Purpose: The present study examined the concurrent and construct validity of the Lateral Step Up (LSU) test, for adolescents with CP.
Method: A total of 35 adolescents, classified as GMFCS Levels I, II and III, were examined using LSU, GMFM - 88 (D & E), other functional mobility measures (TUG, STS, TUDS), body structures and functions (strength, ROM and spasticity).
Results: LSU inter-correlations with: (i) GMFM - 88 (D & E) (r = 0.656), (ii) functional mobility measures (r = -0.567 to 0.721) and (iii) body structures and functions (r = 0.155 to 0.563) were at the appropriate range. The LSU differentiated adolescents with CP (F = 16.185, p = 0.000, η(2) = 0.503), according to their GMFCS (I > II, II > III, I > III). Finally, 50.27% of the LSU variability was explained by GMFCS differences, with 65.7% of adolescents classified correctly across the three levels.
Conclusions: The LSU may be perceived as a valid instrument for assessing the functional mobility of adolescents with CP.
Implications for rehabilitation: • LSU is valid for assessing functional mobility and strength in CP adolescents. • LSU may be used in accordance with other functional mobility measures in the school environment. • The LSU may be used from physical therapists to predict the functional mobility of CP adolescents at GMFCS Levels I–III.