(S (S (S (BASENP (PRP He)) (VP (VBD hurt) (BASENP (PRPD his) (NN back)))) (SBAR (WHADVP (WRB when)) (S (BASENP (PRP he)) (VP (VBD jumped) (PP (IN from) (NP (BASENP (DT the) (NN cab)) (PP (IN of) (BASENP (PRPD his) (NN truck))))))))) (PERIOD .))