highly significantp < 0.001
Formal nested-model comparison confirmed this interpretation: adding ΔR(M–C) to a reduced model already containing Cobb_XR, TK_XR, and anthropometric covariates produced a highly significant improvement in model fit for FVC% (partial F = 103.0, p < 0.001; ΔAIC = −86.7), indicating substantial information gain rather than redundant variance.