below , A muscle back happened higher .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (ATS_1 (ATS_2 (ADVP_0 (RB_0 below)) (COMMA_0 ,)) (NP_0 (DT_0 A) (NN_2 muscle))) (ADVP_0 (RB_0 back))) (VP_3 (VBD_1 happened) (ADJP_0 (JJR_0 higher)))) (DOT_0 .)))