Compartment Syndrome is increased pressure in a compartment which contains muscles or nerves.
In this case, I would assume it would be in the left arm area because that was where he was injured the most.
It depends on your strength levels.
people worry too much about moving heavy weights.
the answer is any amount of weight is enough as long as you can maintain proper form, and complete a series of 10 repetitions 3 times, with about 60 seconds of rest between sets.