mdbg.net has for zhe 着: aspect particle indicating action in progress
That implies it corresponds with -ing. Many times however, I find 着 cannot be translated in this way.
What does 着 do? What difference does it make if it were not used?
From 父亲去世了
他光着脚,手指弯曲着,失去了往日的力量。
His leg bared, fingers bent, gone his former strength.
他的眼睛紧闭着,像两个黑洞。
His eyes tightly closed, like 2 black holes.
嘴巴张着,牙齿都露了。
Mouth open, teeth revealed.