Toward more reliable stability measurements in stance: recommendations for number of measurements, foot position and feedback -- a cross-sectional study among servicemen

Saskia Maria Theresia Van Der Heijden,Maarten Reinders Prins,Peter Van Der Wurff

doi:10.1186/s40779-019-0212-y

Abstract

BackgroundIn the military, insufficient postural stability is a risk factor for developing lower extremity injuries. Postural stability training programs are effective in preventing these injuries. However, an objective method for the measurement of postural stability in servicemen is lacking. The primary objective of this study was to assess the influence of the number of repetitions, different foot positions and real-time visual feedback on postural stability, as well as their effects on the intrasession reliability of postural stability measurements in servicemen. The secondary objective was to assess the concurrent validity of the measurements.MethodsTwenty healthy servicemen between 20 and 50 years of age and in active duty were eligible for this quantitative, cross-sectional study. The measurements took place on a force plate, measuring the mean velocity of the center of pressure. The participants were asked to stand as still as possible in three different foot positions (wide stance, small stance, and on one leg), five times each for 45 s each time, and the measurements were performed with and without real-time visual feedback.ResultsWe observed a significant main effect of foot position (P < 0.001), but not of visual feedback (P = 0.119) or repetition number (P = 0.915). Postural stability decreased in the more challenging foot positions.The ICC estimates varied from 0.809 (one repetition in wide stance) to 0.985 (five repetitions on one leg). The common variance (R2) between different foot positions without feedback varied between 0.008 (wide stance) and 0.412.ConclusionsTo yield reliable data, wide-stance measurements should be conducted three times, and small-stance measurements and measurements on one leg should be conducted two times.The scores of a measurement in a particular foot position cannot predict the scores of measurements in other foot positions.

Highlights

In the military, insufficient postural stability is a risk factor for developing lower extremity injuries
An effective preventive training program type is postural stability training [14]. These training programs are offered to servicemen who demonstrate insufficient postural stability, as they are at increased risk of developing LEinjuries [19, 20]
The lowest mean velocity of the COP (mCOPv) values were found in the wide-stance measurements, followed by the small-stance measurements and measurements on one leg

Summary

Introduction

Insufficient postural stability is a risk factor for developing lower extremity injuries. Postural stability training programs are effective in preventing these injuries. An objective method for the measurement of postural stability in servicemen is lacking. Various types of preventive training programs have been developed to decrease the amount of LE injuries in the military [12,13,14,15,16,17,18]. An effective preventive training program type is postural stability training [14]. These training programs are offered to servicemen who demonstrate insufficient postural stability, as they are at increased risk of developing LE (re)injuries [19, 20]. To the best of our knowledge, a standardized, reliable method for measuring postural stability in the military is lacking

Objectives

Methods

Results

Discussion

Conclusion