Factor structure, stability, and congruence in the functional movement screen

The scoring scheme for the functional movement screen implicitly assumes that the factor structure is consistent, stable, and congruent across different populations. To determine if this is the case, we compared principal components analyses of three samples: a healthy, general population (n = 100), a group of varsity athletes (n = 101), and a group of firefighters (n = 397). The congruence of the principal components derived through these analyses were evaluated across all of the samples, using Tuckers congruence coefficient. Factor extraction was guided by parallel analyses, and interpretation was facilitated by Varimax rotation. We observed factor instability, low factor congruence, and inconsistent factor structure. Additionally, we observed a two-factor structure of the functional movement screen in all of our sample groups. These analyses suggest that, although the independent elements of the functional movement screen may continue to be used, use of the composite score is not supported by the factor structure of the measure.