Sentence:  Since a Skeletal Age rating can be made at any age during <WSD>growth</WSD> , from Elbow , Shoulder , Knee , or Foot as well as Hand , it seems to be the method of choice when one wishes to study most aspects of skeletal developmental progress during childhood . 
Meaning of the word marked with <WSD> tags:  (biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level