Sentence:  And they could n't have entrusted Henri to better hands because `` le professeur '' knows his muscles from the sterno-cleido mastoideus of the neck right down to the tibialis anticus of the <WSD>leg</WSD> - and better still , he knows just what exercises work best for them and what Weider principles to combine them with for fast , fast muscle growth . 
Meaning of the word marked with <WSD> tags:  a human limb; commonly used to refer to a whole limb but technically only the part of the limb between the knee and ankle