[Influence of bodily constitution and physical activity on postural stability].

CONTEXT AND OBJECTIVE

In order for balance to be maintained, the postural control system must process above all visual, vestibular and proprioceptive information and translate this input into appropriate motor responses. The influence of bodily constitution and physical activity on motor responses and thus on postural stability is still unclear. To use computerized dynamic posturography (CDP) to investigate the influence of body height, body mass index (BMI), regular sporting activity and acute maximal exercise on balance.

SUBJECTS AND METHODS

Eighty-four subjects completed a standardized questionnaire on their height, BMI and sporting activity. We then assessed the postural stability of the subjects. Seventeen further subjects performed a maximal exercise test on a bicycle ergometer. We used CDP and a predefined protocol to assess balance at rest, at maximal exercise and then at 5-minute intervals until recovery.

RESULTS

Body height and regular physical activity did not influence balance ability. By contrast, BMI and acute physical exercise had a strong effect. Immediately after maximal exercise, postural stability deteriorated by 44 % compared to the baseline level (p < 0.017). Complete recovery occurred within only 15 minutes.

CONCLUSIONS

Whereas body height and regular physical activity do not influence balance performance, a high BMI value and acute maximal exercise lead to a considerable decrease in postural stability. Our results can thus explain the increasing risk of injury after strenuous physical activity, especially in association with sports that require excellent balance.