gymnastics seemed to improve postural performances only in situations for which their practise is related to, i.e. unipedal with eyes open. These reveal the importance of choosing a relevant postural configuration and visual condition according to the people's training or by extension experience.

Introduction

The control of posture is critical and necessary in activities of daily living like walking, stepping up the stairs, or standing in a bus. In many sports, this acute control can be associated with the final performance of the sportsman. Three different sport categories and so three different effects of this control of the actual posture could be mainly distinguished. In the first one, the control of posture is mainly associated with movements; as in football, rugby or judo. In the second one, standing still is linked to the performance of the athlete. Rifle shooting constitutes one of these activities. Finally, between these extremes, is the third category, which groups all activities requiring both the control of posture associated with movements but also the control of a steady posture. Our interest is this last category and specifically in gymnastics.

In this sport, and specifically in the floor exercise for male gymnasts, maintaining postures is needed and required by the international codification [1]. The “legmount”, the scale (two postures on one leg with the other leg fully extended in a front, side or rear split position in the first one or lifted backward in line with the trunk bended forward parallel to the floor for the second one) or the handstand on the floor are such examples. Before attempting or learning these specific and difficult postures, gymnasts are first trained to maintain less specific ones, such as the unipedal; a posture that any healthy human could perform. In a previous paper [2], we compared performances of gymnasts in various postures (handstand, unipedal and bipedal). The results showed that the level of postural performance or control was inconsistent in all tasks, i.e. no transfer of their performance to any of these postures was observed. Thus, a training to perform a difficult and specific posture might have a slight or no effect at all on the control and performance of unspecific (unipedal) or common (bipedal) ones. However, a general effect of gymnasts’ training and/or competition level may also be involved. Expertise represents ‘a high level of knowledge and skills gained from training and experience’ (Oxford English Dictionary). Thus, it can be argue that this general effect which included gymnasts’ experience, competition level, number of hours of training, etc. can be regrouped as one notion: the effect of expertise. Then, to test such effect of expertise, one could compare elite gymnasts to other athletes who are not trained to stand still. This topic was previously studied in other activities [3], [4], [5], [6], [7]. Essentially, the results indicated a different effect according to the type of posture but also to the sport category (see above). For example, in a bipedal posture, judokas from a national level had better performance than dancers of a similar level or than normal subjects [5], [7]. In the same posture, dancers also performed similarly to normal healthy subjects [5], [8]. However, when performing a posture consistent with their training, the unipedal one, they had significantly better performances [4]. Thus, our first aim is to compare two different populations, expert gymnasts and non-expert non-gymnasts in two postures, bipedal and unipedal.

In a recent paper concerning the effect of vision on postural control in expert gymnasts [9], we showed that they are specifically trained with eyes open. The visual system is a complex system but mainly it can be separated into two essential components. The first one, called foveal vision, is largely concerned with objects’ recognition and identification, textures or colours. The second one, called peripheral vision, detects movements occurring in the environment. These components, neurophysiologically distinguished, are linked by their role in the control of posture [10]. For example, in bipedal posture, any modification of the surroundings (objects position or brightness) affects postural sway [10]. This effect is more pronounced in more challenging balance tasks such as standing with the feet close together [11] or standing on one leg [9]. Closing the eyes is another and simpler way to analyse the impact of this sensory system. We recently investigated the effect of closing the eyes (removal of vision) on postural stability in expert gymnasts [9]. Results showed that the effect of removal of vision did not change with the postural difficulty, but it did change with the body configuration. According to that, one could expect an effect of their training with eyes open. Since gymnasts are trained with eyes open, standing in a specific posture with eyes closed becomes an untrained and new situation. Indeed, if training with eyes open has an effect, positively or negatively, on performance, then the effect of removing vision should be different for (i) athletes who are untrained and (ii) in all postures. Thus, the second aim of this study is to examine the effect of expertise in gymnastics on postural performance and control in an untrained visual condition (with eyes closed).

Section snippets

Participants

Two groups of 13 subjects gave their informed consent to participate in the experiment. The first group were male elite gymnasts (age 21.6 ± 4 years, height 168.3 ± 6 cm and weight 64.1 ± 6 kg) of international level, labelled G. The second group were other sportsmen of regional level (age 22.1 ± 3 years, height 179.2 ± 6 cm and weight 72.8 ± 8 kg) involved in different group activities such as football or handball, labelled OS.

Protocol

Barefooted, they were instructed to keep as still as possible whilst standing in

Anthropometric measures

Anthropometric measures of the groups were significantly different (p < .05). There was no significant correlation between the height or the weight of our subjects and the CG surface and velocity, or CP surface and velocity.

Postural performance

For Scg, there was a main effect of posture, vision and a significant interaction posture × vision (Table 1). In the bipedal (B) posture, post hoc tests showed no significant differences between gymnasts (G) and other sportsmen (OS) irrespective of the visual condition eyes

Discussion

We first want to mention that, even if differences existed between the anthropometric measures in our groups, the absence of relation showed between these differences and all postural parameters tested here allows us to consider this effect as negligible.

The first aim of this study was to know whether a gymnast's expertise affords better postural performance and control in situations (configuration and visual condition) that are consistent with their experience and training. As elite gymnasts

Conclusions

Expertise in gymnastics only has an effect on postural performance when performing configurations that are consistent with those that have been trained and so correspond to gymnastics’ goal. Moreover, this effect is only seen in a visual condition that matches to the one in which elite gymnasts are practicing. Their expertise at keeping still during different and difficult postures also fails to reduce the effect of removal of vision as observed in other sportsmen. Expertise in gymnastics

Conflict of interest statement

There is no financial conflict with the subject matter or materials discussed in this manuscript at any of the authors’ academic institutions or employers. Finally, authors did not receive any financial interest.

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These authors contributed equally to this work.

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