Sentence:  His arm had been giving him some trouble and Rector was not enough of a medical expert to <WSD>determine</WSD> whether it had healed improperly or whether Hino was simply rebelling against the tedious work in the print shop , using the stiffness in his arm as an excuse . 
Meaning of the word marked with <WSD> tags:  establish after a calculation, investigation, experiment, survey, or study