Measures to determine dynamic balance

Abstract

This chapter discusses the theory of dynamic balance as is currently understood and the various methods of assessing it. In order to test dynamic balance, it must first be defined, and this is where an understanding is still evolving. As such, a number of balance assessment methods have evolved concurrently. The chapter starts by introducing some of the concepts of static balance and obvious signs of balance loss. Next, functional testing methods including the TUGT, BBS, DGI, and TBGA are introduced. These are tests that are relatively simple to administer and rely on a rater's assessment of signs like postural instability or sway in completing a task. From there, instrumentation typically found in a movement analysis lab is described along with the assessments used to quantify dynamic balance. Finally, more advanced mathematical methods of teasing out balance impairments from data are described. These last analyses include usage of Lyapunov exponents, autocorrelation, margin of support, and deviation of the COM from the interfoot line. Studies indicating the validity of all methods presented are also described in greater or lesser detail as needed throughout the chapter. This serves to introduce readers to the potential populations in which balance deficits exist, as well as the relative validity and reliability of the tests. In some cases, tests are valid with one population, but not with another. At this juncture, there are a myriad of balance tests, and more are being developed as this is being written. Ultimately, researchers and clinicians must choose the appropriate test based on who they are testing, what specific symptoms they wish to identify or diagnose, and the consideration that balance is multifactoral.