Reliability, Objectivity, Validity and Reference Levels of the Austrian Balance Check (ABC)-A Novel Balance Field Test for Children, Adolescents and Young Adults to Assess Static Balance

Balance is a relevant indicator of physical fitness and correlates with intellectual abilities. Due to limited resources, however, balance tests are underrepresented in fitness checks. To develop an effective field test to assess static balance with minimal cost, little spatial requirement and short testing time, a cross-sectional pilot study was conducted in three different school types (primary school, secondary school, and high school) and the reliability, objectivity and validity of the novel Austrian Balance Check (ABC) were assessed, with the generation of age- and gender-specific reference values. Tests were carried out with participants from regular school classes (RSC) and elite sports school classes (ESC). A total of 1005 participants were included (age range: 6.2 to 19.8 years). Participants in RSC (ICC2.1 = 0.92, 95% CI 0.90 to 0.93) showed excellent values, and those in ESC (ICC2.1 = 0.89, 95% CI 0.85 to 0.93) had good to excellent values in the reliability test. Objectivity was excellent in both groups (RSC (ICC2.1 = 0.99, 95% CI 0.98 to 0.99); ESC (ICC2.1 = 0.98, 95% CI 0.96 to 0.99)). A gold standard comparison using an electronic force plate showed a strong negative correlation: participants with high overall ABC scores showed less movement on the force plate (parameters of the center of pressure: surface area (rho = -0.61), mean velocity (rho = -0.65) and path length (rho = -0.65). The test duration of ABC was significantly (p < 0.001) shorter compared with an established balance test. ABC offers potential benefits by allowing field-based static balance testing in large groups with low cost, minimal time and spatial requirements as well as high reliability, objectivity and validity.