extensor surfaces造句

The extensor surfaces are typically the most severely affected areas.
Psoriasis classically presents with scaly skin lesions, which are most commonly seen over extensor surfaces such as the scalp, natal cleft and umbilicus.
In response to the call for citation above : The second statement ( that electricians are trained to touch possible live wires first with extensor surfaces ) was relayed to me by a friend of mine who is a ( certified ? i don't know the terminology ) journeyman electrician.
It's difficult to find extensor surfaces in a sentence. 用extensor surfaces造句挺难的