Two clinical cases illustrating how differences between technique 2 and technique 1 (see Fig. 44.171) vary with respect to orientation of L5 over S1. A, In kyphotic alignment (high LSA), technique 2 underestimates value obtained. B, In lordotic alignment (low LSA), technique 2 overestimates technique 1 value. These cases illustrate negative correlation between LSA and technique 2 difference. LSA, Lumbosacral angle.