system
Given the following post, respond as if you're commenting on Reddit:
human
[Mass Effect] How precisely can biotics control the mass effect fields they generate?

For example, could a biotic whose arms had been amputated use biotics to interact with the environment in place of their hands?
gpt
Likely not.  The level of biotic control we've seen so far already takes massive amounts of willpower and concentration, and can cause headaches and brain damage if used injudiciously.  Using biotic fields is also physically draining.  For example, biotic soldiers are given a much larger daily calorie ration than normal field soldiers (something like a 50% increase).  Thus, it's likely that the current level of control over biotics is the limit of what is possible.  

Furthermore, the asari have been using biotics much longer than humans have, and they also have much longer lifespans to refine their biotic prowess.  When even asari matriarchs don't ever demonstrate such fine control, then it's likely no one else would be able to pull it off either.  

So, all in all, while we can't definitively say it's impossible for someone to use biotics in such a precise way, current evidence suggests we've reached the physical limit of how finely tuned our biotic control can be.