Reliability of a Measurement Technique to Characterise Standing Properties and to Quantify Balance Capabilities of Healthy Subjects on an Unstable Oscillatory Platform (Posturomed)

Introduction: Specific sensomotoric training is recommended to improve walking dysfunctions, prevent injurious falls or improve the reaction capacities of athletes. The oscillatory Posturomed platform can be used as a simple measuring procedure to characterise balance ability. Standard values for the one legged stance or test-retest reliability are unknown. Method: 55 healthy subjects (37 +/- 15 years) were tested during one legged stance on the unstable Posturomed platform. We recorded the total path of the platform in mm as balance recovery movements (BRM) as well as the ratio of failed attempts. To evaluate Test-Retest-Reliability, 12 subjects were retested one month later. Results: To maintain balance, healthy subjects required twice as many BRM in anterior-posterior (AP) direction (40.7 +/- 26 mm) as in medio-lateral (ML) (17.4 +/- 8 mm). 8% of the recorded attempts were counted as failed attempts due to subjects' unstable standing. On average, subjects required 15.5 +/- 18 mm less BMR when standing on their stronger leg than on the other leg. Younger subjects (25 +/- 2y) required less BMR than older (59 +/- 11y) subjects (49.2 versus 64.7 mm, p = 0.006). Subjects with a high level of physical training required less BMR. Test-Retest measurements showed an average difference of 3.9 +/- 6.1 mm. Discussion: The Posturomed Platform can be used to evaluate stance ability and characterise the patterns of one legged stance. The measurements are reproducible, but include a small learning effect. Further studies including EMG could provide more understanding of neuromuscular control mechanisms and their adaption to training.