Fig. 2

Confirmatory factor analysis for Model 1, Model 2, and Model 5

* Confirmatory factor analysis for the original unidimensional model, presented without added covariance (A; Model 1 A) and with added covariance between items 4–5 and 7–9 (B; Model 1B), a first order 4-factor model based on the four sub-sections in the test (C; Model 2), and a first-order 4-factor model without item 7 (D; Model 5). The factor, i.e., the latent construct, is illustrated by an oval. The item, i.e., the indicator, is illustrated by a rectangle. One-headed arrows from the factors to the items represent the factor loading, and the two-headed arrows represent the covariance between the suggested factors. Each measurement error (ε1–14) is presented by the circle below the item. Item 1 - sit to stand; item 2 - rise to toes; item 3 - stand on 1 leg; items 4, 5, 6 - compensatory stepping correction – forward, backward, lateral; item 7 - stance with feet together and eyes open, on firm surface; item 8 - stance with feet together and eyes closed, on foam surface; item 9 - stance with eyes closed, on an inclined surface; item 10 - walk with change in gait speed; item 11 - walk with horizontal head turns; item 12 - walk with pivot turns; item 13 - step over obstacles; item 14 - timed up & go with dual task. APA = anticipatory postural adjustments; RPC = reactive postural control; SO = sensory orientation; DG = dynamic gait; PR = postural response; SG = stability in gait